Best positioning for strobe to reduce backscatter

[Jak Crow]

I was wondering if there are any recommended positions for a strobe to cut down on backscatter. Right now I just have a basic 18" flexible arm which seems like it may be too short for strobe use. While I've been able to capture some better shots than what I've received from the built in flash w/ diffuser plate, some of my photos using the strobe had much more backscatter than I would have gotten from the camera's flash. For instance, should I have a longer arm to position the strobe higher, or have it set off to the side. At the moment I only have the one strobe to work with and won't be able to get a 2nd for some time.

 

[Peter_C]

You might want to post what equipment you are shooting with and what lens focal lengths you have available.

The most important rule in our dirty water is get as close to the subject as you can, leaving less stuff in the water between the camera and the subject.

 

[bkotheimer]

Scott Gietler's Underwater Photography Guide has a lot of good information on exactly this issue.

 

[Peter_C]

How about a class?
Monterey Shootout - Underwater Photography, Videography, Competition in Monterey, California

"The Art of Light
Presented by: Stephen Frink
Underwater photography is substantially different than that which is done topside. The medium is 800 times more dense, and typically exhibits a cyan or green color cast that is necessary to overcome in order to render the gorgeous hues of the underwater world. The ability to creatively handle artificial light underwater, blending the strobe lights with the ambient light on the scene, is a skill that differentiates the master from the novice. In this seminar, world famous underwater photographer Stephen Frink will explain how to artistically light the underwater world, and the unique denizens within."

 

[ScubaJohn65]

Using 2 strobes will greatly reduce backscatter. Many U/W photographers will use 2 strobes to avoid backscatter and a 3rd light as a framing light. If you're shooting in Monterey, most of your shots will be macro. Depending on your camera, you will probably want diffusers over the strobes to both help reduce backscatter as well as "soften" the light when you are shooting close to your subject.
You can also aim your strobes just behind your subject such that only part of the cone of light from your flash is lighting your subject. This also helps reduce backscatter. If conditions are really green, you can use an LED or HID light and change your camera settings for "natural", ambient light (turn off the strobe). You will need a more powerful underwater light.

 

[MauiScubaSteve]

Using 2 strobes will greatly reduce backscatter. Many U/W photographers will use 2 strobes to avoid backscatter and a 3rd light as a framing light.

I suppose airline travel could have an impact on my observed data, but I question just how you define "many" in your post above? I do not see many U/W photographers using 2 strobes.

"consisting of or amounting to a large but indefinite number" (definition of many)

If we say that there are many divers who dive with U/W cameras, I guess one could say there are many U/W photographers.

On the other hand, one could contend that many of that many are just taking pictures and are not really "photographers."

Then we further diminish the "number" by only talking about U/W photographers who use strobes, then even further reduce the "number" to those who use 2 strobes, and make a final reduction to the "number" with the inclusion of a 3rd light.

Not that it really matters to the topic of this thread, but I find it hard to believe that many U/W photographers use 2 strobes, and even harder to believe that many U/W photographers use 2 strobes "to avoid backscatter."

Also, on the topic of positioning, using 2 strobes can reduce backscatter, but if your positioning is bad it can increase backscatter.

 

[John Gulliver]

If you consider every diver who carries a camera to be an underwater photographer, what you say is of course correct. But if we are talking about serious underwater photographers, above all dSLR users, then many, in fact most, underwater photographers do use two strobes, at least here in Europe.

I suppose airline travel could have an impact on my observed data, but I question just how you define "many" in your post above? I do not see many U/W photographers using 2 strobes.

"consisting of or amounting to a large but indefinite number" (definition of many)

If we say that there are many divers who dive with U/W cameras, I guess one could say there are many U/W photographers.

On the other hand, one could contend that many of that many are just taking pictures and are not really "photographers."

Then we further diminish the "number" by only talking about U/W photographers who use strobes, then even further reduce the "number" to those who use 2 strobes, and make a final reduction to the "number" with the inclusion of a 3rd light.

Not that it really matters to the topic of this thread, but I find it hard to believe that many U/W photographers use 2 strobes, and even harder to believe that many U/W photographers use 2 strobes "to avoid backscatter."

Also, on the topic of positioning, using 2 strobes can reduce backscatter, but if your positioning is bad it can increase backscatter.

 

[MauiScubaSteve]

I am still contending that all the double strobe U/W photographers together do not make a big enough number to be "many." If we only look at U/W photographers who use external strobe, I am certain less than half use 2.

I don't contend that most dSLR's underwater do not have 2 strobes attached, but really, there are not that many dSLR's underwater.

 

[bvanant]

I guess I am confused. What is your definition of many. 2 million, 30,000, 17? I can say with certainty that MOST DSLR shooters that I know use 2 strobes. To me many means more than 1000 and in that case many do use two strobes but how can you try to quantify many? In my dictionary at least many just says a large number with no constraints. By your definition though I guess most of us don't really know many people.

Bill

 

[MauiScubaSteve]

Since the invention of the dSLR, how many have made there way into the hands of photog's?

If the percentage of those dSLR's that go underwater is significantly less than 2% I would say not many dSLR's go underwater.