Inacurate Auto focus

[wadooz]

I've suspected for some time that my Canon 55-250 IS kit lens wasn't giving me as crisp an image as it should be when using Auto Focus. I was advised to test it by downloading Tim Jackson's Focus Test Chart. (http://FocusTestChart.com) Going by this test my lens is actually focusing slightly behind the chosen focus point which gives me blurred images when using wide apertures for a narrow DOF. I've been getting away with upping the F stop to increase the DOF

Is it possible to correct this error and would it be worth the expense considering the low cost of the lens? It's out of warranty unfortunately. I'm planning on getting a new lens soon anyway so should I just cut my losses and buy a new and better zoom lens or have my kit lens fixed? If it's not too expensive to fix I might stretch the finances to a new Sigma 17-70mm F2.8-4 DC MACRO OS HSM. as well.
Any advice would be welcome.
Cheers All.

[chris-p]

I don't know which camera you have, but I know that some of the more high end Canons have a microadjust feature that lets you tweak the AF response for a specific lens. If your camera has that, you're laughing.

If not, I don't know how much it would cost to get it corrected - my guess is it's unlikely to be worth it. It's not going to be cheap - thats for sure. If you're looking at getting a new lens anyway, I'd continue to work around it with a smaller aperture until it's replaced. Have you worked out how much you have to stop down to get the shot sharp?

Of course, you can always focus manually...

[wadooz]

Thanks Chris. Yes you're right I can focus manually but it's not always convenient; especially with my old fart eyes. It's much quicker with auto focus, (when it can be relied upon). I only have to stop down a couple of stops to get decent sharpness depending on the focal length. It's obviously worse at the long end.
My camera is a lowly Canon Rebel (450D) so it doesn't have the bells and whistles to tweak it in camera. I guess I'll continue to stop down and put up with it until I can afford a new better one.
Do you know if the correction would involve a manual tweak or what?

[chris-p]

Originally Posted by wadooz

Do you know if the correction would involve a manual tweak or what?

I'm not exactly sure how they do it - it would have to go to Canon for calibration where they will check the exact focusing of the lens. It normally takes a week or so. I'd suggest you get in touch with their customer services people.

Depending on how far you want to take it, they may do it for free - you'd just have to kick up some fuss. It may be out of warranty but if you bought it in the UK it will have an "expected lifespan" and it seems it's a fault in manufacture so it could well be their responsibility to sort it out. Kick up enough fuss and they'll do it for free just to shut you up!

[wadooz]

I didn't buy it in UK. I bought it from Australia on line from ebay. Can't remember if it came from Hong Kong or China. That'll teach me! When I buy next time I'll stick to Aussie sellers.
Cheers.

[OldBoy]

Originally Posted by wadooz

I didn't buy it in UK. I bought it from Australia on line from ebay. Can't remember if it came from Hong Kong or China. That'll teach me! When I buy next time I'll stick to Aussie sellers.
Cheers.

All lenses have international warranty, so it makes no difference where you brought it.

Under the Sale of Goods Act you can still claim a fault repair after your warranty has run out, as it extends it by upto six years. In the case of a lens it should last for years unless it has been damaged by the user.

[wadooz]

Don't know if we have the same "Sale of goods Act" here in Oz but it's probably worth a try. I'm at work night shift at the mo so I'll have to wait 'til I get up tomorrow. I might make a few calls. I'm sure it hasn't been dropped so I might stand a chance.

[OldBoy]

Originally Posted by wadooz

Don't know if we have the same "Sale of goods Act" here in Oz but it's probably worth a try. I'm at work night shift at the mo so I'll have to wait 'til I get up tomorrow. I might make a few calls. I'm sure it hasn't been dropped so I might stand a chance.

On the internet type in consumer rights and see what comes up. Did a quick search here and found this.

http://newsletter.sgs.com/eNewslette...n-v2-EN-11.pdf

[wadooz]

Well thanks for that OldBoy! Unfortunately I wasn't up early enough to contact the Canon dealers, other more pressing issues had to be dealt with (PC probs). I'll set my alarm and get up sooner tomorrow and see what I can do. Too late now, shops closed.
I think I'll try for a free repair and if that can't be done I'll just live with it and upgrade my everyday lens. The Sigma 17-70mm F2.8-4 DC MACRO OS HSM I mentioned earlier has had some good reviews, and I can get one from an Oz seller for $479.
If I were to upgrade my zoom lens I reckon the Sigma 70-300mm f/4-5.6 DG OS looks like a good buy at $486. The other option I'm considering is the Tamron SP 70-300mm F/4-5.6 Di VC USD.
I just have to choose between upgrading my everyday lens or the zoom. Wish I could do both....
I used to be indecisive but now I'm not so sure.....

[chris-p]

Of the 70-300mm lenses, the Tamron is miles ahead of the Sigma. It'll be a bit more expensive but it's one of the best 70-300mm lenses on the market at the moment (barring the Canon L or DO models)