I have just been trying to take my first long exposures with my M6 TTL. As you know one cannot meter anything over 1sec with the M6 TTL. I was wondering how you get around this? Do you use a independent light meter? If so are that directional enough? As I am traveling without one (probably a big mistake as I am lugging a tripod with me!) is the method I have derived reasonable? What I am doing is as follows:

I use my 35m/1.4f lens and meter the subject with its and the M6s range (to 1.4f at 1sec). Then if I want some depth of field I set the aperture to what I want and then count the number of fstops between my desired dof and the f I use to meter. Then I calculate the exposure time. For 5 stops difference I count 2, 4, 8, 16, 32. Then set the M6 to bulb (b) and open the shutter, count to 32 slowly, then close the shutter. Is this mad or is this common practice? How do you guys meter and take a 32 sec f8 exposure?

-- Matthew (mat@theeto.com), April 18, 2002

Answers

Matthew, When taking pictures at night, a meter reading will usually be incorrect when you are going into the realms of about 10 second and beyond shots. I dont bother taking meter readings, but just take 3 shots, eg 10secs, 20 secsm and 30 secs. One of them is bound to come out correct. Once you have taken a whole load you will be able to judge how long to expose for a given aperture.

-- Karl Yik (karl.yik@dk.com), April 18, 2002.

Your approach is correct. If necessary, you can temporarily change the film speed to one that will allow you to get a reading, then mentally calculate what you need to do the correctly expose with the film you are actually using. Keep in mind that some films experience reciprosity failure, i.e. the 1 stop = 1 stop calculation that you are using will result in underexposure when using slow shutter speeds (especially when you start using shutter speeds measured in seconds). Bracket you very long shots and/or contact film manufacturer for more specific instructions. exposures

-- Jim Lennon (jim@jmlennon.com), April 18, 2002.

Matthew

I use a night exposure guide, I copied from a book. I think one of the Kodak photoguides has one. In my opinion they are all you need. You do need to bracket a stop or a stop and half either way to make sure, but it removes the need to meter anything once night comes. It works just fine. Once you get to being unable to meter with an M6, I pull out my guide - it is that simple.

-- Robin Smith (smith_robin@hotmail.com), April 18, 2002.

Reciprocity failure aside, there's two tricks that I've used to meter in low light.

One is to meter with a fixed long shutter speed, i.e. 1 sec for ASA 100, 1/2 sec for ASA 50, and adjust the film speed dial until correct exposure is indicated. Then divide the dial setting by 100 to get the exposure time in sec. For example, Velvia, metered at 1/2 second, correct exposure indicated at ASA 800, so expose for 8 seconds.

The opposite approach is to meter with the film speed dial set 6 stops too fast (e.g. ASA 6400 for ASA 100 film), adjust the shutter speed dial until correct exposure is indicated, then treat the fraction of a second indicated on the shutter speed dial as a fraction of a MINUTE instead - e.g. 1/4 second on shutter speed dial, expose for 1/4 minute or 16 seconds. This works because you're multiplying by 2^6 or 64, and then dividing by 60, which is approximately the same.

Joe

-- Joe Buechler (jbuechler@toad.net), April 18, 2002.

Matthew:

I've used the method you described and found it useful to about 4sec exposures. Beyond that, I use my Pentax digital spot meter to insure accuracy. Furthermore, once you get beyond about 4sec, you have reciprocity failure to deal with, and all films respond a bit differently.

Cheers,

-- J Flesher (jbflesher@msn.com), April 18, 2002.

I follow the Karl Yik way, that is, estimate 2 or 5 or 10 or so as a starting point and then bracket giving an additional stop and two by doubling the time.

In long exposures it really makes no difference whether you expose for 14 or 15 or 17 seconds, or 55 or 60 or 65 seconds. So counting as you do is close enough.

Ilkka

-- Ilkka (ikuu65@hotmail.com), April 18, 2002.

These are all great tips. I will be trying them all out when I get a chance. It seems true that Leica photographers do need to think about what they are doing when at work. Thanks.

-- matthew (mat@theeto.com), April 22, 2002.

Matthew. FWIW. The M7 has a number of improvements over the M6/M6TTL in the area of long exposures. First, in manual exposure, the shutter speed dial goes to 4 sec (previously 1 sec). In auto, according to the manual, the camera will measure and expose as long as 32 sec. In actual practice, it will measure/expose up to 38 sec. When the shutter speed dial is set to B and the shutter is held open, the display will actually count exposure in seconds to as long as 999 sec (that's long enough for reciprocity failure to set in!).

These have to be considered improvements in the system if you're into timed long exposures.

-- Eliot (erosen@lij.edu), April 22, 2002.