Why not to move to Micro 4:3 for Video

I have recently received a number of messages asking me why I am not upgrading to a micro 4:3 set up.

There are several reasons why I am not doing that even if my photo rig is nearly as heavy as a micro 4:3 or even a DSLR and have to do mostly with video not with stills.

I will try and touch on the key points in this post, please remember those are subjective and by no mean a criticism to other people that use 4:3 set up for video.

Note: my perspective is one of a typical non professional user that has limited time to get the best shots. This is not an absolute point of view it is  clear that if you are a ‘pro’ and have much more time to spend to get few seconds of footage many considerations do not apply.

Composition

The way I have learned to love underwater video is the composition opportunities that it gives. My main source of inspiration is John Boyle and his book that remains the only valid handbook for what I am concerned even if it is a little old.

One of the classics of underwater video is the sequence: wide-medium-close-super close. On a micro four third in order to have good quality you would choose a macro lens or a wide angle lens,  both those choices will prevent a number of shots you either do close and super close or wide and medium and maybe close but not super close.

With a camera with a fixed lens with a range of 28-100mm and wet lenses you can cover the whole spectrum of shots although you may need to swap lenses during the shot the possibility is there.

Optical Quality

Some users try to use one lens to catch all, usually the choice is a Panasonic 14-42mm or an Olympus 12-50mm. However this is not as exciting as it seems in the first place. I have run some comparisons on the optics on DXOMark assuming the 4:3 are on a Panasonic GH3 that really is a mini SLR you can see the results by yourself

Comparison Panasonic 14-42 vs RX100II vs Olympus 12-50
Comparison Panasonic 14-42 vs RX100II vs Olympus 12-50

The RX100II gives better quality than both those lenses and especially it does it at f/1.8 versus the f/3.5 of f/4 of the other lenses.

The RX100 does have issues of distortion and chromatic aberration at the edges because of the extensive correction but is overall sharper at wider aperture. This is very important for video that is shot at ambient light.

Wet Lenses

You can add M67 lenses to the Panasonic 14-42 and the 35 macro port (am talking about Nauticam ports here) the results will be worse than the RX100 as the starting point is worst. There is no M67 mount to use the Olympus 12-50mm lens, I will try to see if the flip diopter can do that without vignette but still this gives only 24mm against the 18mm of the RX100 with an Inon wet lens.

Video Quality

The only cameras that are decent are Panasonic as Olympus video is pathetic. However only the GH3/4 have anything better than a compact in terms of recording formats. The new Sony RX100 Mark III with 50 mbps 24/25p seems almost equally interesting.

Stabilisation

Micro 4:3 cameras do not have in camera stabilization in video mode and most of the lenses (the 14-42 is an exception) do not have optical stabilizers to contain costs. It follows that close ups are shaky and even wide angle has jumps.

Conclusion

With all the considerations above it follows the only real set up would be a lens with a stabilizer, the only available that can also shoot close up with a wet lens is the 14-42mm Panasonic. However this lens seems to have worst optical quality than the on-board lens of the RX100II (I have checked some real life shots myself). The only benefit left is the higher bit rate recording format and this is only if you go on a GH3/GH4, with higher recording formats available for the RX100 Mark III and with an announced Panasonic LX8 with potential 4K I personally do not see a reason to jump on the 4:3 wagon for video. I do believe though that if you take mainly stills there is a compelling reason for 4:3 as you can have one camera fitting almost everything and smaller to pack than a DSLR (but not that much and forget about 200-400mm f/2.8 tele lenses).

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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.

Galapagos: Sony RX100 Mark II Photos

I have mentioned the conditions we found in Galapagos in the previous post so no need to repeat myself.

One of the things I was told before going is that the last dive of the day tends to be pretty dark so not good for video, therefore I used this for photos were I was expecting to use strobes at all times.

I made a mistake as I should have taken the still rig also on the second cousins rock dive anyway I am quite happy on how things turned out considering I did only 4 dives and took 117 photos I am pretty happy I could pick 20 that I consider decent.

The whole set is here

Watching you

The rig I decided to pack at the end had 6+8 inches segment so it looked pretty cumbersome on land.

Photo RIg on Land
Photo RIg on Land

In water the setup looked like a glider with a significant wing span

Photo Rig Underwater
Photo Rig Underwater

The reason why I took arms so long is that I was expecting sharks to be 4-6 feet away and quite a bit of particles in the water.

I was right. Just have a look at the following two shots, the first taken with a Canon S95 and a single 8″ arm.

Turtle with single strobe 8" arm
Turtle with single strobe 8″ arm

You can see the considerable amount of backscatter despite the 1/1600 shutter speed.

This is another turtle on the same dive

Turtle with twin strobes
Turtle with twin strobes

This time two strobes on the longer arms are used, even at 1/320 this looks neat. The turtle looks bigger as the lens is not as wide as the previous, shooting distance is the same.

The arms proved to be good for the sharks as expected, I used aperture of f/4 for most shots, ISO 100/200 and shutter 1/60 to 1/125

This is emotionally the best shot

Galapagos Shark Watching me
Galapagos Shark Watching me

Later on in the snorkeling trips I took couple of split shots.

Unfortunately the weather was not good and the sky cloudy so I had to play with the graduated filter.

Galapagos Penguin Split Shot
Galapagos Penguin Split Shot

The purist will notice that the water line is not neat, as I am shooting with a wet lens the back of the lens has water as well so to avoid to see that I shoot portrait with the back of the lens in the water, which is a limitation but on a good day will produce interesting shots regardless, also the lens is only 9cm diameter and is flat (Inon UWL-H100)

I took some close ups but even the sea horses were huge so no need for close up lenses.

Giant Pacific Seahorse
Giant Pacific Seahorse

Funny enough I took this at f/5.6 1/60 after reading on DXOMark that the RX100 resolution is actually better at f/5.6 than it is at f/11.

The lens is at 35mm equivalent at the shooting distance I used the depth of field is only a couple of cm and as the background is quite plain I did not bother trying a black background that I could possibly not even achieve. This was a TTL shot whilst all the sharks and wide angle were taken with the strobes in manual.

Another great feature on land of the RX100 is the panorama, which I used in Bartolome and other places

Bartolome Panorama
Bartolome Panorama

In general the conditions were very difficult and I am happy with what I could achieve in just 4 dives.

I will be taking the same arms and strobes configuration to the Red Sea in a few weeks but with the Inon UWL-100 with dome. I expect better results as the conditions are usually fabulous in comparison, probably I could do with shorter arms but once in water the set up is not heavy so I will keep it like that