Thanks - may remain mostly in background and fairly quiet - but always lurking!
Sent from my iPhone
On May 19, 2011, at 2:03 PM, "Piers Hemy" <piers@xxxxxxxx> wrote:
> Subject says it all - an old stager is still around, albeit quiet for so
> long.
>
> Good to see you again, John.
>
> Piers
>
> -----Original Message-----
> From: John Lind [mailto:j-a-lind@xxxxxxxxxxx]
> Sent: 19 May 2011 18:41
> To: Olympus Camera Discussion
> Subject: Re: [OM] OM TTL flash behaviour
>
> The amount of light admitted to the film plane in TTL is ambient @ selected
> f-stop & 1/60th plus the necessary duration of flash to satisfy the TTL
> metering.
>
> There are some occasions for desiring to increase ambient by using 1/30th
> (versus opening aperture by a stop) and you cannot do this in TTL, only in
> "Auto" or "Manual" modes. TTL always sets shutter speed to 1/60th *if* it
> needs to fire the flash to get enough light. If ambient is sufficient TTL
> will use shutter speed 1/60 or faster based on selected aperture; flash can
> be forced by stopping down if possible, the increased DoF is acceptable, and
> flash is desired. I've done the latter to force fill by stopping down just
> barely enough to activate the flash.
>
> -- John
>
> Sent from my iPhone
>
> On May 19, 2011, at 10:42 AM, "Walters, Martin"
> <Martin.Walters@xxxxxxxxxxxxxxxxx> wrote:
>
>> In spite of the eloquence and expertise of Dr Flash and others on the
>> list, flash remains something of a "black art" for me. As I rarely use
>> flash, my usual approach is to simply put my non-Oly dedicated flash
>> on TTL and fire away. For info, the flash is a Braun 340 SCA (full
>> TTL with the correct adapter shoe), in auto it has two selectable F
>> stops (F4, F8), a swivel/bounce head with zoom (28-50-100). The filter
>> set includes a diffuser (coverage for 21mm), ND4, and coloured filters.
>>
>> So, I'm taking a flash 101 course, which looks to cover pretty much
>> all the topics. I'm in an interesting position as the only film
>> shooter in the group (we're 8-10). Some of the CanNikon gang appear to
>> have serious gear, and some of those camera/flash combinations are
>> probably more intelligent than I am.
>>
>> After a couple of courses it's obvious that I'll have some challenges
>> and some of the concepts will be theoretical rather than practical
>> (e.g,, flash compensation, though the instructor lent me an EOS to
>> work with; varying sync speed). My dedicated flash has some
>> significant limitations, especially no or only very basic power
>> control (filters on the flash). That being said, the instructor was
>> quite intrigued that I had full TTL capability both on and off camera.
>>
>> One of the things we've looked at is compensation (both exposure and
>> flash). So, this weekend I'm planning to spend some time test shooting
>> to see what happens with various setups under TTL. In the meantime,
>> I'd be grateful for some info on how exposure compensation on an OM2N
>> affects TTL flash. I assume that it will affect both metering and
>> flash, which is controlled by the meter (I believe modern N*kon
>> bodies, for example, treat the two independently). Is this correct?
>> However, that brings up another question: if exposure compensation is
>> active, how does the OM actually compensate, when it automatically
>> fires as 1/60 with a dedicated flash?
>>
>> As a third question, AG and Dr Flash have talked about underexposing
>> the background by 1 or 2 stops. One method mentioned was to set the
>> aperture for 1/30 exposure, and letting the OM fire at 1/60. I
>> understand the concept - and here my ignorance is showing - but does
>> this work in straight auto or in TTL as well?
>>
>> In anticipation of suggestions to get a different flash.... Yes, I've
>> thought about a T32, though it appears only slightly more flexible
>> than the Braun, and a Vivitar 285, which doesn't do TTL but allows
>> control of flash intensity. However, the lazy side of me doesn't want
>> to throw away TTL.
>>
>> As far as sync speed is concerned, I could always get out my Pen F,
>> which syncs at all speeds. Of course, no TTL, and life is probably too
>> short to deal with other challenges!
>>
>> Martin
>>
>>
>> --
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>
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> _________________________________________________________________
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