how to reduce backscatter?

[s.s.seafan]

Hi,

I have been using a Canon S90 with built-in flash and diffuser. For a picture like the following, how could I reduce the amount of white spots (backscatter)? Would external flash help?

I have done some search and found one tip that is often given is to shoot slightly upwards, which was done in this picture. I seem to find that shooting upwards caused more white spots.

I could process in Photoshop to get rid of the white spots on a blue background, using the same method to remove dust and scratch. Is there a better way to do this? Is there a way to remove those on the subject (on the seafan in this case)?

thanks,

Jason

 

[DMDavid]

Backscatter comes from your internal strobe/flash causing a reflection of particles to reflect right back to the light source.
To reduce or eliminate use an external strobe/flash at a slightly downward angle to your subject.

I'm not a professional photographer but I did sleep at a Holiday Inn once.


Posted from my iPhone using Tapatalk

 

[phillybob]

What he said. Or, better yet, use TWO external strobes pointing slightly outward, lighting your subject with the inner edges of the light 'cones'. Some good stuff here...



http://www.uwphotographyguide.com/underwater-photography-strobe-positioning

 

[Bubbletrubble]

Backscatter occurs because the light from the built-in flash is reflecting off of particles in the water and back into the lens.

Minimize/eliminate backscatter using one of the following methods:

1. Get very close to the subject, e.g., take a macro-style close-up, which minimizes the distance to the lens, decreases the number of large particles in-between, and prevents reflected light from being directed back into the lens.
2. Move the light source farther away from the lens, e.g., an external strobe, which changes the incident angle of the light.
3. With a well-lit wide-angle scene, simply turn off the built-in flash. No flash = no backscatter.

It's just too painful to remove lots of backscatter in post-processing.
With my point-and-shoot camera, I choose #3.
A nice external strobe would cost $500+.

 

[DevonDiver]

Backscatter is caused by light reflecting directly off particles in the water. It is unavoidable if your flash is located near your lens.

As other have said, the primary solution is to illuminate the subject using 1 or 2 off-set strobes.

If strobes aren't available, then you need to decide whether the ambient light is sufficient to get a good photo. There's no backscatter if you don't use a flash.

You can also eliminate backscatter using digital photo post-editing. I've described the technique within my article, here;

5 Minute Photoshop Edit for Underwater Photographs

 

[s.s.seafan]

thanks for the quick and definitive answers, off I go to search for the tray and strobe (another money-sinking mission)