M7 Battery usage

I want to use the Leica M7 for astrophotography. How long can I

expect the batteries to hold out during long exposures? What about

when its cold?

 

George

. . . or you could buy an inexpensive Voigtlander body for the task. No need to worry about humidity, batteries, dropped-in-the darkness problems. This is just a thought - I have no knowledge of battery life on the M7. Defining the range of "cold" may be an issue. Really cold is hard on any battery, and the shutter, film, winder, etc.

i don't know the answer to your question but just be sure to if

possible, measure your batteries to make sure they have power

before using.

 

i had a situation where the batteries that came with the camera

where not full capacity.

I presume you mean setting the camera on 'B' mode. In this case the M7 battery opens the shutter, and closes the shutter, but during entire time of the exposure does not consume batteries. So the answer is that astro photography shouldn't use more battery power than any other type of photography with the M7.

The above is wrong. As long as you hold the shutter button down in "B", battery power is required to keep the shutter from closing. For astrophotography any old mechanical body that can be adapted to the telescope would be preferable.

Dear George,

 

Hi, I recently was using my M7 to take pictures of trees when the Santa Ana winds were blowing and I noticed that any exposures longer than a certain period of time (I don't know exactly how long, maybe around fifteen seconds) caused the stars to blur because of the rotation of the Earth. If the M7's meter measures an exposure for longer than 32 seconds when you're using the auto setting the speed will display 32 seconds and will be blinking, but when you press the shutter button it will count down the measured amount of time required (be it 48 seconds or 43 or whatever) and display it. It should be able to handle a whole bunch of long exposures before the batteries start to run out. In cold weather the batteries might cut out every so often (i.e. the bc light will flash four or five times and then it will shut itself down) but if it does this just turn it off for a moment and turn it back on and if you're so inclined go ahead and put it in your jacket and just warm it up a little. Don't breathe on your lens when it's cold because it'll fog up the front element and if it's really cold the "fog" won't evaporate at all outside (so you'll be left with a fogged up lens). Maybe carry an extra pair of batteries around in your jacket just in case. I read about somebody who kept several pairs of batteries in their jacket and kept switching them every so often with the batteries in their camera and they never had a problem with their batteries shorting out in cold weather. Of course that's a lot of busy work but if you don't mind it then that's probably the best preventative course of action.

 

From David Li.

I don't even have an M7 because I don't want one. But batteries are batteries. Just keep a few new ones fresh in your pocket and replace any coldies in the camera when the time comes. This time hasn't ever come yet with my M6 TTL. The idea sounds good and I hardly never found it necessary with my F3, but it always worked there (when necessary).

Jay, if you read page 96 of the M7 manual it clearly states that what I said is correct, according to Leica at least. Who am I to argue? But you obviously feel you know more than they do. Or, perhaps you should wait and get an M7 before pontificating.

Here is the full quote from the M7 manual. "Note: With the 'B' function, batteries are still required to open and close the shutter. However, for the entire duration of the exposure, the open shutter does not consume any power, only a small amount of battery power is required for the camera control."

 

The later part of the quote about the 'small amount of power required for camera control' is the countdown timer which switches off after 16 minutes anyway, and will likely consume less power than the average digital watch. It still plays no part in keeping the shutter open.

I'm not familiar with the M7, but does it have a "T" setting?

Roger, you will have to go back to the LTM (thread mount) Leica's for a 'T' setting I'm afraid.