backscatter when using internal flash to trigger a slave flash?

[Moogyboy]

hey all

Quick question to satisfy my curiosity: I am seriously thinking about a digicam with one of the inexpensive OEM housings (ie Olympus) to augment or replace my Sea & Sea MMII. These housings don't offer sockets for external flashes, but allow you to trigger slaves with the internal flash. My question, having never done it this way, is wouldn't there still be backscatter that way? I would think that it would, and thus would in some measure negate the whole purpose of having an external flash in the first place. Hope this isn't too ignorant of a question.

thx

Billy S.

 

[cdiver2]

Part right, yes you will get backscatter from the internal strobe. Backscatter is not the whole reason for having a external strobe, stronger strobe and being able to place the light from different directions (above, left or right of subject) are also other reasons for a external strobe. But yes the internal strobe firing is not desirable.

 

[fins]

hey all

Quick question to satisfy my curiosity: I am seriously thinking about a digicam with one of the inexpensive OEM housings (ie Olympus) to augment or replace my Sea & Sea MMII. These housings don't offer sockets for external flashes, but allow you to trigger slaves with the internal flash. My question, having never done it this way, is wouldn't there still be backscatter that way? I would think that it would, and thus would in some measure negate the whole purpose of having an external flash in the first place. Hope this isn't too ignorant of a question.

thx

Billy S.

Billy,

My rig (Oly 5050, PT-015, Inon D-180) like many is setup to have the internal flash trigger the external strobe. To prevent back scatter generated by light from the internal flash you put a sticker over the 5050 internal flash. This sticker stops the bright light from the internal flash but allows the infrared signal to pass through which triggers the external flash.

 

[Moogyboy]

Ah. I presume this sticker is supplied with either the camera, housing, or flash?

cheers

Billy S.

 

[fins]

Ah. I presume this sticker is supplied with either the camera, housing, or flash?

cheers

Billy S.

Yes it is.

 

[jlyle]

Ah. I presume this sticker is supplied with either the camera, housing, or flash?

cheers

Billy S.

On my rig - duct tape!

 

[Kim]

Ah. I presume this sticker is supplied with either the camera, housing, or flash?

I got mine supplied with the Inon D-180.

On my rig - duct tape!

Does that work too? I live and learn!

 

[whitedragon13]

Whoa! I had no idea. My sealife cam uses a reflector to trigger the external flash...it fires 3 times before the strobe goes. Does my reflector act as the "duct tape" or do I need to put tape directly over the camera body?

 

[miketsp]

Believe it or not you can use a piece of transparent plastic tubing as a flexible light guide! This lets you tape the front of the internal strobe with black adhesive tape. Just leave a hole where you glue or tape your tubing. Differently from a fibre optical cable where the light travels in the middle, in this case your internal strobe light output will travel in the wall itself and you take this tube to the slave sensor.
Try it with different diameters and wall thicknesses.

 

[Dee]

I also use an Inon D-180 strobe with my C-5050/PT-15. The mask comes with the strobe and fits over the internal flash on the camera before you place it in the housing.

Another system is the use used by S&S with their YS90DX. It's a velcro patch that fits over the internal flash on the OUTSIDE of the housing. Both systems prevent backscatter but the advantage to the S&S velcro patch is if, for whatever reason, you want/need to use the internal flash, you simply remove the velcro patch and turn off the strobe. With the Inon mask on the camera, it blocks the flash directly at the camera.