Category Archives: wide angle

Panasonic GX7 First Test

So time has come for my first video with a micro four third camera the Panasonic GX7. I had only 3 dives in Sharm and conditions on Naama Bay beach were not the best but still good enough to give the set up a good try, this is the resulting video.

I used the Nauticam housing with the Macro 35 port and the M67-LD adapter so that I could use the Inon UWL-H100 wet lens.

As it is not possible to fix the position of the lens I had to take the hood off and therefore I used an Ikelite UR/PRO filter for the 100mm lens. I had to use gaffer tape on the lens and inside the filter or it would be loose but it worked.

The first dive was with the URPRO filter in auto white balance, I was hoping this would give me good results but instead everything came with a strong yellow cast.

From the second dive I used custom white balance and the results were much much better.

To give an idea of the issue this is a shot of a grey card with the UR/PRO filter on land with white balance fixed.

URPRO test card
URPRO test card

You can see what kind of effect the filter bear it is orange in colour.

Other than this I was pretty happy with the GX7 especially because I could use the full zoom with the wide angle lens this is the first time I see it working. The moray eel shot towards the end of the video is an example.

Back home I was not happy at all about the UR/PRO and the inability to work with auto white balance. Probably I could have played with the tint but it did not come to mind. So I got in touch with Peter Rowlands of Magic Filters to see if they had an option that would fit on the Ikelite mount. Peter sent me two sample and they fit perfectly in the ikelite frame, though this is not commercially available I guess you can request those if you are not happy with the ikelite UR/PRO.

This is the same test card with the magic auto filter.

DSC04030

You can see that it looks less orange and also slightly colder.

I did some tests and the UR/PRO is a warmer filter with 2700K temperature whilst the magic auto is 3200K. The magic is however more red and has more magenta tint than the UR/PRO.

For me this means that the magic will work better in auto and will require less custom white balance. However those 500K difference mean you will eventually need to custom white balance once you go below 18-21 meters. I know people say filter work until 21 meters anyway but I have tried with deeproof down to 30 and on a bright day it was still good.

So if you are not happy with the yellow cast of your UR/PRO in auto white balance is definitely worth giving magic filters a go.

The GX7 confirmed all the good features including the ex tele mode

Here the shrimps are shot with a single Inon UCL-165 and then the close up of the head uses ex tele that pushes well over super macro.

Look at the incredible ability to refocus in video mode. See how focus locks on the shrimps when I press the button.

Overall the GX7 can do pretty much everything on a single dive with a wet wide angle lens and a close up lens. You can cover from 100 degrees wide to super macro. The fact you can zoom with the wide angle removes the need to take the lens off at every occasion and in fact in the red sea you barely need to have any other lens.

I was not particularly happy with the lack of hood that the ikelite filter wants removed so I experienced the occasional flare. Still pretty good result.

The clip looks much better at home than it does on youtube where the gap with the RX100 seems much smaller.

So as far as video is concerned if you don’t need 4K the GX7 gives you extremely high quality footage and reasonable cost.

A final note I shot this video in 24p at home I can’t tell the difference with 25p see if you can see it!

Panasonic Lumix G X Vario 14-42mm with Fisheye Converter DMW-GFC1

The Panasonic 8mm Fisheye lens for micro four third is a clear winner for close focus wide angle however the lack of zoom and the really wide 180º cover mean that there are many subjects that will look tiny in the frame.

The next option in terms of width is the Panasonic 7-14mm wide angle lens however this requires a large dome for optimal performance making the set up expensive.

Is there anything else left if you don’t want to buy a wet lens and you already have the Panasonic PZ 14-42 X Lumix G?

Panasonic produces an add on lens DMW-GFC1 that is declared to provide 10.5mm equivalent and reduce minimum focussing distance to 16 cm all specs can be found here.

This add on lens can be used with the 4.33″ dome for the 8mm fisheye and the 30 extension.

I took a few test shots and the results are pretty good.

This first shot is at f/5 and is very sharp in the centre.

Fisheye Converter f/5

Fisheye Converter f/5

Getting a bit closer and stopping at f/8 the results are pretty good for an adapter that is less than £100 on amazon.

