Category Archives: Underwater Photography

Buoyancy, Floats arms, Underwater Photography, UNDERWATER VIDEO

Increase the your rig’s buoyancy using floats or float arms

March 15, 2014 interceptor121 11 Comments

As you add up lenses and accessories to your underwater photography or compact video rig you start experiencing an increase in weight first on land and afterwards in water.

My current rig for photography weights in excess of 5 Kg (11 lbs) and in water this is very near to 2 Kg (4.4 lbs). The housing and the hardware are usually the main culprit but even strobes or lights can easily add weight. As you add more and more components the weight of your rig ramps up.

I use locline arms for video and this greatly helps reducing weight both in and outside water. My compact video rig is around 500 grams or 1.1 lbs in water but also very lights outside water. The Sola lights really help with their incredibly compact size. The heaviest items are the tray and handle and the lenses.

For my video rigs I use STIX jumbo floats on the tray and on the locline segments. Each one of those floats gives around 160 grams 5.6 Oz lift in water.

Stix floats are available as large and jumbo format more information directly on the 4th generation designs web site here

For stills I use aluminum arms as I find them more precise but also need longer arms and be able to sustain a heavier weight for a strobe outside water. Strobes frequently weight over half a kg with batteries, this is too much for a 1/2″ locline arm and stiffer 3/4″ segments are required. I don’t particularly like the 3/4″ segments and I prefer ball and clamp solutions. 3/4″ segment can hold easily a strobe but can’t be really too long.

This is my basic still set up I had for the Panasonic LX7

Even in this case I tried to use as many floats as possible to keep it light around the usual half Kg 1.1 lbs underwater weight.

For my RX100 I have two strobes and arms with 8″ and 5″ long segments.

As you can read this is 5.5 Kg on land and even with 6 Jumbo stix floats the underwater weight is over 680 grams or 1.5 lbs this for me is a bit too much to carry around so I started looking into alternative solutions.

Left Inon Mega M - Center ULCS 8" with 3 Jumbo Floats - Right ULCS 5" with 2 Large Floats — Left Inon Mega M – Center ULCS 8″ with 3 Jumbo Floats – Right ULCS 5″ with 2 Large Floats

The ultralight buoyancy arms provide too little lift in my opinion to be worth using so I looked at float arms in carbon or plastic material as an alternative. I came across Inon and Nauticam products and so I ran some comparison based on some metrics I have defined myself.

Update 16 March I also include Stix float arms now.

Those are:

Buoyancy per $: how much lift do you get per $ spent
Buoyancy per mm: how much lift do you get per mm effective length*
Buoyancy per gram: how much lift do you get in relation to the on land weight of the arm

*effective length is measured from the center of the arm balls

I refer to US $ prices just for convenience the same would apply even more in UK/Euro terms so here are some results

Standard Float Arms

You would use standard float arms if you have an acrylic dome on an SLR or mirror-less or a plastic housing that gives considerable lift as those solution give limited lift in water ranging from 75 to 333 grams.

Arm Type	Buoyancy	Cost Total	Weight	Depth Rating
ULCS S + 2 Stix L	154	$57.50	101	40m/130ft
Stix 6″ L	142	$43.00	101	40m/130ft
Inon S	75	$75.95	142	70m/230ft
ULCS M + 3 Stix L	237	$66.75	146	40m/130ft
Stix 9″ L	260	$48.00	146	40m/130ft
Nauticam M	240	$80.00	200	100m/330ft
Inon M	135	$89.95	181	70m/230ft

I have compared an ULCS 5″ and 8″ segment with Nauticam 60 mm diameter and Inon arms of the same diameter 52 mm or 2″. Those are the results. Update the new graph also includes Stix arms made of aluminum with plastic balls and their own floats.

In this category you can see that a STIX arm with large floats beats a carbon or plastic float arms on all metrics in fact on the shorter segment nauticam does not even produce a float arm solution.

An ULCS 5″ segment with 2 large floats give a lift of 154 grams or 5.4 Oz and an 8″ segment a good 237 grams or 8.5 Oz, Stix arms offer 142 and 260 grams respectively in the 6″ and 9″ lengths.

This solution gives more lift in water and is lighter on land I see no benefits investing in a float arm in this range of buoyancy and for this reason I have not even considered ULCS buoyancy arms. A pack of large stix floats costs $25 for 4 units of 99 grams or 3.5 Oz lift each and those can be moved on your arm segments making it a very flexible option.

Mega Floats

I define as mega floats anything that offers at least 2 grams lift for each mm effective length. I put the Stix arms in this category even if they fall short in this metric as they are comparable and cost effective.

Each one of those solutions will provide in excess of 274 grams or 9 Oz lift in water. In this category we have the ULCS arms with Stix jumbo floats as the most agile solution at 2.5″ or 63.5 mm diameter, this has the benefit of not requiring extra long clamps to fold two segments with floats fully. Nauticam and Inon both have segments with 90 mm and 97 mm diameter. Inon segments have an extra benefit compared to Nauticam for compact camera users using wet lenses as they can support up to 2 single lens holder for each segment as in the picture earlier in this post. Stix arms made of plastic are the cheapest in this category though can’t offer the same amount of buoyancy of carbon or ABS arms.

Arm Type	Buoyancy	Cost Total	Weight	Depth Rating
ULCS S + STIX J	274	$62.50	122	40m/130ft
STIX 6″	284	$43.00	122	40m/130ft
Inon S Mega	390	$82.95	219	70m/230ft
Nauticam S Mega	375	$90.00	240	100m/330ft
Inon M Mega	650	$93.95	295	70m/230ft
ULCS M + STIX J	416	$74.25	175	40m/130ft
STIX 9″	425	$51.00	178	40m/130ft
Nauticam M Mega	655	$120.00	275	100m/330ft

Those are the results:

Stix float arms score higher on a Buoyancy/$ metric and also lead the way in terms of buoyancy/weight ratio however the amount of lift offered is limited and this solution does score low on the buoyancy/mm metric. Especially in the medium segment around 8/9 inches you can see that there is not much difference on a buoyancy/$ between a 9″ stix arm and an Inon M mega.

You do get a problem with this big arms if you want to fold the segments on themselves. Currently ULCS provides the AC-CSB clamp for 2″ arm segments but even with that you can’t fold two mega arms.

