The Gentleman's Underwater Bubble Blower Thread

[Michael Hastings]

A little Reduser history. IIRC I was the first to propose the idea of using Nikonos lenses on RED back in 2007 in the original bubble blower thread. It was never a particularly difficult engineering problem with making it work, but there were a couple practical issues that worked against the idea.

1) The biggest issue is the limited angle of view on an S35 sized sensor. The Nikonos 15 was designed to cover the full frame 24x36mm film size with a 94 degree angle of view. 94 degrees would be pretty good even though by then virtually all professional shooting was being done with lenses that had 100-110 degree field of view. But on S35 you would only get about 75 degrees and that trade off is generally too much. The whole idea of using ultra wide lenses underwater is to get as close as possible to the subject to reduce the amount of water between subject and lens. Most shooters realize that because of the density of even the clearest water, getting closer produces very significantly better clarity because the water acts as a progressive diffusion filter. However, they often don't consider the other effect which is the loss of color saturation because not only are colors being muted by passing through the water from the surface but also by passing through the water from subject to lens. So the trade off is that although the Nikonos 15 generally will give better edge to edge sharpness versus any dome/lens combination (it seems that there are two things working for the 15 - first the front "dome" element is perfectly aligned with the lens elements and second it seems that Nikon did some corrections on the edges) the downside is that the loss in clarity and color saturation with the Nikonos is usually more of a problem in terms of things that normal people see than the lower resolution and chromatic aberrations that you get with normal dome/ultrawide lenses.

2) The nikonos mount essentially becomes the mount for the camera which means that if the lens should leak the water would go directly to your sensor and internal electronics which is pretty bad news. And you have to remember that ALL of the available Nikonos 15 lenses were at least 10 to 25 years old and the lens elements can leak. Secondly the mount itself isn't particularly robust. That wasn't much of an issue when the camera (Nikonos) weighed only a pound or two, but a bump on the lens with a 20 to 30 pound housing behind it could easily dislodge the lens and cause a leak - again right to your sensor. With a normal housing, a leak will typically run to the bottom of the housing and you have a chance of surfacing before ruining your camera and the camera is somewhat water resistant so water drops are probably survivable - whereas even a few drops through the mount would likely be catastrophic to the sensor and/or internal electronics.

The Nikonos lenses would be ideal for the VistaVision/FF35 size sensor. Depending how long you have been around Reduser, you may recall that the original Epic timeline called for a FF35 36x24mm sensor to be delivered in Winter 2009 - so we were seriously thinking of offering a Nikonos version housing but the reality is that RED just started delivering (a few) VV/FF35 size sensors last year.

 

[Tom Hamilton]

Re splits and methods for dealing with water dispersal from ports, here is some stunning surf work by Chris Bryan - 1000 fps - Phantom Flex 4K - Arri Ultra Primes:

http://www.thesurfslab.com/2016/09/chris-bryan-1000-frames-per-second.html

Some notes:

00:56 - very even shearing of water from port, probably not a hydrophobic product, such as Rain-X, as no droplets form
03:32 - some remarkably artistic bokeh effects from droplets, putting that one in my back pocket
06:54 - panning shot with water droplets on port causing significant lens flare
07:53 - unrelated, but an interesting demonstration of Darwinian natural selection

Cheers

 

[Lee Kelly]

To continue the whole nikonos thing, it depends what you are into.
A lot of underwater filmmakers shoot natural history style content with ultra wide lenses nice and close to corals and sea horses and get nice results. If you put the same ultra wide lens infront ofa person they get a big nose and its not very flattering.
I use the nikonos system all the time and just got home from a shoot in Japan where the action/portraits we shot were perfect with the nikonos. Its absolutely correct about the lack of sharpness the further away you take the lens from subject and the 15mm isnt a super wide fisheye lens so if you want wide wide with this lens, you will suffer image degradation. I have the 12mm fisheye by sea and sea and that is a great little lens but hard to find. We didnt use it in Japan as we were trying to maintain straight lines and symmetry with our shots in a pool and fisheye distortion looks horrible. Up close and personal with the 15mm its amazing and we had awesome images shooting talent in a full frame composition, as well as a little wider.
There are many disadvantages to nikonos but depending on what you are into the positives outweigh the negatives for me.

Chris Bryan does amazing work!

 

[Peter Lightowler]

Quick question for the group, does anyone perform a manual white balance while underwater?
I know the WB is not baked in to the image but I noticed today that I was recording a lot more Red colour information after performing a manual WB on a slate.

Doing a quick grade in Resolve is giving me very good results as I am now recording more red channel information to begin with.

Cheers Pete.

 

[Lee Kelly]

Hi Pete,

Hope youre well.
Yes I will often try a white balance down there, however, as you all know, it can be a little time consuming and is somewhat constantly changing as you recompose.

