Tag Archives: white balance

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.

ambient light, AVCHD, housing, Panasonic LX7, Stabilization, UNDERWATER VIDEO, White Balance

Underwater Video Tips: Best video settings for Panasonic LX7

July 14, 2013 interceptor121 3 Comments

I thought of doing a debrief of the settings I use as I see few people that have bought this camera and have few niggles to go through and the obvious learning curve of new equipment so here we go.

Which Video Setting

It is always possible to reduce detail if needed so always shoot in the highest mode AVCHD progressive that in the menu is called PSH this records at 28 Mbps.

Which Mode to Use for Video

The LX7 has a one touch video mode that is accessible in still mode. When you press this button, even if the camera is in Aperture or Shutter priority and even in Manual, the movie clip is recorded in Program mode.

It follows that the mode to use to have full control is the creative video mode accessible through the mode dial.

Standard Setting for Creative Video Mode

I use the Shutter priority setting submenu in this mode. This is because the LX7 does not follow the 180 degrees shutter rule in video program mode.

Set your shutter speed to 1/100 for PAL and 1/125 for NTSC so that your shutter speed is double of the frame rate (1/50 for PAL and 1/60 for NTSC).

Exposure Lock Button

I never use the manual or the aperture priority mode as I find the lens fairly sharp even in macro and very small subjects. When I have changing light I point the camera to the exposure I want and the click Exposure Lock. To disable focus lock you need to go into the menu and set the button to AE lock only.

Exposure Control

I personally find the standard exposure of the LX7 underwater far too bright. So using the exposure compensation dial found by pressing the shutter speed wheel I dial down to -2/3. This is personal sometimes I even go down to -1.

ISO and Max ISO

The LX7 has a very bright lens even at telephoto end and this lens produces also a very sharp image. In the worst case of deep water with low light I found that having an underexposed but cleaner picture at ISO400 is better than letting the camera go all the way to high ISO. So in the menu I set ISO MAX to 400 or in some cases I push this down to 800. I set the ISO to Auto as the camera generally keeps it very low anyway.

Autofocus

I leave autofocus for video mode to on and I ensure that the autofocus is set to single area. Be careful as the default setting is face detection and that does not work well underwater! Multi area and tracking are not available in video mode.

Zoom

In video you can extend the 90mm lens to 180 with the iZoom and to 360mm with digital zoom. I set iZoom to on and Digital zoom to off as I have seen that the iZoom is very useful in macro and the picture quality is not visibly affected.

Metering Mode

I use multi metering for landscapes and centred weighted for close ups and macro.

iDynamic

This is a tricky setting; generally I keep it off or on Low as the standard settings clip the highlights. In doubt turn it off.

Photo Style

This setting controls contrast, sharpness, saturation and noise reduction. I use the standard setting that is a little bit oversaturated. If you do a lot of colour corrections in post processing use the Natural setting. The footage will be less saturated and a bit less sharp with less noise reduction.

White Balance

I use two custom settings WB1 and WB2 one for shooting with ambient light and the other one with lights that I only use in special circumstances.

Stabiliser

I leave this on and it does not affect the field of view.

Zoom Resume

Zoom resume has to be left off as this delays the camera ready to shoot time and ends up with missed opportunities.

Menu Resume

It is useful to leave this on.

Custom Menus

I record all my settings for shooting in ambient light in the C1 mode this has all the settings are describes and recalls the Custom White Balance 1.

I then set another menu C2-1 with auto white balance for shooting with lights and menu C2-2 for shooting with lights and WB2.

This is an example video shot with those settings and no additional lenses this is with video lights and auto white balance little to no correction in post processing.

This other video is with some grading applied and ambient light for most

I hope you found this useful and happy shooting!

filter, gopro, UNDERWATER VIDEO

Underwater Video Tips: Improving your Polar Pro Red Filter for GoPro

May 15, 2013 interceptor121 1 Comment

Just before leaving to North Sulawesi and in the process of packing I realised I had not completed the tweak of my GoPro Hero2 Set up.

I do not use the GoPro for video but for time lapse however the modification that I will present here is valid for both video and stills or time lapse.

Some users of the PolarPro filter have noticed that when you point the camera to the sunball or on a very bright day there is quite a bit of flare with this filter in the image corners.

Flare occurs when stray light enters the frame and reduces contrast giving a result a picture with washed out colours.

Flare is more relevant to wide angle and is usually reduced with lens hoods however our GoPro does not have anything like that and due to the large field of view probably it is better to be so otherwise the hood would be visible.

So what can we do to improve our polarpro filter and why does it flare more than others in the first place?

The PolarPro is the lowest price push up filter for the gopro and the reason is that its build is very simple. All other filters will have a dark rubber ring on the edge that has the dual effect to secure the filter to the housing and eliminate the stray light that may enter from the side. The polarpro is one single piece of acrylic and does not have this ring around the lens.

So let’s build one cheaply all you need is genuine gaffer tape, to make it look better I suggest black matt gaffer.

Pull enough length to cover the whole external ring of the polar pro filter and lay it on it to go from the edge of the front side back to the where the lateral panel ends. Once you have measured the approximate length make note of the width and then remove the gaffer. Pull the tape so that it rips at the width required and then tape the exterior making sure the smooth part is on the front side. Then create another strip a bit longer for the inner part. Make sure it is going straight and with no bubble and then once you get to the opening for the button come outside and overlap the exterior ring.