Here a few example of the issue I mentioned a mega arm with a 5″ segment with float reaches maybe 30º and without the float around 20º

Mega float + 5" segment — Mega float + 5″ segment

Ultimately I do not think is a big issue as you can use the strobe adapter segment and still achieve all possible positions for your light anyway if you are concerned do get a couple of the longer clamps.

This is my rig with the float arms it does look neat compared to the version with STIX floats

Sony RX100 Mark II rig with Inon Mega float arms

Conclusion

Unless you have a plastic housing or a housing nearly neutral in water floats or float arms at 2″ diameter are not really effective, produce limited lift and are not a really cost effective way to add buoyancy to your rig. 2″ floats can be used to trim your rig in case larger floats are too buoyancy but are not a primary way to achieve the purpose. For example if I wanted to make my rig neutral I could add 2 large Stix floats on each arm.

Stix floats offer a lot of flexibility as you can take them off arm segments and put them elsewhere in a flexible way. Stix floats are also an option just within recreational limits 40m/130ft past this depth the floats loose buoyancy and eventually crush. Stix do offer custom materials float that resist greater depths on request.

Mega arms are a bit clumsy but do provide the lift needed and are cost effective even if a bit heavy on land. My preference if you use wet lenses is for the Inon arms, those are the most cost effective and provide the most lift and can also support lens holders. Inon arms are rated for 70 m/230 ft if you go deeper you need the Nauticam arms that ca go down to 100 m/330 ft. So for technical photographer float arms are really the only way forward in terms of off the shelf solutions. Obviously you can get bespoke solution using submarine grade divinycell but that is beyond the expertise and reach of a normal user.

How much lift do you need?

To calculate the buoyancy of your rig you can use manufacturers data sheets (Inon is brilliant, ULCS does provide some weights, housing manufacturers usually don’t). Failing that you can calculate this item by item using a graduated measuring container or last resort put your whole rig in water and use a luggage scale.

Caution

I balance my rig to have it neutral WITHOUT wet lenses this is for safety reasons. If you use a heavy wide angle wet lens and your rig is overall neutral the moment you take the lens off the port your rig will start to go up. Likewise if you had to loose your lens your rig would float and could escape to the surface. If you want to balance the overall rig you need to find a solution to balance the lenses themselves otherwise severe risks of runaway ascent chasing the rig could incur

housing, SONY RX100M2, Underwater Photography, UNDERWATER VIDEO

Leak Sentinel V3 for RX100 Mark II – Review and Stress Bench Test

March 9, 2014 interceptor121 5 Comments

Following the failed test on the Nauticam Electrical Sync Cord bulkhead I was out in the market to check what else could be done with the M16 port on the RX100 Mark II housing.

I bumped into the leak sentinel while at the London Dive Show. As you may know Nauticam provides now a vacuum system with temperature compensation on all new micro 4:3 and DSLR housings. Also older models can be retrofitted but not the RX100 because essentially the moisture sensor is much simpler.

So if the Nauticam housing has already a moisture sensor why bother adding a vacuum test. The advantages are numerous:

A moisture sensor still requires the housing to be put into water to be tested
A moisture sensor starts beeping when water has already made its way into the housing, if you are in a situation where you have a mandatory safety stop or a deco stop you don’t want really to have the additional stress of a camera flood.
With a leak sensor you can check the integrity of the housing before the dive and without putting it in water
You can rapidly change battery and the likes and not worry if you have compromised the seal of your housing

With all of this in mind I went off and contacted Vivid housings

After an email exchange about the design of the product I was convinced that it was worth getting it so I ordered one and after just 3 days it turned up in my post directly from Slovenia.

The system comes with an M16 adapter to screw on the housing bulkhead. The best way to remove the cap on the Mark II housing is using a CR2032 battery like the one of the moisture sensor.

I set up the system on the housing as in the featured image and started my preparation. It takes 3 pump strokes to get a green light and the instructions say to add between half and a full stroke to make sure it is not on the edge. I had 4 full strokes.

I prepared the housing and camera in a room at 21C and waited 20 minutes before putting it in water at 15C.

I then put the camera in video recording mode for one hour, the Rx100 has a limit at 30′ so I had to record two files. After one hour the system was still showing a green light I took it out of the water and follow the depressurization procedure and extracted the camera. Measuring the temperature inside the battery compartment the sensor indicated 28C.

Now this made me think to the fact that this solution, although equipped with a temperature sensor, does not actually manage temperature compensation. If you know anything about physics you know that the following is true for an gas also known as Gay Lussac law

the pressure of a gas of fixed mass and fixed volume is directly proportional to the gas’s absolute temperature

As our housing is rigid and not compressible this means that the ratio between temperature and pressure is constant.

This also means that if the temperature increases because the camera warms up with use the vacuum will drop (pressure increases), this could create a false positive.

I therefore performed the following steps

I immersed in water at 32C and started shooting a video clip.
After around 50 minutes the led started to alternate red and green. The camera has the temperature warning indicating a possible temperature close to 40 degrees
I kept the camera in water pretty sure there was no leak and then at 60 minutes took it out of the water
After few minutes outside water in a room at 21C the light went back to green
The camera temperature in the battery compartment was 36C

The ambient pressure was 1016 mpa so I estimate I created around 750mpa inside the housing with 4 full strokes, however as the camera sustained an increase of 19 degrees from 21 to 40 the pressure sustained an increase of 6.5% bringing it in the warning area of the leak sentinel and generated a false positive.

Now there are a few considerations to be done:

1. If you shoot pictures even firing the flash is unlikely to get the camera as hot as when you shoot video
2. The water in the dive will seldom be 30C anyway
3. It is preferable to prepare the camera in a temperature as close as possible to the diving temperature and in the driest environment available
4. It is possible to estimate the amount of vacuum each pump strokes gives and compensate for the temperature changes

The worst possible scenario is a video camera housing prepared in an air conditioned environment this is the only scenario where temperature compensation is useful.

Generally the suggestion of the user manual to give one or half pump strokes should be changed. Say that I have a large housing and it takes 10 strokes to create the vacuum, I would suggest another 3 strokes is diving in warm water otherwise the possibility of false positives is increased.

For what concerns the RX100 and only for very warm water shooting a lot of video there is a theoretical possibility that the camera overheats, and if the housing had been assembled in a much colder room, this gives a false positive.

