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CeeDave

Sharks to infinity..what to do?

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Hi CeeDave,

 

If the image is on your server, use the IMG button above to enter the URL of the image.

 

If the image is on your Hard Drive at home, then you can attach it, but it must fit within the size limitations. Hit "Help" for posting photos as attachments.

 

Cheers

James

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Trying again...last time the attachment didn't attach. And me servers is fubar, so I can't link.

 

The attached film image was shot at about 100' on the Alcyone Pinnacle at Cocos, Costa Rica. Photo shot with a Nikonos V, 20 mm lens, metered manually with a Sekonic uw meter. I did not record exposure info on this shot, but the mediocre viz (~40 ft) and depth had the light fairly low, so I'd reckon it's like, umm, about f4 at 1/60 or 125 or so (200 ISO).

 

While the frame is filled wonderfully (even by Cocos standards), these lighting conditions were tough. I wanted to get some illumination down low and capture silouhettes up high. I judged the sharks too far off for my SB105 (GN ~ 32 or 34) to be much good. Besides lighting, I pretty much had to stay concealed in the crevice on the seamount -- though I was on a rebreather, the hammers are very shy. Finally, I was loath to strobe because (1) the reddish cast I'd likely get at such a distance and (2) the tendency to blow the highlights on the white underbellies of the hammers.

 

So: the composition is pretty good, and I do like the moodiness of the shot.

But: I lost too much low and high...always a problem.

What do you think?

*Could a strobe have helped?

*I know nothing about multiple strobe use. Might that help? Would it make sense to have a remote slave?

*Would filters have had any beneficial effect, in spite of eating light?

*How about blue-filtering the strobe? Any update on the effectiveness of this technique?

*Any experience using filters AND diffusers?

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CeeDave - What a super photo-op!

 

It's a memorable image, and yes, it is difficult to do much with it to improve it.

 

You might try this: In Photoshop or Photoshop Elements, try

 

IMAGE ~ ADJUSTMENT ~ EQUALIZE

 

It brightens up the lower part a bit and makes it a little more pleasing, IMHO.

 

At this point, you may want to consider desaturating the image for a grayscale image.

 

:)

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Yes, I agree you were to far away for an SB105 to have done much except create scatter. As it was the Nik coped well with the difficulty confronting it, to produce an even average with detail in the sharks below whilst not blowing out the top.

 

I had a quick fiddle, but couldn't do too much as the file is so small.

 

To have successfully strobed this shot would have taken at least 2 SB104's

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Thanks for your comments. Apologies for the image size and quality ... I hope to have my new server up soon and then I can link to decent files. The JPG was crunched down from a 4000 dpi film scan, so the resampling is extreme (1000-fold in file size). The actual image shows a bit better range than the JPG indicates.

 

Jimbo, I have tweaked it a bit with PS and done a greyscale image -- as you suggest, it looks pretty good. Probably too subtle for my printer, though.

 

Crybergoldfish -- and others -- any recommendations on readings for use of multiple strobes, from theory to mechanics to technique? Nothing I've found so far goes into much detail in terms of how strobes "add" or nitty gritty of how to do it. I reckon an especially fine studio book would work nearly as well as an uw book. I know there're elements of art and experience, but a bit of reading always helps get me going.

 

...in fact, I'd kinda like to see a "suggested readings" thread...anyone (preferably someone who know a lot more than me) concur?

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...in fact, I'd kinda like to see a "suggested readings" thread...anyone (preferably someone who know a lot more than me) concur?

I can highly recommend "Wonders of the Reef" by Stephen Frink. It's full of Stephen's gorgeous underwater photography, but it has a lot of good tips on underwater photography as well.

 

Well worth owning!

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I wanted to get some illumination down low and capture silouhettes up high. I judged the sharks too far off for my SB105 (GN ~ 32 or 34) to be much good.

 

Those schooling hammerheads are fantastic! I'm very jealous.

 

Shots which combine silhouettes above with well-illuminated close subjects below are visually exciting, but also difficult to pull off. To get well-defined silhouettes in the bright water on the top, you'd probably need to stop down to f/11 or f/16, though any reduction in aperture would help. (You said you thought the image was shot at f/4 1/60 or 1/125.) But that would mean losing the sharks in the darker water in the bottom half of the frame unless you could illuminate them with strobes.

