AF Microadjustment Help!

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06-02-2009, 03:37 PM
Mark Elberson

AF Microadjustment Help!

After reading this article "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?
06-02-2009, 05:33 PM
Oren

Re: AF Microadjustment Help!

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?
06-02-2009, 07:32 PM
Mark Elberson

Re: AF Microadjustment Help!

Quote:

Originally Posted by 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?
<div style="clear: both;"]</div>

You can always put it back to "disable" :)
06-06-2009, 03:23 PM
Mark Elberson

Re: AF Microadjustment Help!
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
06-07-2009, 12:39 AM
Daniel Browning

Re: AF Microadjustment Help!
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:
1. Setup the test chart at 45 degrees, cable release, yadda yadda, etc.
2. Live view
3. Initiate one shot autofocus
4. Check for front- or back-focus in the 5X view and 10X view.
5. Initiate one shot autofocus a few more times to make sure it wasn't a fluke.
6. Make a guess about how much microadjustment is needed. (E.g. try +10)
7. Autofocus again and examine at 5X and 10X.
8. Too much? Try +5 instead of +10.
9. Autofocus again and check liveview. Now not enough? Try +7.
10. Ahh... just right.
Liveview is a revolution. I can't live without it.
06-07-2009, 06:58 AM
Oren

Re: AF Microadjustment Help!

Did you take photos just from -5 to +5 or these 2 points where the 2 with the best results?
06-07-2009, 01:07 PM
Mark Elberson

Re: AF Microadjustment Help!

Thanks Daniel. I'll give that a try!

Have you done all of your glass? What's the largest adjustment you had to make?
06-07-2009, 02:01 PM
Daniel Browning

Re: AF Microadjustment Help!

Quote:

Originally Posted by Mark Elberson

Have you done all of your glass?

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

Quote:

Originally Posted by Mark Elberson

What's the largest adjustment you had to make?

+9 for the 70-200 f/4 IS.
06-08-2009, 12:25 AM
Bob

Re: AF Microadjustment Help!

<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;"] – Otherwise, very small movements on the tripod will give a pixel shift causing the image to look different – 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’ 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 – 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;"]
06-08-2009, 08:52 AM
pierlux

Re: AF Microadjustment Help!

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.

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 .

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

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

Pierluigi
06-09-2009, 03:56 PM
Mark Elberson

Re: AF Microadjustment Help!

Quote:

Originally Posted by Oren

Did you take photos just from -5 to +5 or these 2 points where the 2 with the best results?
<div style="CLEAR: both"]</div>

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
06-09-2009, 04:05 PM
Oren

Re: AF Microadjustment Help!

What if your lens would be the best at say +6?
06-10-2009, 07:39 PM
btaylor

Re: AF Microadjustment Help!

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.
06-10-2009, 08:09 PM
HiFiGuy1

Re: AF Microadjustment Help!

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! [:)]