To minimize this possibility prepare your housing at the normal ambient temperature of your dive site is generally the best practice for tropical diving. I also do not recommend practices like preparing your housing in a cold air conditioned cabin, some people think they avoid condensation not thinking that a 20+ degrees thermal shock does do any good to the camera.

Ultimately at €200 including worldwide shipping I can definitely recommend the leak sentinel to all RX100 users. Considering the cost of your investment even at the price of the RX100 Mark II of $750/£649/€699 this is a good tool and more than anything give you the extra reassurance of having a watertight housing, and also helps you in all your situations where you have a battery change or you have to open the housing before the end of your day.

Fisheye lens, SONY RX100, SONY RX100M2, Underwater Photography, wide angle

Which Fisheye Lens for the RX100?

February 27, 2014 interceptor121 12 Comments

Recently I have started building my RX100 Mark II photo rig and as part of this I had to choose a wet fisheye lens.

For video I do not like the barrel distortion of a fisheye lens, and on top of that you can’t attach a push on filter to a dome so for me those are two big no when it comes to the RX100 and its white balance error woes.

For still instead I shoot only RAW never white balance in the water and a fisheye lens is required so that I can have human size strobe arms when shooting close focus wide angle at distances between 0 and 16”.

I will focus my discussion on the Nauticam housing starting off with a 67mm thread and go from there.

Currently there are 3 options on the market for the RX100 and come from 3 difference manufacturers. I will go through each one briefly and then we will look more in detail at the two I consider best.

The first lens is the FIX UWL-28M52R, this lens is the smallest of all and was originally design to nicely complement the form factor of a Canon S100 in a fix housing, hence the 52mm thread. The lens has a magnification factor of 0.41x and a diameter of 126mm including the hood, the lens is actually much smaller at around 90mm.

Fix has introduced this lens in 2011 as a replacement of the previous UWL-04 model for two reasons, the first is to have a smaller lens as the UWL-04 was a too big in comparison of the housing, second probably cost though this was never declared. However other people tests and plenty of in water images show that this lens is actually worse than its predecessor. It is also smaller making split over-under shots more difficult.

When Fix withdraw the UWL-04 the manufacturer of the lens continued the production and finally put it back on the market under the i-divesite brand. This lens is the same as the Fix except the label.

Both lenses the old and new fix are pretty much a copy of the old Inon UFL-165, both made of 4 glass elements and an acrylic dome with hard anti scratch coating.

Here is a set of shots for the UWL-04 and the various parts in the box.

The last lens on the market is the Inon UWL-H100 with dome. This lens is available with an M67 mount and with an LD bayonet mount. Due to the size and weight of those lenses in water (100 to 500 grams weight and diameter between 125 and 152 mm) a bayonet mount is my preferred choice.

The Inon lens is actually made entirely of glass, the dome is the biggest at 115mm for the lens with an overall diameter of 132mm. This lens is the more suitable to split over under shot and promises a better contrast and less flare than the other lenses with plastic domes. Inon had some concerns about plastic domes and flare following the performance issue of their UFL165 so went for 100% glass for all next generation lenses.

Vignetting with RX100

In certain conditions all those lenses actually have some vignette in water. Despite what you read on shop websites if you look at real pictures there is a bit of that.

The Fix and Idas lenses have an issue with the lateral hood, the shots look clear of vignette on land but in water the magnification of the hood petals makes them show in the picture, we are talking a minimum crop required around 1% and usually on one side. The Inon UWL-H100 has a different issue and it gives in specific situations a tiny bit of vignette in the corners, around 2% of the image needs to be cropped. Both lenses will not vignette when image stabilization is deactivated, the image stabilizer tends to aggravate the issue so if you are obsessed switch it off and try to be steady shooting at speeds of 1/125^th of a second or faster. For example on the amount of vignette see the following

UWL-04 note the vignette left center — UWL-04 note the vignette upper left center

DSC02620Corrected — UWL-28M52R again vignette on the left upper side

SONY DSC — UWL-H100 vignette in left corners

I would like to thank Alex Tattersall, Tamas Plotek and Troy Williams for those in water pictures.

Inon UWL-100 28AD

Inon has another lens that is suitable for the RX100 and is the UWL-100 28AD a lens originally introduced in 2005. This lens has a smaller rear element than the UWL-H100 and it is not suited to many cameras with a very large lens aperture. The RX100 however works fine with this lens and contrary to the newer UWL-H100 this lens does not vignette in water or on land. The reason is that the de-magnification of this lens is less than the newer lens 0.63x vs 0.6x. This is the lens I have chosen for my RX100 Mark II and I will compare it here with the UWL-04 I have recently bought for my Canon S95. There are no substantial differences between the UWL-100 28AD and the UWL-H100 in terms of optical quality.

Here are few pictures to compare the lenses, take into account that whilst the weight on land is comparable, once in water the Inon lens is heavier at 400 grams versus 160 of the UWL-04.

UWL-04 UWL-100 profile

Image Quality

There is no need to take the lenses in water to compare image quality generally things get worse in water not better so it is sufficient to take a shot on land and see how that goes to have a relative comparison between two lenses. In this example the cameras are on a table exactly in the same position when the shots are taken and use the same settings of ISO, aperture and shutter speed.

The first impression is that the UWL-04 is a tad wider but more rectilinear, the Inon lens has definitely more barrel distortion and is more a fisheye than the UWL-04 is. Looking at mid upper frame you can see that at diagonal level the UWL-100 28AD is actually wider than the UWL-04 that remains wider horizontally. This means looking at the specs can be misleading and results depend on the camera lens combination.

So how do these lenses compare when it comes to corner sharpness and flare?

This is a shot with the UWL-100 in very harsh conditions with sun-rays hitting the lens directly on the dome, you can clearly see the ghosting that comes from it.

This is the same shot in the same place taken with the UWL-04 you immediate notice that the ghosting has a green color. This is most likely due to lack of anti-reflection coating inside the dome and to the color of the inner lens mount.

Looking at the image the picture taken with the Inon has a clearer ghosting but then is sharp in the rest of the image, the UWL-04 image has flare around it with comparable less contrast as we move from the center to the corners.

The other two images are a crop in the corner, you can see that despite the high level of distortion you can still distinguish some detail of the small grass bush in the Inon image, the UWL-04 instead is softer and the bush is basically a uniform green shape with no detail at all.

