Andaman Sea Blackwater

gokhankuzu wrote:

No. When you use flash, iso 800 degrades the quality of the photo at least 4 times. It prevents you from getting details. You can experience it. You have a TTL converter, a check with 100 iso in the same shot and one with 800. And see the difference.

With ISO 100, the shot will be massively underexposed, and I will have to turn up the exposure in post-processing to get a usable image. However, I just looked it up, and found that I misremembered about dual-gain kicking in at ISO 800 - it comes in at ISO 400. See here: https://www.dpreview.com/forums/post/57425727

You got a side view of the fish in your photos and even f8 is too much for clear focus depth of field.

The extra depth of field is there to compensate for the camera not putting the focus at exactly the right point when the shot is taken. It's a buffer that accounts for the subject (and camera) movement.

You have a TTL converter. Again, at the same time, take the aperture to 8 and shoot the same. The difference will be unbelievable and the quality will increase a lot. After f11, the light will shine and you can't get enough detail.

Let's see your blackwater shots taken at f/8. Mine are a blurry mess.

Try f8 and iso 100 and see the difference. You will track much better with your diaphragm wide. Because your camera sensor will see the light. for F25 can't see anything.

A6300 keeps the diaphragm open while focusing; it only stops down to the configured value while taking the shot.

TTL converter will provide the best light in all conditions.

No it won't, and believe me, I've tried. It kinda-sorta works in a limited range of apertures while shooting macro; all my attempts at using TTL with Retra strobes while shooting wide-angle ended up with extremely dark shots. Funnily enough, when I was using SeaFrogs ST-100 Pro strobes and triggering off the pop-up flash, TTL worked much better (but there was no manual option). With the Retras, I'm using manual mode on all dives except blackwater.

Changing the diaphragm from 8 to 25 to 32 will not gain you anything. You should try to approach the fish more sensitively. F32 and f25 take very poor-quality photos.

Are you speaking from personal experience or photo theory? If it's the former, please post some of your blackwater images taken with the settings that you recommend. If it's the latter, I suggest you take your camera on a blackwater dive and get some appreciation of the operational challenges involved. Your profile puts you in US; I don't know if there's much blackwater diving conducted in California, but Florida is one of the bigger blackwater hotspots.