350D + 17-85mm IS USM problems

[pohpoh]

Hi there,

Newbie here, got a question to consult you all. I got a 2nd hand 350D recently and was trying to buy a 2nd hand 17-85mm lens for it. But when I tested the lens, the camera does not focus properly, it kept going in focus to out of focus repetitively, then eventually focusing on a blur image.

Would like to know if this means my camera has a problem or is it a problem with the lens? Or is it an incompatibility issue? I tried all different settings, different shooting modes, but I can't get a clear picture at all. Please advise if you have any ideas what could be wrong!

Thanks alot for your help!

[ahbian]

Is it a low contrast subject that you are testing on? There's no testing during the purchase?

[Flashbulb]

Originally Posted by pohpoh Hi there, Newbie here, got a question to consult you all. I got a 2nd hand 350D recently and was trying to buy a 2nd hand 17-85mm lens for it. But when I tested the lens, the camera does not focus properly, it kept going in focus to out of focus repetitively, then eventually focusing on a blur image. Would like to know if this means my camera has a problem or is it a problem with the lens? Or is it an incompatibility issue? I tried all different settings, different shooting modes, but I can't get a clear picture at all. Please advise if you have any ideas what could be wrong! Thanks alot for your help!

what was the distance from the subject to your camera and the lighting condition?

try from a distance in somewhat bright light...

[ombre]

Originally Posted by pohpoh Hi there, Newbie here, got a question to consult you all. I got a 2nd hand 350D recently and was trying to buy a 2nd hand 17-85mm lens for it. But when I tested the lens, the camera does not focus properly, it kept going in focus to out of focus repetitively, then eventually focusing on a blur image. Would like to know if this means my camera has a problem or is it a problem with the lens? Or is it an incompatibility issue? I tried all different settings, different shooting modes, but I can't get a clear picture at all. Please advise if you have any ideas what could be wrong! Thanks alot for your help!

Curious, why did you choose to start with this lens?

In anycase, try focusing something near (woah, not so near...), 1.5 meters is a safe range, with enough light, and is neither black or white. Even solid tones are hard to focus, try to put your AF points where there are distinct intersecting lines perhaps. like table edges vs the floor.

alternatively you could have a front or back focusing issue lens. Try focusing on a printed document, see if the point that lights up is sharper compared to the other parts of the paper. (center focus is the best to do this of course)

dSLR focusing is much harder than your point and shoots, where the AF is sharp almost 95% of the time. Mainly because the DOF is so wide.

If all else fails, see if you can contact the seller to refund if he offers personal warranty, if not you may have to bring it to the service center.

I'm just curious, did you mount the lens right? =X Do you know how to? (I didn't know when I first got DSLR!)

[pohpoh]

Originally Posted by ombre Curious, why did you choose to start with this lens? In anycase, try focusing something near (woah, not so near...), 1.5 meters is a safe range, with enough light, and is neither black or white. Even solid tones are hard to focus, try to put your AF points where there are distinct intersecting lines perhaps. like table edges vs the floor. alternatively you could have a front or back focusing issue lens. Try focusing on a printed document, see if the point that lights up is sharper compared to the other parts of the paper. (center focus is the best to do this of course) dSLR focusing is much harder than your point and shoots, where the AF is sharp almost 95% of the time. Mainly because the DOF is so wide. If all else fails, see if you can contact the seller to refund if he offers personal warranty, if not you may have to bring it to the service center. I'm just curious, did you mount the lens right? =X Do you know how to? (I didn't know when I first got DSLR!)

Wow thanks for the quick replies. Actually I was testing the lens out before purchasing it from the seller when I found out about the problem. Anyways, I chose this lens coz I wanted a versatile lens with IS, so I figured that range was pretty good for me.

I tried it out at under different lightings from a variety of distances, I think between like 0.5m to maybe about 50m but the focus just couldn't get it right. When I tried to focus the lens just kept 'clicking' like it was trying to focus, but it eventually ends up with a blur image. This problem isn't obvious at a low zoom, but got more serious when I zoomed further out. The seller tried to troubleshoot but couldn't get it right too. I've no such problems with my 18-55 so I'm really puzzled why this is happening.

[ndroo]

Originally Posted by ombre Curious, why did you choose to start with this lens?

What's wrong with that?

[darkness]

Is there any chance of trying out the lens on a different body?

[ombre]

Originally Posted by ndroo What's wrong with that?

Personal preference I guess. The way I see it, its a short slow lens with IS. I won't bring this lens out at night because of the speed, thus I probably won't use the IS. 2ndly its 3 times the price of the IS kit lens? It just doesn't seem to me a good combination of benefits vs cost. I'm not sure how you see it though.

[CasonLyn]

Originally Posted by pohpoh Wow thanks for the quick replies. Actually I was testing the lens out before purchasing it from the seller when I found out about the problem. Anyways, I chose this lens coz I wanted a versatile lens with IS, so I figured that range was pretty good for me. I tried it out at under different lightings from a variety of distances, I think between like 0.5m to maybe about 50m but the focus just couldn't get it right. When I tried to focus the lens just kept 'clicking' like it was trying to focus, but it eventually ends up with a blur image. This problem isn't obvious at a low zoom, but got more serious when I zoomed further out. The seller tried to troubleshoot but couldn't get it right too. I've no such problems with my 18-55 so I'm really puzzled why this is happening.

are you on AI-Servo AF mode?

[pohpoh]

Originally Posted by CasonLyn are you on AI-Servo AF mode?

hmm nope, like I mentioned, I resetted the cam settings, so was on One Shot, tried all the 3 modes in fact, still couldn't work.