Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

The Gentleman's Underwater Bubble Blower Thread

I believe Rudi has stated it quite correctly, this from a well-known blog;

"What is Black Shading Calibration?

You may have never heard of black shading calibration before unless you’ve already worked with Epic, own one, or work within a rental house. That’s because with the RED One, black shading calibration was mostly reserved for after a major change in the camera’s software such as a firmware update or factory reset.

Epic is different, though.

In the Epic manual itself, RED recommends doing a black shading calibration in certain instances like:
  • When shooting long exposure (about more than 1/24 sec) or high-speed framerates
  • When there is a “significant” temperature shift to the sensor from the prior calibration
  • After major software changes (not mentioned by RED, but generally recommended)
Granted, this won’t be something you have to do every day, but it will crop up much more frequently than it ever did with the RED One — especially if you switch between studio environments and exteriors where the temperature change could be drastic."


With housings in and out varying water temperatures, exposed to strong sunlight on deck, the black shading process becomes quite significant.


 
Tom, I don't understand why the temperature of the camera in the housing should be any different than when shooting on land. I have two Epics, sync box and a 3D monitor all cramped in one small housing - all of which I run for the entire duration of the dive (more than an hour) and I have never experienced elevated temperatures or colour shifts that you are referring to. In my latest frame grab I have not changed the colours in the post, just applied an S curve to obtain the look that I was after - a very easy thing to do.

If the camera gets too hot, I would assume a problem with either the camera or the housing. Either way, I would not expect colour shifts, but rather increased noise level.

I believe that, if the footage is properly exposed, properly lit, filtered and composed, it should not require rocket science in post processing to look good.
 
Pawel Achtel said:
Tom, I don't understand why the temperature of the camera in the housing should be any different than when shooting on land. I have two Epics, sync box and a 3D monitor all cramped in one small housing - all of which I run for the entire duration of the dive (more than an hour) and I have never experienced elevated temperatures or colour shifts that you are referring to. In my latest frame grab I have not changed the colours in the post, just applied an S curve to obtain the look that I was after - a very easy thing to do.

If the camera gets too hot, I would assume a problem with either the camera or the housing. Either way, I would not expect colour shifts, but rather increased noise level.

I believe that, if the footage is properly exposed, properly lit, filtered and composed, it should not require rocket science in post processing to look good.
Click to expand...

Yes indeed Pawel. But you must account for the considerable thermal shock delivered to the Epic sensor, after being in an underwater housing for extended lengths of time at ever-increasing temps, then opened up for battery and media change. I am guessing something on the order of 50 degrees F variances, huge by any electronic standard.

There is no reason not to do a black shade calibration on an hourly basis, it only takes but a few minutes, and is entirely automated.

As Rudi has clearly stated, a properly calibrated camera capture makes the post process that much simpler to deal with.
 
Tom Hamilton said:
...There is no reason not to do a black shade calibration on an hourly basis, it only takes but a few minutes, and is entirely automated...
Click to expand...
:confused1:
Sorry, I have never experienced the problems Rudi and you are describing and I think doing black shading every hour is a waste of time.
 
Last edited:
On another subject, that of Black Shading and color correction, I put together this video to show how creating a custom look and shooting that in camera gives me a much better starting point once I bring the footage into the computer. I did a BSC at the beginning of the dive trip (a 14 day run) and was changing frame rates frequently and did not see any significant color shift between shots. (Maybe I'll look into that a bit more next week when I'm in PNG).

What I did find was that as we were at the same dive site over and over - just concentrating on the mantas (and unfortunately did not get the awesome aggregation that we had two years ago) - once the white balance was set and if one stays at relatively the same depth and at the same exposure, you can very easily use a custom look and shoot with that and come up with some images that look very pleasing to the eye before additional grading is necessary. Being RAW you can always reset to defaults if you find yourself at a new depth where the look doesn't work. Case in point, I saw two guitar sharks cruising the reef at about 50 feet and I had been shooting the mantas in 25-30 ft. I dropped down and got one pass at these prehistoric creatures. Once topside I was able to reset my look and re-grade to get a nice piece of footage!

I'm thinking I'll work on some various depth presets including looks and white balance and get in the habit of selecting those during the dive.

http://vimeo.com/user7993603/review/54119820/936f6f7a08
 
Ron Lagerlof said:
On another subject, that of Black Shading and color correction, I put together this video to show how creating a custom look and shooting that in camera gives me a much better starting point once I bring the footage into the computer. I did a BSC at the beginning of the dive trip (a 14 day run) and was changing frame rates frequently and did not see any significant color shift between shots. (Maybe I'll look into that a bit more next week when I'm in PNG).

What I did find was that as we were at the same dive site over and over - just concentrating on the mantas (and unfortunately did not get the awesome aggregation that we had two years ago) - once the white balance was set and if one stays at relatively the same depth and at the same exposure, you can very easily use a custom look and shoot with that and come up with some images that look very pleasing to the eye before additional grading is necessary. Being RAW you can always reset to defaults if you find yourself at a new depth where the look doesn't work. Case in point, I saw two guitar sharks cruising the reef at about 50 feet and I had been shooting the mantas in 25-30 ft. I dropped down and got one pass at these prehistoric creatures. Once topside I was able to reset my look and re-grade to get a nice piece of footage!

