Powering Off to Change lens - Do we need to? (DSLR)

[roger pfister]

I notice that neither my 5D manual nor my 300D manual says you

should power off while changing a lens. Do I need to?

 

I have, for some reason, always thought I did. I notice that the 5D

knowns when a lens is being atached/detached so it could do what it

needs to do "automaaticaly" when no lens is attached.

 

--

Roger

[phule]

Current thread in the digital cameras forum:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Ezba

[stephen sullivan]

I don't remember reading anywhere, where it tells you do to so.

 

That said, I do. Reason, I found when I didn't, 20D with an EF 85 1.8, the mirror would often lock up. Also, from time to time, the camera would display error codes when paired with other EF lenses. Now that I turn off the power, prior to changing lenses, this doesn't happen.

 

Also, when the power is turned on, the CMOS is charged. A charged CMOS / CCD is a dust magnet.

[KenPapai]

And some have claimed the opposite, the sensor, when the camera is ON, is not actually "charged" and thus not a dust magnet. In any case I recommend to one and all to turn off the camera and then change lenses. I doubt it makes much difference though and it certainly cannot hurt.

[wild nature]

I have been shooting with 1Ds and 1Ds MII only but I consulted with the Canon repair consultants center in NJ after I sent one of my cameras for routine cleaning and he indeed mentioned to me that it is wise to turn your camera off and wait a few seconds before changing lenses since the sensor is actually electrically charged (although not necesarely "active")and it will atract more dust than usual.

I have myself been changing lenses in these cameras many many times during several days in shooting safaries, never without any problems, except for the excepted dusts in the sensor that gets inside regardless of how carefull you are. Cleaning the sensor every night with a simple gentle air blow several times have reduced this problem for me to the minimum. Also, I now have three bodies and I now keep dedicated lenses to each body I have not have to change lenses that often any more.

So, my advice would be to go ahead and change the lenses as needed, but turn the camera off first and wait a few seconds. Clean your sensor every night before your next shooting day.

 

Regards,

 

Cesar.

[jcolwell]

I don't turn my 20D off to change lenses. I don't turn it off to change the batteries either. Heck, the only time I turn it off is when I want to activate the speed dial and push the switch in the wrong direction. I sometimes remember to turn off the 580EX when I put it away, which raises a different concern: if a flash goes off in a bag and nobody sees it, does it make any light?

[fourfa]

what does it matter if the sensor is charged or not while changing the lens? the shutter is closed. The danger is getting dust into the mirror box, which *later* goes through the shutter plane onto the sensor. The sensor's state while changing lenses doesn't matter.

[William Kahn]

Any time you're connecting/disconnecting electronic components it's really a good idea to power-off. That answer comes from 30 years of experience in electronics. I love the smell of fried circuits in the morning.....

[toddklassy]

According to Luminous-Landscape.com:

 

"There are a lot of theories floating around, but I have yet to hear from anyone that has good authoritative information. One of my conjectures is that it's better to change lenses with the camera's power turned off. This is because with the power off the imaging chip is not in a charged state, and any dust entering the mirror housing has less chance of being attracted to the chip by a static charge. Is this true? I have no idea, and no real way of testing it. But I also say "Bless you," when someone sneezes, to ward off evil spirits, so, so much for rationality."

 

Todd Klassy

[andreas_holmstr_m]

I never turn my 1Ds off just for changing lenses...

[jnicholson]

The one thing I've read in some piece of Canon documentation is that you must not remove an IS lens when the IS is active (actually on, not just turned on). I have no idea why. That said, you'd have to be pretty adept at removing lenses to manage to do that.

[digitmstr]

I like to power off simply because I don't like active contacts when something is being removed or attached to ANY electronic device. It's a habit of mine (good or bad...).

[splat]

With my digital rebel I don't turn it off. It just takes too long starting up. With my 20D I turn it off sometimes and sometime I don't. I wouldn't sweat it either way. If you have time and think of it I doubt turning off the camera will hurt. If your in a rush or just forgetful don't sweat it. The camera will continue to function just fine.

 

BTW I don't turn the camera off when I change batteries or flash cards either. The camera shuts itself down when you open the battery door or CF door so flicking the switch seems like a waste of effort.

[daniel_taylor]

"The one thing I've read in some piece of Canon documentation is that you must not remove an IS lens when the IS is active (actually on, not just turned on). I have no idea why. That said, you'd have to be pretty adept at removing lenses to manage to do that."

 

The IS element most likely "parks" itself just before turning off so that it can't move around freely. Removing the lens while it's in motion cuts power before it would have a chance to park. Then you have an element that's free to shake around as you move the lens.

 

Other than that, I see no reason to turn the power off to change a lens. The sensor is behind a closed metal curtain, it's not going to attract any dust.

[alex loveridge]

As I understand it, DSLR's have shutters same as normal SLR's (if i'm wrong here ignore me, i'm an fool) therefore, whether the camera is on or off when you change the lens doesn't matter 'cos the lens is shielded, so in theory changing a lens on a DSLR is no more damaging than on a normal SLR (remember film camera's may be nearly obsolete, but they do have electrical contacts between lens and body!) so don't worry about it.

 

But then who knows? Maybe in 5 years time you'll be able to say "my camera still works fine 'cos I turned it off when I changed the lens and yours doesn't! Ha Ha!"

 

I'm not sure that much data exists on this subject, my feeling is that camera manufacturers would have forseen this eventuality and designed the camera to cope.

[alex loveridge]

update to previous reply, the lens isn't shielded, the sensor is! blame my stupidity on too much beer and shots! (hey, its 2am here!)

[dk.]

"The one thing I've read in some piece of Canon documentation is that you must not remove an IS lens when the IS is active (actually on, not just turned on). <B>I have no idea why.</B>"---

 

LOL.

[roger krueger]

Where do people keep getting this nonsense about the sensor magically sucking dust

THROUGH the mirror and THROUGH the shutter. I want a little baggie of whatever they're

smoking.

 

The electrical contacts issue at least makes some sense, but I've never bothered, and have

never had a problem with my 1dsII, even though I own no zooms and swap primes like a

fiend, sometimes under pretty ugly circumstances. (I shoot punk shows. Ever had to blot

beer off your mirror during a lens change? While struggling to avoid being knocked down?

Lotsa fun :-)

[jnicholson]

Daniel, that makes perfect sense. Should've thought of that. David, huh?

[jim_larson1]

Note: the 20D "off" button is basically "sleep". No real difference. If you want to "reboot" the camera. . .you need to pull the batteries.

[ron c sunshine coast,qld,a]

Here we go again with this dumb subject.

<P>NO you do not have to turn off your camera to change a lens.

<BR>There is a shutter completely covering the sensor at all times.

<P>I doubt anyone will take notice of what i just said though-others in this thread have said it and also been ignored

[craig l]

I'm sorry, did you say something, Ron? 8^)

[jwd]

Simlpe answer, Yes. That said, in any electrical system, where live elecrical contacts approach a ground a spark will jump. That spark will be hot enough to fuse metal - the spark may be small and you may be unable to see it, but each spark will contribute pitting to the contact surface. It may not be much, but over any long term of use (years probably) you will degrade the contact and as that happens the lens performance as well.

 

JWD

[david_sillik]

All electrical/electronic devices should be turned off before changing componets. Not doing so will not only stress the contacts it will stress all other componets in the loop. This is a basic pratice not only for safety but for preventing the componet damage caused by repeated making and breaking of contacts which in turn will cause electrical spikes.