Once finished it should look like this

This is the other side you notice the part we ripped of the gaffer is on the outer side

Gaffer type does not mark and will stay there for a good number of dives. I am going to test this and see how long it goes but I expect more than 20 dives before it falls apart.

What you have seen here can be done for the Hero3 filters and it is actually simpler as the filter has no button opening

There has been a new Mako product coming at the low cost end and that one has a rubber ring so I would recommend trying it if you don’t have a filter already

ambient light, Dome Port, Panasonic LX7, Underwater Photography, UNDERWATER VIDEO, White Balance, wide angle

Wide Angle Lenses and Adapters for Panasonic LX7

April 27, 2013 interceptor121 20 Comments

Who has followed my initial LX7 tests is aware of the few issues I have had at wide angle with the LX7.

One was the reflections back on the lens that I have now hopefully resolved using a black marker and changing the camera from white (and silver lens ring) to black and the other was flare.

Flare is an issue at wide angle even on land. What causes flare? Stray light coming from the sides that washes out the picture and eliminates contrast in the process.

Wide angle lens tend to have an ability to catch stray light from the sides and top and this is the reason why wet wide angle lenses have to be really coated well so that this effect is diminished, however it still can happen.

And it did happen to me with the Inon UWL-H100. The general advice to eliminate or reduce flare is to have a lens hood however lens hoods are generally not an option for wet lenses with an M67 thread mount. The only lens that I know that can position the hood on a screw mount is the fix UWL28M52 or UWL04 most of the other lens do not have a hood and have a circular lens unprotected from stray light. And this usually means at some point you will get flare.

So how do you get around it? In the case of the LX7 is pretty much a forced choice as the Inon UWL-H100 is the only lens that does not vignette at 28mm equivalent focal lenght so the possible solution is to put a hood on the lens.

Inon sells a hood for the UWL-H100 but the hood is attached through 6 allen bolts and its position can’t be fine tuned so to use the hood it is a requirement to change mount from M67 to the LD bayonet. You need also to convert the lens itself into an LD bayonet. If you go to your Inon dealer there is a relatively cheap service part that allows you to convert your M67 lens into a bayonet.

The LD bayonet is the latest incarnation of bayonet mount released by Inon. Whilst the old AD mount relied on a mechanical action to secure the lens, the new LD bayonet is much shallower and relies on a pin lock release to stay in place. There are two adapters on the market that are capable of attaching LD bayonet lenses to an M67 thread, one produced by Nauticam themselves and the other by the Japanese Fisheye Fix.

There is a price difference between the adapters with the Fix being 20% more expensive.

The Nauticam adapter is the largest of the two. It has 6 allen bolts on the front and a thumb screw lock on the back to fix it in position. With LD lenses there is only one position to put the lens hood in the correct place so if for some reason the thread ends in the wrong place with your housing you will need to unscrew the front of the adapter to ensure the release lock is on the upper left of the port this happens the same way on the fix adapter. Make sure the little spring does not jump off in the process…Once the release lock is in the right area the fine tuning of the hood position is done with the thumb screw. A possible weakness is that if your housing port has no room for the thumb screw then this adapter is not good for you.

Whilst the Nauticam is made of plastic and metal the Fix seems to be 100% aluminum, this adapter looks better but does not have a mechanism to fix in place it relies on the strength of the M67 thread, however this locking system is compatible with any 67mm threaded port.

The fix allows to perfectly fine tune the hood position and it shows.

The alignment mechanism of the Nauticam adapter creates an alignment issue with the hood where the lens is few degrees turned clockwise.

With the fix this does not happen.

The hood can be properly aligned. Note that in both cases this does not mean more vignetting as the corners are not covered by the hood.

The other check I do is the position of the back of the lens, if there is a gap between the thread and the back of the lens this can create vignetting so it has to be as close as possible or even protruding as the Inon UWL-H100 mount type 2 does.

Let’s have a look at the back of those two adapters with teh UWL-H100 28LD attached.

The Nauticam thread is somewhat too long so the lens sits slightly more inside the thread line.

With the fix the situation changes sightly.

There seems to be little difference we will now check if there is an impact on the possible vignette in water.

As we can see there is a little bit of residual vignette on the bottom right corner when the lens is at 28mm equivalent focal length,

This is the same situation with the Fix

There is still a dark bottom right corner but it is less.

Inserting a 1.25mm spacer between the inner housing and the left side of the camera improves matters, this is because the lens of the LX7 is somewhat misaligned in the Nauticam housing and this corrects it.

With the spacer in the housing and the Nauticam adapter there is a tiny little residue of vignette but overall this is ok.

With the fix adapter this is the result.

No dark corners left.

So this is the recap:

You can change the UWL-H100 28M67 into an LD version with a cheap service part
Once the lens has an LD mount it is possible to attach the hood this will reduce flare
Vignetting is slightly increased but can be eliminated with a spacer with the Fix adapter
There is an issue of hood alignment an increased vignetting with the Nauticam LD adapter

A final note: inserting a spacer in the housing is risky, you need to know what you are doing as in theory the chance of flooding could increase so this is not for everyone.