Fisheye Converter f/8
Fisheye Converter f/8

Barrel distortion is contained so this combination may be good for wrecks where the fisheye effect is a bit disturbing.

If you have the Lumix G Vario X PZ 14-42mm you may want to invest in this little accessory before getting the much more expensive 8mm fisheye even if the Nauticam 30 extension is required. Later on the extension can be used with the flat port 35 and the Olympus 60mm for super macro and the 4.33″ dome of course with the 8mm.

I think it is amazing how much can be obtained out of this lens if we consider wet diopters, wet wide angle lenses and this adapter before you need to get a second lens.

This lens could also work for video with the Panasonic GH4 at 4K however zoom is not recommended with it.

Video Feature Sony RX100 Mark II in Malta

Following from my previous post I managed to get together a clip out of the 5 dives I did

The first day was somewhat plagued by visibility a bit lower than the norm for the location but the second day was fabulous

For this trip I brought with me the Inon UWL-H100 and the red push on filter from deep roof H20 and the Inon UCL-330 as I was expecting medium size fish and nothing really small

Here is the outcome

I am quite happy how things turned out so let me share the settings with you

First I shot most of the footage in 25p AVCHD mode only some small sections are shot at 50p and actually I did not need to slow down any of the material.

For the wide shots I used steady shot in normal mode and shutter priority at 1/50th. With the filter on I had auto white balance with tint correction G2 A1. I noticed that the camera was giving red tint in some situation and so added a bit of green back. The Amber correction instead is for the RX100 itself the camera does not have vibrant yellow and is a bit blue.

Tunas
Tunas – AWB with filter

For the first time I use creative mode changing the standard contrast to -3 in order to prevent crushing of blacks.

Exposure was set all along to -1/3 and metering to multi area with AUTO ISO limited 160-800.

I think the results are so good that in fact I have performed no colour correction to any shots in ambient light.

Opening the tuna farm
Opening the tuna farm – AWB with filter

For shots with lights I set up first colour temperature to 6500K and A1 to match the lights but then in some of the far shots this resulted a bit cold so I adjusted very slightly in post the temperature.

Seahorse
Seahorse – AWB UCL330

Only 40″ are adjusted in the whole video in essence is as shot and the editing took me half hour.

In cave
In cave –  AWB no filter

I did a bit of analysis and the camera was operating for most at ISO200 with aperture around f/3.5 – f/4.0 which is really the sweet spot of the lens.

I did have some challenges using the UCL330 for some nudibranches  that really required a stronger lens so they look a bit small, there was also surge so I had to fight with focus problems but all in all very happy.

Nudibranch
Nudibranch – AWB UCL330

The longer working distance of the UCL330 (20-30 cm or 8″ to 1′) proved challenging on walls as you are too far to hang on to anything or use a stick. I will bear this in mind in the future.

For the close up shots I used steady shot active.

I also wanted to say that a few times the camera did manage to white balance properly however the results were not exciting and frankly not worth the hassle. Using the filter is just so much better with the auto white balance.

Introducing the Sales Corner

I receive so many queries about equipment that I thought I would put some of my items on sale.

My cupboard is near enough to explode and I need to streamline the equipment I have. Currently I have 3 strobes, a huge selection of ball and clamp arms, 3/4 and 1/2 locline arms, float arms, floats, video lights, tray bases, around 15 clamps and some 6 macro wet lenses and 3 wide angle wet lenses with 3 different mounts.

I guess it is time for a clear up so I will add a section with items on sale where I will list some of the combination items.

The idea is to provide a full set of lenses or a tray + float solution as those seem to be the most asked for items in my set up.

So if you look on the menu you will see the link Sales items with details of the various sets. I can also sell the items individually but I think this makes little sense as I’d rather do that on ebay.

Many people read my posts and then go to gear shops but there there is always a little mistake or problem getting the whole set up from here you avoid that. I priced the items based on 50% of retail UK price and I would ship to UK and Europe, other overseas will attract import duty so it is not worth it in my opinion.

If there is anything you like  use the contact form on the relative page to inquiry

Tweaking the Sony RX100 Mark II Video Performance

I am currently in Malta for few days relaxing and I manage to squeeze in some dives. The Mediterranean sea is nothing sensational (from a pure diving point of view) but does offer clear water, and some brisk thermoclines, and a combination of algae, blue water, caves and silvery fish that is challenging on the dynamic range of our little RX100.

