Fill Flash with an Incident Meter?

[jeffrey_abelson]

I'm going to try to use a LH2 (200b) mounted on the camera (via

Lindahl) with the 12" octogonal soft box recommended by timber. For

some shooting, I'll use a flash meter, having the model hold the

meter w/me on camera and use the softbox as the main light- so that's

no problem. For others, I want to use the softbox for fill. Can I

just take an ambient reading and then use the flash meterto figure

the output for one lower stop i.e. the ambient reads f11 and I adjust

the output and distance until the flashmeter reads f8? There's also a

cheat chart for the 200b based on distance and power setting - could

I use that chart to figure light output in the same concept: ambient

= f/11 - norman cheat chart says 10 feet (asa100) at 50ws =f/8?

One last question - what kind of compensation would one make in terms

of +/- stops (with a softbox) if one uses the cheat sheet or guide

number to figure output?

 

Thanks so much for all your help!

 

Jeffrey

[ellis_vener_photography]

<I> Can I just take an ambient reading and then use the flash meterto figure the

output for one lower stop i.e. the ambient reads f11 and I adjust the output and

distance until the flashmeter reads f8? </I><P>Yes. but make sure the shutter speed

is set to the shutter speed you will be using.<P><I>One last question - what

kind of compensation would one make in terms of +/- stops (with a softbox) if one

uses the cheat sheet or guide number to figure output? </I><P>You need to run

your own tests with your flash meter to figure out how your particular set up will

affect light output. Unless someone has direct experience with your rig, you should

take their recommendations as to what the compensation factor should be with

several grains of salt.

[timberwolf1]

I use the rule of a 2 f stops loss when using a soft box. I also over expose about 1/2 f

stop for color negative film. As a result of my over exposure, I would open up another 1/

2 stop to do a fill from your numbers.