David, I agree with your point of view. What do you mean by the last part “ light from ABOVE emulating sunlight”?
Let's see if a mod can split this thread
On WA shots I used to place my light arms more or less at the same height of my camera. Now I try to place them higher than my camera trying to have a light angle coming from above. I like the shadows I get. Of course every reef is different so your mileage may vary.
Now I have 4 lights. Two old Keldan Luna 8 CRI (5K lumen each I guess). Two prototypes built by a friend of mine (12K lumen each). I never mounted them together. IMHO I would get a correctly exposed flat image, nothing more.
When a keen buddy is available I give him the most powerful set. I fill the subject in front of me with my Keldan and my buddy "flies" 1,5 meters above my head trying to light up the scene/subject from above. Then we play with different angles.
I find that in this way you get amazing shadows. Sometime we get a sense of depth impossible to get in other ways.
Sometime we try a different approach: I light up part of the scene in front of me filming my buddy which in turn light up further far away. Sometimes we get clips we like a lot, sometimes just trash.
This video was made from two dives we experimented a lot this technique. I made a lot of mistakes (i.e. I left my lights on while being well far away from the subject getting only a lot of backscatter. The Gerardia Savaglia was completely burnt on the highlights cause I haven't zebra on my GH3) nevertheless you can see several examples of what I'm trying to explain.
The amphora at 1:12 and 1:24 is light up from my lights and from my buddy above. The same scene at 1:30 is light up only by me and as you can see it's not simply a matter of exposure. The clip at 1:12 has a completely different depth of field.
We used the same "tricks" on most of the clips of this video:
You can see what you can get on a big sponge light up from the opposite at 2:13.
Again the small gerardia savaglia from 2:40 is light up from above even in the close up clip.
At 3:22 you can see my buddy moving upwards while I film the small dendrophyllia and you can see how the reef appears under this kind of light.
At 4:29 an example of me lighting up part of the scene in front of me while my buddy, in turn, lights up further far away. We gently move together giving a great "sense of depth" IMHO.
I understand that I have very particular tastes for UW imaging. I do not pretend to be mainstream and sometime I'm very contentious here
Once you have several lights and some collaborative buddy you can be very creative.
Right now I'm just interested in a 1080p output but a lot of doubts and questions arises...
On several articles and posts on the net I read that converting from 4K to 1080 results in a far "better" image and colors. IIRC I even read that I could get a 1080 4:2:2 clips from a 4K 4:2:0 clips. Mumble Mumble...
Could you elaborate on this and share your current workflow?
If I'm not interested in crop i could create a 1080p project and throw 4K clips at it.
I could create a 4K project, eventually take advantage of some crop and finally export everything at 1080p.
I made some test with the two above scenarios and frankly I couldn't find substantial differences between the two. I use Edius so I have no transcoding. I just edit directly the original 4K clips as usual. Of course the 4K project is slower than the 1080p one.