[Dave]

Have experienced focus & exposure problems with Canon 24-105mm @ F4, which disappear from f/4.5 upwards Anyone else experienced this problem with the Canon 24-105 ?

Shot taken on tripod, focused using live view at max zoom, to ensure perfect focus, mirror lockup plus 2 sec timer, to ensure rock steady shot. 100% crop shots for comparison. The gif will flick between F/4 & F/4.5 :-



You'll notice ther F/4 shot has a ghosting effect feel to the shot vs the sharp f/4.5 shot. Notice how the edge of the letters of "ROB" go grey & soft at F/4 vs black & sharp @ f/4.5

Have tried on both 40D bodies with same results, so proves it's the lens. Have also tried Canon 70-200 F4 on same test & you can't tell the difference between f/4.0 & f/4.5, once again proving the 24-105 lens is at fault

[silkstone]

That's odd. It looks like some form of flare - that was a problem with some earlier models of this lens, but should have been sorted by now. (See Canon EF 24-105mm f/4 L IS USM Lens Review)

It's particularly strange that there's such a difference with a very small change in aperture. Were you using a UV filter?

No doubt someone else with this lens will come along with the results of a similar test.

[brian wright22]

Dave what serial number is yours? is it below UT1000 if so there has been a recall from Canon.

Also did you have a filter on the front?

[Dave]

Originally Posted by silkstone

It's particularly strange that there's such a difference with a very small change in aperture. Were you using a UV filter?

Nope

[Dave]

Originally Posted by brian wright22

Dave what serial number is yours? is it below UT1000 if so there has been a recall from Canon.

Thanks Brian, can see that here :- Canon Special Announcement EF Lenses - Canon UK

Mine starts UV, so it was 2007 :- Canon L Lens - How to identify Production Year

[Whipspeed]

Send it back. They have a really quick turnaround for warranty and other repairs. I've sent a lens back twice, once for warranty and once as it had been dropped and got it back in a week. That was the repair centre at Elstree.

[Dave]

I did send it back to supplier for replacement, but they appear to have sent me the same lens back <UPDATE> Supplier has confirmed this is a replacement lens

Do the warranty places cover your return P&P though, as under Sales of Good Act the supplier must. It's £10 for this weight lens.

[stepheno]

Tested an hour ago

f4


f4.5

[brian wright22]

Originally Posted by Dave

I did send it back to supplier for replacement, but they appear to have sent me the same lens back

Do the warranty places cover your return P&P though, as under Sales of Good Act the supplier must. It's £10 for this weight lens.

Dave I had to get my 17-85mm Canon Lens repaired and decided to send it to Canon @ Borehamwood UK. It cost me £11 to send it which I didn't get back but I was not charged for its return under warranty.

I think you would not pay anything either way if you take it back to the selling dealer because usually they have a pickup usually once a week. Well that was the case with my Minolta warranty return.
.

[P-E]

Did the supplier say if this lens was a new replacement Dave?

[Dave]

Originally Posted by P-E

Did the supplier say if this lens was a new replacement Dave?

Yep, I insisted on replacement lens . <UPDATE> Supplier has confirmed this a replacement lens

[P-E]

Originally Posted by Dave

Yep, I insisted on replacement lens . Not impressed.

Don't suppose you got the serial number from the one you sent in?

Have you contacted them again to say this one is showing the same problem.....or you have had the original one returned to you?