Update 28 Feb I have taken some shots with the UWL-H100 and the UFL165AD here are the overviews

The UWL-H100 is actually wider than the UWL-04 with the Sony RX100 despite the advertised 144.5 degrees versus 165 of the UWL-04. Has the same level of detail of the UWL-100 28AD

The UFL165AD flare issue is obvious in this shot both lower corners are compromised, this confirms why the UWL-04 is the best option for the Canon S series in terms of flare or vignette.

Looking at the UWL-H100 crop you can see the vignette more apparent in the upper corner and the image sharpness, it is possible that with an M67 mount there is no vignette with a Nauticam housing in most conditions, with LD mount you need to turn image stabiliser off or crop. Considering this is the widest lens it is not a big issue. Once cropped the UWL-H100 gives still the widest field of view but someone maybe be annoyed by this. Zooming in results in the same field of view of the UWL-10- 28AD

Ergonomics

The Inon lens presents the benefit of a bayonet mount, although the lens is heavy it can be removed in water quite easily, the UWL-04 has some issues whereby the adapter ring would unscrew instead of the lens, this can be avoided fixing the adapter on the lens but then there is no lens cap that would fit the larger M67 screw in the box so you need to buy one yourself, generally the size of the petals make this lens impossible to handle in water and is more like diving with a dome port. It has to be noted though that you can zoom through with both lenses so still continue and take portrait shots and close ups. Obviously for real close or macro you do need to take the lens off which with the UWL-04 you can basically forget.

Cost

The UWL-04 costs $460 in US as shown here with dome cover and step down ring, and £362 in UK. The Inon UWL-100 28AD with dome costs $907.80 including an M67-ADF adapter in US and £775 in UK. All in all the Inon is around near to double the price of the UWL-04. The UWL-H100 is even more expensive at $970 for the M67 version and $942 for the LD bayonet, you then need to add $160 for an adapter for a total of $1,102 that is a lot of money another reason for the 28AD version.

Conclusion

The Inon is the best lens for the RX100 and there is no doubt, however it costs more than double the UWL-04 not everybody will be able to afford it. The UWL-04 is a somewhat basic lens that lacks sophistication and is essentially not removable in water but comes at a great price. In terms of field of view the lenses are very similar with the Inon lenses having more fisheye distortion and a wider diagonal field of view. The UWL-04 is more rectilinear and as consequence has less field of view diagonally. Only one lens has zero vignette at the wide end and this is the UWL-100 28AD with dome.

In Water Shots

~~I don’t have shots in water yet pending my next trip but two galleries that give an idea are here:~~

For the Inon UWL-100 28AD with dome look at my Red Sea Gallery https://www.flickr.com/photos/interceptor121/sets/72157645375379256/

For the UWL-04 instead this is an excellent one

http://www.flickr.com/photos/13930495@N06/sets/72157636133030726/

The second shooter has got rid of the UWL-04 to buy an Inon as not happy with corner sharpness!

My perspective is if I look at the pictures I can barely tell the difference however looking close the Inon lens is sharper at one f/stop less, the UWL-04 requires stopping at f/8 or smaller, you can happily shoot f/5.6 with the Inon which means you need less light and less strobe power.

macro, SONY RX100, SONY RX100M2, Underwater Photography, wide angle

My Sony RX100 Mark II Photo Rig Analysis

February 21, 2014 interceptor121 56 Comments

So the time has come to talk about photography more in depth. I have actually given up stills in favor of video since a few years as I find video gets me closer to behaviors than stills do, I guess am just not patient enough to capture behaviors on still as that involves waiting!

Anyway this is the rig as it is today without the floats.

Sony RX100 Mark II Still Rig as of 2014 January 20th

The RX100 is a demanding compact for the very same reason why it is the best compact the huge sensor it sports. If you come from shooting a canon or panasonic or even Olympus on a 1/1.7″ sensor you find the RX100 to be very unforgiving. In essence you can’t really just point and shoot you need to put some more thinking into your shots.

The rig that I have put together for stills has the same meticulous attention to detail than my video rig has, you would say OCD probably but here it is.

So let’s start with the housing, Nauticam just makes the best most ergonomic housing for the RX100 period. There is nothing you can think of improving about this housing. Even if the bulkhead connector is useless you can actually put a vacuum valve on it to put it to full use.

Nauticam do offer an M67 thread native on all their compact housings but I find this tedious to say the least. The beauty of a compact is that you can shoot wide and macro on the same dive, the M67 thread in essence negates this as it makes virtually impossible to change lenses on a dive. This is the reason why I went for the Inon 28AD mount for my rig using an inexpensive 10 bar adapter priced at $20 or £15.

M67-ADF adapter with Inon UWL-100 attached

Once you connect the Inon UWL-100 28AD the lens is very close to the housing to the point of nearly touching the port. This means you get no vignette with this lens with the added dome, and actually a larger field of view in water than you get with the UWL-H100. Why is that? The UWL-100 28AD has less magnification so it does not vignette even on land, once you add the dome you get almost the same field of view in water around 150º. The lens is just a tad lighter than the UWL-H100 with an in water weight of 400 grams.

The choice of the 28AD mount means you can only use the UCL-165AD close up lenses, that if attached would crash into the glass, you need therefore a 28AD->AD adapter from Inon.

28AD to AD adapter with UCL-165AD attached

You do get vignette until 50mm however this is not an issue as you shoot those lenses at the tele-end.

This is the whole lens set with the two adapters.

Two UCL-165AD, UWL-100 28AD with dome, 28AD->ADF adapter, M67-28ADF adapter

As discussed in other posts the two stacked diopters give you super macro, they are also light with 35 grams each in water. The small amount of fringing they give can be eliminated in lightroom with a single click.

Inon UCL-165AD x2 with Inon 28AD to AD adapter

The wide angle lens sports a 115mm optical glass dome with inner anti-reflection coating. If you are into observing fine detail you will notice that the dome is not actually a full semicircle but flatter, if you add the special coating this means no flare and increased contrast. If you wonder why shots taken with Inon dome lenses are sharper is because only 1% of the incoming light is reflected, against 3% of an acrylic dome, the glass dome due to the coating don’t flare, plastic ones do as simple as that.

Now let’s move on to the strobes a twin Inon Z240 set. I have been a sea and sea user for years until I managed to damage my YS-01 and got no assistance at all from S&S since then I decided to go elsewhere.

