Olympus-OM
[Top] [All Lists]

Re: [OM] what happend to my flash shots?!

Subject: Re: [OM] what happend to my flash shots?!
From: Acer/Siddiq <waltherppk@xxxxxxxxxxxxx>
Date: Fri, 25 Jan 2002 16:55:52 -0800
1/25/02 7:55:31 AM, ClassicVW@xxxxxxx wrote:
>  On Fri, 25 Jan 2002 Tom@xxxxxxxxxxxxx wrote: 
>
>  > 1. Some light from the diffuser reached the sensor, shutting it off too 
>  > soon. 
>
>  I'd have to disagree with this. I've employed Acer's method before (with the
>  curved piece of opaque plastic). Mine was from a plastic milk gallon which
>  may be a lot thinner and more 'clear' than the alcohol bottle he used. I've

i dunno, the plastic milk i've seen here are pretty close in terms of 
translucency (as i see it, not measured!)

>  had mine curved to actually allow light to spill over the top and bottom of
>  the plastic piece, and I've had no problem with the light being directed
>  into the sensor. Maybe my curve is closer to the flash and doesn't bounce it
>  back? I make the plastic *a bit* shorter (top to bottom) than the flash
>  tube's height so *some* light gets out directly, but the "hot" part of the
>  tube is softened thru the plastic. 

ditto: flush fit on the side, just about the height of the flashtube, but 
curved SLIGHTLY out, so there's some 
spill light

>  I also suspect that Acer's plastic interfered with the flash output more
>  than the reported 1/3 stop the flash meter told him. I'd bet a roll of film
>  it was closer to two stops considering the material used. That, and if it
>  was in a large reception hall, did him in. 

measured loss was ~1/2-2/3 stop, using gossen scout aimed at the sky, w/ and 
w/o the plastic piece. it 
would appear the loss as shown on the negs is at least a stop :( but then try 
this:

figure one stop light loss. filmspeed is 80 for GN calcs. T32 panel at ISO80 
shows 12ft for f8... that's what i 
used! 



< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz