Olympus-OM
[Top] [All Lists]

[OM] Manual flash, was: Radio receivers compatible with FL-36R/FL-50R?

Subject: [OM] Manual flash, was: Radio receivers compatible with FL-36R/FL-50R?
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Sun, 07 Dec 2008 09:46:36 -0500
Your comment about the apparently orphaned Sunpak Auto26SR got me to 
thinking about how to make effective use of it and also a T32.  I 
commented the other day that a T32 wasn't particularly good for manual 
shooting since it only has two power levels.  But, if you're shooting 
other than direct flash (and you should whenever you can) in a 
moderately large room you can use the T32 at full power anyhow.

I've never used a T32 this way before but I just tried a test exposure 
in my living room with the T32 at full power on the 5D.  The living room 
is about 15x21 feet (5x7 meters), has a white ceiling and very light 
walls.  I was standing about 1/3 of the way into the room and pointing 
at the far wall. I set the T32 bounce head one click down from vertical. 
  Zoom lens at 28mm and f/5.6, camera at ISO 400 and 1/30 second.  Oops! 
  A little too bright.  Close down to f/8.  Ah, just right.  If there 
were people in the room that were too close I might have had to close 
down some more to keep them from being overexposed.  But it only took 
two shots to know I was zeroed in on the correct exposure.  Probably 
faster than using a meter.  Also note that the lens is at mid aperture 
and the ISO is at a middle value.  That means there's plenty of 
opportunity for adjustment to fit your specific room conditions.  When 
using the T32 in this manner it would probably be a good idea to tape a 
small white card vertically up from the case just behind the flash head. 
  That will direct a small amount of light forward to fill the shadows 
from the bounced light coming down from the ceiling.

Note to Moose:  If you pull the 540EZ's wide diffuser panel out and 
leave it sticking straight out of the case instead of bringing it down 
over the flash head, when the flash head is directed toward the ceiling 
for bounce the diffuser panel will also reflect some light forward for fill.

If you have a T32 and BG2 and another flash such as Moose's modestly 
powered Sunpak you can put the T32 on the BG2 and use it swiveled around 
(even somewhat behind you) to help fill the room with light and cut down 
shadows.  Then use the small flash in the hot shoe bounced off the 
ceiling between you and the subject.  Just as before, a couple of test 
shots will quickly zero in on the correct exposure.

Bounce flash is very important for two reasons.  One is just filling the 
room with light that's bouncing around and cutting down on harsh 
shadows.  The second has to do with the inverse square law and the 
sensitivity of correct exposure to distance.  Assume I'm standing 10 
feet from a subject and the correct exposure is f/8 for direct flash. 
Multiply 10 by 1.4 (the square root of 2) and you get 14.  Divide 14 by 
2 and you get 7.  At 7 and 14 feet the exposure has already changed by a 
full stop.  At 7 feet the correct exposure is f/11 and at 14 feet it's 
f/5.6.  If your subject suddenly moves toward you even a foot or two or 
(more likely) you're not a super accurate judge of distance there will 
be a significant exposure error with direct flash.  As it turns out, the 
longer the light path the lesser the sensitivity to exposure errors from 
a given error in estimating distance.

But if you were using bounce flash in a room with an 8 foot ceiling and 
with the flash head 6 feet from the floor the light path is 10.8 feet 
which is a little extra margin.  In a room with a 10 foot ceiling the 
light path would be about 13 feet.  If the subject suddenly moved 3 feet 
closer the light path is still 10.6 feet and not 7 with the result that 
the exposure error is less than a stop as it would have been otherwise.

Dr. Flash


Moose wrote:
> Quoting Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>:
> 
>>> If you're going to go with manual controls then you can use very cheap, 
>>> used flash heads.  Film based TTL flash units like the T-32 go very cheaply 
>>> because they don't work on digital.  But the T-32 isn't a particularly good 
>>> choice for manual control since it only offers two power levels.  The Canon 
>>> 540EZ which has 8 levels can be had for as low as $60 from KEH (BGN if they 
>>> have one). 
> 
> I bought a KEH bargain one on Chuck's recommendation and was very 
> pleased. I seldom use flash, but when I needed it for an event in a 
> dimly lit building, it really delivered the goods. I think he is right 
> about going manual for flash where the light isn't changing and distance 
> is fairly steady, too.
> 
> Test to get the histogram right, then just fire away.
> 
>>> They tend to sell for a lot more than that on ebay.  I think they're being 
>>> sold to Canon DSLR newbies who don't know the flash won't work in TTL mode. 
>>>  :-)
> Still nice on an EOS camera, as it does communicate and provide extra 
> info on the LCD. The zoom head is useful too. The IR focus assist 
> feature is amazing.
>>> Other good choices are the Sunpak 422/433/444 or 383 (5 power levels).  The 
>>> 400 series are discontinued film TTL models, the 383 was (until recently) a 
>>> current production manual flash.  All are basically the
>>> same flash unit with the same power.
> I've also got a Sunpak Auto26SR, GN 86 @ 35mm up to 120 @ 135mm with the 
> manual zoom head. Five power levels and twist and tilt head. It was 
> cheap on the 'Bay. Unlikely to see use with the 540EZ around now, unless 
> I ever want a two flash manual setup.
> 
> Moose
> 
> 
> ------------------------------------------------------------------------
> 
> 
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com 
> Version: 8.0.176 / Virus Database: 270.9.15/1834 - Release Date: 12/6/2008 
> 4:55 PM
> 
-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

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