Mantas Glowing White on Kona Manta Night Dive

I am relatively new to dslr and am shooting the nikon d200 in an ikelite housing with 2 ikelite ds125 strobes. I did the manta feeding in kona and found that most of my close pictures of the manta had the white belly glowing to the point that it ruined the picture. I also had a lot of trouble with all the dive lights really messing up the photos.

I am shooting Aperture Priority with ISO 200 and used F11 all the way down to F3 getting the same glow. Strobes are TTL, but I shot a few with the strobes off that were actually a bit better than the ones with the strobe.

I know I should have gotten tips earlier, but maybe I can fix this next time I do a similar dive.

thanks

jon

Do you mean the whites on the manta's belly are blowing out? In that case, you should be raising the f stop, not lowering it (ie closing the aperture, not opening it). Switching to ISO100 will also make a difference.

There's a couple of good books about UW photography out there that explains this stuff and more really well. By all means ask questions here, but that might be a good starting point, especially before your next trip.

Ryan.

If you are shooting with the strobes in TTL, changing the f-stop will likely not make much difference. TTL attempts to give you a proper exposure by averaging the overall image into what it thinks is a prpoer exposure. Often, when you have a high level of contrast in the scene (dark blacks and bright whites), the shadows may be underexposed and/or the whites may be overexposed. This is exacerbated when the subject does not fill most of the scene. In those cases, the camera keeps the strobes on trying to illuminate the black portion of the image, and the result is that the subject is overexposed.

One of the things people really need to understand quickly when doing underwater photography is that most images can be thought of in two parts, the background and the foreground. The photographer needs to decide what to do with each one. In simplest terms, the combination of shutter speed and aperture sets the background exposure and the combination of strobes and aperture control the foreground. When in TTL, the aperture does not control the foreground exposure as much because the camera will adjust strobe output to compensate (mreo strobe output for a higher f-stop and les strobe output for a more open aperture setting). So in your case, aperture priority is setting the background exposure for you. If the strobes are blowing out the subject, you can adjust the strobe exposure compensation down (you, in effect, did this by turning them off). You might also, for a bright white subject, try adjust the overall exposure compensation down. Another trick is to use something more akin to spot metering so that the subject is metered, not the whole frame.

When Ryan is talking about the fact that you should be raising, not lowering the f-stop, that really applies more to when you are controlling the strobes manually. in that case, you set the strobe for a particluar output and the aperture setting controls how much of the light actually gets through the lens. I prefer manual strobe control for wide angle, though others are very successful using TTL and dialing in negative flash exposure compensation.

Just some thoughts,

Mike

I believe Mike has hit your problem on the button.

Cheers

Todd

thanks for the input guys. I am getting really dissattisfied with the automatic settings on my d200. I have been getting a lot of blurry shots with subjects that are not that difficult to shoot. A couple of harlequin shrimp at the bottom of a coral for example. Over half came out blurry with only slight camera movement from the surge. I am going to start shooting manual with some generic settings and tweak them slightly as I go. Planning on 1/160s and F 11 and use my housing to do the +/-1 on my F Stop. I will adjust my strobes manually a bit to see what that does for me. I am just starting to use the exposure adjustment, but I will take your advice and try lowering that a bit.

I took a lot of shots a few months back with my Nikon 105mm in Lembeh and got very few shots with any blur. I had to dump a lot of pictures that came out dark while i was lowering the f stop to brighten it up. I shoot with the histogram and once i get full to the right, I usually have a good shot.

I am doing very little different with the sigma 17-70 and just not getting good shots and lots of blurry shots. The guys I am diving with are telling me to stick with nikon american made glass, there is just no substitute. Are the cheaper lenses really that much worse?

thanks for the input guys. I am getting really dissattisfied with the automatic settings on my d200. I have been getting a lot of blurry shots with subjects that are not that difficult to shoot. A couple of harlequin shrimp at the bottom of a coral for example. Over half came out blurry with only slight camera movement from the surge. I am going to start shooting manual with some generic settings and tweak them slightly as I go. Planning on 1/160s and F 11 and use my housing to do the +/-1 on my F Stop. I will adjust my strobes manually a bit to see what that does for me. I am just starting to use the exposure adjustment, but I will take your advice and try lowering that a bit.

 

I took a lot of shots a few months back with my Nikon 105mm in Lembeh and got very few shots with any blur. I had to dump a lot of pictures that came out dark while i was lowering the f stop to brighten it up. I shoot with the histogram and once i get full to the right, I usually have a good shot.

 

I am doing very little different with the sigma 17-70 and just not getting good shots and lots of blurry shots. The guys I am diving with are telling me to stick with nikon american made glass, there is just no substitute. Are the cheaper lenses really that much worse?

With all due respect, those people are snobs . While there is likely some quality difference, there shouldn't be so much that your pictures are actually blurred. That is most likely due to using a shutter speed that is too slow. Using the histogram is a good idea. 1/160 should be more than fast enough to capture 99% of underwater action. I usually use 1/125 as a starting point. f/11 is fine, though for macro, you'll likely want to go higher for better depth of field. Not sure what the range of flash adjustment there is on the housing but I would imagine that leaving the strobes in TTL and adjusting them from the housing should work just fine.