The purpose of this trip is mostly to refine the video settings and go more in depth in few topics. I wanted to try specifically the following:

  • Metering modes
  • Creative modes
  • Stabiliser modes
  • Tracking focus
  • Medium size fish portraits
  • White balance
  • Caves and low light

Some of my settings will be the same and I am not intending to changed them those are:

Auto ISO: 160 – 800

DRO: Auto

Starting off with metering, the first attempt was to try and use the camera on 0 exposure compensation with centred weighted average metering.

Entering Cave Fairly Bright
Entering Cave Fairly Bright

Pretty soon I realised this gave issues of banding of the blue water, this was apparent not only in backlit shots but also in normal wide angle of fish in specific cases. So after dive number 1 I changed it to the standard -0.3 from dive 2.

I set a new creative style with contrast at -3 in the hope to recover detail and seem to be working fine with the shots still having plenty of contrast.

Lowered Constrast on -3
Lowered Constrast on -3

I also tried spot metering for close up but it makes no sense the video lights are too wide and ended up with burned highlights at the edges of the frame so back to centred weighted average for close up shots.

Spot metering
Spot metering

So when it comes to metering my settings are:

Wide angle: multi area

Close up: centered weighted average

I did some tests with stabiliser in steadyshot mode, this gives back some field of view and the lens offers 100 degrees diagonal and 90 horizontal, I actually think a bit more anyway with fairly stable conditions this worked fine. At longer focal length for close up I am still using active mode.

Schooling Fish 100 fov
Schooling Fish 100 fov

I have a +3 diopter for this test as I realised in my last still trip I don’t have a lens for medium size fish, the lens worked very well and I also tried the camera tracking focus but it seems it won’t work with fireworms or similar. So either keep normal focus or manual with peaking.

Tracking focus fail
Tracking focus fail
Rock FIsh UCL 330
Rock FIsh UCL 330

White balance has been a subject of discussion, I did manage this time to white balance a few times but to be honest it was not worth the effort there is a better correction of the purple hue of the filter but this can be corrected setting Green to 1 or 2 in AWB. I also changed the AWB to include a correction with Amber 1 as per examples. Very happy with the results I think this is the final set up with this filter lacking a proper orange filter.

AWB corrected
AWB corrected

Shooting in low light was rewarding with ISO maxed out at 800. I am becoming less and less a fan of video lights in cave due to the amount of backscatter am getting. I think I will default at using the lights as dive torches instead of wide beams of even leaving them off for effect.

Backscatter
Backscatter
Cave in natural light
Cave in natural light

 

Red Sea Workshop with Alex Mustard – Part VI Schooling Fish

On Friday we were up for our last 3 dives at Shark Reef the current had not changed but this time I decided to give more a go to the schooling fish after setting up all the backgrounds I wanted.

As you can see from the image on the title we had more of the usual divers chasing fish but this did not deter me this time as I developed a specific technique to do the dive that I used fully on the last two photo dives.

So after a bit of experimental shots like this one

Batfish school from Top
Batfish school from Top

It was time to give it a proper go. To be honest is not that I like batfish that much and probably this is one fish that you can shoot in RAW in ambient light however if you do that you need to sacrifice quite a few ISO stops. With strobes the issue is to get the school in a formation that allows you to do a good job with lighting. This is my best shot for the session.
Schooling Batfish on Reef
What I like about this shot is the light on the fish or most of it where you can see yellow fins but also the background and a hint of surface.

Other fish that featured on the day were jacks but catching a school of those running past is quite hard unless the school is really big and they circle you.

Jacks Schooling
Jacks Schooling

In those type of formation you have all sort of issues with hightlights form the strobes in fact I was shooting 1/4 of power.

Giant trevallies made a more interesting single fish shot like this one.

Giant Trevally
Contrary to what you may think this is a shot with strobes otherwise you would not see the texture of the fish as you see it. Maybe a busy background but good technical exercise.

