Lens changing with power on...

[jptreen]

<p>...I read in the 'missive to Ned...' post something that implied that changing lenses with the camera switched on could be damaging. Have I got the wrong end of the stick here, or have I been potentially damaging my DSLRs a lot over the past couple of years?</p>

[jgredline]

<p>I was thinking the same thing. I am always changing lenses and never turn off the camera, so I am with you with the same question?</p>

[personalphotos]

<p>The only thing I have ever heard was a greater problem with dust. With the camera on, there's a static charge to the sensor. So it will attract more dust to the surface. So removing the lens will stir up any dust and possibly add some dust to the sensor.</p>

<p>The other consideration is the contacts are electronic and connected to a circuit board both on the camera and inside the lens. So if there was a static charge across a couple of contacts, it's possible to damage the circuit. I would imagine that's pretty rare though and was taken into consideration during design.</p>

<p>As a matter of routine, I've made it a habit to turn the camera off between changes, removing cards or when not in use.</p>

[jgredline]

<p>Thanks Peter. I will make it a habit to turn it off. I don't have any dust problems. Infact, I have really been impressed by this.</p>

[michael_elenko]

<p>I always turn off the camera after a lens change because I am concerned about whether the anti-shake system is smart enough to adjust itself to the news lens value on the fly. It is an easy thing to test that I've never gotten around to.</p>

<p>If one uses an older lens without an electronic data exchange capability that requires you to manually enter in the focal length for the anti-shake system, then I would strongly recommend shutting off and restarting the camera.</p>

<p>ME</p>

[mountainvisions]

<p>Dust...the sensor has a charge and attracts dust. I've heard leave it off for a few minutes (if possible) before changing lenses. I don't regularly follow that, but I do make sure it is off.</p>

<p>On a positive note, no dust specs on my sensors in a LOOOOOONG time. It might work, might not, but I'm sticking with it.</p>

[jgredline]

<p>Good points Micahel and points I have never even considered. Thank you!</p>

[duane_mills]

<p>One additional point worth mentioning. The AF screw drive. Say you leave the power on, are beginning to put a new lens on and accidently touch the shutter release a little thereby engaging the AF. You could damage the camera, the lens or both.</p>

[bob-c]

<p>John-Paul, thanks for posting this question. I have often wondered the same thing because I almost always forget to turn the camera off. I'll do a better job of remembering now. </p>

[jptreen]

<p>Cheers guys, it's certainly food for thought. I will do my best to switch the camera off when I change lenses, but it's such an old habit that I think it'll certainly take some trial and error before I get it right!</p>

<p>I'll have to see whether it affects the amount of dust that gets onto my sensor.</p>

[mountainvisions]

<p>I hadn't really thought about the AF issues myself. Yeah, it would be bad if you were rotating the lens off as you hit the AF button!</p>

<p>But I believe you will see less dust on the sensor/shots with this method, and that alone is a good reason to turn it off.</p>

<p>I also recognized the issue Mike E was mentioning with the SR. I would assume that with a FA or DA lens the camera would recognize the lens FL on the fly, but I have not checked if the FL menu comes up for non chipped lenses. If they are changed with the camera on! So another good reason to play it safe, and flip the power switch!</p>

<p>Also, if you have dust removal set for startup, it's a good way to help keep the sensor clean when you change lenses.</p>

[miserere_mei]

<p>I've been photoshopping an S-shaped hair off my photos this afternoon. Not fun.</p>

<p>Has little to do with the topic, but I just thought I'd share my annoyance :-)</p>

[mountainvisions]

<p>Actually it does, keeping hairs off might be a factor of turning off the camera.</p>

<p>I have had a few hairs in my photos. Not fun! And cloning them out of complex scenes is nearly impossible!</p>

[jim_b9]

<p>Well if Pentax thought it was necessary to power off the camera to change lenses, they probably would have incorporated an auto-off feature that activated as soon as you pushed the lens release button.</p>