Jump to content

Recommended Posts

Thanks Dreifish. I agree the first video is amazing! That is underwater white balance and no filter? That sure opens up possibilities, as one could use lights on the same dive, without surfacing to take off the filter.

 

Question: How deep do you think you can go with the Underwater white balance able to do the job -- without a filter? How shallow can you be and still use the underwater auto white balance, rather than auto white balance? AGain, your video here is something to aspire to, and I love the drone shot too!

 

I can't see the second video either. Would love to see it!

 

Thanks for posting!

I changed the settings on the second video. Should be viewable now.

 

UAWB works great from 0-10 metres usually. It actually works ok on land too (try it for yourself -- I've forgotten it in this mode a few times when filming on the boat) so I don't think you need to worry about getting too shallow.

 

Keep in mind though that the shots at the beginning of the Mawan video are basically the most ideal conditions you could hope for for underwater ambient light filming -- 3-5 meters depth, midday, bright sun behind me, 20m+ visibility. Basically any camera should do well in such conditions, so I think the quality of the video says more about the conditions than sony's white balance capabilities underwater.

 

Now that I have video lights, I don't use a filter anymore. I basically shot with ambient light in AUWB mode down to 7-8 meters, and custom white balance 5200k and lights below 15. 8-15m is an interesting area where I'm still experimenting. I hope to get AUWB + lights to work together in this area, because lights alone create a harsh transition between the lit foreground and unlit background. But I may need cooling gels for my lights.

Share this post


Link to post
Share on other sites

I used the Nauticam "Wet wide angle lens." and a 28 mm inside the housing. They don't describe it with an equivalent mm, but rather they say it gives a 120 degree view. I haven't tried to determine what mm equivalent that is.

 

I personally would be interested in comparing the quality of the Nauticam Wet wide angle with something that was exclusively Sony on the inside of the housing. I just accepted the advice of the Backscatter saleman.

 

It seems so far there isn't a good fisheye lens option to the cam UW. The Sony 16mm f/2.8 Alpha Fisheye lens requires Sony A to E mount adapter that will not fit into the housing due to its large diameter, and Canon 8-15mm fisheye lens requires a Metabones adapter that according to Metabones itself is unreliable when it comes to continuous focus while shooting movies and closeup shots.

 

dreifish, love the second video as well. Good job.

 

My theory is since lights (strobes or videos) restore colors underwater, is not to use any filter or change the color matrix of the WB to avoid any unwanted extra color cast especially red. Without lights however, filters and/or WB customization will be required. This is according to my modest UW still photography experience.

Expose first for the background without the lights to get the desired blue and use the lights to fill the subject.

  • Like 1

Share this post


Link to post
Share on other sites

By the way gents... did anyone of you used a fisheye lens on the A7S or A7R cam?

 

So, my Mawan video is shot entirely with a mild fisheye lens -- actually, two. Parts of it are using the Sony 28mm + Nauticam WWL-1, both in full frame mode (120-130* FOV) and APS-C crop mode. I also used my Canon 8-15mm + (sometimes Kenko 1.4x TC) in both full frame and APS-C crop. The filtered shots are all with the 28mm/wet lens combo. I haven't filtered the Canon 8-15mm, which I use with a cheap ($100) Photodiox adapter.

 

A few thoughts -- I love fisheye for photos, both at 15mm and at 8mm for circular fisheye effects -- my favorite way to shoot reef scenes. You can see, for example, my profile pic, and other examples on my website. However, for video, fisheye distortion can be quite distracting in shots where the camera is moving. So I tend to try to mitigate the fisheye look as much as possible -- by shooting in APS-C crop mode and with the TC in the case of the Canon. So the end result is only moderately fisheye, but still a bit wider than the 16-35mm at 16mm.

 

Having used both the Canon 8-15mm and the 28mm + Nauticam WWL-1, I ended up selling the second combination. Why? Because for photos, 130* is not wide enough for me -- I always found myself wanting to go wider. And for video, I don't really use a fisheye very often at all, and when I do, I shoot it at 15mm + 1.4xTC + APS-C mode. So effectively, a 31.5mm fisheye. Which I think pretty much corresponds to the widest end of the 16-35mm rectilinear lens.

