Not such a quick question

[N01Chris]

I noticed my camera (canon 7d) was slightly out of focus with my 70-200 f4l lens and decided to use the micro-adjustment to fix it, I set up a sheet of text with many lines of text on a table at 45degrees to the table, i then proceded to hook my 7d up to my laptop and start a studio session in ightroom so I could see the photos bigger almost instantaneously, i then set my 7d on a tripod parellel to the tble and on level with the middle of the text and set it to fire from the computer (no camera shake) adjusted the micro-adjustment until it was just about right (I got to -20 but it still seamed to be a bit off) but then i noticed that if i had it on 0 and half pressed the shutter button twice it would correct itself to pretty much perfect focus, but since -20 was better for for the first press I left it on that (btw this was on one shot focus)

I then noticed today when I took both the camera and lens combination out with my dog for a walk, knowing that my dog is black and it is overcast and snowing, I wasn't expecting much however they didn't come out that bad exposure wise but quite a few of them were out of focus ever so slightly :/ me thinking it could be the micro-adjustment did a few shots with it off and on -20, I noticed that 0 was sharper but still not perfect, later on or tomorrow I may do another test where I should do it with measured out lines or try a different technique.

I bought my 7d a couple of weeks ago so its still in warranty but I fear that it is my 70-200 f4l which i bought last march or april (not too sure) but also should still be in warranty, if micro-adjustment was not to work would I be able to send them off to canon and adjusted professionally, for free? and would this knock the focus on my other lenses?

 

[hollis_f]

II set up a sheet of text with many lines of text on a table at 45degrees to the table

And there's your problem. Your poor camera has no idea what bit of text it should focus on, so your results will be useless. Your target for focusing needs to be flat and parallel with the camera's sensor, so that all of the target is at the same distance, so it doesn't matter which bit it focuses on.

 

[odd jim]

Also, if you micro adjust a zoom, it'll be bang on on whatever focal length you adjust it to, but then it'll be out at other lengths.

I would only use MA on a prime lens for that reason.

I'd try and swap it for another 70-200.

 

[Chris O]

Agree with both of the above, however if you want to see how better to set up a focus target, google spyder Lenscal. The idea is that you focus on the flat target with the 45 degree scale just off to one side.
Simple to do, just put a cereal box next to your scale, focus on that & then look at your scale.

 

[N01Chris]

Also, if you micro adjust a zoom, it'll be bang on on whatever focal length you adjust it to, but then it'll be out at other lengths.

I would only use MA on a prime lens for that reason.

I'd try and swap it for another 70-200.

i dunno, will amazon swap it? it worked fine on my 500d up untill now when i got my 7d? I think it's worth a ring though, also will they be bothered about the paint coming of in one place? or should i just not mention it?

 

[N01Chris]

And there's your problem. Your poor camera has no idea what bit of text it should focus on, so your results will be useless. Your target for focusing needs to be flat and parallel with the camera's sensor, so that all of the target is at the same distance, so it doesn't matter which bit it focuses on.

ah I see

trying that now

 

[N01Chris]

Agree with both of the above, however if you want to see how better to set up a focus target, google spyder Lenscal. The idea is that you focus on the flat target with the 45 degree scale just off to one side.
Simple to do, just put a cereal box next to your scale, focus on that & then look at your scale.

unfortunatly its -40 (should be more really) at 200mm and at 70mm it looks like its around -20 ish (cant get it quite right) so I'm thinking of returning it to amazon, however they might just turn around and say its the camera so should I say that it can't be because all my other lenses are fine? (but the 70-200 was fine on my 500d ) or should I try and change my 7d?

edit: i ment -20 at 200mm and around -10 at 70mm

 

[AndyB1976]

I think Amazon direct you to Canon after 30days during their return process.

I had issues with my 50mm and was going to return after a relatively short period of time. It was a good few years ago now so can't quite remember the timescales of how long I had the lens, I think I had it about 5weeks. I was expecting the usual simplified returns process.

I never went through with the return as I read that the 50mm 1.8 can be a bit hit and miss at fully open so decided for £80, just to stick with it a smaller apertures.

