This is a very basic question using the Leica flash: Are folks setting the f stop on the camera, such as at 5.6, and then the same on the flash (with perhaps -1.5 - 2)? Or using the meter and letting the flash compensate for wherever the f stop has been set? Thanx.

-- Bob Stevens (matlaw@hargray.com), March 23, 2002

Answers

Bob: Are you using a TTL or classic? I use a Sunpak 383 with a classic and set the f stop on the camera corresponding to the auto setting I want on the flash. I let the flash take care of the exposure from this point on. I don't know about the TTL.

-- Mark A. Johnson (logical1@catholic.org), March 23, 2002.

bob,

setting flash to an f/stop only give you range information. whatever you set on lens, since this is ttl and not auto flash, is thereby what the flash "uses." if you want flash to be your main light source, don't set compensation. you might want to drag the shutter to about -1 stop ambient underexposure, though. if using flash as fill, not main source, then set ambient exposure and set flash to -1.5 or -2 stops via ttl override. use a fairly open stop to stay within range of flash and insure a fast recycle time.

good luck! charles

ps--sf20 seems to work great for all this, by the way...

-- Charles (c.mason@uaf.edu), March 23, 2002.

Mark: I am using the ttl; Charles, if you just set and f stop, and "let it rip", are you metering to get to that f stop, or setting an f stop with a particular DOF in mind? Thanx! Bob.

-- Bob Stevens (matlaw@hargray.com), March 24, 2002.

bob, When I am using a flash, it is usually under one of two circumstances--either in a low light (usually indoors) situation where I want flash to provide the main light in the image, or in a fill flash situation, where I want to add flash to the shadows of a photograph in order to lessen contrast, or light a backlit face, for example. The Leica with TTL and SF20 is really good at the first, not so good at the latter. For the first, I almost always want to let a little ambient light in. Also, in order to be able to shoot fast, I want a quick recycle time. So I will usually always shoot at a wide f/stop (4-1.4). After I pick the stop, I then slow my shutter speed down, watching my meter, until the meter says I am about a stop under. Then fire away. You do have to pay attention to the range of the flash. Too close and it will overexpose at too wide a stop, and too far away and you won't get enough flash to light scene. But 99% of what I use flash for is in the 3-10 foot people range, so really not a problem. I also add a warming filter to my flash when shooting color, just tape a filter right on it.

Now in the latter situation, the problem with the Ms, as you probably know, is a slow (1/50) flash synch. This is why they higher synch SLR cameras are so good at fill flash. If you are shooting ISO 100 film in bright sun, the sunny 16 rule calls for an exposure of approx. f/16 @ 1/100 (or 1/125 on many cameras). For many Leica lenses, f/16 is the smallest aperture. So shooting with a flash necessitates 1/50 @ f/16, or a stop over. This problem gets worse with higher ISO films, which need an even faster shutter speed (1/ISO) at f/16 in bright sun. So bottom line is you end up overexposing your film (deadly with chromes) when using an M Leica in bright sun in a fill flash situation. But if you use a slow enough film, or aren't in bright sun, then the usual method is to meter the ambient light AT SYNCH SPEED OR SLOWER, then check the f/stop and on Auto flashes choose a flash setting the is a stop or two wider open (then the flash outputs less light then the main source, and leave the shadows as shadows, but not so dark and contrasty). On TTL, such as the SF20, with the ability to tell the flash that no matter what I am shooting at, expose a stop or two less (minus compensation), then it is easier.

Does this all make sense? In all my years of teaching, understanding flash is the hardest things I see students grapple with. Remember that, when dragging the shutter to let in ambient light, or when using the flash as a fill, you are in a sense double exposing. Trick is to really get a feel for EACH part of this "double" exposure, and how they play off each other and add up together.

And shoot lots of film and take notes, if you really want to learn it well. TTL works great, but you still have to know how to tell it what you want.

Good Luck!

-- Charles (c.mason@uaf.edu), March 24, 2002.