 

In terms of image quality, I saw no difference between the 8-15, with or without TC, and the 28mm/WWL-1 combo. If anything, the 8-15 is sharper, which I found strange, since everyone else seems to think the 28mm/WWL-1 combo is the bomb. For me, the 8-15 has several advantages over the WWL-1:

  • a wider range. Combined with the 1.4x TC and APS-C crop mode on the A7RII, I can go from 8mm circular fisheye all the way to 31.5mm fisheye. The Tokina 10-17 that everyone loves on APS-C cameras can only do 15mm-25.5mm by comparison, or up to 36.5mm fisheye with a 1.4x TC. But it lacks the circular fisheye at the wide end, and that's very important for me for images.
  • no need to deal with the super-heavy front element (WWL-1) skewing the housing trim
  • can be used with a 140mm dome (roughly same size as the WWL-1, same CFWA ability) or with a larger 200 or 230mm dome for split shots (split shots are very difficult with the WWL-1 because the water between the back of the WWL-1 and your port)

 

 

 

Hi Andrei: What lenses were you using, particularly on the first, as I can't see the second yet? thanks.

 

As for the first video, see above. The second video, Batu Bolong, is shot entirely on the 16-35mm behind the Nauticam 8.5" dome. This is the combination I currently favor for video shooting because of it's amazing versitility on the A7RII. Since I can shoot 4k at either full frame or with an APS-C crop, the Sony 16-35mm lens gives me an effective focal length from 16mm - 50mm. Outside of macro situations, I'd say there's very little underwater you can't shoot well with that range. And I've even gotten some nice footage of a flamboyant cuttlefish (roughly palm-sized) with it.

 

This is a bit of a tangent, but as the Backscatter guys mentioned in their review, I feel the A7RII has some very distinct advantages when filming 4k underwater because of the ability to film either in full frame mode or APS-C crop. This means I can get both wide, medium and close-up shots with the 16-35mm, and can get both macro (1.0x magnification) and super-macro (1.5x) magnification with the Sony 90mm lens. Add a flip adapter an a Nauticam SMC-1, and suddenly you can get wide, medium and close-up shots at the macro range, too. No other stills/video hybrid out there offers you that kind of flexibility currently.

Share this post


Link to post
Share on other sites

 

It seems so far there isn't a good fisheye lens option to the cam UW. The Sony 16mm f/2.8 Alpha Fisheye lens requires Sony A to E mount adapter that will not fit into the housing due to its large diameter, and Canon 8-15mm fisheye lens requires a Metabones adapter that according to Metabones itself is unreliable when it comes to continuous focus while shooting movies and closeup shots.

 

dreifish, love the second video as well. Good job.

 

Thanks Ammar!

 

I absolutely love the Canon 8-15mm on my A7RII. Even with a cheap photodiox adapter, it focuses flawlessly for wide angle pictures. I don't really use it for video, but in general I'd stay away from autofocus in video with any lenses, including the Sony 16-35mm. The way it hunts for focus when you're stepped down to F8 or narrower is very distracting and makes the footage unusable, IMO. I'm not sure if this is because it uses contrast detection instead of phase detection when stepped down past F5.6, but, whatever the reason, it basically means autofocus is unusable underwater in video. I always prefocus (back-button focus) before I start filming. If I have to refocus during the shot, I pretty much treat it as a new shot from then on.

 

The only problem I have with the Canon 8-15 is that, with Nauticam, it requires a step-up n100 to n120 port adapter + 1 (or 2) extention rings. This is a bit clunky, at it also means you have to mount the lens from the front, you can't insert the camera into the housing with the lens already mounted. That would be a minor annoyance, but it quickly becomes a major annoyance when you realize that the A7RII burns through batteries incredibly fast. If I'm shooting video, I have to switch batteries after every dive. For photos only, you may be able to make a battery last 2 dives, but I would not feel comfortable trying for 3 unless I barely used the camera on the first two dives. Since I do a lot of day trips where the boat goes out for 3 dives, that means I have to open up the housing twice on the boat, take the dome off, take the lens off, open the back, take the body out, replace the battery, put the body back in, put the lens back on, and replace the dome. This is a nightmare situation during a 1 hour surface interval. This, along with the limited underwater white balance options, is why I'm contemplating a different camera for my current work.

