Discussion
Going to have a go at micro-adjusting my 7D/15-85, primarily as I'm not happy with the sharpness with this lens - but will have a play with my other lenses whilst I'm at it.
Google throws up thousands of results for focus charts to download and print - can anyone recommend one that they've worked with ?
Google throws up thousands of results for focus charts to download and print - can anyone recommend one that they've worked with ?
dsc do some free charts you can download as pdfs:
http://www.dsclabs.com/free_charts.htm
Print off the seimens star chart, bottom left, on a decent high res printer, and mount it onto thick card or thin bit of ply, and your away
LongQ said:
This looks really good - that's my Sunday morning sorted!Seight_Returns said:
Going to have a go at micro-adjusting my 7D/15-85, primarily as I'm not happy with the sharpness with this lens - but will have a play with my other lenses whilst I'm at it.
Google throws up thousands of results for focus charts to download and print - can anyone recommend one that they've worked with ?
I don't know the 15-85 but I assume it has some potential for manual focus. In which case can you get it as sharp as you would like when focusing manually?. If not the micro-focus adjustment for the AF will do nothing for you.Google throws up thousands of results for focus charts to download and print - can anyone recommend one that they've worked with ?
When I had a 7D on rental I tried the Micro-focus adjustment with my 70-300 DO lens and felt the results were, by and large, inconclusive. I could make things worse but not obviously better. Subsequently I realised that there was a general focus problem (it ws more often than not very soft at teh long end of the zoom) and had the lens serviced and calibrated. Much better after that although still a bit soft at the extreme end of the range but I suspect they all are. I have not revisited microfocus with that lens on my 1D3 but I did try a couple of other lenses, briefly, and found no obvious benefits at all.
LongQ said:
I don't know the 15-85 but I assume it has some potential for manual focus. In which case can you get it as sharp as you would like when focusing manually?. If not the micro-focus adjustment for the AF will do nothing for you.
Yes - I find that I can get better results with the 15-85 focusing manually - or by using the contrast detect focusing in Liveview - which is why I'm hopeful that MFA might improve things.I have no complaints at all with the focusing/sharpness of my 10-22 and 70-300L on my 7D. I've asked the question here and elsewhere whether I should expect the same IQ from my 15-85 and the answer seems to be yes.
Seight_Returns said:
LongQ said:
I don't know the 15-85 but I assume it has some potential for manual focus. In which case can you get it as sharp as you would like when focusing manually?. If not the micro-focus adjustment for the AF will do nothing for you.
Yes - I find that I can get better results with the 15-85 focusing manually - or by using the contrast detect focusing in Liveview - which is why I'm hopeful that MFA might improve things.I have no complaints at all with the focusing/sharpness of my 10-22 and 70-300L on my 7D. I've asked the question here and elsewhere whether I should expect the same IQ from my 15-85 and the answer seems to be yes.
)Consider sending the lens to Canon for service and calibration. My 70-300 DO was slowly going 'bad' on AF but would often throw up a sharp image in the problem range - so I thought it was me or just the lens design. Service and calibration resulted in a marked improvement all round, though is it still a tad soft at the very longest end. I suspect that is how they are.
I don't see that I've got anything to lose other than an hour of my time having a go at MFA, I'll post the results but probably won't be until the w/e now. Thanks for the link to the systematic approach to MFA, I'll use it.
When you send your lens in for calibration, did you just send the lens, or the lens and the camera ? If I may be cheeky enough to ask - how much did it cost ? My camera and lens are both out of warranty.
When you send your lens in for calibration, did you just send the lens, or the lens and the camera ? If I may be cheeky enough to ask - how much did it cost ? My camera and lens are both out of warranty.
Seight_Returns said:
I don't see that I've got anything to lose other than an hour of my time having a go at MFA, I'll post the results but probably won't be until the w/e now. Thanks for the link to the systematic approach to MFA, I'll use it.
When you send your lens in for calibration, did you just send the lens, or the lens and the camera ? If I may be cheeky enough to ask - how much did it cost ? My camera and lens are both out of warranty.
Yep, nothing to loose by trying it but in my case, used as an example, it was not the immediate answer so I thought it was best to make that point.When you send your lens in for calibration, did you just send the lens, or the lens and the camera ? If I may be cheeky enough to ask - how much did it cost ? My camera and lens are both out of warranty.
I just took the lens in to a service agent. Turns out that, being a DO lens, it went back to Canon anyway. The fixed service charge was £160. Parts and VAT included. I suspect that going direct may have shaved a bit off that based on subsequent information gleaned. But that was a year ago so prices may have changed.
Seight_Returns said:
Thanks - much appreciated. I'll set my tripod up in the kitchen on Saturday and see how I get on. Fingers crossed - will post the results either way.
I could Ebay the suspect 15-85 and buy a new one with a warranty for less than £160 - moral dilemma !
That is a challenge. The 70-300 DO lists at abot £1200 these days. eBay has had a few (unusually) just recently and selling for about £500. (It's regarded to be of an 'L' spec standard.)I could Ebay the suspect 15-85 and buy a new one with a warranty for less than £160 - moral dilemma !
I bought mine for somewhat less than that, albeit heavily used, and hammered it for a year or so before the problem became apparent so I figured the service cost, though unwelcome, was not so bad.
When it first came back it was rubbish so I returned it. Apparently something else had broken in the focus mechanism after calibration (hmm) so it was serviced again with no additional charge and is really much better for the attention. Part of my thinking was along the lines of having it serviced would, if needed, give me an opportunity to get it that of personalised attention whereas buying a used replacement would not (unless I stood the cost of service as well ...). Buying new, even when they were available for under £1000, was not really an option.
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