My recommendation to those who want to improve contrast with the UWL-H100 is to convert to LD mount, attach the hood and get a Fisheye Fix LDF-M67 Pro adapter. Changing to bayonet has other advantages making lens swaps in water much faster and easier compared to the thread version especially with a lens as heavy as the UWL-H100.

There are few design issues and manufacturing errors in the Nauticam LD adapter that create issues with the LX7, most likely other cameras that are not so fussy will have no problems but if you have an LX7 avoid the Nauticam adapter entirely until a new production version is defined. I have given Nauticam the feedback and they will probably react.

ambient light, AVCHD, close up lens, macro, Panasonic LX7, Stabilization, UNDERWATER VIDEO, White Balance, wide angle

Grenada Trip First LX7 release

April 2, 2013 interceptor121 8 Comments

I have just completed the first draft of the clips taken with the LX7 in my trip last week. Links are here:

Youtube may not work in some cases so use vimeo instead

For who wants to know the lens choice for wide angle was as follows

Wet mate: Molinere Sculpture Park, Purple Rain, Veronica L, Shark Reef

Inon UWL-H100: Bianca C (28-40 meters) , Northern Exposures, Southern Comfort, Quarter Wreck, Shake’em (20-32 meters)

You can see in the section of the Veronica L that missing those extra degrees field of view did not allow me to take the full wreck by side even if it was not that big. On couple of reef dives I already had the Inon on the previous wreck dive so I left it you can compare performance of the two lenses in terms of sharpness and flare. Generally I feel the wet mate has less flare and is sharper however it does have an issue of reflections as covered in the previous post.

As always I have used iMovie to edit the AVCHD progressive files that I converted to normal mp4 using the workflow in a previous post. There are no dramatic alterations of colour or exposure and no stabilization has been run in any part of the video (in some parts like the snake eel moving it shows) all was done with custom white balance using the camera functionality, considering how deep were some of the wrecks this is very good I believe.

I would love your comments this was mostly an exploration trip so it is interesting to compare to the RX100 Raja Ampat videos

ambient light, AVCHD, close up lens, diopters, Dome Port, macro, Panasonic LX7, UNDERWATER VIDEO, White Balance, wide angle

Panasonic LX7 reference compact for underwater video

March 31, 2013 interceptor121 10 Comments

So I finally had the opportunity to take the LX7 on a trip after some pool tests.
After my attempts last year with the Sony RX100 I was a bit skeptical that I could actually find something better for video but I think the LX7 beats it.
I put together a sample just to give an idea of equipment used and how it works, please note this is not altered in any way

There is a picture of the rig in this blog on a specific page but let me confirm once again in detail
Panasonic LX7
Nauticam LX7 housing
Ultralight TR-DM tray with extension TR-DUP and two TR-DH handles without ball.
12 segments locline arms on 3/4″ mount base and reducer on the handles
Two sola 1200
Nauticam wet mate
Inon UCL165AD on bespoke M67 adapter
Inon UWL-H100 28M67
Inon M67 double lens holder on custom mount

In a previous post I highlighted that for most the wet mate will be the only lens needed however I had some wreck dives and the 18mm of the Inon wide angle are more appropriate.
I also gave a try to the panasonic intelligent zoom that allows for 2x digital magnification and sharpening that for me works very well and you can see it in the footage. This allows a user with just the wet mate to further zoom without need of a close up lens or a use with a single +6 diopter to achieve super macro.

Pedersen Shrimp with two stacked UCL165AD and intelligent zoom 7.5x The frame height is less than 1cm — Pedersen Shrimp with two stacked UCL165AD and intelligent zoom 7.5x
The frame height is less than 1cm

I found the white balance of the camera excellent on both my hand or sand. I had issues with my padi slate that many times returned a ‘scene too bright’ error. Maybe this is the reason why backscatter failed this camera for video?? Who knows.
You can see that even at 36 meters the colour are as good as they can be.

White Balance on Bianca C 36 meters depth

For macro shots I used the temperature setting at 6500K, I found the white balance tint fine tuning to be excellent to further enhance it.
I shot in shutter priority the whole time with shutter speed of 1/100 or 1/50 depending on conditions and type of shot. The camera autoISO and choice of aperture privilege noise reduction however as the lens of the LX7 is really sharp the relatively wide aperture did not mean soft corners.
I tried the various photo styles and at the end settled for the standard one, I found the natural really to have too little contrast.
I thought of shooting in mp4 for wide and AVCHD progressive for close up but this would have meant two different frame rates to edit, at the end I shot at the highest available setting to avoid confusion.
I had received a new port from nauticam so I had no vignette at 28mm and the full 100 degrees the inon lens can offer.
The ergonomics of the camera that have fixed commands for aperture and shutter proved to be convenient and the built in neutral density filter was very effective at shallow depth or on the surface.
In essence I think that the issues backscatter mention are non existent.
I did have a few problems with the wet lenses though.