 

 

 

 

My theory is since lights (strobes or videos) restore colors underwater, is not to use any filter or change the color matrix of the WB to avoid any unwanted extra color cast especially red. Without lights however, filters and/or WB customization will be required. This is according to my modest UW still photography experience.

Expose first for the background without the lights to get the desired blue and use the lights to fill the subject.

 

This approach works well for wide-angle photo shooting. It also works for wide angle video, but with the caveat that video lights are much weaker than strobes. Even with two 14000 lumen lights, I can only really fill the foreground to maybe 50cm in front of the lights. So it works, but only for smaller subjects. You're never going to be able to fill in a 2m gorgonian sea fan, as you might if shooting a CFWA still.

Share this post


Link to post
Share on other sites

If I may just add one more argument to that great summary from dreifish for not shooting SLOG underwater: Due to its curve SLOG is not really ideal for low light situations and you are much more likely to get blocking and noise.

 

This is due to the fact that in SLOG you got lots of dynamic range at the highlights, but this comes at the expense of not so much dynamic range in the lowlights / midrange. However, as protecting highlights is not the key issue for underwater filming I would use "normal" or Cinegamma Settings (PP5 or 6 on the A7SII if I recall correctly) instead.

 

 

Bubffm, have you tried shooting with the Cinegamma Settings? In theory, a cinegamma setting that preserves the rec709 color space may be a good compromise with a slightly wider dynamic range/better highlight rolloff than no picture profile, while avoiding the messed up colors of SLOG/SGAMUT. That seems to more or less play out on land.

 

I've yet to do a thorough comparison myself underwater - it would be great if someone could!

Share this post


Link to post
Share on other sites

 

Bubffm, have you tried shooting with the Cinegamma Settings? In theory, a cinegamma setting that preserves the rec709 color space may be a good compromise with a slightly wider dynamic range/better highlight rolloff than no picture profile, while avoiding the messed up colors of SLOG/SGAMUT. That seems to more or less play out on land.

 

I've yet to do a thorough comparison myself underwater - it would be great if someone could!

 

 

No, unfortunately not as I am using the AX100 underwater these days. I just thought I throw this in as a potential hint for you guys. As you say, theoretically it could be a good compromise. Might be worth trying out the next time you get wet :-)

  • Like 1

Share this post


Link to post
Share on other sites

 

Bubffm, have you tried shooting with the Cinegamma Settings? In theory, a cinegamma setting that preserves the rec709 color space may be a good compromise with a slightly wider dynamic range/better highlight rolloff than no picture profile, while avoiding the messed up colors of SLOG/SGAMUT. That seems to more or less play out on land.

 

I've yet to do a thorough comparison myself underwater - it would be great if someone could!

Guys:

 

I am leaving for a one-week trip to Grand Cayman next Thursday, and am up for conducting some tests. Will be diving 2 tanks a day for 6 days, so I will have some time to review footage in the eventing.

 

Dreifish, what would the advantage be of a Cinegamma setting? You had be convinced to leave picture profiles alone for the future. It certainly makes life easier.

Share this post


Link to post
Share on other sites

Guys:

 

I am leaving for a one-week trip to Grand Cayman next Thursday, and am up for conducting some tests. Will be diving 2 tanks a day for 6 days, so I will have some time to review footage in the eventing.

 

Wish you good hunting :)

Share this post


Link to post
Share on other sites

I will be leaving on sunday to Palos.

This one is from NEX6 (SONY SENSOR).

 

https://vimeo.com/181713323

YEs Alfredo I really like this too. Your editing and music choice is always very nice. I did not know much about this camera, so I googled it. How do you like it. Does it have white balance characteristics like the a7s II? I assume this was shot with auto underwater white balance?

Share this post


Link to post
Share on other sites

Hi GP7 the NEX-6 is an old camera, later was A6000 and this year the A6300 all of them in APS-C sensor.

