Changing Lenses with power on dangerous to Memory Card?

xarqi wrote in post #4160748
I've heard this said, but I've never believed it. The sensor is behind both the shutter and the mirror at this time. I can't see how either the electrostatic field can pass through these (the mirror at least must be conductive due to the metallic coating), or how the dust could reach the sensor through them. Can someone enlighten me please?

Edit: I mistyped shutter, and got bleeped! Tee hee.

Grentz wrote in post #4160776
I almost always change my lenses with the power still on and have never had an issue with my 30D. Then again, I can pretty much leave my 30D on most of the time since it goes to sleep which seems to be the same as the off position

Wekkel wrote in post #4160793
I changed lenses numerous times with power on. I don't know whether it is harmful but everything is still working. Hell, I even openend the shutter to get a lens in a higher diafragma, decoupling it from the camera with the shutter still open.

It's a crazy world!

e r y k wrote in post #4160841
i believe thats been proven false, the electric field around the sensor isnt strong enough to pick up any dust.

proxes wrote in post #4160844
I never understood the whole, don't change lenses when the power is on because the sensor is charged, thing.

If dust gets in the chamber while you're changing the lens on it's trapped in there. Once you turn the camera back on that dust is going to stick to the sensor anyways.

lakiluno wrote in post #4160851
anyway, the sensor is only charged up during use - taking photographs, and liveview.

BSBXTi wrote in post #4161655
I taken off a lens or two by accident with the camera on

Jon wrote in post #4161908
I've been going for years without shutting the camera off during lens changes and haven't experienced any problems with any of my cameras or cards. As far as shutting the camera down during lens changes to avoid dust on the sensor - like others have said - the shutter's in the way. And even if you were to shut the camera off, dust would still get into the mirror box and be attracted to the sensor the next time the flipping mirror stirred it up and the open shutter exposed the sensor.

proxes wrote in post #4161928
Also I never turn my camera off. I just let it go into sleep mode and tap the shutter button when I'm ready to go.

JBaz wrote in post #4161959
The only bad time to change the lens when the power on is when you're outside and it's raining... Shoot, justing being outside when the camera exposed is bad enough unless you have a 1D. Even then, I'd still protect it.

Oh? I see!

As mentioned above, I don't think changing lenses with the camera on will do any harm to the camera. The memory card damage is a new one though. I've never heard of that one before.

I think, from my experience, that the camera goes into power off mode at some point when you change lenses. I've never heard anyone claim that their camera/lens was fried from changing lenses in a shoot because they didnt lick the off switch, and I'm sure that I'm not the only photographer to do so as a matter of course.

Add to that the fact that the lens and camera manuals never state camera-off as a necessity, and that makes a compelling argument that the camera is designed to allow for changing lenses when the camera is in an "on" state.

I could be wrong, and would love to hear horror stories!

Tony

I change my lenses regardless of wether the camera is on or not. Also, I've never had it shut down due to it - although I'm not going to be doing it, I'm sure it'd work fine if you took the lens off in the middle of a burst. Obviously your image quality is going to suffer, but meh.

If you remove the lens with the camera on, it remains on, the aperture on the LCD scale reads "00" and you can still press the shutter and the shutter will release as well.

With dslr's, I think the only time that the sensor has an electric charge is when the shot is being taken. When not taking an image there shouldn't be a charge, unlike point and shoots which always leave the sensor on hence the "live view" on the LCD for composition.

I have pretty much the same experience, I have changed lenses with the power on, with no detrimental effects. One would think that a short can occur when the lens contacts slide against the body's, but so far nothing has happened yet.

i do this all the time. no problem.

what about taking memory out while camera ON , I heard this is bad.

it's ok as long as you are wearing your tinfoil hat.

Just don't remove the card when the camera is writing data to to card (orange light flashing right after shooting).

EWek11 wrote in post #4160511
I was just speaking with someone who was told that you can cause damage to your memory card if you change lenses with the power in the "on" position. I've changed lenses many times and I rarely ever turn my power switch off, and I've never had any damage, but is it possible?

do it all te time - never caused any problems
Did it with the 20D, 30D and the 5D,
never got ANY dist on the first two and only a few on the 5D

thebrewer wrote in post #4164419
it's ok as long as you are wearing your tinfoil hat.

If you want to reverse your lens for a macro shot, you must leave the camera on while removing the lens so the aperture will remain at its selected setting.

-js

I think if it was truly bad to remove the lens with the camera on, they'd build an interlock switch to power down camera off as the lens is twisted off, or, Canon would at least mention that it can cause harm in their owner's manuals.

As far a 'charging' the sensor... CMOS is low powered. There is only about 3 volts maximum on the sensor. It's nothing like a TV screen that crackles as you place your finger near it... A 3 volt charge is not going to attract any dust and it's certainly not going to suck it in from several inches in front of the camera, around the mirror and through the closed shutter blades.

Jim_T wrote in post #4166355
As far a 'charging' the sensor... CMOS is low powered. There is only about 3 volts maximum on the sensor. It's nothing like a TV screen that crackles as you place your finger near it... A 3 volt charge is not going to attract any dust and it's certainly not going to suck it in from several inches in front of the camera, around the mirror and through the closed shutter blades.

<set offtopic meander>

While I agree with your conclusion, I'm not certain the physics is correct here. I've been wrong lots of times, but I thought I'd mention it. One way or another, somebody could learn something new, maybe me, so that has to be good, right?

So - voltage is joules per coulomb, a measure of the energy associated with a charge, but the strength of the electrostatic field depends not on the energy per charge, but on the charge itself. Pack enough electrons together, even if they only have 3V of energy per coulomb, and you can produce a very high strength field, can't you?

I don't really know if this is right, and if it is, if it is what is happening in a CMOS sensor, but who knows? Literally. Who knows? Anyone want to point out where I've goofed?

I heard a Canon rep explain that there is no charge to the senor except at the time of exposure. He was asked the same question and emphatically stated that there would be no more dust if the the camera was on as opposed to off.

If powered on sensor collects more dust, how come that, according to Canon’s own instructions, sensor cleaning can be performed only with camera powered on?!

Hermeto wrote in post #4167009
If powered on sensor collects more dust, how come that, according to Canon’s own instructions, sensor cleaning can be performed only with camera powered on?!

heh