I’d like to see the article. And I would have to disagree…the SLR probably has something on the inside running, and just waiting to be used. Some SLR’s even have a little LCD panel to show you what mode you are in, etc. I would say the best way to avoid draining battery when not in use is to either turn it off, or take out your battery and keep it separate in the carrying case.

Like most digital cameras, a dSLR will likely have an auto-power save feature to quiesce the camera if you leave it on, but don’t do anything with it for a while.

Otherwise, from a Nikon D40 perspective, I can tell you that, if nothing else, the large LCD screen on the back that’s providing real-time updates as to aperture, exposure, and other status is certainly draining battery.

But what you read and what you reported here might be in different context, I suspect.

Like many electronics and appliances, if you keep turning them on and off in a high frequency, the startup and shutdown power consumption might be more than the energy saved during the break.

Nobody will leave something on for an extended period of time.

You may be referring to the fact that unlike a point & shoot digital camera, a DSLR uses through-the-lens composition and does not need a powered LCD screen for the photographer to see what the camera sees. A DSLR camera body is very like a conventional film SLR in this respect. Its power consumption when on will be proportionally less (if you aren’t using the LCD), but it’s still going to use more power for the CCD and especially the autoexposure and autofocus mechanisms than it does when it’s off. It will obviously use the most power when you’re actively shooting the picture.

false

I agree with boxing. I think what you read might have meant that if you’re planning on taking a picture, waiting a while, then taking more pictures, you might as well leave the camera on because you’ll waste as much or more juice turning it off and on.

If that’s NOT what the article meant, then it’s just wrong. I mean, I know batteries do drain over time when not used, but think about this… if your battery sat for a week without being used, you could turn it on no problem and use it like normal. If your battery sat for a week powered ON, it would use a ton more juice. Even if it does power itself down, they’re usually just in “hibernate” mode, which still uses more energy than “off.”

I sometimes leave my Canon 30D on for days in my bag, forgetting to flick it off after a shoot. I see no change in the rate of battery depletion, regardless if I leave it on or off. When it goes into sleep mode, I don’t think that it is using any juice. Other cameras may vary, especially the point-n-shooters.

false, when the camera is on and it’s not doing anything it goes into a “sleep” mode like a laptop does, a very very low power state, however it does consume some power.

I found this saying in the d40 manual on http://kenrockwell.com .

yea like i said, only when it’s in sleep mode which that basically is the same as turning it off except it’s just up in memory, with the D40 it’s on 24/7 (i don’t know about other nikon Ds but i have seen proof of this in mine)

because whenever I attach a new lens or put my SD card back in it, it recognizes the connection and flashes a light at me, so.. yea, something is going on there.