 

The WB is very simillar in all of them but NEX6 no AUWB. And the focus system is very far from the hybrid system of A7RII.

 

Usually I shooted with lights and AWB.

Share this post


Link to post
Share on other sites

Hi GP7 the NEX-6 is an old camera, later was A6000 and this year the A6300 all of them in APS-C sensor.

 

The WB is very simillar in all of them but NEX6 no AUWB. And the focus system is very far from the hybrid system of A7RII.

 

Usually I shooted with lights and AWB.

Nice work, Alfredo. What lens/dome combination and what lights are you using for these shots?

 

And can you tell us more about the conditions of the dive -- e.g. how deep is the wreck? Visibility? Are the wide angle shots where no lights were used (e.g. very beginning of the video, at 0:43, 0:59, 1:33, around the 2:00 mark) also done in AWB mode? The blues seem to be preserved well in the initial shots, though there's a bit too much green for my taste from 1:30 on, and hints of ugly magneta water around the 2:00 mark.

 

I think I'll try shooting a bit in AWB mode when I'm using my lights as well. Have you noticed any advantage in doing this vs. just shooting in a custom fixed white balance set to the color temperature of your lights?

 

If I can offer one suggestion, perhaps you could try experimenting with some stabilization effects in post-processing? I think you did a good job of keeping the camera steady (it's much harder with these small cameras), but software stabilization could add a bit of extra polish.

 

As more and more people seem to be shooting with Sony mirrorless cameras underwater, I think it'll be a benefit to the whole community if we can work out the best settings/accessories to use, a sort of best-practices document.

Share this post


Link to post
Share on other sites

Guys:

 

I am leaving for a one-week trip to Grand Cayman next Thursday, and am up for conducting some tests. Will be diving 2 tanks a day for 6 days, so I will have some time to review footage in the eventing.

 

Dreifish, what would the advantage be of a Cinegamma setting? You had be convinced to leave picture profiles alone for the future. It certainly makes life easier.

 

Geo, I think you'll be quite happy sticking to no picture profile for your Grand Cayman trip. You can acquire very nice footage in this mode underwater.

 

The Cinegamma settings allow you a bit more control about how the camera records highlight and shadow information. Some of them will allow you to capture slightly more light-level gradations in the highlights or shadows areas of the image before those areas clip to pure white or pure black. That's the theory. It's not as much extra gradation as a log gamma curve (e.g. SLOG2 or SLOG3) would allow you to capture, but it's more than you get using the no picture profile settings. They also have the advantage of letting you use the Rec709 color space (which is the color space you'll be outputting your video in for TV/web use) rather than the SGAMUT color space that you're forced to use with SLOG. This means you won't have weird color shifts that you need to fix in post as you would with SLOG.

 

In practice, there's some disadvantages and things to consider:

  • You need to post-process your footage to get the best out of it. Like with SLOG, you're squeezing more dynamic range into the same 8 bits of luminance data. The camera records all light levels from 0 - 255, with 0 being black and 255 being white. Cinnegamas and SLOG give you the option to try to squeeze in 10 or 12 stops of dynamic range into those 255 levels, rather then the roughly 8 stops you get with no picture profile. This will end up producing a video file that has less contrast initially. So to get the same "pop" you'll need to boost the contrast in post processing. No picture profile lets you use the video files as is, without this extra step, so it's a distinct advantage if you have tight deadlines or you don't want to spend loads of time color correcting the footage.
  • You trade detail in the midtones for extra detail in the shadows/highlights. Because you're squeezing in more information into the same 255 levels, you'll get less levels to represent the midtones -- which is usually where your subject is. So instead of having 255 levels to describe the black-to-white gradation of a manta's belly, for example, with cinnegamas you'll only get, say, 128, because the other 128 are now being used to record the gradations in the shadows of the coral the manta is hovering over, and in the sunrays. These are details you would otherwise lose clipping. So by choosing a cinnegama or slog profile, you're basically choosing to emphasize detail in the highlights and shadows at the expense of midtone detail. Now, there may be scenes where this is the right choice, but, overall, I think it's rare that you need more than 8 stops to showcase the underwater world well. Do you really need that much detail in your sunbursts? Or in the shadows? Or would you rather use that data to make your main subject look better?