Lens Marking reflection on Wet mate dome

The wet mate proved to be a great little tool very sharp and light however none of the sides of the glass have anti reflective coating. In bright scenes or backlit scenes I did not have many issues with flare however I could see the marking on the lens reflected back on the wet mate and in the picture. I suggest putting an inon anti ghost sticker or gaffer tape to hide those shining markers or to colour them with permanent black ink.
Other than this the wet mate performs very well in all reef scenes and close up of critter a few inches big.
The inon diopter did not cause any trouble other than the obvious vignetting until 70mm. One pleasant surprise is the LX7 autofocus. Having struggled with the poor focus of the RX100 at high magnification I was astonished that the LX7 finds focus even with two stacked diopters and keeps it!!! I never had to use manual focus that with the RX100 was the norm at macro range.
I had bought the UCL165 and UCL330 in m67 format but decided to sell them as I will actually switch to bayonet very soon for the wide angle.
The Inon UWL-H100 was probably the most disappointing find of the trip. Image was sharp in normal condition however this lens tends to flare quite a bit and this creates block noise in the water column in video, when I used my hand to shade the lens the flare went away. Inon sells a lens hood for the 28LD version of this lens but not for the M67 as there would be issues to align the hood petals to the frame.

Considering that the lens is very heavy in water at 350 grams and that screwing and unscrewing was a concern mid water I have decided to convert the lens into an LD bayonet. Inon sells a replacement service part for the 28LD that can be used to replace the M67 thread of the lens. Other than this part the two lenses M67 and 28LD are identical. I will use a nauticam m67 LD adapter I hope this will not increase the vignette. I will connect my AD mount close up with a AD->LD converter when using the wide angle and then use an AD->M67 converter when I use the wetmate. This saves me buying two different diopters and I can stack the two UCL165AD I already have. They do vignette a lot at medium but who cares when you shoot at full zoom.
I look forward to testing the UWL-H100 with the lens hood I am sure results will be better. On the other hand when the sunlight is behind the shots have incredible sharpness with this lens.
So the LX7 gets 5 stars from my side and I leave you with two recommendations:
1. Apply a form of anti ghost sticker to the LX7 lens
2. If you want to get the Inon UWL-H100 go for the LD mount so that you can put the lens hood on

ambient light, close up lens, diopters, Dome Port, macro, Panasonic LX7, Underwater Photography, UNDERWATER VIDEO, White Balance, wide angle

Wet lenses choices for Panasonic LX7

March 3, 2013 interceptor121 14 Comments

When compact cameras were designed for 35mm it was quite common to shoot just with a camera and strobe; this allowed the average user to take decent close up pictures as long as the camera was capable of focusing within a couple of inches from the subject.

Years later manufacturers started introducing wider lenses first came 28mm equivalent and most recently 24mm, these cameras give an increased field of view on land of 75 and 84 degrees diagonal.

There is a common misconception that as the camera has a wider lens you don’t need to buy a wet lens for underwater activities. This is also reported in otherwise good articles like this one: http://www.scubaboard.com/forums/tips-techniques/46508-getting-started-amateur-underwater-photography-buying-your-first-camera.html

So why is it a bad idea to shoot just with the bare camera and no add-on lenses?

Two key reasons:

Once in water the 84 degrees diagonal of a 24mm equivalent camera reduce to 54 or less because of the water medium
At focal lengths shorter than 35mm pincushion distortion becomes stronger to the point the pictures are awful.

Pincushion Distortion at 24mm with flat port

So if you plan to use your wider compact camera underwater without lenses make sure you zoom to 35mm to avoid distortion.

This is the same picture at 35mm note how the image is now rectilinear.

At 35mm we are back were we were in the mid 2000 and all we can do is close-ups so there is no advantage having a wider lens for underwater use with a compact.

Another common misconception is that a compact camera takes great macro just with the internal flash. Firstly a macro picture has a 24mm height of the capture area, nearly no compacts on the market are capable of this: the Panasonic LX7 and the Canon G15 within the current range are the exceptions. However at 1cm distance the internal flash is completely obscured by the lens, which means there really is no macro without a strobe and a close up lens: all you can shoot are close-ups.

This explains the need for wet lenses in water, wide-angle lenses to increase the field of view and allow us to get closer and take advantage of artificial lighting, close up lenses that also allow us to get closer using the full zoom of the camera and shoot at increased magnification without being on top of our subject.

The needs of photography and video differ as lighting tools differ, photos require strobe to freeze motion, video instead uses fixed lights. Photos are also taken at much wider angle than videos and fisheye effect is accepted, an effect that in video is generally not welcome.

With this in mind what are the wet lens options for the Panasonic LX7?

It depends of course on the planned usage of the camera.

Underwater Photographers

The LX7 has extremely good close up capabilities out of the box, however the capture area is around 12×8 cm that is not exactly small. If we want our nudibranch of shrimp to fill more of the frame we need a close up lens.

From my tests the Inon UCL165 brings around 2.5x magnification with the LX7.

I have tried stacking two UCL165 but the amount of chromatic aberration is too much for my liking, I found that 9 diopters is the max before fringing becomes a real problem and I do not recommend stacking two of those lenses or two equivalent Dyron diopters. I think the most flexible set up is a UCL165 and UCL330, this covers all possible working distances. I do not have a UCL330 yet so I can confirm but I have taken shots with a very similar lens (Olympus PTMC-01) and the results are excellent with a capture area of 48×32 mm that is very close to real macro. The zoom of the LX7 is the real limit here as it maxes out at 90mm versus the 120 of a Canon S110 or 140 of the Canon G15.

For close focus and ambient light wide-angle the bad news is that there is no fisheye lens that works well with the LX7 this is due to the extremely large lens.

