I have a 60D - and was wondering if most people leave a lens attached - or if you unmount and cap everything when not using.

I'm worried that taking the lens off can allow dust to get inside the camera.

but does leaving it on put stress on the camera/lens junction?

any pros and cons?

I leave a mid-range zoom on the body at all times. I have the battery charged and a card in the slot. I have 800 ISO dialed in and I'm ready to go as fast as I can switch it on.

Robert, you have a good question that I am also wondering since I just bought a Canon T4i with tthe 18-130mm lens.

I keep an EF-S 15-85mm on my 60D all the time, just for the "grab & go" ease of things.

It lives in a photo gear backpack with shaped dividers which hold everything securely.

I think I'll leave the lens on, too. I have a friend who always disassembles and caps everything - but it seems like a waste of time.

Tell your friend that Canon USA does it that way too for every trade show and table event I've ever seen. Batteries and media out, everything disassembled and capped, every time.

For the vast majority of my camera's from the Rebel's to the 7D, 5D, basically any camera w/o a grip, I leave a lens on, whichever one I used last. The only exception is probably the 120-300/2.8 which I don't have too many bags that can handle it with a body mounted.

On the 1Dm2 and 1Ds which have a built-in grip, I remove the lenses and store with just a cap. Again, it's more to do with how they fit in a bag.

Is there any risk of damage to either camera or lens if left attached perminent?

Only if you drop it

No photographer I know does not leave a standard lens on his cameras, nor does any eng cameraman.

I know a guy with a RED who always dissasembles it for transport, but he mainly uses the RED 18-something zoom lens which is a heavy beast, and he packs everything into a pelicase for transport.

ENG cameras and DSLRs don't have to be disassembled even for transport. I have worked with 2/3" eng cameras that had had their same lenses on for years.

Maybe you shouldn't leave a very heavy telephoto zoom on your DSLR, but why would you. Just keep your standard zoom on and you're good.

By the way: don't leave batteries in the camera if you don't use it for months. Most cameras that I know will empty the batteries slowly and possibly destroy them after a while.