Canon 28mm-135mm not stopping down to f3.5

I just bought this lens used to pair it with my 7d body i also just bought today. got home, charged the battery and tested the camera. body works flawlessly but the lens is not stopping down to 3.5

the widest it will go is 5.6 at any focal length. i tried manual mode, av mode, reset all setting and nothing made it work. just wandering if anyone has a simple solution i may have overlooked before i ask for my money back. i did buy it from Cl but i messaged the guy as soon as i found out and he responded so that is a good sign of potentially getting my money back.

thank you.

How are you determining that it wont stop down? That lens has variable max apeture so it may be reporting the nearest full stop. Set it to TV mode and make sure you underexpose, take a shot and look at the exif to see if shows wide open.

Astheros wrote in post #13801408
I just bought this lens used to pair it with my 7d body i also just bought today. got home, charged the battery and tested the camera. body works flawlessly but the lens is not stopping down to 3.5

the widest it will go is 5.6 at any focal length. i tried manual mode, av mode, reset all setting and nothing made it work. just wandering if anyone has a simple solution i may have overlooked before i ask for my money back. i did buy it from Cl but i messaged the guy as soon as i found out and he responded so that is a good sign of potentially getting my money back.

thank you.

At the 28mm side if I recall it will do 3.5 at 135mm it only goes to 5.6.

yeah. if i go with a focal length of 28mm. its widest length. it should go into f3.5 in manual mode. i understand that its variable aperture but at 28mm, it has to be able to go to 3.5 and it doesnt in any mode.

i think its broken. as i was carrying it home, i was getting ridiculous lens creep as well. not sure if that should have been a sign for me

Astheros wrote in post #13801526
yeah. if i go with a focal length of 28mm. its widest length. it should go into f3.5 in manual mode. i understand that its variable aperture but at 28mm, it has to be able to go to 3.5 and it doesnt in any mode.

i think its broken. as i was carrying it home, i was getting ridiculous lens creep as well. not sure if that should have been a sign for me

That lens will have some lens creep, especially if its pointed down. But the real world effect of that is negligible unless you are using a copy stand.

you could try and clean the lens contacts...if you're in manual mode, the aperture isn't going to switch over just cause you go wide...it's going to stay at f5.6...switch to AV mode...go wide, and then see how wide-open you can go...

what i meant is that in manual mode. if youre wide open in focal length. the aperture will also go wide open (provided of course i change it) i didnt mean it will automatically change it for me. i set it to manual mode and went to 28mm.....changed aperture and its stuck at 5.6 (it goes up but not any further down)

i talked to the guy and i will be giving it back to him. i know its not a huge problem but sometimes i do use these lenses where not enough light is present so any additional fstops are good to have. maybe we can work out a different price.

thanks everyone. i am fairly experienced to know this was broken, its just that its one of those things were you ask eventhough you know the answer. (just in case)

i'd say it was a big problem...no disrespect was meant by the 'set the aperture open' comment...but quite a few times around here, it's the little things people forget...glad it seems to be working out for you

none was taken. i appreciate the help.

Set the lens at 28mm and take a shot (at f/5.6 presumably). Then check the EXIF to see what focal length it thinks you used. My bet is that it still shows the long end and there's a focal length encoder error in the lens.

Bob

it does show that all pictures are being taken at 135mm. is this something that can be fixed? i already planned to meet the guy tomorrow to get my money back but just wandering. thanks

There are few things that can't be fixed but it's not an expensive lens and you may not find it cost effective. The reported aperture is wrong and it's likely that it is around f/3.5 given the relationship to FL. Maybe work out some serious discount with the seller and use it "as is".

Bob

My old 28-135 has the same problem. Also, AF is quite slow at wide end..
There is sensor in lens barrel that determines focal lenght and i think it's faulty.
I'll fix it someday tho..