Archived posting to the Leica Users Group, 2002/01/14

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Re: NEW M7 MAJOR CROCK-POT CROW PARMESAN
From: Rolfe Tessem <rolfe@ldp.com>
Date: Mon, 14 Jan 2002 13:21:24 -0500
References: <200201140602.WAA23576@mejac.palo-alto.ca.us>

> Date: Sun, 13 Jan 2002 19:58:45 -0800
> From: Mark Rabiner <mark@markrabiner.com>
> Subject: Re: [Leica] Re: NEW M7 MAJOR CROCK-POT CROW PARMESAN
> Message-ID: <3C425775.60853244@markrabiner.com>
> References: <200201132018.MAA12053@mejac.palo-alto.ca.us> <3C4243FA.1050802@ldp.com>
> 
> ><Snip> 
> > One other thought on TTL flash: this is really a simple-minded
> > technology that is limited to a single on-camera or possibly a single
> > off-camera flash. I think it was probably designed with wedding
> > photographers in mind. Once you get into any kind of multiple light
> > setup, the TTL stuff is useless anyway. You just have to meter the flash
> >   and do it the old-fashioned way.
> > 
> > Sometimes, less is more.
> > 
> > --
> > Rolfe Tessem
> 
> Rolfe you might check out your impressions or hunches before you foist
> it upon us as gospel.
> I know Metz has long had wireless TTL Multi flash.
> I'm pretty sure Nikon does.
> Which would make me think Canon also does and that this is not at all uncommon.
> 
> TTL is not necessary. It's just a little more accurate and reassuring.
> And convenient.
> Not at all just for wedding photographers of course.
> And in no way limiting.

Hi Mark,

I certainly didn't mean to stir up a hornets nest with my flash comments
;-).

Let me clarify the comment on TTL flash. It is true that several
manufacturers allow multiple units to be hooked up and triggered
simultaneously, while having exposure controlled by the camera's TTL
circuitry. The one I'm most familiar with is Quantum.

But all this buys you is the assurance that you will get a correct
exposure on the film. The TTL stuff knows nothing about what kind of
ratios you want between and among the various flash units. So how do you
regulate the ratio? With all of them I'm familiar with, you have to
physically position the units so the ratio will work out properly (one
unit twice the distance from the subject as another, for example), since
the TTL circuit is going to squelch all the units simultaneously once it
senses that enough light has reached the film. If you're going to go to
that kind of trouble, you may as well just use the units in manual,
position them where you want, and meter the scene.

As far as I know, and I'm pretty sure about this, as I've described it
above is how all the systems you mention work. Which is why I said that
TTL flash metering is really only of utility when using a single unit.
And I didn't say it was *just* for wedding photographers; I stated my
opinion that it was probably designed with their needs in mind.

- --
Rolfe Tessem
rolfe@ldp.com
New York City
- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html