vivitar flash question

[noah b]

Hey all, I'm curious about something on my 285. Usually I'll set the aperture to 2.8 and the flash to 1/16th power. If I pushed the flash to full power and set to f/8, would it turn out the same? I think it would but am unsure at this moment, and are curious if anyone else has faced this situation.

 

[bmattock]

Well, let's see.

1/16 power versus 1/8 power should be double the light. f/2.8 to f/4 is double the exposure. So if you go from 1/16 power to 1/8 power, you should to go f/4.

That means 1/4 power is f/8, 1/2 power is f/16, and full power is f/32.

But honestly? I'm not sure. I think that's right. I guess I'd have to experiment with it.

 

[mh2000]

I'm pretty sure that you would be at f11 (1/16,1/8,1/4.1/2.1/1 vs 2.8, 4, 5.6, 8, 11).

I only used mine in manual mode on digital though... so I got to cheap and chimp my histogram... on film, always in auto-mode.

 

[bmattock]

I only used mine in manual mode on digital though... so I got to cheap and chimp my histogram... on film, always in auto-mode.

Me, too, these days. I used to have to know all that stuff, but TTL (and P-TTL for my Pentax) is generally pretty reliable.

 

[BTMarcais]

ditto for mh2000. f/11 it is.

 

[charjohncarter]

On my Minolta, each halving of the power is equivalent to one stop. Therefore, if it is the same as mine; f8 is equivalent to 1/2 power. Like the others, full power is f11.

 

[noah b]

Ah excellent, I've been experimenting with different bounce flash techniques and didn't want to completely botch a roll of film. thanks