Personally, I'm ok with sacrificing a bit of detail in the highlights and shadows to get a picture with more contrast/pop with limited post-processing. Over the years, I've come to believe that a wide dynamic range is really not that important underwater, since we're often working with artificial light (strobes or torches) that fill in the details in the shadows. Does more dynamic range help? Sure it does, especially with careful post-processing to tone-map that dynamic range into the smaller space of you output format. But it has less visual impact than nice colors and nice contrast.

 

To give you guys a visual reference for what I'm talking about, here is a short video with two scenes shot using no picture profile, cinegamma 1, cinegamma 2, cinegamma 4 and slog2, in that order. I took this footage yesterday with the A7RII set to UAWB, depth 3m, midday, good visibility. SLOG2 footage is at ISO800, F11. Other footage is at ISO200, F11. No post-processing was done. I also thew in a shot at the end to show what WB: Sunny looks like by comparison to UAWB.

 

https://youtu.be/Ap84hmJ4gpQ

 

As you can see, it's not a huge difference between No PP and Cinegamma 1, 2 and 4. SLOG does show a big difference, but that's because of the SGAMUT color space messing everything up. If there's any colorists out there that want to play with the footage to see if you can make the Cinegammas or SLOG look nicer than no picture profile, I'm happy to share it. It's about 144MB in h.264 1080p. If someone can suggest a web host, I can even put up the original 4k files.

  • Like 2

Share this post


Link to post
Share on other sites

Thanks for the clip - I have to say the no picture profile with UAWB looks great! There appears to be very little that needs doing to the footage straight out of the camera. Thats impressive!

 

Would love a copy of the SGAMUT footage to play with, I've just got a Atomos Flame and housing, and contemplating moving to VLog on my GH4 - so having a look at this log footage would be good to see how it works.

 

Have a look at mega.nz for free storage :)

Share this post


Link to post
Share on other sites

Hi dreifish my setup was NEX6 + 16-55mm OSS. Housing RecSea + WA Dome. Almost everything shot at 16mm as I pefer to aproach than zoom. Lights + AWB.

 

615f90eeab848ddc4f56aeba725bdeb7.jpg

 

b6788dae0c0f69e6a842aed773143360.jpg

 

5e093fe91e57f84f0e8bf3410b76e7f2.jpg

Share this post


Link to post
Share on other sites

Thanks dreifish, very interesting test. to me personally cinegamma 4 looks best, followed by no picture profile. But as you say the differences are really small.

Edited by bubffm

Share this post


Link to post
Share on other sites

Thanks dreifish, very interesting test. to me personally cinegamma 4 looks best, followed by no picture profile. But as you say the differences are really small.

 

Yes, actually Cinegamma 4 looks pretty good in that scene.

 

I did some more testing on land today and realized that you can actually set up a custom picture profile with SLOG2 gamma and the photo color space instead of SGAMUT. On land, the colors looked much more natural in this combination than with SGAMUT, and the dynamic range remained the same. This seems very promising to me. As between the 4 cinegammas, the land testing I did today suggests there isn't much difference, but Cinnegamma 1 does a slightly better job of protecting the highlights than the other three. Interestingly, Cinegamma 1-3 have a base ISO of 100, while Cinegamma 4 requires ISO 200 base. SLOG, of course, requires ISO 800 base on the A7RII.

 

Tomorrow, if I get a chance, I'll try to shoot some test footage with:

 

  1. No Picture Profile
  2. Gamma: Cine1, Color: Photo
  3. Gamma: Cine4, Color: Photo
  4. Gamma: Slog2, Color: Photo, AND
  5. Gamma: Slog2, Color: SGAMUT

I also did some land testing of the different color modes selectable for custom picture profiles, but saw only subtle differences between them other than SGAMUT. Perhaps I'll test them underwater someday -- but for now, I'm happy with the "Photo" color profile.