I have tested the Inon UWL-H100 and I had to wait for a new port to be delivered from Nauticam as their original one was too long and had vignetting even at 28mm. This lens yields more than 100 degrees diagonal and is my preferred choice for the LX7 for stills. There is however a good amount of blue and yellow fringing if I really have to be picky so the extended field of view comes at some price.

I use Inon lenses however a possible candidate is the Epoque DCL30, this lens is reported to work with 28mm equivalent cameras however the rear lens is smaller than the Inon so I believe this needs confirmation. There is a $70 difference in US and £70 here in UK between the two lenses and considering that a dome will not worth I encourage testing this lens as the results may be acceptable. I think bluewater photo markets this lens in US under their own brand.

Underwater Videographer

If you plan to use the LX7 for video the situation is different, as the camera close up performance is extremely good and usually macro video is very hard. Most time we shoot with ambient light and if visibility is acceptable getting that close is not so important considering the LX7 ability to manipulate white balance.

The first suggestion is to get a Nauticam Wet Mate, this is a sealed air dome that gives us back the air field of view and works extremely well without any chromatic aberration and extremely sharp corners. This lens keeps the image rectilinear that is also a good thing for video.

LX7 with Nauticam Wet-Mate (do not compare with the Inon Picture this is taken from further away)

For majority of reef dives the wet mate is all is needed as this also allows the full use of the zoom without soft corners that occur if you zoom into a wet wide-angle lens. This lens is the most versatile for general video use and costs $250, great value from Nauticam.

There are however specific situations where the wet mate is not sufficient, as before close up performance with the bare port is good but not great for smaller critter, so a close up lens would be the next addition, again an Inon UCL165 or a Dyron Double Diopter would work just fine and have the same power.

When shooting at closer distance with lights, or when there is large fish or wrecks a wet lens is important as the 84 degrees diagonal of the LX7 are actually only 76 horizontal. Again the Inon UWL-H100 is my choice but would check again for the Epoque DCL-30. One characteristic of the LX7 that is interesting is that the diagonal field of view of the camera remains constant when picture format changes, this means the horizontal field of view is larger at 16:9 movie mode than it is at 3:2 for pictures.

Field of view with the LX7

Those are the maximum angles of coverage horizontal of the LX7 as I measured them at 3:2:

Bare Port 24mm: 50°
Wet mate 24mm: 71.5°
Inon UWL-H100: 88°

At 16:9 there is a wider field of view of:

Bare Port 24mm: 54°
Wet mate 24mm: 76.2°
Inon UWL-H100: 93°

In general terms with the wet mate we can cover 1.56x the horizontal field of view of the flat port and with the wide-angle 2.1x.

The wide-angle offers an additional 35% over the wet mate don’t be mislead by the apparent small difference between 84° and 100° as those are diagonal measures not horizontal and those few degrees more count.

At 1 meter distance the maximum subject size with the wet mate in movie mode is 1.56 meters and with the wide-angle this becomes 2.1, that confirms that the wet-mate is good for general use and the wide-angle is only required for close scenes of larger fish or wrecks.

Those are the three lenses I have used for those tests. A final consideration is about the lens mount. I will use the LX7 for video so my choice has been a 67mm mount, because this is the only format that the wet-mate offers.

If I was using the LX7 only for pictures I would prefer the flexibility of the Inon LD mount even if this costs a bit more as it makes it so much easier to swap lenses in water when you have a bayonet mount.

ambient light, housing, Panasonic LX7, SONY RX100, Stabilization, White Balance

Underwater Video Tips: Panasonic LX7 Settings and Features

January 20, 2013 interceptor121 5 Comments

My previous testing of underwater video with the Sony RX100 has been quite successful I was initially pretty hard on myself but I would say the performance was as good as it could have been taking into account the conditions

Most of my videos considering the conditions look better than dedicated single chip camcorders on the market and as good as some badly shot 3-chip camcorders

It is worth noting that a decent camera in a good housing like Gates or Light and Motion costs in excess of $3,000 without any lenses or lights, whilst with the same amount of money you can get a complete set up for a high end compact camera with included two sola 1200 and various lenses.

The restrictions of a still camera though still apply at least to the Sony RX100 and those are:

No use of zoom at wide angle with wet lenses (problem of set up not specific to RX100)
Clumsy operation of functions like white balance
having to change wet lenses multiple times in the same dive because close up performance is average

So is there something else out there that at similar or lower price point can get us high quality underwater video?

I believe there is and it is the Panasonic Lumix DMC-LX7, this camera has a bright f/1.4 lens with good sharpness, a 24mm lens and more effective ergonomics than the Sony.

Obviously I am talking about video here as I do believe the RX100 is the camera to beat in terms of compact for still pictures. For video especially at wide angle we are shooting mostly with ambient light and the corner softness of the RX100 does show with wide apertures. So whilst for your photos at close focus wide angle with a strobe the camera does an outstanding job for an HD video at 1080p the image does not look that crisp.

I am glad I got the RX100 as this is going to be the next camera for stills once I abandon the Canon S95.

Ok moving on to the Panasonic LX7 I did a little stress test pointing at the fireplace in low light to see how the two cameras respond, the clips are done 1 minute after the other so have similar ambient light available. It is clear that the LX7 is a winner in virtue of the brighter lens not only that the wider 24mm lens against the 28mm of the Sony shows a clear advantage.