 

Of course, you were also right to leave the SB105 turned off - the sharks are way too far away for strobes. Some strobes might claim a range of up to 3 meters at f/4 with ISO 200 film. Maybe in gin clear water, but I've never seen good strobe fill at that distance. Remember, moreover, that you need a tighter aperture to get good silhouettes on the top. At f/8, your strobe range might be only 2.0 - 2.5 meters, and probably less. I'm guessing the closest hammerheads were at least 4 meters away, right?

 

*Could a strobe have helped?

*I know nothing about multiple strobe use. Might that help? Would it make sense to have a remote slave?

*Would filters have had any beneficial effect, in spite of eating light?

*How about blue-filtering the strobe? Any update on the effectiveness of this technique?

*Any experience using filters AND diffusers?

 

Adding a second strobe doesn't increase the range of illumination. The idea of using two strobes is to provide more even illumination over a broader area, but the maximum range (depending on strobe power and aperture) is still the same as with a single strobe.

 

I don't believe there are any filters which can effectively extend underwater strobe range. (If I'm wrong about this, I hope someone will let me know.) Diffusers soften the beam and help spread the illumination over a wider area, but also reduce the maximum illumination range of a strobe.

 

This doesn't look like a situation where a remote slave would have helped. You would need to get the slave strobe close enough to the sharks to illuminate them. Which means the diver carrying the slave would probably have to be in the shot, not to mention the practical difficulty of coordinating all this in the kind of shooting situation you describe. Anyway, if it had been possible for a diver with your remote slave to get that close to the sharks, then presumably you could have got that close too.

 

Since you couldn't get closer to the sharks down low, this was strictly an ambient light shooting situation.

I still think using a different exposure combination with a smaller aperture might have given better definition to the silhouettes at the top. But since you were already shooting at 1/60 or 1/125, you couldn't have stopped down more than one or at most two stops unless you were willing to push the entire roll of film in processing, though this might have been worth considering.

 

Crybergoldfish -- and others -- any recommendations on readings for use of multiple strobes, from theory to mechanics to technique? Nothing I've found so far goes into much detail in terms of how strobes "add" or nitty gritty of how to do it. I reckon an especially fine studio book would work nearly as well as an uw book.

 

In addition to Steven Frink's excellent book which Cybergoldfish mentioned, you might look at the fine text on underwater photography by Martin Edge as well as some of the wonderful books written by the great Jim Church, who sadly died earlier this year. (I'd give you names and publishing details, but my copies of Martin and Jim's books are all on loan to another diver-photographer, who has kept them over a month!) There's some great explanations of how to shoot silhouettes (with the Nikonos, but it applies to any underwater camera) in one of the Church books.

 

My own advice on using multiple strobes for wide-angle is to get the strobes out to the sides as far as possible (i.e., use the widest arms you can handle), don't angle the strobes in - keep them pointed straight ahead or even slightly out, and, as always, bracket, bracket, bracket.

 

Here's the URL to one of my shots where I was trying to do something like what you were, but under much less difficult conditions (and much, much, less exciting subjects.) Sweetllips and Divers This is the closest I've come to getting this to work. I think the key was that I was able to get very close to the sweetlips in the bottom of the frame, which gave me the EV room to use a tighter aperture (though not tight enough) to get decenyt silhouettes on the divers at the top of the frame.

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Rdelfs,

 

Thanks for the ideas and comments. You have given me a lot to think about. A few specifics below...

 

I'm guessing the closest hammerheads were at least 4 meters away, right?

/

Some were probably about 3 m, but still too far, yup .

 

Adding a second strobe doesn't increase the range of illumination.

/

I need to think about this more. If the transmitted light of a strobe falls off like Energy/r^2, shouldn't twice the energy give me twice the illumination? I grant that when the distance r gets "big" the falloff is fast, but two times teeny is still bigger than teeny, right?

 

I don't believe there are any filters which can effectively extend underwater strobe range.

/

 

I imagine not, but because the strobe CT is lower than the blue water, it might throw a red cast because of contrasts with the "ambient" color temperature... though by the time the light has traveled 3m this effect is probably gone. I still need to learn more about the rate of temperature shift with distance.