 

[Michael Hastings]

Quick question for the group, does anyone perform a manual white balance while underwater?
I know the WB is not baked in to the image but I noticed today that I was recording a lot more Red colour information after performing a manual WB on a slate.

Doing a quick grade in Resolve is giving me very good results as I am now recording more red channel information to begin with.

Cheers Pete.

With Redcode the white balance is just metadata - you don't actually record more red channel info, but it can give you a closer starting point for grading.

If you were only recording proRES on the newer cameras it would make a big difference to do a white balance because that balance is "baked in"

The thing to remember about raw is that all it really is recording is the grayscale intensity level of each pixel (i.e the "brightness level") nothing more. Each pixel has a red green or blue filter in front of it and the software (either the incamera firmware or the Redcine, Resolve, Adobe, etc) knows which filter it was and does its own interpretation of what that will mean in the final picture. That is why the color science, and/or "improvements" in the interpreting software can give you "better" images over time as the software is improved. But in the end the original data is the same - hence "raw".

So your white balance really is just the metadata (basically just a simple text description) telling Redcine, Resolve, Adobe to emphasize the reds. So for example let's say the raw breaks down the brightness number of each pixel to 1000 levels so your camera recorded many of the blue filtered pixels at close to 1000 (so for this example take one blue pixel at 980) and many of the red pixels at 20 (so for this example take the red filtered pixel next to the blue filtered pixel at 20) all your white balance is doing is telling your software to translate (reduce) for example that 980 blue to 700 and translate (boost that red 20 pixel to 300 for a "better" balance.

 

[Tom Hamilton]

Quick question for the group, does anyone perform a manual white balance while underwater?
I know the WB is not baked in to the image but I noticed today that I was recording a lot more Red colour information after performing a manual WB on a slate.

Doing a quick grade in Resolve is giving me very good results as I am now recording more red channel information to begin with.

Cheers Pete.

I perform manual white balance underwater. As R3D has been described as not being 'true' raw, it does seem to provide more latitude in post, as Pete describes above. It also gives a truer representation on the monitor of what the finished product should look like, allowing for better composition and framing.

 

[Peter Lightowler]

Hi Pete,

Hope youre well.
Yes I will often try a white balance down there, however, as you all know, it can be a little time consuming and is somewhat constantly changing as you recompose.

G'day Lee, I am well mate. Yes it can be a fiddly process that is for sure. Do you use a white slate at all for the WB?

With Redcode the white balance is just metadata - you don't actually record more red channel info, but it can give you a closer starting point for grading.

If you were only recording proRES on the newer cameras it would make a big difference to do a white balance because that balance is "baked in"

The thing to remember about raw is that all it really is recording is the grayscale intensity level of each pixel (i.e the "brightness level") nothing more. Each pixel has a red green or blue filter in front of it and the software (either the incamera firmware or the Redcine, Resolve, Adobe, etc) knows which filter it was and does its own interpretation of what that will mean in the final picture. That is why the color science, and/or "improvements" in the interpreting software can give you "better" images over time as the software is improved. But in the end the original data is the same - hence "raw".

So your white balance really is just the metadata (basically just a simple text description) telling Redcine, Resolve, Adobe to emphasize the reds. So for example let's say the raw breaks down the brightness number of each pixel to 1000 levels so your camera recorded many of the blue filtered pixels at close to 1000 (so for this example take one blue pixel at 980) and many of the red pixels at 20 (so for this example take the red filtered pixel next to the blue filtered pixel at 20) all your white balance is doing is telling your software to translate (reduce) for example that 980 blue to 700 and translate (boost that red 20 pixel to 300 for a "better" balance.

Thanks for the info Michael. I understand the principle of Raw but in the limited testing that I have done, using a WB number preset versus performing a WB underwater, there was a vast difference in the amount of Red colour recorded. Without doing a manual WB, there was simply no red colour recorded at depth and the scopes showed that. Hence I had a hell of a time grading the footage as you can't boost something that simply does not exist. Do you perform a WB at all or just leave it set to a specific number?

I perform manual white balance underwater. As R3D has been described as not being 'true' raw, it does seem to provide more latitude in post, as Pete describes above. It also gives a truer representation on the monitor of what the finished product should look like, allowing for better composition and framing.

Thanks Tom. I am still coming to terms with shooting on the Red U/W. My initial testing seems to suggest that doing a manual W/B makes a huge difference to the amount of colour recorded. I still need to get my head around the Red Raw situation to understand more about how it works.

 

[Rui Guerra]

Peter,

Your findings are the same as mine. Whenever I have time I do an underwater WB with a 18% grey card plastic slate (in fact I use two, glued with tape side by side, to have a bigger area and fill the frame). If you program a button to do that, it will take just a few seconds. If I have a significant depth charge, I do another WB measure.