What I love about the Z240 is the variety of controls to manage shadows, the sharp aiming light with a red filter good for the most skittish critters. Contrary to what many people think I aim directly at the subject in macro as the distance is short and backscatter is not an issue so no point aiming the strobes away for me.

FIT Sea and Sea adapter for Inon Strobes

I happened to have a pair of Sea and Sea optical L cable that served me well and had no will to change, FIT produces this cost effective adapter that goes on your Z240 and makes it compatible, I just love it.

I believe Inon Z MV strobe head adapter has no equal in ergonomics but for some reason a part that is $20 in Japan sells at over $40 in US and £30 in UK so is not that popular. My second choice would be the Nauticam strobe adapter that has got the small feet needed to correctly lock on the strobe head.

With the Z240 doing wonders as aiming light there is no real room for a focus light however I have a set of Sola Video 1200 and what I like is that you can use them as dive light. I have connected them with a locline cold shoe, this will soon change to a ball mount, as the cold shoe is on the left side. Probably I will get a Sola Dive 800 so I can leave my two trays set for video and stills on the boat.

Looking at the tray I use ultralight, it simple and sturdy and allows me to center the port in the middle of the tray.

The most attentive will see that the two handles have different colors.

Why is that? Firstly I want to place the handles at maximum distance, second by placing two different handle I can ensure the ball is at the same height, this would not be true if I was using the same handle on both sides. I use a TR-DM with a TR-DUPL long extension to make the tray 30cm or 12″.

So this is what it looks like, there will be floats on it, I estimate I need 8 floats to make the rig neutral with the lenses off. I am planning to place 3 on each 8″ arm segment and two on the tray however I might change this to 2 on each arm and a bespoke float on the tray bottom. I will run some test to see what works best.

So that’s all folks surely there will be questions and I look forward to answer them.

Just want to remind you that if you are in the market for a compact still or video rig I provide a personal shopper service for £30 or $45 that provides an end to end service on your budget where all you have to do is to call the shop to pay. Of course we would discuss any observations about the set up before this gets finalized, but am sure better to spend a little amount instead of making expensive mistakes!

UPDATE 9 June 2014 I have made some more changes to the rig the current version (never say final) is here

Photo Rig Current

housing, SONY RX100, SONY RX100M2, Strobe, Underwater Photography

Sony RX100 Mark II Bulkhead Connection Flop

February 16, 2014 interceptor121 3 Comments

In this post I will investigate for your enjoyment the bulkhead connector available for the Sony RX100 Mark II and will see why this is unfortunately an accessory that is not worth buying. There are other ways to put the M16 port to use for example with a leak detection system but if were thinking of firing strobes using electrical sync cords then think again.

I was today at the London International Dive Show where I met Dr Alex Tattersall of Nauticam UK that also introduced me to Catherine Lai, daughter of Edward CEO and founder of Nauticam and herself operations director.

I felt a bit sorry when I had to explain why the bulkhead was not a workable solution and if you have a look at the youtube video you will understand why, this has been shot by my fiance’ on an iPhone so apologies for the portrait format and occasional shake.

Right so if you didn’t manage to hear the audio or understand the subtitles here is the plain text explanation.

The bulkhead has a single X pin that connects to the center of the RX100 multi-shoe, now this is the same interface that is on the newer Nex and on the A7. The Sony multi-shoe has a complex 21 pin interface that used with compatible accessories can trigger an external TTL flash.

In order for an external device to be recognized the interface of the connector need to connect to the 21 pin slot not just to the center. Nauticam bulkhead adapter is not so complex and only connect only on the center pin.

So the result is that the external connection is not recognized and if you leave the flash set to fill flash, as you would do with an optical connection, the internal RX100 flash pops out and fires away negating the benefit of the electrical connection.

So in order to make it work you need to set the internal flash to OFF. As the pin on the multi-shoe is always live this works perfectly so when you press the shutter the nikonos interface triggers the external strobe which is what should happen.

The little but significant inconvenient is that if you set the flash to off the LCD goes pretty much black as the RX100 has live view on the LCD and only lights up when you half press the shutter. This means is practically impossible to compose any shot unless you have a really bright focus light or there is sufficient ambient light. In any case for a close focus wide angle shot that you will take with this camera with apertures between f/8 and f/11 the screen will look pitch black as in the video even if you set the LCD to sunny weather.

Whilst the A7 and Nex have an option to disable live view in the LCD, the RX100 does not have such option so you are pretty much done and this accessory is not worth buying as it also introduces an additional point of failure for the housing and one for each strobe.

So the supposed big advantage of the Mark II goes out of the window, time to despair? Not at all!!!

As previously anticipated in my first impression post https://interceptor121.wordpress.com/2013/07/27/sony-rx100m2-first-impressions/

I had the impression that the internal flash was recycling much faster than the original RX100, well I have done some tests and I can confirm what imaging-resource has measured: the flash recycling time at full power goes from 7.2 sec of the RX100 down to 4.4 seconds of the Mark II.

Now this is significant because after your shot you need anyway 2 seconds to recharge the strobes and look at the image preview after the shot and probably another 2 seconds to recompose the shot, at that time the RX100 Mark II will be ready to shoot again at full power.

The improved CIPA rating of the Mark II also means well in excess of 200 shots at full flash before having to change the battery so there is no big deal that the electrical option is not workable, get yourself a twin set of Inon Z240 (my current favourite) or Sea and Sea YS-D1 and you will have no issues compared to any other compact as the RX100 Mark II has the highest CIPA rating of all compacts on the market that are good underwater.

In fact the most significant improvement of the RX100 Mark II in addition to the better performance in low light is certainly the strobe recycle time, from 7.2 to 4.4 is nearly a 40% improvement and the Mark II is faster to recycle than a Canon S120 although not as fast as the G15 or as fast as the Panasonic LX7 or Olympus XZ2. However we are talking about 1.2 seconds difference I doubt that is such a big deal

Clearly the RX100 Mark II is the best compact camera for both still and videos and I look forward to shooting more stills with it.

Underwater Photography, UNDERWATER VIDEO, Video Lights, wide angle

Choosing a video light for your Underwater Video Rig

January 5, 2014 interceptor121 22 Comments

I thought of writing a brief article about video lights.

In the last years LED lights have become incredibly cost effective and there are many products on sale that look promising and cheap.

