First off, I would like to thank everyone for their previous help. This discussion board is awesome! I just purchased an elan 7e and am wondering how much of a drain on the batteries it would be if I left it open in bulb mode. My old camera could only stay open for an hour or two before the battery went dead and the shutter and mirror closed. How long could I do this with an elan 7e. Past archives have hinted that some cameras do not drain the battery when the shutter is open but I cannot find any info on this feature for the elan 7e. Any help would be great. P.S. Any good film or settings for time lapse star exposure?

-- shadowman (mshadow818@msn.com), January 22, 2002

Answers

The Elan 7E uses an electromagnetic shutter that consumes power while it is open. An older camera like the EOS 10S or the EOS 3 or 1V might be better. Or even get an all-manual camera body since astrophotography does not require in-camera metering, autofocus, or a fast motor wind :-)

I could not find the BULB power consumption at Photo.net, nor is it in the archives of the EOS Mailing List or the Elan 7E group.

So I measured it myself using a BP-300 on my Elan 7E. BULB drain is a constant 130 mA, not including a 450 mA transient for opening and closing the shutter. At 6V, this is about 0.78 W power consumption.

From the power-discharge curves for a high-capacity alkaline battery (e.g. X91 Energizer E2 alkalikne AA = 3135 mAh), I would expect between 10 and 20 hours of service life.

That should be sufficient for one night's shooting.

-- Julian Loke (elan7e-owner@yahoogroups.com), January 24, 2002.

Thanks, that was exactly what I was looking for.

-- shadowman (mshadow818@msn.com), January 25, 2002.