The next best option is to record a few seconds with the slate in the frame to have it in post and to pick the WB using the pick tool.

Another thing that will improve the results is using lights, even if they are weak; make sure that you have them on while doing the WB measurement or while recording the WB slate to use in post.

 

[Lee Kelly]

Yeah Pete,

I have not dont this much with my Red setup but have with my Alexa rig. I was having an issue with a white slate due to it being a little over exposed compared to my scene and this meant adjusting iris doing white balance and readjusting iris again which all takes valuable seconds each time. I ended up starting with a grey card like Rui and that was much easier to keep exposure in check.

 

[Rui Guerra]

Yeah Pete,

I have not dont this much with my Red setup but have with my Alexa rig. I was having an issue with a white slate due to it being a little over exposed compared to my scene and this meant adjusting iris doing white balance and readjusting iris again which all takes valuable seconds each time. I ended up starting with a grey card like Rui and that was much easier to keep exposure in check.

Yes, That's one of the reasons to use a gray WB slate (mine have a white side and a gray one) and not a white one. Besides that, it's much easier to control glare from the slate.
With a pre-programed RED button it takes just a couple of seconds to adjust it. The slate should cover the entire frame. If that's not possible, record a few seconds with the slate in the frame and use it in post.

 

[Tom Hamilton]

I have Mares fins with a broad grey strip down the middle, very close to 18%, and one function button set to auto WB calc, saves time when you run out of hands (although I have been asked once or twice why I'm using such an expensive camera to take pictures of my fins).

Alternatively, you can take your grey slate to a paint shop, most have very accurate computer color match, buy a small can of marine grade paint and splash one of your fins with it.

 

[Mauricio Handler]

Hello All
Has anyone of you used the Red 17-50 underwater?
Any opinions, thoughts?
Anyone know the angle of coverage of at the 17mm @ 5kHD and 6kHD both of Epic Dragon and Epic Weapon?
Many thanks -

Mauricio -

 

[Michael Hastings]

Hello All
Has anyone of you used the Red 17-50 underwater?
Any opinions, thoughts?
Anyone know the angle of coverage of at the 17mm @ 5kHD and 6kHD both of Epic Dragon and Epic Weapon?
Many thanks -

Mauricio -

Mauricio:

Phil Holland has some great tools on his website PHFX.com

5KHD should give you a crop factor (versus 36x24mm still full frame) of 1.5x so your 17 would be equivalent to a 25mm on full frame still camera, so about 80 degrees

And 6HD gives you a crop factor (versus 36x24mm still full frame) of 1.25x so your 17 would be equivalent to a 21mm on full frame still camera, so about 90 degrees

 

[Mauricio Handler]

Hi Michael
Many thanks for your note. I will review it all.
Hope you are well.
Best- M

 

[Russ Fill]

Hello All
Has anyone of you used the Red 17-50 underwater?
Any opinions, thoughts?
Anyone know the angle of coverage of at the 17mm @ 5kHD and 6kHD both of Epic Dragon and Epic Weapon?
Many thanks -

Mauricio -

Ive used it almost all the time on my Helium S35... I know very different than the Dragon but It is a very good short zoom underwater and it will focus close enough to make you smash your dome in to the reef if your not careful. Just joking but seriously it has a very close focus so with it set to 50mm you can do some very closeup work and at 17 it works very well for wides. Like I said its a work horse for me in the gates housing with a dome port.

 

[Mauricio Handler]

Hello Russ
Thanks for your note on the 17-50. Can you please give me an idea of the angle of coverage on the HS35? 8k and or 6KHD at 17mm . Many thanks! Mauricio-

 

[Michael Hastings]

Mauricio:

Curious why you are interested in the Red 17-50 when the same lens is available as the original in Canon and Nikon mounts for less than $400 and has the added advantage of being controllable via RED Canon and Nikon mounts?

I understand there are some DPs that do all of their other shooting with PL mounts lenses but didn't think that was your situation.

And it seems there are other lenses more suitable for wide angle underwater - inexpensive like the Tokina 11-20 2.8 or Canon 10-22 or the much more expensive Canon 11-24L which seems to be the premier underwater lens at the moment ($2999 but about the same as a used Red 17-50 PL) or the Nikon 14-24 if you are a Nikon guy.

 

[Mauricio Handler]

HI Michael-
Indeed it is a good question... I have access to a Red 17-50 and wanted to confirm its features... I am a Nikon user and have as you stated used wider, better glass for all my underwater.
Having access to this lens, I wanted to confirm if indeed it was better quality etc etc.
For me, not having electronic aperture is a minus. But you are correct that there is lighter, wider and possibly sharper glass out there for the natural history work I do.
My questions were more to compare and evaluate this Red 17-50 vs others. Thanks for the follow up- best MH

 

[M_Young]

So what are considered to be the better lenses shot through a dome to a RED camera ?