 

The A7 cameras really have a lot of options for customizing the video profile you record. It's almost overwhelming, the different combinations you can create. More testing is needed to be thorough, but I think for now, no picture profile + UAWB is a good default choice for underwater shooting in the 0-10m range.

 

Share this post


Link to post
Share on other sites

Thanks for the clip - I have to say the no picture profile with UAWB looks great! There appears to be very little that needs doing to the footage straight out of the camera. Thats impressive!

 

Would love a copy of the SGAMUT footage to play with, I've just got a Atomos Flame and housing, and contemplating moving to VLog on my GH4 - so having a look at this log footage would be good to see how it works.

 

Have a look at mega.nz for free storage :)

 

The files from yesterday are now up: https://mega.nz/#F!6d9xWZRD!YmQhqe9ill3d_51te5UAxw

Enjoy :)

Edited by dreifish

Share this post


Link to post
Share on other sites

Any password ?? Cant download...

Oops.. updated the link with the decryption key. Should work now?

  • Like 1

Share this post


Link to post
Share on other sites

 

Geo, I think you'll be quite happy sticking to no picture profile for your Grand Cayman trip. You can acquire very nice footage in this mode underwater.

 

The Cinegamma settings allow you a bit more control about how the camera records highlight and shadow information. Some of them will allow you to capture slightly more light-level gradations in the highlights or shadows areas of the image before those areas clip to pure white or pure black. That's the theory. It's not as much extra gradation as a log gamma curve (e.g. SLOG2 or SLOG3) would allow you to capture, but it's more than you get using the no picture profile settings. They also have the advantage of letting you use the Rec709 color space (which is the color space you'll be outputting your video in for TV/web use) rather than the SGAMUT color space that you're forced to use with SLOG. This means you won't have weird color shifts that you need to fix in post as you would with SLOG.

 

In practice, there's some disadvantages and things to consider:

  • You need to post-process your footage to get the best out of it. Like with SLOG, you're squeezing more dynamic range into the same 8 bits of luminance data. The camera records all light levels from 0 - 255, with 0 being black and 255 being white. Cinnegamas and SLOG give you the option to try to squeeze in 10 or 12 stops of dynamic range into those 255 levels, rather then the roughly 8 stops you get with no picture profile. This will end up producing a video file that has less contrast initially. So to get the same "pop" you'll need to boost the contrast in post processing. No picture profile lets you use the video files as is, without this extra step, so it's a distinct advantage if you have tight deadlines or you don't want to spend loads of time color correcting the footage.
  • You trade detail in the midtones for extra detail in the shadows/highlights. Because you're squeezing in more information into the same 255 levels, you'll get less levels to represent the midtones -- which is usually where your subject is. So instead of having 255 levels to describe the black-to-white gradation of a manta's belly, for example, with cinnegamas you'll only get, say, 128, because the other 128 are now being used to record the gradations in the shadows of the coral the manta is hovering over, and in the sunrays. These are details you would otherwise lose clipping. So by choosing a cinnegama or slog profile, you're basically choosing to emphasize detail in the highlights and shadows at the expense of midtone detail. Now, there may be scenes where this is the right choice, but, overall, I think it's rare that you need more than 8 stops to showcase the underwater world well. Do you really need that much detail in your sunbursts? Or in the shadows? Or would you rather use that data to make your main subject look better?

Personally, I'm ok with sacrificing a bit of detail in the highlights and shadows to get a picture with more contrast/pop with limited post-processing. Over the years, I've come to believe that a wide dynamic range is really not that important underwater, since we're often working with artificial light (strobes or torches) that fill in the details in the shadows. Does more dynamic range help? Sure it does, especially with careful post-processing to tone-map that dynamic range into the smaller space of you output format. But it has less visual impact than nice colors and nice contrast.

 

To give you guys a visual reference for what I'm talking about, here is a short video with two scenes shot using no picture profile, cinegamma 1, cinegamma 2, cinegamma 4 and slog2, in that order. I took this footage yesterday with the A7RII set to UAWB, depth 3m, midday, good visibility. SLOG2 footage is at ISO800, F11. Other footage is at ISO200, F11. No post-processing was done. I also thew in a shot at the end to show what WB: Sunny looks like by comparison to UAWB.