I also attempted a few anthias shots just to try a well tested technique to get them buzzing out the reef

Red Reefs
In the middle of the dives while I was waiting the barracuda school came out to play. Barracudas are quite tough as they require strobes to lit properly and I find the multitude of black and white shots that you see a bit boring as the fish texture is what makes the shot.

You have several challenges with the formation, if the school is big is difficult to take it all unless you are on the bottom or on the top. In the first case you need to control bubbles in the second you shoot the bottom so better be neat.

Anyway with a bit of patience I got the shot that I wanted

Arrows
It is impossible to illuminate properly all of them but this shot has got the right geometry and I think is quite pleasant.

On the second dive I was lucky to spend some time with a Giant Barracuda that was literally commanding the school at sight, very rewarding from a diving point of view I got so excited that I kept shooting with a relatively slow shutter speed however the fish that is lit by the strobe is well crisp.

Giant Barracuda issuing orders
Giant Barracuda issuing orders

This shot is much deeper than the previous so the blue is colder but still makes for an interesting shot.

On dive 3 I decided to do a bit of video although I had not taken my favorite lens so I had to apply a filter directly on the camera lens. Moreover I had forgot the setting Toy effect on from some other experiment and whilst this is off in RAW it came back in video so the result is a soft warmer image…yuk still was fun to put it together so here it goes

It was time to rinse the gear (if you could call that hosing it quickly on the dive platform) and get ready to leave the day after. On the last day we were asked to put together a selection of our best 10 pictures and were give a video with some gopro footage taken by the ops manager plus our slideshow. Considering the time it was spent to do it the result is excellent.I hope this has given you an idea of the workshop that I definitely recommend, on the next post I will write my personal lessons learned from such experience.

Red Sea Workshop with Alex Mustard – Part V Tiran & Mermaids

As the currents were not playing ball we decided to head to Tiran to dive Jackson reef.

I love jackson as a dive and a video dive but I was a bit vary from a photography point of view as lighting can be a problem.

Anyway there was an option for a hammerhead dive in the early morning or a first dive on Jackson followed by a second before returning to Ras Katy for an afternoon and sunset dive.

Hammerhead are found on the back of Jackson reef when there are shallow thermoclines with the surface at 26C the chances were low however I had alternative ideas for that dive.

As foreseen there were no hammerheads so towards the end of the dive I tried a few shots of the Lara Wreck (that is on the surface) through the Snell window despite the strong surf.

The resulting shot is currently my desktop theme and is here.
Lara from the reef
I tried to get the wreck on the surface, the breaking surf, the sunball, some fish or at least silhouette of fish and the hard coral to give a dramatic moody look to the image.

On dive two was time to have a relaxing dive with not much effort on photos. I saw few tunas at around 28 meters that is unusual and a turtle and some other critters though the shots are not particularly exciting.

In one occasion a dive guide came to be all excited as he had seen a turtle so I went there and bumped into our own guides that were out for a fun dive.

Turtle and Dive Guide
Turtle and Dive Guide

They usually are asked to get out of the frame instead I took the shot for their facebook perusal.

When the turtle had enough she shot off to the surface and I tried a silhouette however I forgot the strobe on

Failed Silhouette
Failed Silhouette

Nothing that lighroom can’t fix and this is the resulting shot after adjustment

Silhouette after lightroom
Silhouette after lightroom

Not bad huh?

Back at Ras Katy I tried few more portraits like this one

Fish Portrait
Fish Portrait

Though my favorite is another
Masked Butterflies

At sunset I was part of the mermaid group, we had a model Katrin Felton  suprising what a phenomena Mermaid tails have become.

We had a 2-3 shots in different poses however only the first was successful as the snell windows was ruined by one of the photographer that keept shooting with strobe…and getting in the way as she did not listen to the briefing properly well no big deal.

Anyway I gave it a shot afterwards Kat was not particularly happy about the barrel distortion that she said makes her look fat! Unfortunately I did not have a rectilinear lens anyway if you find yourself in this kind of set up make sure you have one.

Mermaid Kat I
All in all it was a bit of fun again I tried to include some fish, the reef, the mermaid, the sun rays. I looked at other pictures of the mermaid and I think she can’t appreciate how important is not to see the knees too much but I guess she likes to focus more on her figure on how slim she looks lol!

