problem with 50mm canon 1.8

uns12345

Hi,
I bought a 50mm canon lens second hand on ebay and while i'm very happy with the optics quality the AF hunts constantly even in bright sunlight. Is this common in these lenses or have I bought a dud?
Any advice appreciated Im new to Photography and as this is quite a common lens with great reviews I just wondered if this is a common problem, I'm using the lens on a 40d?

hmboards

The focus isn't the fastest on this lens, but mine never had problems in bright light.

nonsequitir

Had one of these for a year before I dropped it an smashed it :-(

I found the lens hunted a lot over f4 and less so at 2.0 up to 3.5. In low light, I switched to manual. If it's from eBay, then I wouldn't have a clue really, but it could be defective?

stick-dan

This lense is rarely off my camera and i've never experienced a problem with it

DougL

nonsequitir wrote: »

Had one of these for a year before I dropped it an smashed it :-(

I found the lens hunted a lot over f4 and less so at 2.0 up to 3.5. In low light, I switched to manual. If it's from eBay, then I wouldn't have a clue really, but it could be defective?

The lens should always focus at the widest possible aperture and then stop down when you fire the shutter. So, the aperture you set should have zero impact on focus.

-Doug

Diabhal_Glas

Sounds like a dud, is it too late to return? E bay support generally stick on the side of the buyer

hbr

uns12345 wrote: »

Hi,
I bought a 50mm canon lens second hand on ebay and while i'm very happy with the optics quality the AF hunts constantly even in bright sunlight. Is this common in these lenses or have I bought a dud?
Any advice appreciated Im new to Photography and as this is quite a common lens with great reviews I just wondered if this is a common problem, I'm using the lens on a 40d?

What focus mode is your camera in? One shot or servo?

uns12345

The problem seems to occur more when in aperture mode, I bought the lens because of all the great reviews of its depth of field so was trying that out. In Program mode the problem isn't so bad in brighter lights. The camera is in servo mode would this affect it? Going to use it some more today and see how I feel, would prefer not to go through the hassle of returning it, not sure how this works with ebay, postage etc (the seller was in scotland)
was so looking forward to getting this so a little disappointed!

hbr

uns12345 wrote: »

The camera is in servo mode would this affect it?

Yes. That might be the cause of your problem. Try using one-shot AF.

In Servo mode, the camera will continuously try to focus on the
subject. This is great for tracking fast moving subjects, but not
ideal for static subjects.

uns12345

Thanks have tried it in one shot and its much improved!!!
operator error after all!

hbr

uns12345 wrote: »

Thanks have tried it in one shot and its much improved!!!
operator error after all!

Glad to hear that it is ok. It would be a PITA to have
to send it back to a foreign seller.

Enjoy your new nifty fifty.

magicbastarder

servo mode also allows the camera to fire when it has a much looser lock on the subject, cos waiting until it has a perfect lock would slow it down too much.

Thecageyone

It's a Canon, whaddaya expect? [jk]


I came in to suggest it might be the mode you have it in. In single shot it won't fire until it focuses. So all shots should really be in focus. Servo gives shutter release priority over focus ... so might not exactly be just that if you still find the issue. As it should fire without even fully focusing in that mode.

uns12345

Seems to be working fine now I think it was the settings I had, thanks for all the help. I'm still learning only got the camera 3 weeks ago, took this with it today!

hmboards

hbr wrote: »

What focus mode is your camera in? One shot or servo?

Well spotted!