Changing Lens

[BillT]

Can anyone give me some info. on whether it is O.K. to change lens on a 35mm SLR camera mid roll, without damaging the 35mm film.

& Oblige

BillT

[straightarm]

You won't damage the film as the shutter is closed.

Simon

[BillT]

Simon

Thanks for your quick, wellcome reply

BillT

[another view]

No problem here. I would add that if you have an autofocus camera, it's best to turn it off before changing lenses. Not that I always follow my own advice - but it's a good habit to get into.

[Outdoorsman]

No problem here. I would add that if you have an autofocus camera, it's best to turn it off before changing lenses. Not that I always follow my own advice - but it's a good habit to get into.

Hold on- I got confused. Turn what off- the AF or the body itself? And most importantly, why should it be turned off when changing lenses? Why a good habit? I've never heard this before, and if it's really important, I'd like to know! Thanks.

[Sebastian]

Hold on- I got confused. Turn what off- the AF or the body itself? And most importantly, why should it be turned off when changing lenses? Why a good habit? I've never heard this before, and if it's really important, I'd like to know! Thanks.

Turn off the CAMERA. Why? Because the contacts can short out causing errors or lockups. Nikon specifically writes in their manuals that lens changes should be made with the camera off. My D100s did not like swapping lenses while on. First few times would be fine, eventually they would start going nuts, fEE errors and such. Turning them off and then on would be the only solution. Once I had to pull the battery though, one of them just locked up tight.

So far the 10D is fine with swapping while on. Though I know that Canons are really sensitive to the contacts being tight and clean, so I'm sure I'm tempting fate here. Time will tell.

[Sebastian]

Can anyone give me some info. on whether it is O.K. to change lens on a 35mm SLR camera mid roll, without damaging the 35mm film.

& Oblige

BillT

BillT,

The lens is always open, light is always getting in. What blocks it is the shutter, which only opens to expose the film plane. And before the shutter is the mirror, it deflects light into the prism so you can actually see something in the viewfinder.

[another view]

Hold on- I got confused. Turn what off- the AF or the body itself? And most importantly, why should it be turned off when changing lenses? Why a good habit? I've never heard this before, and if it's really important, I'd like to know! Thanks.

- What Sebastian said. There is a row of several contacts just inside the lens mount (and on the base of the lens), near the top - at least with Nikon. When you twist a lens on or off, you slide the contacts across each other.I've never had a problem with my Nikon 8008s, F4S or F100 but it's just a good thing to do. Shorting contacts in a piece of electronics like that may have cumulative effects and I really don't want to end up with an expensive paperweight! I try to be more careful with the S2 because it's digital, but the other day I changed with it on and had no problems. The S2 and D100 are both built on an N80, so they might not be so durable as the others.

[Outdoorsman]

Turn off the CAMERA. Why? Because the contacts can short out causing errors or lockups. Nikon specifically writes in their manuals that lens changes should be made with the camera off. My D100s did not like swapping lenses while on. First few times would be fine, eventually they would start going nuts, fEE errors and such. Turning them off and then on would be the only solution. Once I had to pull the battery though, one of them just locked up tight.

So far the 10D is fine with swapping while on. Though I know that Canons are really sensitive to the contacts being tight and clean, so I'm sure I'm tempting fate here. Time will tell.

This is opening a can of worms. I should premise with this: My whole life I've been the bane of humans because I always ask too many questions. Animals don't seem to mind much, though...
1) How can the contacts short out? And what do you mean by "short out"?
2) How do you know that Canon products are sensitive to the contacts being tight and clean? (not questioning your knowledge, just wondering where you learned it). I've always kept the contacts on my equipment clean, but only because I know to do this with any piece of electronics. And how do you keep the contacts tight? I've never known of a way to adjust the lens mounts other than the screws that hold them to the body and lens barrel.
I've never shut off my camera to change lenses, and I've never had a problem. Sometimes turning off the camera is very inconvenient in situations where I have to shoot fast. I guess my point is that this is all news to me, and I'd really like to know what I might be doing to my equipment- if I'm doing harm, it would be very helpful to be aware of it. Thanks!!!

[Sebastian]

This is opening a can of worms. I should premise with this: My whole life I've been the bane of humans because I always ask too many questions. Animals don't seem to mind much, though...
1) How can the contacts short out? And what do you mean by "short out"?
2) How do you know that Canon products are sensitive to the contacts being tight and clean? (not questioning your knowledge, just wondering where you learned it). I've always kept the contacts on my equipment clean, but only because I know to do this with any piece of electronics. And how do you keep the contacts tight? I've never known of a way to adjust the lens mounts other than the screws that hold them to the body and lens barrel.
I've never shut off my camera to change lenses, and I've never had a problem. Sometimes turning off the camera is very inconvenient in situations where I have to shoot fast. I guess my point is that this is all news to me, and I'd really like to know what I might be doing to my equipment- if I'm doing harm, it would be very helpful to be aware of it. Thanks!!!

1) Short our probably was the wrong term to use. THink of it this way, if the processors are expecting a communication from the lens, and in the middle of it there is no response, the computer can hang. Just like old PCs used to do if something was unplugged while on.

Conincidentally, thanks to the recent Rebel hack I found out that the 10D and the Rebel both run on embedded DOS, so they are truely computers that take pictures.

2) Because every time there is an error with a camera, everyone recommends to check the contacts. Since Canon cameras depend 100% on the electronic connectors, that is the first and most likely area to cause an error. By tight I mean that the screws need to be kept tight on the lens mounts on the body and lens. It's pretty common for them to come lose. Obviously more likely with ehavier usage. Sometimes though, the pins can get sticky and not put enough pressure on the contact. Not liekly to happen, but it has happened. Just another thing to look out for.