 

 

In addition to Steven Frink's excellent book which Cybergoldfish mentioned, you might look at the fine text on underwater photography by Martin Edge as well as some of the wonderful books written by the great Jim Church

 

I've read Edge and Church, and will check out Frink.

 

Sweetllips and Divers

/

Beautiful shot, and very much the sort of effect I dream of. Nice silouhettes, good focus and flash on the fish, great blue water.

 

Thanks.

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I'm going to link in Robert's pic. It's a beauty:

 

SweetDiver01_B.jpg

 

I did that by using the IMG button above and entering the URL to robert's picture. I hope you don't mind Robert!

 

I noticed a few things when looking at Robert's shot. One: there are a few fish that are distracting, such as the one in the lower right and there is one that is in the "strobe shadow" of another fish. In my opinion, when lighting close focus WA, I sometimes move my strobes up a bit, so they are pointing straight ahead and also down.

 

Here's one of my shots from Stetson that shows the same problem:

 

DSCF2899.jpg

 

Notice that the squirrel fish and some of the moray is in the "shadow" of the coral? It would have been better if I had moved my right strobe up.

 

Cheers

James

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I'd written:

>>Adding a second strobe doesn't increase the range of illumination.

 

SeeDave replied:

>I need to think about this more. If the transmitted light of a strobe falls off like Energy/r^2, shouldn't twice >the energy give me twice the illumination? I grant that when the distance r gets "big" the falloff is fast, but >two times teeny is still bigger than teeny, right?

 

When two strobes are used, they're normally positioned out to both sides inorder to illuminate a broader area, so they don't act as a single-point source. But even assuming that you strapped two big strobes together to increase the illumination, you don't get anything like twice the range. The conventional formula for using two identical strobes with the light superimposed is:

 

f number = 1.4 x (Guide Number for a Single Strobe / Distance)

 

I'm don't believe that this formula necessarily holds true underwater, where the exponential light fall-off as distance increases is much sharper than in air. But even if it did, all this would give you is one additional stop of aperture, or an equivalent 1.4x increase in range at the same f-stop. Say, from 5 to 7 feet.

 

The image of sweetlips and divers (which James kindly linked in) does illustrate how sharp the illumination drop-off is with a medium-tight aperture - it was probably f/11 but I'm not sure. This was shot with a 20 mm lens on a F801s, so it's essentially the equivalent to the Nikonos 15 mm. The sweetlips are very close.

 

Actually, the problems with the strobe illumination on that image are more profound than James' comments may suggest. I was having serious problems with my strobes on this trip (like most trips these days). If you look at the image, it's clear that the left strobe didn't fire at all. All the strobe illumination is coming from the far right, creating very unnatural-looking lighting. Had the other strobe fired propertly, the terrible shadows of tails and things would have been smoothed out, and there might have been even illumination across the bottom of the frame, and maybe a bit better lighting of the second school of a different species of fish visible on the far left.

 

Had I known that I only had one functional strobe, I would have repositioned the arm straight up over the housing. That might have been better, but the beam of the single strobe still wouldn't have been broad enough to illuminate the entire frame.

 

Despite these problems, it's still the closest I've come to getting this technique to work. And the missing left strobe does make it very easy to see the fall-off in light from the right strobe across the frame.

 

(How do people make quotes appear in nice boxes, by the way?)

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Thanks for all the discussion; this has really helped. Returning to that original photo, and following up on the "ambient light" discussion, I did find that using a digital (i.e., PhotoShop) gradient mask improved the photograph slightly. I masked the top center most heavily and tapered the gradient to zero at the bottom corners.

 

For now, I will keep playing with ambient light with the some filtering, or use a single strobe where appropriate --- and add in some gentle digital manipulations. I need to watch some experts set up and take advantage of dual strobes before I melt my credit card down again.

 

To make a quote box, just use the "quote" button near the top of each message - the quote button *in the header line of the article, not the one on the reply edit page*. It will build you a box that you can edit...nice coding!

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(How do people make quotes appear in nice boxes, by the way?)

You mean like this?

 

You press the "quote" button instead of the "add reply" button.

 

You can also use the quote tag like this:

 

I am an idiot!

 

Finally, you can attribute a quote directly using the "quote=" tag, like this:

 

I have a glass left eye.

 

Tags are enclosed in square brackets and closed with a preceeding slash inside square brackets. The easiest way to use them is through the "Code Buttons" helpers.

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