Cannot get my 70-200 F4L IS to focus

[jbee]

Hi all - i have been absent from the forum for a while as I was getting quite disillusioned with my L series Lens . Two weeks ago i went to Healsville saw a great raptor display there and of the 266 shots I took with this lens i got maybe 5 in focus. All the shots with the kit lens 18-120 came out fine. This pattern has been reflected in the year since I splashed out on this setup with a new 7D.

Today I had two Yellowtailed Cockys in the garden and again got it out to try my hand, and again all the shots were out of focus when using the head as the spot focus point. then I noticed the point that was in focus was a spot about 2 to 3 feet behind the bird, so i tried focusing the camera on a spot about 3 foot in front of the bird, holding the focus lock while recomposing the shot and bingo That shot was just fine, Finally.


Are there any of you guys in Launceston who are familiar with this lens willing to meet me and try my lens on your camera so that I can narrow down the issue to the body or the lens. I would really appreciate it if there is someone willing to help who also owns this lens and would be willing to let me cross check by snapping a few shots with my body and their lens that would also be great. I am not asking for an overnight lend or anything just a few shots with either combo.


Cheers - John

[ricktas]

Sounds like your lens/camera needs calibrating John. What camera body and does it have a micro AF adjust' feature. This is for a Nikon but gives you the idea : http://www.focustestchart.com/chart.html

But it may mean you need to send the body and lens to Canon and get them to calibrate the two, so that it works perfectly

[Tatts]

It may be possible to fix with the micro adjustment on your 7d.
Did you buy it new? if it is out of calibration then it might be possible to have it fixed under warranty.

*Edit - need to type faster ;)

[fess67]

hi John,

I am not near you but have the 2.8 version of the lens and have used it on both the 50D and 5D.

First off, I agree with the previous comments, there may well be a calibration issue. Google calibrate 7D and have a look through some of that information.

Additionally, I was the same as you to start with, many of my shots were out of focus and like you I was a little dismayed. In my case it turned out to be a lack of practice with that lens. Some settings changes and a bit more practice adn mine now behaves (most of the time :p)

Have a look back at the out of focus images. Examine focal length and shutter speed. At 200 on the 7D you have an effective focal length of 320 so if your shutter speed is below this clarity can be affected. The F4 is not that fast so unless you up the ISO getting a good enough shutter speed may become an issue depending on light conditions. Can you tell if you were in 'one shot', 'AI focus" or 'AI servo" Have you tried (moving targets) having all focusing points enabled and AI Servo mode?

It may well be an issue with the lens however worth having an investigation session to see if it is more simple to fix :). Sorry if you know all this stuff, just came to mind as possibilities.

Good luck.

[reaction]

3ft seems more than what microadjust can deal with.
take it in for warranty.

[ElectricImages]

If you want to test your body with other lenses, just head to a camera store and ask to try out some of their lenses with your own body. :)

[jbee]

Hi everyone firstly sorry for my late reply back to you all, i had a massive food allergy problem rear its head yesterday that has knocked me for six since then.

Thanks for the replies and advice I will take it to the c amera store tommorow and have a word with the guy there. I will also look at the links provided re the micro adjust feature as well as my 7D does have that. I will check the settings you suggested to fess67

I think it just went out of waranty but as i bought it on Visa i get the double waranty. might have to call in that deal :)

Cheers - John

[jbee]

Good news it wasn't me :)
The Lens is back from Canon with a new focusing Mechanism installed - only had a chance to check quickly last weekend and it seems good now. Will do more testing at the weekend.

Thanks for the help and advice everyone, I should be back into it now, really looking forward to a new found enthusiasm

Cheers - John