All in all another great day and a different perspective on shooting model underwater.

 

Sony RX100 Mark III – Is it worth upgrading?

UPDATED 23 July 2014

Once again Sony has updated their RX100 camera with a stunning new release that will surely be a market leader at least until the release of the new promised Panasonic large compact sensor with 4K video recording.

So the question is again is it worth throwing our hard-earned money to this new model and housing or should we stay with what we have got? The Mark I and II are still available at reduced price though it is becoming harder to find Mark I housing as new.

The answer to the question is: it depends on what you are planning to do with your RX100, for some users an upgrade may not be required or even not advised let’s see why. no don’t waste any time with the Mark III.

Every time a new camera is released and reviewed I get a bunch of emails with subject: New Camera XYZ what do you think?

The best reviews you find online are made by sites that specialize in land photography and no consideration is given to underwater use. So not necessarily a camera that is a top performer on land will remain such underwater as this depends on specific characteristics that may be different or even opposite to land requirements.

So those reviews cannot be taken as they are they need interpretation. Personally I use two sites for camera reviews imaging resource and dxo mark I use the first to understand ergonomics, performance and to compare images with other cameras side to side, and the second to check sensor quality and lenses. Imaging resource has made a good article to compare the various RX100 on land read it here

http://www.imaging-resource.com/news/2014/06/16/battle-of-the-rx100s-sonys-rx100-vs-rx100-ii-vs-rx100-iii

If you look at a sensor comparison on DXOMark you would conclude that there is no need to upgrade at all if you use your camera primarily for still pictures as the sensor are practically identical in performance as this table demonstrates:

RX100 Sensor Ratings
RX100 Sensor Ratings

As you can see the differences in dynamic range, color depth or ISO are pretty much intangible.

However there are other metrics that are also important let’s see which ones and why.

Flash Recycling

We want our camera on board flash to recycle quickly after a full dump as the RX100 has only TTL flash and the flash can’t set to a minimum manual setting without consequences. Those are the flash recycling times at full output (a full dump will always occur when you don’t aim strobes directly at the subject for example wide angle)

Mark I: 7.2 seconds

Mark II” 4.4 seconds

Mark III: 3.3 seconds

The Mark III is pretty quick and the Mark II is acceptable the first release is definitely too slow.

Minimum Capture Area & Zoom

What is the smallest area that can be captured at wide end at the closest focus distance? This gives you an idea of out of the box close up performance

I do not have precise metrics yet but looking at comparable images on imaging-resource seems like the Mark III is worse than the Mark I and II of at least 20% with a capture width around 90mm versus the already not very good 76mm of the Mark I and II.

To fix this issue we use close up lenses in water that fix to a great extent the focal length and then zoom in to achieve magnification which means longer camera lens more magnification I roughly estimate that the Mark III will be worse of a factor of 0.7x so things will look 1.4x bigger with the Mark III this is terrible news for macro shooters as it means you need to be on top of the subject to fill the frame, this is in some cases not possible.

I have estimated that you need 11 diopters to achieve 1:1 macro so the Subsee 10 and Inon UCL100 that gave real macro on the Mark I and II won’t be sufficient. With two UCL-165 or Dyron 7 you are looking at 2.58″ or 6.5 cm from the back of the first close up lens that means you will be right on top of the subject which is not really an option.

Update July 18th: Nauticam has confirmed that even with their SMC lens the most powerful diopter on the market the capture area is 38mm wide so does NOT achieve 1:1 macro as I suggested…

 

Lens Focal Range

The new mark III has a 24-70mm lens compared to the 28-100mm of the Mark I and II what does this mean?

  • Less magnification with close up lenses and no real 1:1 macro
  • Vignetting or even not possible to use fisheye lenses designed for 28mm lenses

This means that with the Mark III your scene selection will be restricted  compared to the 150 to 24 of the mark I and II.

Update 23 July I have done some tests that confirm my suspicions please look at the following frames. The Mark III once zoom to 28mm actually works fine with the Mark II housing except the power button.