A special mention goes to the GoPro a very cost effective option for underwater video plagued by poor performance in low light. The GoPro market seem to have injected new life into the video light marketplace and of course calls for products that are not expensive in line with the typical profile of the GoPro user.

There are many examples of footage with what you would consider powerful lights that actually do not look that bright or even nice, why is that?

Lights are now measured in Lumens which is the SI unit of measure of luminous flux a light is said to emit one lumen if it emits one candela over a solid angle of one steradian. This sounds all very complicated and not very helpful so let’s try to make some sense of this.

Usually when we go an buy a light we are given three key pieces of information:

Lumens – this in a way is considered the power of the light*
Beam angle – this is the maximum horizontal beam that the light can cover – note this does not relate with solid angles but is merely a 2D view
Color – this represent how white is the light, a good light should not exceed 6500K which is what is considered a day light white

*we will see that this is actually incorrect

Let’s have a look at a typical best buy the Archon Video Light W38VR, this light is declared to have the following:

1400 Lumens
120 degrees beam angle
5000K temperature

Looking at the specifications this looks like a very warm (5000K) wide beam light and very powerful so how comes that with a subject at one meter or 3 feet distance this light seems to have no effect on a bright day?

The reason is that lumens are not a real indication of the amount of light that hits the subject but just the total light emitted which includes the light that illuminates the water between us and the subject that we actually are not interest at all in illuminating.

If you had to do a video production in studio you would be looking at intensity of 1000 lux where a lux is measured in lumens/m2. The lux is the density of light that hits a flat surface at a given distance.

With a few calculations we see that the Archon light because of the very wide beam is effective at two feet and produces around 1200 Lux which is great however at 3 feet this drops to 550 Lux which is not that great.

Many times when comparing the new cheaper lights to expensive lights like Sola or Fix despite the less nominal lumens declared the sola or fix seem brighter at the same distance.

So let’s evaluate the lux produced by a Sola 1200 a light much more expensive than the Archon with only a 60 degrees beam.

At two feet the sola produces around 4000 Lux which would nearly tan a fish, at 3 feet it still produces nearly 1800 Lux dropping to the studio value of 1000 Lux at a distance of 4 feet or 1.2 meters. This is because the illumination is in a smaller and narrower beam and is like the light was more dense.

Of course this has the disbenefit of a narrower beam so we need to step away from the subject in order to cover it properly, this diagram gives an idea

The two set of lines contain the video lights beams, we can see that those beams cross and them keep as combined angle of coverage the same beam of the lights themselves, that is the ideal spot for our lights as there are no shadows there.

Another consideration is the angle of coverage that we need for our camera lens to follow the lights, two 60 degrees beam lights actually cover a 100 degrees diagonal lens or 90 degrees horizontal lens typical of a 18mm lens. The GoPro and all compact cameras with a 100 degree lens fall in this group.

Another consideration to be done is that due to the light angle of coverage there is a minimum distance to be kept if we want to avoid our subject to be in the shade, this minimum distance depends on the light beam and the distance between them.

Once you get closer than one foot it is not necessary anymore to point the lights forward as the amount of water is limited and the lights can be pointed directly at the subject like in this example

So assuming we want to be at a distance of one foot or 30cm how far do the lights need to be?

For a 60 degrees beam the lights need to be 36 cm away or around 12 inches. For a light like the Archon with 120 degrees beam the distance between the arms needs to be 1 meters or 40″. Considering a tray is around 30 cm or 12″ this means you need arms at least 13″ in order to cover something at one foot and to cover a subject at 2 feet you need two meters distance that means again 33″ worth of arms.

What happens if you only have the tray with the lights on and your subject is at 3 feet with two very wide video lights of 120 degrees beam?

You illuminate already after 3″ from the camera
The two lights emit 550 Lux that combined are not such a small output

The net result is that a lot of the water in front of the subject is illuminated and this creates backscatter where all the silt in the water gets reflection and ultimately deteriorates the quality of the footage.

If you ever wonder why underwater photographers that shoot super wide have two 16″ arm segments this is why the want to avoid backscatter with their 110 degrees strobes and still be around one foot distance with their fisheye lens.

So what are the conclusions that we can draw:

A wide beam light is only good if you have long arms, the wider the beam the longer the arms otherwise the beams just light up the particles in front of the subject producing backscatter
Lumens are not a real indication of the effectiveness of the light per se but need to be taken into account with the beam angle and a lux calculation needs to be performed you want to aim for 1000 lux at the distance of choice
Light beams need to be evaluated together with the camera lens horizontal field of coverage 60-80 degree beam angles are adequate for most of the video rigs out there and more is only justified for fisheye type of lens not commonly used in video

I hope you find this information useful and get in touch if you want to discuss, the subject is not that simple!

close up lens, diopters, macro, SONY RX100, SONY RX100M2, Stabilization, Underwater Photography, UNDERWATER VIDEO

Sony RX100 – Which close up lens gives real macro?

September 15, 2013 interceptor121 3 Comments

As we know the Sony RX100 cameras, we will refer to both Mark I and II as the lens is the same, do not offer the best out of the box super close up performance.

To be clear no compact camera really does macro, as no compact can capture an area 36×24 mm in size without being on top of the subject and having a shadow cast on it.

The RX100 however are particularly unexciting as the capture area is pretty large at 76x51mm at the minimum focus distance of 5cm. This means a reproduction factor of less than 1:2 so things are half life size in traditional terms.

In water the minimum focus distance increases and so does magnification so performance is all in all the same.

This means that a typical small subject like a medium size nudibranch measuring 4cm will fill a bit more than half the frame, not great.

The problem can be addressed by close up lenses that have a set power that determines the focal length and working distance where we can use the full camera zoom.

So the close up lens sets the working distance whilst the camera zoom sets the magnification.

A typical close up lens will have a power of 5 or 6 diopters with a working distance in water of 200 or 165mm, what does it mean for the RX100?

I have done some testing in water using a ruler and an Inon UCL165 this is the result:

Our capture width is now 46mm so our 4cm nudibranch will nearly fill the frame. The working distance of this lens is 165mm so this is a very versatile solution as most critters have no problem being approached so close.

What happens with a +10 close up lens with a focal length of 100mm, this is another test

A +10 diopter like the Subsee or Inon UCL100 achieves exactly 35mm so life size macro. However a lens like this will not focus at longer focal distances without zooming out, furthermore there are plenty of subject that do not need this magnification.