Now what else is good about the LX7 the major feature are definitely the ergonomics, let’s have a look at the rear controls.

The first button of interest is the AF/AEL lock that you can configure to lock focus, exposure or both. Now having this with one touch means that any shot of moving fish in front of the camera or a dive into a cave will resist the camera hunting for focus or trying to change the exposure.

The other button of interest is the WB you can recall and set white balance in any non automatic mode including video, in addition there are two custom settings for white balance and you can alter the tint after setting that is great.

The ISO button is also very useful but mostly for picture and a half press will tell you what combination of aperture, shutter and ISO the camera would shoot at.

This also brings one of the weaknesses of the camera and is the camera’s video Program submode. For some reason this behaves like the still camera program mode so does not take into any account the 180 shutter rule, so be careful and never use the camera in Creative Video mode with the Program submode as results will not be good.

So how should you shoot video with your Panasonic LX7? Simple you should shoot in shutter speed priority or in specific cases in manual.

I think the shutter speed priority is the simplest starting point, so let’ assume you are in the PAL system where video is 25 frames per second you should set shutter priority and speed of 1/50 for wide angle with ISO in Auto. Depending on available light the LX7 will keep the lens at widest aperture and ISO until needed and then start closing the lens, this is fine for us as it is better to have lower noise image than huge depth of field.

If you want to influence depth of field for example in a macro situation when you are zooming in a lot you can take a half press and set the ISO manually until you have the aperture you like. The LX7 sets ISO in 1/3 of f-stop so the fine-tuning possible is incredible.

I would not trust the camera aperture priority mode as the LX7 will quite happily reduce the shutter speed all the way to 1/30 of a second before increasing the ISO and this would give blurred footage.

Shooting macro with the LX7 may require you to operate at double frame rate modes of 50 or 60 fps in that case again in shutter priority mode or manual start with a shutter of 1/100 or 1/125 and pump up your lights until you see the aperture closing. If the image is still soft increase the ISO manually to get where you want to be take into account that this camera has really a lot of corner sharpness so in general it is not needed to get to small aperture as much as it is with other cameras.

So which housing for the LX7? I have done a quick review of the Nauticam in the unboxing video here

This housing is really impressive and makes the camera actually even easier to operate when outside the housing!

Now with all those good things why is the LX7 not as good as the RX100 for still pictures:

Too wide lens: 24mm makes it difficult to get wide angle lenses and impossible to use a fisheye
Resolution is only 10MP in RAW pictures this shows, not in video though
Smaller sensor again the performance at the same ISO is better with the RX100 when you have a strobe

For video some of those drawbacks become actually plus points:

The 24mm lens when coupled with the Nauticam wet mate dome has 84° field of view in water that is good for most situations
Smaller sensor means more depth of field at same aperture

Another factor to consider with regards to the LX7 is the 1cm minimum focus distance, this means that diopters are only needed for ~~super macro~~ very small subjects as the capture area of the camera is incredibly small less than half the RX100.

Other plus points of the LX7

Neutral density filter, -3 f-stops means the camera will not jump to shutter speeds of 1/1000 in bright sunlight but stay at the normal speed with the lens wide open
Stabiliser: the LX7 optical stabiliser is rock solid and gives the same performance of the RX100 active stabiliser without any cropping of reduction of the field of view
A normal Mp4 1080p video mode at 20 Mb/s bitrate that is great for general purpose wide angle

In the next post we will have a look at the Nauticam Wet Mate and the diopter that I have chosen for the LX7

filter, gopro, UNDERWATER VIDEO, White Balance

Underwater Video Tips: Polar Pro Red Filter for GoPro

January 13, 2013 interceptor121 Leave a comment

Time for part two of the filter discussion that involves a review of the PolarPro Red Filter for GoPro

You can see in the featured image how the retail package presents, it is pretty simple inside we find the filter itself, a tether and a little bag to store the filter that also serves the purpose of cleaning it.

This is the cheapest removable filter for Gopro at a price of $29.99 and it is also available in Magenta version, that for reason explained in the previous post I recommend to skip entirely.

This is the image on the back of the package with the product details

The declared working depth is 10 to 70 feet or 3-21 meters. For what we have seen in the previous post this is somewhat optimistic and will be true only in ideal conditions of blue sky and 100 feet visibility in clear blue water, in different conditions the maximum depth will be less.

The filter is made of Optical acrylic and there are no defects on it, it is fairly light and snap comfortably on and off the GoPro dive housing.

It may be worth seeing what is the effect of this filter on the GoPro

As we can see the polar pro red filter actually casts a light magenta tint on the gopro image.

This is the same image without the filter

So as a Hero2 user would I spend $29.99 for Polar Pro or $83.00 for the SRP dome the only true removable filters? Or should we say what do I get for additional $53?

Let’s have a look at performance of the two filters in daylight those are measured with another camera that can set a custom white balance keeping fixed shutter speed and ISO and seeing how the aperture changes:

Polar Pro UR/PRO

Temperature 3200K 2900K

Tint M7 M5

Fstop loss 1+1/3 1+1/3

So the UR/PRO is warmer than the Polar Pro and has got little tint to it. It may be useful to compare using a camera with custom white balance how the histograms look if we fix the white point and then apply the filters.