 

[N01Chris]

after some more testing with Chris O's Idea both my 50 1.8 and 18-55 kit lens are slightly front focusing :/ im gunna test all them on my 500d and then i'll be able to determine whether its the camera or lens (the fact that ive only noticed it in real life with the 70-200 suggests that it is quite a bit worse on that)

 

[N01Chris]

I think Amazon direct you to Canon after 30days during their return process.

I had issues with my 50mm and was going to return after a relatively short period of time. It was a good few years ago now so can't quite remember the timescales of how long I had the lens, I think I had it about 5weeks. I was expecting the usual simplified returns process.

I never went through with the return as I read that the 50mm 1.8 can be a bit hit and miss at fully open so decided for £80, just to stick with it a smaller apertures.

im not happy but It looks like it might just be my 7d and i got that in the week after christmas so i'll be able to return that easily i hope

 

[N01Chris]

further test results show that it is the 70-200 that is forward focusing on my 500d at the same distance and settingsa and the focus is in the exact same place as my 7d my 50mm i can micro-adjust as its a prime so thats fine (do i adjust it from a certain distance? Ive been doing it at about 2 meters away for the 70-200 and about a meter for the 50?) and my 18-55 i only ever use at the 18mm end and usually use live view (for landscapes).

this is using Chris O's method he explained

I'll try and see if I can return the 70-200 for a replacement but If they don't then I'll have to either send it off to canon (in which I'll probably have to pay) or live with it

any other suggestions?

 

[N01Chris]

just to let you's know, amazon wont exchange it (i've read on their website i think correctly but i may ring them) I've sent canon an email describing the fault just to see if they will calibrate it for free and I've used Chris O's methord for calibrating the lens using micro-adjustment and at -19 it seems to be sharp right through the zoom range (I just tested the zomed parts marked out e.g 70, 100, 135 and 200)

 

[N01Chris]

sorry for wasting your time but it looks like i've fixed it, must have been my cold hands making the images blurry this morning :')

 

[odd jim]

Lol, at least it's sorted (I hope!)

 

[N01Chris]

Lol, at least it's sorted (I hope!)

yea, im gunna take it out today and double check, i think i was being a bit critical, it looked ever so slightly out of focus but it must of been something else (probibly shutter speed being 1/30 and my tripod isnt so stable) and when I was looking at the book with text adjacent to my 'cereal box' the focus was perfectly in line with the box (and turns out my 50 didn't need any adjustment (before i was adjusting it at f1.8....)

 

[Chris O]

glad you are sorted!
I spent ages trying to sort out my nifty 1.8, got it bang on at about 2m @1.8 but ten everything else at 1.8 was soft :bang:
Manual focus seems to be the way with my 50 unfortunately.

 

[N01Chris]

ive been out and all seems good with the new setrtings however i encountered error 40 at one point :/ I couldnt turn it on or use it but i took the battery out and put it back in and it worked, im going out again soon but if it does it again do you think i should exchange it before the 30 day return thing ends on the 29th or not?

edit: could it be that its cold outside?

 

[odd jim]

Error 40 is indeed a batter error in the 7d (it uses very complex batteries!). It could be down to the cold so I wouldn't worry too much...

 

[N01Chris]

Error 40 is indeed a batter error in the 7d (it uses very complex batteries!). It could be down to the cold so I wouldn't worry too much...

ill keep an eye on it for the time being, the last return date is the 29th of jan so i have 3 days to test it further, if it happens a lot in a short period Ill replace it but its only happened once so far and its an easy fix (although opening the battery compartment with gloves is not )

 

[AndyB1976]

yea, im gunna take it out today and double check, i think i was being a bit critical, it looked ever so slightly out of focus but it must of been something else (probibly shutter speed being 1/30 and my tripod isnt so stable) and when I was looking at the book with text adjacent to my 'cereal box' the focus was perfectly in line with the box (and turns out my 50 didn't need any adjustment (before i was adjusting it at f1.8....)

Ideally get it on a tripod and use a remote or timer to eliminate any possible camera/tripod shake.

 

[N01Chris]

Ideally get it on a tripod and use a remote or timer to eliminate any possible camera/tripod shake.

I was using the two second timer but my tripod has been a bit flimsy since my trip to Scotland where I used it extensively for star shots and long exposures until a part broke and is now held together with a screw and other diy stuff