RX100 Mark III with Inon UCL-165 Close up lens
RX100 Mark III with Inon UCL-165 Close up lens

With a single Inon UCL-165 (+6.06 in water) the minimum capture area width is 5.4 cm which is bigger than the Mark II 4.8 cm. Not only that the distance from the top of the lens is only 9cm.

With stacked UCL-165+UCL330 total power 9.09 diopter we get this

Stacked UCL-165+UCL330
Stacked UCL-165+UCL330

4.4 cm width however we start running into problems as the minimum distance from the lens is only 4cm.

We finally achieve 1:1 with two stacked UCL-165 however the distance from the top of the lens is 3cm definitely too little

two UCL-165 stacked
two UCL-165 stacked

I have also tried the Mark III at 28mm and it still vignettes with the Inon UWL-H100 in air until around 30mm. Instead the old UWL-100 28AD is fine at 28mm either way image looks narrower than with the Mark II but this may be an issue with the old housing.

So basically no macro with the Mark III and no decent fisheye as expected.

Underwater Photography Conclusion

Due to the reasons above the best camera for the job is the RX100 Mark II, with the Mark I coming close but being penalized by the strobe recycle time, the Mark III really is not an option for the serious shooter due to limitations of the lens.

Let’s have a look at some other features of the Mark III that are not relevant for stills as much as they are for video.

ND filter

Shooting at the surface with plenty of ambient light or on land can create problems if you want to follow the 180 shutter rule, the ND filter of the Mark III ensures your footage will be smooth on land and in water. Take into account that on land you can apply optical ND filters (I have it for the Mark II) so this is really for underwater use when you are shooting at 1/50 or 1/60 shutter speed and the scene is too bright when you hit f/11 and the lowest possible ISO. Having now tested this feature I confirm it is really valid on land on a bright day to keep the aperture wide.

Clear Image Zoom

This is a special digital zoom with edge enhancement that only worked on JPEG stills on Mark I and II but is now available on video on the mark III. This means an additional 2x zoom is available bringing the focal length to 140mm that is more than adequate for macro. This is not an option on RAW images so irrelevant for still users.

23 July update Having done some tests for macro video (as stacking two diopters is not an option) the image quality suffers but anyway this is all you are left with lacking any other options.

Clear image zoom 1.5x on single UCL-165
Clear image zoom 1.5x on single UCL-165

Image stabilizer

The Mark III adds a further stabilizer mode with additional crop that takes the lens to 96mm equivalent in video mode. This is well worth for super macro hand-held footage and effectively provides an option where you can either use the super steady shot and no clear image zoom when hand-held or leave on only the optical stabilizer and use clear image zoom. If you shoot macro on walls and not on flat sand this is a well worth feature.

Update 23 July 2014

Following a side by side comparison you can find on this link

It follows that there is really no 5 axis stabilisation and only an additional mode with more crop with correction for rolling shutter that anyway does not really work!

Full Sensor Readout Video

The mark III reads the whole sensor not just alternate lines when capturing video this increases should increase the resolution to a great degree and increases the perceived resolution and clarity of your videos. However this does not seem to correspond to real life tests. See this sample with a side by side comparison the Mark III looks visibly worse than its predecessor even on the higher bitrate XAVC!!!

Video Formats

The Mark II introduced a well welcomes 24 Mbps 24/25 fps mode now the Mark III introduces a 50 Mbps mode in XAVC (that can be rewrapped into normal MP4) that produces even better footage although it will be quite demanding on your workstation and most likely some of your home devices will struggle playing the files (my Apple Tv 3rd generation only plays up to 25 Mbps) when uploading files online this will downgrade to 8 Mbps so won’t matter unless you have a good player at home. improves nothing and requires manipulation as the files are actually not MP4 compliant as they have WAV audio (!) they are also inside the AVCHD folder which is painful. As seen above seems like the encoding has got worse on the AVCHD files and only the higher bitrate compares but still does not match the mark II at the lower 24 Mbps!!!

HDMI connection

You can now connect the Mark III to an external HDMI recorder if you are into that kind of semi pro usage. For the normal user this is not relevant: if you are into spending that money probably you have already a DSLR or a Panasonic GH4.

Video Auto Focus

The auto focus in video has got worse you can see an example in the stabiliser test, and actually plenty of frames are blurred on the mark III. Awful!