This is an image captured with a Sony RX100 after white balance

The colours look natural as they should be we now put the PolarPro filter on the RX100 lens keeping the same shutter and ISO the camera opens the aperture to compensate for the light loss

Warmer image with a magenta tint

If now we push the URPRO on the RX100 lens we get this image

The image is globally warmer and has no obvious tint.

Let’s now have a look at the histograms this is the original image

Nice histogram pretty balanced, let’s have a look at the histogram with the PolarPro

We see the blue and green reduced but a behavior with spikes for all colors, this is due to the tint of the filter

If we look at the UR/PRO the histogram is typical of a color shift to warm

Note the lack of spikes and more balanced profile

Both the UR/PRO and PolarPro settle at identical exposure ISO400, f/2.5 1/50 of a sec with a 1 and 1/3 f-stop loss from the camera without filter that has a f/4 aperture.

So what does this mean? The UR/PRO behaves like a camera CTO filter most likely a CTO 1+1/2 if not double shifting the color temperature down in a similar fashion for the whole spectrum as it does not have a tint.

The PolarPro does the same with a less warm bottom end and a clear magenta tint that acts as a green filter. The magenta also creates spikes in the green and blur that are characteristic of a selective filter.

So which one is better? Overall the UR/PRO can’t be faulted as it does not introduce any tint and is warmer will most likely work in blue water at greater depths, how much greater is impossible to say. The UR/PRO is also very well balanced the proof is in the Gopro photo in auto there is no hue of any type which means this filter can be put in the camera at fairly shallow depths and still perform well.

The PolarPro seems to be a combination of a CTO filter plus a minus quarter or half green, this filter will be less effective at depth but work well both as red filter in blue water and because of the tint also in greenish water. It will however generate unnatural tint in blue water.

The ergonomics of the PolarPro are great the light piece of plastic is essential a design copy of the GoPro flat port cap the button is accessible and you can see the display if you need to. For $29.99 you can’t ask for more especially as it does well in water that is greener too. I can imagine it will require some tint correction in post in really blue water but this I have only seen in the Bahamas or Turks and Caicos anywhere else the green tinge was there and this cheap filter will take care of it. Also the Auto WB of the GoPro seem to love green so this will really do well in most occasions and I look forward to test it in fresh water where so far I have not used any filter.

Now that we know how the filter is done and what it can do how do we justify this?

A number of explanations, we have to hope that there has been no manipulation of the clips, so let’s continue with this assumption:

The water color in California is quite green as there is plenty of kelp and algae
The PolarPro has a magenta tint, the URPRO is just warming the color temperature
The SRP dome has a design issue as there is a layer of water between the lens and the filter that may absorb color and can’t be recovered
The GoPro White balance itself is pretty green

The combination of those factors could explain the difference in performance in this test.

Now coming to the Hero3 what about SRP Blurfix 3 versus PolarPro considering the filter themselves are the same?

The SRP blurfix is now closer to the lens so not affected by water between lens and filter, it has a 55mm thread which means you can add a polarizer very useful for outdoor shots on the boat, total cost:

SRP Naked $32 + Red Filter $77 + Polarizer $31 = $140

Polar Pro Red Filter $29.99 + PolarPro Polarizer $29.99 = $60

A hefty $80 difference for a piece of equipment the Hero3 that costs $399 is this justified? If we take out the Polarizer and consider the SRP dome for Hero3 at $77 the difference is still $47.

I would say it depends, for the average user that has an Hero2 or Hero3 and uses it at normal depths and is not after the maximum quality the PolarPro is just fine affordable and keep the overall cost down, it can also be removed and the ergonomics are great.

If instead you want to use the filter at greater depths and especially in water that are really blue the URPRO cannot be beaten however the price differential is substantial.

Now some people will say hang on a minute filters have to be tested in water etc etc. Well that is not definitive either because filters perform differently in different conditions, different locations so there is not an absolute best ever this is why cameras have custom white balance. Filters are not rocket science there is a lot that can be foreseen just by looking at histograms and temperature and we can set our expectations quite easily.

If you are in the market for a removable GoPro filter at $29.99 the PolarPro Red filter is a killer as it works well in green water too.

If instead you are not after a removable filter just get yourself a sheet of Lee double CTO and a pair of scissors and cut it to go inside the housing, this will cost 50 cents and be perfectly fine.

If you are a perfectionist and want to push your gopro to the maximum working depth of a filter and want a removable option the SRP UR/PRO is for you.

ambient light, filter, gopro, UNDERWATER VIDEO, White Balance, wide angle

Underwater Video Tips: Using filters with your GoPro or Compact Camera

January 5, 2013 interceptor121 8 Comments

Filters Test

Following a number of posts about filters in various GoPro forums I decided to check in detail the behavior of the UR/PRO filters and see what is that they really do.

I guess the reason is that people do not really know or want to know the physics behind it and prefer to entertain many discussion that involve trial and error.

One of the most interesting one is this clip here that generated some ferocious comments by some users of other products that of course were not pleased having spent money that their choice seemed not to be the best.

To understand a bit more about what filters do we need to look at light temperature graphs like the one below.

Light colour is measured in K and high value means cold blue light and low values represent warm red light.

