70-200 focus hunting

S

StuD

Messages
426
Edit My Images
No
My recently purchased Canon 70-200 F4 L is having a few issues with focusing. It seems to focus more regularly on closer objects (within a few metres). Anything at a distance (at a guess I'd say 5m+) it hunts back and forward and doesn't lock or locks and beeps to confirm even though it's quite a bit out of focus through the viewfinder. If I manually adjust it will usually confirm my focus okay.

Any thoughts on what may be causing this? I've tried the lens on both my 50D and 400D, and confirmed that other lenses work correctly. I don't think there are any smears or marks on the lens which may be causing this.
 
Is your lens set to 1.2 > infinity by any chance? If so, change it t 3 > infinity and give it a go.

I missed a few shots because I accidently moved that switch. :lol:
 
I've tried both settings, didn't have a problem until yesterday. I'm hoping it's something obvious I'm missing.
 
see now i just got a nikon 70-200 2.8 vr and this happens with me.... im using a d700 so great camera so should deal with it hands down. mine will focus fine then all of a suddon will lock out of focus if i just a twist a little then all is fine again .... seems like it gets stuck some times u know, and needs a little help but the price i paid i dont want to help it ! haha
 
I've been playing around just now in a quite low light room and the 400D focuses with the 70-200 on most things, obviously not so well with low contrast items. Yesterday however it was having problems outdoors on a relatively sunny day with people's faces. The only difference I can think of was the distance. I'll give it another shot tomorrow outside to see how it copes.
 
Were the people standing with the sun behind them per chance?

Also will your lens manual focus that distance fine (ie nothing faulty)
 
Hi Richard, no, the sun was at about 30° over my left shoulder. Yes, manual focus is absolutely fine.
 
I would have suggested as martyp did, but that is out of the equation now :thinking: Take a look at these videos explaining about the focusing on the 50D http://www.video.bhphotovideo.com/ it could help you to understand it better. Just out of curiosity and I am not suggesting you have no understanding of anything ;) Is this happening in any particular mode on the camera? does it make a difference which metering or focus points you choose? Keep us informed, one last thing was the lens new or used when you purchased it?
 
I've tried it on both my 50D and 400D, same result. It was purchased new (within a couple of months) and under warranty but I'd prefer to rule out operator error before making a warranty claim.
 
I have recently fitted a tripod collar - could this affect focusing somehow?
 
StuD said:
I have recently fitted a tripod collar - could this affect focusing somehow?
Click to expand...

I would not have thought so as there is a recess on the lens for it to fit into.
If it was me I would just walk into the nearest camera shop with camera and lens, give em a big smile and say.

Call me stupid if you want to, but! could you explain why this is happening. Apart from giving the guy behind the counter the feel good factor if he sorts it for you, it aint gonna cost any money :D If they say you defo have a problem with it, then you have just cause and an explanation to return it.
 
Last edited:
The nearest decent camera shop is probably about 45 miles away and I'm not sure that they'd be too happy if I walked in with a camera and lens that I didn't buy from them and asked them to have a look at it.

Thanks for the advice though.
 
i agree with u8myufo,i did similar,when my camera was back focussing,they blew out the sensor,cleaned it with a static brush,and confirmed it was nacked,told me id be looking at 100 to 150 for full calibration,clean etc.,sold it on e bay clearly stating the problem and bought a new 50d,not from them,but i have been and spent with them since,a good camera shop will see it as offering you a service,that you just don't get of the web,a bad one will not entertain the idea,Give it a go
 
StuD said:
Hi Richard, no, the sun was at about 30° over my left shoulder. Yes, manual focus is absolutely fine.
Click to expand...

Hmm, that sounds quite odd. Can you reliably replicate the issue now?
 
You must log in or register to reply here.
Back
Top