AF Microadjustment Help!

[Mark Elberson]

After reading this article "This lens is soft" and other myths ("http://www.lensrentals.com/news/2008.12.22/this-lens-is-soft-and-other-myths) I decided that I am doing myself a huge disservice by not "calibrating" each of my lenses to my body using the AF Microadjustment tool provided in my 50D.


What is the best/easiest way to do this? I am assuming I need to take some exposures using a tripod and cable release at varied Microadjustment settings but would be a good target to shoot? I wish I had a ISO 12233 Chart to do so but what can I use that's just lying around my house? A page from a magazine? When I evaluate each exposure should I do it at 100%? Should I shoot wide open?

[Oren]

I feel the same - I'm not taking advantage of my AF Microadjustment. Mainly because of fear and lack of time. My fear is that I screw up something... if I do, is there a "reset" setting which will bring back my lens to the same state it was before?

[Mark Elberson]

I feel the same - I'm not taking advantage of my AF Microadjustment. Mainly because of fear and lack of time. My fear is that I screw up something... if I do, is there a "reset" setting which will bring back my lens to the same state it was before?
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You can always put it back to "disable" :)

[Mark Elberson]

So I tried to calibrate 2 lenses this morning with little success. I took 11 pictures ranging from -5 through +5 for each lens. The weird thing is that when I examined the results I noticed that best be sharpness was at -4 and +3 for one of the lenses. That didn't make any sense to me. This how I did it. I would love some advice on how to achieve better results!

Tripod mounted with cable release
Magazine page on wall at about minimum focusing distance for lens
Wide open
RAW

[Daniel Browning]

I think it is faster and more accurate to set microadjustment in liveview with a high-res LCD and 10X magnification like on your 50D. For example:

Setup the test chart at 45 degrees, cable release, yadda yadda, etc.
Live view
Initiate one shot autofocus
Check for front- or back-focus in the 5X view and 10X view.

Initiate one shot autofocus a few more times to make sure it wasn't a fluke.
Make a guess about how much microadjustment is needed. (E.g. try +10)
Autofocus again and examine at 5X and 10X.
Too much? Try +5 instead of +10.
Autofocus again and check liveview. Now not enough? Try +7.
Ahh... just right.



Liveview is a revolution. I can't live without it.

[Oren]

Did you take photos just from -5 to +5 or these 2 points where the 2 with the best results?

[Mark Elberson]

Thanks Daniel. I'll give that a try!


Have you done all of your glass? What's the largest adjustment you had to make?

[Daniel Browning]

Have you done all of your glass?


Yes. First thing I do after inhaling the factory fresh scent. :)



What's the largest adjustment you had to make?


+9 for the 70-200 f/4 IS.

[Bob]

<p class="MsoNormal" style="margin: 0in 0in 10pt;"]<span style="font-size: small;"]<span style="font-family: Calibri;"]Mark -- Something to consider:<span style="mso-spacerun: yes;"]
<p class="MsoListParagraphCxSpFirst" style="text-indent: -0.25in; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1;"]<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"]<span style="mso-list: Ignore;"]<span style="font-family: Calibri; font-size: small;"]1.)<span style="font: 7pt 'Times New Roman';"] <span style="font-family: Calibri; font-size: small;"]Make sure the distance that you focus from will give 2 to 3 pixels for marks on the test target.<span style="mso-spacerun: yes;"] &ndash; Otherwise, very small movements on the tripod will give a pixel shift causing the image to look different &ndash; less or more clear.
<p class="MsoListParagraphCxSpMiddle" style="text-indent: -0.25in; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1;"]<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"]<span style="mso-list: Ignore;"]<span style="font-family: Calibri; font-size: small;"]2.)<span style="font: 7pt 'Times New Roman';"] <span style="font-family: Calibri; font-size: small;"]Lens&rsquo; IS is turned-off
<p class="MsoListParagraphCxSpMiddle" style="text-indent: -0.25in; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1;"]<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"]<span style="mso-list: Ignore;"]<span style="font-family: Calibri; font-size: small;"]3.)<span style="font: 7pt 'Times New Roman';"] <span style="font-family: Calibri; font-size: small;"]Mirror lock-up is enabled
<p class="MsoListParagraphCxSpLast" style="text-indent: -0.25in; margin: 0in 0in 10pt 0.5in; mso-list: l0 level1 lfo1;"]<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"]<span style="mso-list: Ignore;"]<span style="font-family: Calibri; font-size: small;"]4.)<span style="font: 7pt 'Times New Roman';"] <span style="font-family: Calibri; font-size: small;"]Take 2 to 3 photos at each setting &ndash; keeping the sharpest image to judge the adjustment.
<p class="MsoListParagraphCxSpLast" style="text-indent: -0.25in; margin: 0in 0in 10pt 0.5in; mso-list: l0 level1 lfo1;"]

[pierlux]

Hi all!


Bryan describes a method to perform AF microadjustment on his 50D review: http://www.the-digital-picture.com/Reviews/Canon-EOS-50D-Digital-SLR-Camera-Review.aspx ("http://www.the-digital-picture.com/Reviews/Canon-EOS-50D-Digital-SLR-Camera-Review.aspx).


Chuck Westfall reports an (excellent) unofficial procedure for micro focus adjustment on his tech tips of December 2008 relatively to the 1D/1Ds MkIII which is applicable also to the 5DII/50D: http://www.digitaljournalist.org/issue0812/tech-tips.html ("http://www.digitaljournalist.org/issue0812/tech-tips.html).


Additional useful information is available here: http://regex.info/blog/photo-tech/focus-chart ("http://regex.info/blog/photo-tech/focus-chart) and here: http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html ("http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html) .


Hope I wrote exactly what I meant to say...


Pierluigi

[Mark Elberson]

Did you take photos just from -5 to +5 or these 2 points where the 2 with the best results?
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I took 11 photos (-5,-4,-3,-2,-1,0,1,2,3,4,5)


I haven't had time to try Daniel's technique but hope to this week/weekend

[Oren]

What if your lens would be the best at say +6?

[btaylor]

Wouldn't it be lovely if Canon released a firmware version including AF Microadjustment for the 40D!!!! Likelyhood is very low but just once it'd be nice if they thought about their existing customers as well as potential customers. I love my 40D but I'd hate to spend big $$$ on a 70-200 f/2.8(if the financial planner gives the go ahead - I don't think I could hide that one and pretend it's always been in the camera bag)and not be able to use it properly if it didn't focus precisely.

[HiFiGuy1]

I do, too. I am largely very content with my 40D, but I feel that AF microadjustment is a critically important functional addition to a camera. I don't really want a 50D, to be honest, but that one thing might drive me to do it eventually. Either that, or the 1D Mark IV that I know is coming one day. How do I KNOW, you may ask? Because I hear it calling my name! [:)]