Close up lenses can be stacked so this is the result of two + 6 diopters

The width is now 32mm which is 1.1:1 so more than macro. This is adequate even for pygmy seahorse and with the incredible resolution of the RX100 cropping is not a big issue. Working distance is around 8.5cm which is still tolerated by small critters.

For completeness I have also tested a +16 combination

At around 26mm this is 1.4:1 so real super macro, the working distance is however only 6.25cm which is really close and will scare most critters away.

Conclusions:

Without any close up lens the RX100 can only capture 5cm objects without extensive cropping
A close up lens with a working distance of 165mm allows for most of the critters we consider small but without super macro effects unless cropped
Two stacked +6 diopters offer super macro and can also be cropped for more suggestive effect
A single +10 close up lens achieves real macro however it is not versatile enough for every day usage
Stacking lenses does introduce chromatic aberration but this can be eliminated in photos and is barely noticed in video

Pay attention when you select your close up lenses that the focal distance that is in the specification is measured in water otherwise you will find yourself with a useless purchase

housing, SONY RX100M2, Underwater Photography, UNDERWATER VIDEO

Sony RX100 Mark II – Nauticam Housing Review

September 1, 2013 interceptor121 1 Comment

I have just received this week the NA-RX100II housing also known with product code 17408

This housing is essentially identically to the already very successful NA-RX100 more specifically it looks identically to the NA-RX100V video version.

This looks apparent if we look at the left side of the housing where a screw can attach a bulkhead

According to Nauticam you can attach both the SmallHD 4.3 LCD monitor to use as external monitoring for video or an electrical sync cord to attach a strobe via a hot shoe 5 pin connector. This will not support TTL but will allow to fire an external strobe without triggering the internal flash. This means that there will not be any issue of recycle time especially true at wide angle or when using strobe with edge lighting.

Now I believe this is great news for those underwater photographer that are downgrading from DSLR as this was probably one of the key limitation of the RX100 that will now be overcome.

Remember that the RX100II seems to have other significant improvements with respect to the Mark I in terms of corner sharpness that can make this already excellent camera an absolute killer.

I wonder if it is possible to enable and disable the hot shoe and use both electrical and optical connectors as in macro TTL the camera performs very well indeed and this would only be available with optical connections.

If you are interested in the mini video review of this housing you can find it here

I will do some tank tests for corner sharpness in the next days so stay tuned

The housing is priced at £699 in UK as it was with the Mark I so should be $950 in US. Great value for the additional bulk head port!

Update the M16 port on the side will have an hot shoe accessory but won’t have an HDMI bulkhead, this because there is not enough space to connect the HDMI cable on the bottom of the RX100. The V version will have some more space under the camera to allow the cable to go in

ambient light, AVCHD, close up lens, diopters, filter, iMovie, SONY RX100, Underwater Photography, UNDERWATER VIDEO, White Balance, wide angle

Sony RX100M2– First Impressions

July 27, 2013 interceptor121 6 Comments

I have been fortunate to receive one of the first RX100M2 that have reached the market so I thought of sharing with you my first impression and what I believe will be the potential for underwater imaging use.

This is the link to the unboxing video of the camera

I posted a summary of the RX100 capabilities for underwater video some time ago on this blog the post is here:

Probably the best thing is to revisit my review and update any significant differences between the RX100 Mark 2 and the original version which is still on the market and will remain at least until the end of 2013.

Key Strengths

Bright Lens – Not changed

The RX100M2 has exactly the same lens of its predecessor RX100, it is true that when zoomed the minimum aperture drops down to f/4.9 however this is not a concern for underwater imaging as usually long focal lengths are for macro and we are interested in very small aperture to allow for greater depth of field.

Low Noise – Improvement!

In virtue of the new retro illuminated sensor the mark 2 has one full f-stop advantage over the original RX100. This means that ISO800 is a breeze and potentially we could go as low as ISO1600. I would not do that but what it means is a cleaner image at depth in ambient light.

Image Quality – Improvement

Image quality is outstanding and the lack of aggressive contract and sharpness filters in the default settings means more room for correction in post processing.

Video Mode Control – no change

The RX100 had complete control on video mode and the mark 2 maintains the standard. Very important is that the program mode is excellent and keeps the shutter speed at 1/100 or 1/125 when used in active mode which is ideal for 50/60p smooth footage.

Manual Focus – no change

Same as for the RX100

Battery Life – Improvement

According to Sony battery life has improved from an already outstanding CIPA 330 to a declared value of CIPA 350. The new Mark 2 has also an hot shoe so in theory if any manufactures produces a wired TTL enabled housing this means plenty of shooting before changing the battery pack. We suspect though that only ikelite will have this option on the housing.

Active Steadyshot – no change

I initially slagged the RX100 stabilization system based on performance on land. However at a more in depth analysis it turns out that the RX100 active steadyshot, even if at cost of an image crop is very effective for sudden camera movement and for high magnification macro. The Stabilizer is not as sticky as others so when you eventually vibrate it does not jump. Although the performance for stills is poor to irrelevant and so is the normal mode the active mode is very effective for underwater use. The mark 2 is built exactly with the same algorithm and combination of optical and electronic.

Tedious Workarounds Comparison

Some of the ergonomics of the RX100 are not the best and seriously deduct from an otherwise excellent experience, the most annoying issues:

Lack of focus lock – no change

For some reason Sony decided to skip on this essential feature, the workaround involves switching to manual focus however it is then possible to accidentally change focus if the front ring is set to control focus. The RX100M2 has the same issue.

Setting Custom White Balance in Video – No change

Setting custom white balance is only possible in the still modes, while in fact if you shoot RAW don’t actually need white balancing. This is the largest non sense of this camera that requires the user to navigate out into Program to ensure white balance is set correctly and you don’t end up with the Custom WB Error message. Though this is annoying is not such a killer as it would initially seem if you take your movies in one of this still modes which is valid for wide angle and ambient light shot. For macro you will need to switch to movie mode aperture priority in AWB. If you keep this discipline this is issue is mitigated. The RX100M2 does not change this and I believe this is due to the fact that the shutter button that is used to set custom white balance is disabled in video.

Lack of 24/25/30 progressive modes at 1080HD – Improvement!

The RX100M2 shoots at 50/60p as well as 25/24p in addition to that you can switch between PAL and NTSC which is great!!!