Underwater Video Conclusion

The Mark I with only a 28 Mbps 50/60p mode is definitely a poor choice, the Mark II is acceptable to most users. and the mark III promises even better performance if you are a serious video user and have another camera to take pictures the Mark III may be well worth it.

The Mark III despite some useful feature is actually a let down and perform worse in practical terms than the mark II that remains my camera of choice.

Summary

If you have a Mark I camera and are frustrated with flash recycling you should be looking at a cheaper upgrade to the Mark II.

If you have a Mark II and your priority is photography upgrading is NOT recommended.

If you don’t have any RX100 get yourself a Mark II or wait for the new Panasonic as the Mark III is pretty much a pile of crap.

Is it the first time I am actually sending back a camera and invoking consumer rights but when I spoke to the camera shop they told me they had other returns and this is not really an upgrade!!!

Look Right inThe above image was shot at 100mm equivalent with one diopter with the RX100 Mark II. You won’t be able to fill the frame with the same close up lens and the Mark III camera

Snell Windows with your compact camera

Snell’s window is a phenomenon by which an underwater viewer sees everything above the surface through a cone of light of width of about 96 degrees [From Martin Edge: Underwater Photography].

During my last Gapapagos Trip there was a bit of an issue in terms of photography subjects, in essence most of them were fairly big like sharks, turtles, eagle rays and of course divers.

After a while shooting or trying to shoot those uncooperative models I had the idea to try and do different things such as silhouettes and Snell windows. You can also combine both as we did in this case.

So what do you need to shoot image of a Snell window:

1. A lens that is wide enough, you need a bit more than 96º field of view to take the whole window

2. Something interesting on the surface (if you have calm water you can see right through)

3. An interesting subject as silhouette to contrast the clear water if there are waves and you can’t easily see through.

A normal flat wet wide angle lens for our compact camera is not sufficient to capture the snell’s windows as in this example

Safety Stop
Divers at Safety Stop – taken with Inon UWL-H100 at wide end

Take into account that even with a fisheye lens on an SLR you can’t capture the Snell’s window on the vertical axis as the field of view will fall short a few degrees.

With a compact camera a semifisheye lens will capture the edges of the window if correctly aimed on the diagonal and horizontal dimensions and will fall short on the vertical.

Snell to boat
Snell window divers exiting the water or ascending – UWL-04 semi fisheye lens Canon S95

I am reporting some of the calculated field of view for the most popular lenses at present for compact at 3:2 image format

Wet Lens Diag FOV Hor Fov Ver FOV Flare/Ghost
UWL-04 151.95 123.22 79.85 Ghost Possible
UWL-100 28AD 149.01 120.97 78.48 No
UWL-28 160.56 129.75 83.81 Both
UWL-H100 157.85 127.71 82.58 No

 

All those lenses will take a good Snell’s window I have not tried the UWL-28 and I have some concerns this lens may flare as it usually does but I do not know for sure.

Both the Inon lenses produce sharp images with no defect.

In general small sensor cameras like the Canon S series will work fine with the fix/idas lenses and should produce good results also of normal shots through the water.

Using the UWL-04 or UWL-28 with large sensor cameras like the RX100 there could be a sharpness issue a larger apertures so make sure you close that at f/8 or smaller instead of using the shutter speed to balance exposure if you want to go through the water.

Snell’s windows are uncommon with compact camera shooters as they are considered an advanced subject but they can be taken. I will be taking more in a next trip to Egypt I hope for calm surface conditions so I can go through the surface with the shots. Failing that this is very easy to practice in a swimming pool.

Have fun shooting snell’s windows!

Sony RX100 White Balance Woes

In one of my first posts on this blog I covered the subject of setting white balance with the Sony RX100.

It may be useful to have a quick recap on the topic:

  • For pictures setting a custom white balance is not useful if you shoot in RAW as the amount of correction in post processing is far superior*
  • For video (that is shot in compressed format) setting the appropriate white balance for your shots is essential

There are exceptions to this rule, some people like to set custom white balance even in RAW when they shoot ambient light pictures. This is because changing the white balance shifts the histogram and therefore if you had taken a shot with an incorrect white balance you may retrieve wrong information from the histogram. Personally I do not do this most of the ambient light shots I judge by eye and not histogram or are silhouettes anyway but may be useful to know.