Doesn't the camera adjust shutter speed automatically in Ap? That is the thinking I was basing my choice to switch to Manual on.

My wife quit diving two days early, so I have two charters to use and only the manta dive to use them on. I guess fate is making me take another shot at getting some framers and telling me to learn how to do this properly.

I am going to shoot in Manual with 1/160 and F11 to start. I will lower the Shuttter speed a bit and try 1/125 to see how that works for me. I have -1 1/3 to + 1 1/3 in 1/3 F stop increments on the Ikelite. If I get the blowout of the whites, I will lower the strobes manually to 1/2 or lower if i have to.

I have two more hours, I think I will shoot some birds and gekkos.

Thanks for the input.

jon

With all due respect, those people are snobs . While there is likely some quality difference, there shouldn't be so much that your pictures are actually blurred. That is most likely due to using a shutter speed that is too slow. Using the histogram is a good idea. 1/160 should be more than fast enough to capture 99% of underwater action. I usually use 1/125 as a starting point. f/11 is fine, though for macro, you'll likely want to go higher for better depth of field. Not sure what the range of flash adjustment there is on the housing but I would imagine that leaving the strobes in TTL and adjusting them from the housing should work just fine.

Doesn't the camera adjust shutter speed automatically in Ap? That is the thinking I was basing my choice to switch to Manual on.

 

I am going to shoot in Manual with 1/160 and F11 to start. I will lower the Shuttter speed a bit and try 1/125 to see how that works for me. I have -1 1/3 to + 1 1/3 in 1/3 F stop increments on the Ikelite. If I get the blowout of the whites, I will lower the strobes manually to 1/2 or lower if i have to.

Yes, and that could very well be part of the problem. If you stop way down and select a higher aperture, the camera may select a very low shutter speed. You should also check to see what the camera defaults to in automatic modes and a flash connected. May be something like 1/60 if the aperture value is really high. You might also try metering quickly at the start to see. I would shoot to make sure the camera is underexposing and the strobes are filling in the missing light.

Jon, can I ask what your thoughts are for selecting to shoot in aperture priority?

I have never used that setting underwater. I have selected shutter priority for fast moving subjects in wide angle. I prefer to shoot in manual and adjust iso if needed for more light to achieve a desired aperture/depth of field and or shutter speed.

Cheers

Todd

For the Blurry images.

There could be 2 issues as I see it. Either the lowest allowed shutter speed in A-mode. The Nikon default is 1/60s. That works fine for most macro objects. Some wideangle needs faster shutterspeeds.

Could it be down to the Auto focus settings instead? Which auto focus mode do you use? AF-S, AF-A or AF-C?

For Wideangle my experience is that the Manual Settings gets you the best results. It is however a lot of fiddling around to get the blue water correct. The settings changes also in case the Object comes above, level or below you.

TTL is not a good idea if the Object is more than a meter away.

/Erik

Todd,

what is your experience with the Shutter priority?

I have never really played around with it UW. I imagine that it could be useful with sharks and Mantas that are somewhat unpredictable where they end ( below, above or level).

With Manual it is of course the risk that you do not anticipate the correct position and screw up in the stressed changing of the settings.

Hmm, don't you just move the fiddling around to the Strobe instead?

/Erik

Shutter priority for dolphins in natural light. Results, have been excellent. With the constant moving up and down in the water column it has given me a much higher percentage of keepers.

Ok, then even I understand

Dolphins are usually moving pretty fast and natural light implies no strobes. Then it should be working pretty good I assume.

This bloody moving around in the water column faster than I manage to readjust the aperture & shutter speed is annoying

/Erik

Looking through this thread; I cannot see that anyone mentioned that the manta feeding is at night. So in this situation only one thing counts, that is your strobe exposure - in other words, the combination of strobe power setting, ISO and aperture. Shutter speed will make little or no difference unless there is a lot of ambient light from video lights etc. I would strongly suggest you learn to shoot manual, and be totally comfortable that you understand your exposure settings for all situations before considering using TTL especially for wide angle where you have to consider background and foregound exposure separately. Macro is much simpler to use TTL.

A few hints:

Set to ISO 100

Shutter Speed about 1/100th (though this is least important and could be slower)

Aperture f8-11

Strobes 1/2 power

Set your back LCD review screen to the one where blown Highlights blink. Either the one with no histogram or the one with the three small histograms and small image. This is probably the most important thing to do.

After you take a picture, check for any blinking highlights, if there are any, turn down strobe or close aperture.

As the mantas are moving remember you may have to make quick adjustments to strobe power or Aperture to compensate for being closer to or further from the animals, and the highlights will blow very quickly when they get really close.

This approach is a good starting point for wide angle during the day as well, except that you should set your initial exposure by using your light meter for one stop under exposure (again starting with 1/100 and f8-11) for the background, and then adjust strobe for appropriate foreground subject exposure.

But the single best tool you have to avoid highlights blowing out is the blinking highlight indicator.