AVCHD – Improvement!

The RX100M2 has not only the progressive modes at double frame rate but also AVCHD 1.0 compliant format, this means that if you choose the 24M 24/25 p mode you can import with all editing programs without issue. Not only that but if you use the wireless import utility this converts also the AVCHD progressive files in mp4 for you. This is great improvement

Key Weaknesses comparison

The RX100 had also some key weaknesses let’s see how the mark 2 fares.

Macro Performance – no change

Exactly the same as its predecessor the RX100M2 has a minimum focus distance of 5cm on land that becomes around 7 in water. Like with the RX100 because of the large capture area you will need diopters for macro shots. On a positive note once you have a close up lens the performance is incredible when coupled with manual focus with peaking.

~~Stabilizer~~

Sony has adopted a lens shift approach in this camera instead of the sensor shift of the higher end alpha, maybe due to large size of the sensor compared to the camera body. They have then added some software processing in camera but the results are just average. There are many other cameras that do better than the RX100.

Soft Corners at Wide End – Improvement

The RX100 first generation had soft corners until f/5.6 the situation changes dramatically as we can see in this test card comparison shot. Not sure if there was an issue with the RX100 original sensor but this looks excellent and as sharp as the panasonic LX7 or Canon G15.

Look for yourself!!!

No Neutral Density Filter – marginal deterioration

As its predecessor there is no neutral density also on the mark2. A little tip for video is to shoot with filters that take away 1 1/3 f-stop. This is not ideal but helps. There were some speculation that because the minimum ISO in RAW is now 100 instead of 80 sunballs would be more difficult to shoot. 1/3 of an f-stop does not really make any difference I believe this is more a statement so that the RX100 housing that are in stock sell out at full price.

Other features

I have to say that the tilting screen is fantastic to shoot on a tripod on lens. I doubt any housing can accommodate for this but the feature is outstanding

And this is the rear

Conclusion

So the question is should I buy the RX100M2 or the RX100 maybe grabbing a deal? Recsea has already announced a housing for the mark 2 and Nauticam is working on it. I believe that when it comes to still photography the difference between the two cameras are not substantial as many shots are with strobes I have however noticed a much faster internal flash cycle time. I do not want to be definite but looks like a full dump takes around seconds to recharge. Also to be considered that in US the price difference is $100 so definitely the Mark2 is the way forward. In UK/Europe the difference on the list price is £150/€180 which is much more.

So I would say if you are planning to use the camera for video go for the RX100M2 the improvements are significant both in terms of video formats but also in terms of sharpness at wide apertures. If your main interest is photography and you live in US go for the mark 2 in Europe instead I would grab a deal on the RX100 when the price of the housing drops.

I am waiting for a test housing from Nauticam as soon as I have it I will post an unboxing video followed by some pool tests.

mandarin fish, Underwater Photography, UNDERWATER VIDEO

Tips for capturing Mating Mandarin Fish

June 16, 2013 interceptor121 2 Comments

I was in Indonesia during the second part of May and I had in mind to take some clips and stills of mating mandarin fish

Mandarin Fish are very skittish creatures. During the day if you can see them they are usually hanging right close to sea urchins to make your life difficult.

Their movements are jerky and fast and they are very hard to capture. Mandarin fish mate every day at sunset, and they can be seen in specific spots around the world. Indonesia is the country that has more of those spots that are public knowledge.

The spot where they mate is usually shallow, 3 to 5 meters depth, and made entirely of rubble of broken coral.

So when you go and see Mandarin Fish mating all you are going to see is Mandarin Fish as other than the fish that prey on their eggs and the odd nudibranchs or squid there is really nothing else.

The rubble is usually quite light color and unpleasant to film, mandarin fish go swimming around those broken coral bits and only emerge from it for their mating ritual that lasts 4 seconds in total until the disperse eggs and sperm into the water.

Mandarin fish hates our light especially video lights and anything more than 150 lumens means the fish will just not show up and choose another place to make. This is very bad news because it means that all mandarin fish footage has to be taken at high ISO or high gain, with a lot of noise in the picture, it is important to have a camera that performs well in low light conditions and will produce footage that is watchable.

Video requires continuous light and as said before mandarin fish hate light especially cold light as your typical 6500K video light.

In order to make our set up more mandarin fish friendly there are few options:

Buy two special red stealth lights such as Sola Photo light
Buy red filters for your normal video light those also serve the purpose of reducing power output
Use some sort of red diffuser for your lights

If you already have video lights and they don’t have the special red beam you are left with option 2 and 3.

A set of 2.2″ red filters will do the trick for the Sola lights

Sola+2.2" red filter — Sola+2.2″ red filter

I had ordered two red filters for my Sola video lights and of course these did not arrive on time for the trip so I had to improvise as you can see in this pictures that features my red speedo shorts!

As you can see the mandarin fish really hang out on the rubble.

The red weak light does not disturb the mandarin fish when they come out to play and allows you to get quite close shots.

I took a video whilst in Bunaken using my Panasonic LX7. I used the flat port and zoom between 50 and 90 mm. I performed custom white balance on the rubble with the red lights on.

The result is in this video

I also shot few stills in another dive. If you want to take pictures of mandarin fish you have a similar challenge in terms of not scaring the fish but also you need to be able to know when to shoot.

Those are my suggested settings:

Shoot a normal lens around 90mm equivalent
Disable any form of pre-flash as that scares the fish and stops the mating act
Try to pre-focus as you will be in low light and don’t want blurred pictures
Shoot RAW
Try to follow a couple of fish from the start and count to 4
The eggs are released at 4 any other shot can be taken earlier
If possible (it was not possible for me) try to point the camera up to avoid the rubble
Set high shutter speed to have a dark background and get rid of the rubble

The featured image and this other one are my two best shots, there is minimal cropping

I took all my shots at the minimum aperture to have maximum depth of field but this I believe is an error and gives too much detail of the rubble behind.

I think the video that is shot at wide apertures is better and less distracting.

Another tip of environmental nature is that usually the rubble patch with the mandarin fish is small more than 2 cameras and there are just too many and the max is 4 dives plus the guide. I am glad I did my mandarin dives in Bunaken and not in Lembeh where you can get up to 10 people on the same spot whilst in Bunaken I was on my own twice.

I hope you found those tips useful and good luck with your next mandarin dive!

Interceptor121 Photography & Video Workshops