Andaman Sea Blackwater

gokhankuzu wrote:

Wrong. If you shoot in full focus, the extra depth of field provides a clear depth of field. Sharpness is lost as soon as the camera or fish is out of focus. the entire depth of field deviates from clarity when the focus changes. When using diopters like +5, +10, values like f25 are useful. Unless you're using a diopter, f25 just dims the entire image behind the fish. As long as you open the diaphragm, the whole image behind the fish begins to light up.

There is nothing to 'dim behind the fish' aside from some plankton.

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

I am writing again, after f11, the light falling on all sensors is diffracted and the quality deteriorates. That's why none of the fish you put in is clear enough. You can't get quality photos at f25. Sharpness depends on shutter speed and the moment you focus. I'll find the f8s samples on my hard drive and put it here for you later.

I'm referring specifically to images taken on blackwater dives.

Then your TTL converter is not electrically connected.

Of course it isn't. Had you bothered to look up the specs on Retra Flash Prime/Pro, you'd know that it only features optical input.

What exactly do you mean by blackwater? Night diving, cave diving, hole diving, under the rock diving or diving in dark waters below 60 meters? I am a photogrammetry engineer and I have 25 years of underwater photography experience. All my equipment so far is professional grade. I generally used Sea&Sea systems. I had it done in special-custom products.

Oh, so you simply have zero comprehension of what I'm talking about... okay.

Blackwater dives are conducted at night, in open water, away from the reef or any other solid features. Depending on location, depths can range from a few tens of meters (I was diving over 78m of water) to kilometers (places like Hawaii feature some spectacularly deep drop-offs). Regardless, you're not expected to see the bottom at any point during the dive. Prior to the dive, a buoy with an attached 15-20m line is released into the water; the line has a number of powerful LED torches attached to it at regular intervals. The line is free to drift with the currents, and the illuminated buoy is used by the boat crew to track it. The torches serve two functions. One, they provide a visual reference for the divers - they are visible from a significant distance away, and help you to return to the group if you drift away. Two, the light serves to attract various small critters, which attract predators, which in turn attract bigger predators, and so on. This type of diving is notable for encountering the larval and juvenile forms of many marine animals that are pelagic early in their lifecycle, before metamorphosing into their adult forms and settling on the bottom. Likewise, you an encounter creatures that spend the daylight at significant depths inaccessible to divers, and migrate upwards in the water column to feed during night-time.

However, with everything being free-swimming, often transparent, reflective, or both at the same time, subject sizes trending toward the small and tiny, water being dense with planktonic particles, and anything outside your torch beam being completely invisible, difficulties in obtaining properly focused and lit images are... considerable. If you check out the blackwater diving group on Facebook, where many images include the settings at which they were taken, you will find that f/18~f/25 is the most common aperture range, for precisely the reasons I have outlined in my earlier posts. If you want to prove that most everyone shooting blackwater is Doing It Wrong™, and you're right - get a flight to Florida, do a few blackwater dives with any of the multitude of operators who are doing these dives over there, and post your work. No, images taken on a reef, or during regular night dives do not count - the challenges are completely different, even if you're absolutely certain that your imagination tells you they aren't.