As we know underwater red gets absorbed approximately at a rate of 1 f-stop every 2.5 meters we go deeper compared to blue light with the result that red colour disappears pretty quick followed by green to become completely blue at depth.

Some time ago cameras were shooting film not digital and there was no way to correct colours when the film itself got developed. So to perform some decent underwater photography people used strobes and fisheye lenses to get really near and blast the reef with light in order to restore the real colors.

This worked very well for close shots but was useless for wide angle at distance, so color correcting filters that could go underwater were developed for ambient light photography.

So what is a CC filter? A common misconception is that filters add colours to the picture, whilst this is practically true this is technically incorrect.

So what does a CC filter really do? As the word says it filters light, more specifically filters selected part of the color spectrum. This is done at expense of available light so if we use a filter we will have less total light or for our purposes exposure. This is well explained on the URPRO website where they talk about film sensitivity, if you use a filter you will loose 1 f-stop so use a higher ISO film.

http://www.urprofilters.com/content.do?region=FilterInstructions

The filter can be designed for different purposes and depending on its color and opacity will be more or less aggressive. If you read very carefully the urpro website says that there is a maximum distance that the filter will be effective at.

UNDERWATER FILTER DISTANCE

Photographically and visually reds, oranges and other warm colors become dominated by the natural blue-green (cyan) effects of the water when it is more than 8-10 feet deep.

Because all water is a continuous filter, the deeper a subsea photographer goes beneath the surface, the more colors are naturally “filtered out” of the spectrum.

As a result, the depth of the water must be added to the distance between the camera (or flash) and the subject to give the underwater filter distance. Use the following formula to determine the correct underwater filter distance:

+ Depth of water above the photographer
+ Distance from camera (or flash) to subject

= Underwater filter distance

Scuba divers using a still camera or a movie camera must combine the depth of the water plus the distance of the camera from the subject. This sum should not exceed 80 feet for color negative films and video, and should not exceed 30 feet for color slides. In all cases, the best color is achieved when the camera is close to the subject!

What that means is that the working distance of the distance is not the same as depth so you can push a filter say down to 24 meters but then the distance to subject needs to be zero. So if you are shooting something 3 meters or 10 feet away in 21 meters of 70 feet that as much as you can get.

When it comes to underwater use we are mostly interested in eliminating blue in tropical waters or green in cold algae waters.

In order to eliminate blue that has a high colour temperature we need warm colors typically something around orange. This will some of the blue beams and also part of the green beams and will produce filter light that is of a warmer color and will look ‘more red’.

But how much does for example a URPRO orange filter for blue water really warm up the light?

I have done some empirical tests with my Sony RX100 in a day where the Sony would measure a temperature of 6500K which pretty much correspond to cloudy day indoor.

The URPRO orange filter which is the same that is on the SRP filter for GOPRO measured 2800K with a tint of 5 Magenta. It also measured an overall absorption of 1 and 1/3 fstop of total light. I measure this filter instead of the one I have (which is not SRP and we can cover why in another place) because I think the SRP is the market lead at this time and it uses UR/PRO filters.

So the URPRO orange filter has approximately a 3700K warming effect with a strong magenta tint. This means that a camera with auto white balance and an average lens like a GoPro can restore some color in the image until the overall color of the light is around 10,000K in water. After that the filter essentially stops working and the light absorption is so much that it just becomes plain noise. I think this website gives a good idea

http://www.seos-project.eu/modules/oceancolour/oceancolour-c01-p07.html

So the reason why the picture stops having any red and starts looking green is that there is no red left in the light!

The breaking point seems to be around 18-21 meters or 60-70 feet and corresponds to our personal experiences I would say.

So what about custom white balance? We are pretty much in the same situation we can re-balance the camera up to 10,000K and add magenta or orange tint to the picture but you reach a point where there is too much red color noise.

The other advantage of custom white balance is that there is no light absorption so the picture ends up being less noisy as at the same aperture a loss of 1 and 1/3 fstop is like saying doubling the ISO from 800 to 1600 to capture the same scene. This is the reason a camera with custom white balance will always outperform the same camera with a filter at depth in terms of picture noise.

And what about Magenta filters? This is an interesting one as magenta filter absorb little light around 1/3 of fstops for URPRO and warm up the colour very little around 700-800K with a magenta tinge more prominent. A magenta filter will therefore absorb less light in total and introduce just a tint to the image.

From my tests a magenta filter is totally worthless on a camera that can white balance and frankly not that good at depth on camera with auto mode only. The reason is that light will get cold very soon at depth and the camera will be outside the AUTO white balance operating range (2700-7000 on average) pretty soon.

So what it means for users of GoPro cameras? The summary is pretty much like this:

In blue water filters are worth down to around 18 meters or 60 feet

In green water filters are worth even less as the color temperature very soon reaches a temperature where the auto white balance of the gopro is out of range

Although I have not yet measured I would think probably max 10 meters and that is it as I had similar results with my Sanyo that has same sensor size of the gopro and actually a faster lens.

Hope gopro users find this post useful as well as other users of compact camera to shoot video in ambient light.

In the next post I will compare the optical quality of the SRP dome port with the PolarPro snap on filter that generated such a debate on youtube and we will see why this filter could perform better than the SRP dome.

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