I'm thinking I'll work on some various depth presets including looks and white balance and get in the habit of selecting those during the dive.

http://vimeo.com/user7993603/review/54119820/936f6f7a08
Click to expand...

Great stuff Ron!
If you make a preset for underwater don't you think if you get some turbidity in the water it will affect your settings? Even cloud cover changes color underwater depending on depth of course?
 
Ron,
one more question, what settings did you calibrate your black to?
thanks,
 
Pawel Achtel said:
My only explanation is that perhaps your camera is faulty. Your suggestions make absolutely no sense to me. :)
Click to expand...

Well, in fact, I have concluded that at least one of the cameras that I have been checking footage from has real problems. Even after BSC the underwater footage is awful, plain awful, and it has nothing to do with exposure or lenses. I suspect at least one more camera may have the same problems, and although I need to be careful with this until the camera has been inspected by RED, I would caution all of you who keep getting abnormal magenta tints on your blue water and green/grey midtones that do not let themselves be pushed to any direction, to calibrate your cameras and see if that makes a difference. If not, well, no Bayer sensored camera should be rendering water other than blue or cyan....
 
Pawel Achtel said:
:confused1:
Sorry, I have never experienced the problems Rudi and you are describing and I think doing black shading every hour is a waste of time.
Click to expand...

Since this is the gentleman's thread, I have to say I agree with Pawel - I haven't seen those kinds of problems. but maybe I need to get out and shoot more and I will keep an eye out.
 
James Killion said:
Great stuff Ron!
If you make a preset for underwater don't you think if you get some turbidity in the water it will affect your settings? Even cloud cover changes color underwater depending on depth of course?
Click to expand...

James, the point I was making was that setting a look based on similar conditions and depth makes for a good starting point. My "jump settings" if you will... As I mentioned you can completely dial the shot back to the default "RAW" settings and start re-working the grade if the in-camera look isn't working. Nothing is baked in, unlike the settings and "look" of DSLR video. The thing is, you can come up from a dive from a 5DIII or 1DX/C with a pretty damn good looking image being loaded onto your computer. I like being able to have a look I like right upon downloading my mag and then can tweak it all I want (more or less) from there - and especially not falling apart...

To your other question, I did black shading at the 36 fps/180 setting.

To Mark's question, yes, that is the venerable Tokina 10-17 at about 12...

Thanks all!
Ron
 
Ron Lagerlof said:
James, the point I was making was that setting a look based on similar conditions and depth makes for a good starting point. My "jump settings" if you will... As I mentioned you can completely dial the shot back to the default "RAW" settings and start re-working the grade if the in-camera look isn't working. Nothing is baked in, unlike the settings and "look" of DSLR video. The thing is, you can come up from a dive from a 5DIII or 1DX/C with a pretty damn good looking image being loaded onto your computer. I like being able to have a look I like right upon downloading my mag and then can tweak it all I want (more or less) from there - and especially not falling apart...

To your other question, I did black shading at the 36 fps/180 setting.

To Mark's question, yes, that is the venerable Tokina 10-17 at about 12...

Thanks all!
Ron
Click to expand...
Great point Ron, but don't you believe that their is some kind of baking so to speak going on?
 
James Killion said:
Great point Ron, but don't you believe that their is some kind of baking so to speak going on?
Click to expand...

I don't think so, James. If you look at this video, the middle shot was right out of camera with the custom look. The first shot was after I removed all metadata from the look in Redcine X (selecting "D" on all the panels) so it definitely took me back to what the default camera raw settings were. The third shot was after a slight white balance and curves adjustment (I'm not crazy about the blue now - but it does a good job of showing the whites and blacks of the manta...)

http://vimeo.com/user7993603/review/54119820/936f6f7a08

EDIT: BTW - I'm doing all my field work on an uncalibrated MB Pro 17" monitor, so some of the color choices are a bit arbitrary.
 
Last edited:
Ron Lagerlof said:
I don't think so, James. If you look at this video, the middle shot was right out of camera with the custom look. The first shot was after I removed all metadata from the look in Redcine X (selecting "D" on all the panels) so it definitely took me back to what the default camera raw settings were. The third shot was after a slight white balance and curves adjustment (I'm not crazy about the blue now - but it does a good job of showing the whites and blacks of the manta...)

http://vimeo.com/user7993603/review/54119820/936f6f7a08



EDIT: BTW - I'm doing all my field work on an uncalibrated MB Pro 17" monitor, so some of the color choices are a bit arbitrary.
Click to expand...

Ron,

thanks for the video demo! So setting a look is just a make you feel good while filming thing. I like to calibrate my black balance to the settings I plan on using and leaving the default look settings on the camera and do all editing in post. for some reason I get a feeling of some baking going on and think it better to make all adjustments after. the only thing I like to set is white balance.

Id like to hear how the others following this post setup before an UW shoot?

Thanks again Ron!
 
Jon,
I've heard that black shading while the camera is hot reduces the noise. I have tried it but have not noticed to much of a difference.
 
You must log in or register to reply here.
Back
Top