The other exception is when you shoot a raw video format with bit rates in excess of 100 Mbps, in that case the footage is captured in a bland format lacking any real depth and contrast and things are corrected in post processing. This does not apply to any consumer camera that works in AVCHD or Mp4 with bit rate lower than 50 Mbps in any case.

It follows that setting the appropriate white balance for our videos is something that is important otherwise our clips will look dull, green or have some sort of color cast we do not like.

As many of you RX100 I have experience with the infamous Custom White Balance 9900K error. In theory if you set your custom white balance with the camera in P mode over a neutral target this error should only occur if the color temperature is out of range (>9900K) unfortunately this is not the case and you get this error pretty much always with our beloved camera. At the beginning I thought that this was due to my cheap PADI slate, but after various attempts against my hand, sand, buddy’s tank, the sun I have to think there is some genuine issue here.

So I got myself whibal card, that on my test on land performs amazingly well with both the RX100 and the Nikon D7100.

The first thing we can realize is that the auto white balance setting is rather cool in outdoor scenes, whilst it tends to be warmer in indoor scenes with artificial light.

Auto White Balance
Auto White Balance

When you take a custom white balance the colors appear warmer and the bluish cast departs and the yellows come back.

DSC01608

This is particularly bad news if you shoot underwater without a filter and think of using auto white balance as those results will be pretty ugly.

The whibal card has a specific black mark that if illuminated tells you the white balance reading is incorrect because of reflections. I thought this was the key to the 9900 Error, unfortunately I was wrong.

It just fails 100% reliably really painful so I could not get rid of my trusted red filter for the Galapagos trip. I even tried setting the white balance with the filter and it would fail as well.

So I went back to auto white balance and red filter and I am pretty happy with the results, many people have asked me if I have manipulated the footage in post processing as the colors look very deep and some have even said unnatural. Even so shooting at 1/50 means a relatively low ISO and in the specific trip another f/stop of aperture was not really significant but I would have like to have the option of working without the filter, sadly this was not an option.

For what concerns white balance just a few things I want to say:

1. At depth there is no color anyway so what your eye can see it is not what it is, the proof is when you use lights or strobes things look much better than the naked eye. Using your visual as a reference can produce dull results.

2. You have to set an appropriate white balance for your scene, this means removing the cast. If a scene has no cast and the colors look saturated this is not a white balance issue on its own but may due to the camera settings. The RX100II is one of the less saturated camera on the market. The mark I instead is pretty saturated take this into account.

3. Footage that looks dull IS in fact ugly. The fact you set custom white balance with or without a filter does not mean that results is the perfect result, there is no such thing in fact and as colors disappear at depth white balance is not that effective anyway

Nick Hope sometime ago published some interesting tests on wetpixel

http://wetpixel.com/forums/index.php?showtopic=16970&page=8#entry122288

It turns out that there is more than meets the eye.

Just to clarify the only color correction in my Galapagos clip is:

1. In the scene of the dolphins I was pointing the camera upwards and did not have time to take the filter off so ended up with a red cast, I performed a white balance adjustment in iMovie on the opposite value of the tint I was getting until I liked it.

2. In the scene where there is a group of Galapagos sharks and the close up of the eagle ray I have reduced the blue gain as it was over saturated

In all other cases the only changes were increase of contrast or reduction of brightness. When the water was green like at the end in the Punta Vicente Roca scene I did not touch it to make it look artificially blue.

Again for those who ask I use a deeproof push on filter for the Inon UWL-H100 this filter is my preferred for the only reason that is actually the only one available on the market that fits on the lens. Personally I would much prefer a plastic filter like the ikelite/URPRO but this one is glass. It seems to correspond to a deep sunset 2700K with magenta tint of +5 on the RX100 but I have no tools to measure it I can only say it works.

So my recommendation for the RX100 is to get this solution as the Inon lens has the best optical quality and a hood that comes very handy to reduce flare. There are other lenses that fit the RX100 but have no hood. Obviously an not even considering the fisheye style lenses as distortion is ugly and placing a filter under the lens is a very bad idea.