 

https://youtu.be/Ap84hmJ4gpQ

 

As you can see, it's not a huge difference between No PP and Cinegamma 1, 2 and 4. SLOG does show a big difference, but that's because of the SGAMUT color space messing everything up. If there's any colorists out there that want to play with the footage to see if you can make the Cinegammas or SLOG look nicer than no picture profile, I'm happy to share it. It's about 144MB in h.264 1080p. If someone can suggest a web host, I can even put up the original 4k files.

Andrei:

 

Thank you for posting these tests. This is the sort of thing I was hoping we could do. I must say that my personal, subjective impression is that no picture profile looks better than the Cinegammas -- precisely for the reasons you mention here. Underwater photography rather changes the rules from what the cinematographers are attempting to achieve above water. I have been studying post processing, and "delogging" sLog 2 and 3 footage in Premiere Pro. I am collecting LUTS. I bet you are too and I would be surprised if you are not already pretty good at doing these things and better than I. I would, however, enjoy trying to delog the slog 2 footage you have here, and color correcting it. If you send me your email address I will give you access to my drop box. I have set up an underwater folder to faciliate exactly what you are mentioning here. One fellow in England color corrected some of my erroneous footage, taken in Cozumel, when I was attempting to do custom white balance at about 70 feet, with this camera. Somehow it resulted in an awful magenta cast that could not be corrected. Hence, I started this topic.

 

I find sLog2 or 3 difficult to work with for other reasons. Here are some issues we can discuss in this group:

 

FOCUS: First, Is it harder to focus in sLog footage? I too use manual focus with a "prefocus" on the back of the camera, and yes I constantly refocus when necessary. But does the camera's prefocus ability differ in different color profiles? A subsidiary question is whether the use of the "gamma assist" function on the a7s II (not sure if they have it on the a7r II) affects the focus.

 

FACILITATION OF PHOTOGRAPHY. Next, one of the advantages to shooting in no picture profile is the ability to move back and forth between video and RAW photography. I can do this on the fly, in a second or two, by just pulling a different trigger on my Nauticam housing. My take on it is that I can't take RAW photos when camera is set to sLog. If that is true, then I have to switch picture profiles before taking the photograph. This takes much longer, and if the camera is finding it harder to focus, this really compounds things.

 

WHITE BALANCE. I can't take a custom white balance in sLog2 or sLog3. The camera simply refuses to do it. The big, big, big result of the discussion on this topic, for me, is that I have abandoned custom white balance for ambient light (which everyone told me to religiously use including the company which sold me the camera and the housing) in favor of underwater auto white balance, which the purists pooh-pooh. But this too raises an issue. Does underwater auto white balance work differently sLog 2 and 3 does it does without a picture profile, or with a cinegamma profile? I think the delogging experiment will help answer this question.

 

I am delighted that everyone is having fun discussing these issues. I will get back to people with the tests I am planning for my trip to Grand Cayman next week! That way people can make suggestions and corrections.

 

GLP

Setup ready 4 next week !!!

 

edda2b5896e2d6b1bcdf0f7e566af479.jpg

That is quite the setup! Much bigger than mine.

 

Does the dog actually use the camera, and how is he at diving? I bet it helps to have an assistant like that.

Share this post


Link to post
Share on other sites

Hi GP7 the NEX-6 is an old camera, later was A6000 and this year the A6300 all of them in APS-C sensor.

 

The WB is very simillar in all of them but NEX6 no AUWB. And the focus system is very far from the hybrid system of A7RII.

 

Usually I shooted with lights and AWB.

Yes I am going to be testing out the underwater auto white balance vs. the auto white balance on the next trip.

Share this post


Link to post
Share on other sites

Well as I saw with vectorscope and waveform. All of the shots are overexposed ( remember to underexpose -0.7ev ).

Not the problem with slog that has lot of information on highlights but allmost nothing in lows. Very low saturation aswell.

Nothing I couldnt fix in 1minute with a contrast curve and the color balance...

  • Like 1

Share this post


Link to post
Share on other sites

Sponsors

Advertisements



×
×
  • Create New...