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Author Topic: What's wrong with the microadjustment?!  (Read 3539 times)

Mt Spokane Photography

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Re: What's wrong with the microadjustment?!
« Reply #15 on: February 09, 2012, 07:59:22 PM »
http://FocusTestChart.com

i use this chart

you can only calibrate each lens at 1 focal length (i thin the 1Dx you can do 2)
so always calibrate for where you will potentially have the shallowest depth of field

ie longest zoom and MFD

then to test infinity shoot distant targets after calibration to check


I have three lenses I struggle very much with , 24 L II, 50 L and the 85 L II.

I just now adjusted the 50 L to -7 and it seems to be sharp at the "0" mark of my LensCal, but I take it off the tripod and shoot at something with a bit more distance (10 meters) and everything is COMPLETELY off. I just kept shooting near and farther (only 10 meters inside as it is dark outside) and ended up at +3, so what's the point of these tools. With the two other cameras it worked perfectly. SO now, at +3, it's only almost right and sharp from mfd to 10 meters, will try outside tomorrow, hopefully find something I can use. Can't understand why this camera is so difficult, when the two others were soo easy, it's the same lenses.


I believe you.  There is something going on.  You are lucky that you have other camera bodies to compare.  These things do happen, send the body and one of the troublesome lenses together to Canon explaining how it works differently from the others.

Make sure you have bright light when testing them, low light can be troublesome with AF.  If I get some time, i'll try to compare various light levels with AF accuracy using FoCal.


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Re: What's wrong with the microadjustment?!
« Reply #15 on: February 09, 2012, 07:59:22 PM »

neuroanatomist

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Re: What's wrong with the microadjustment?!
« Reply #16 on: February 09, 2012, 08:57:32 PM »
1m (where my LensCal is)

I micro adjust all my lenses at MFD

This is really not a good idea, unless you'll always be shooting at the MFD.  Canon recommends setting the AFMA at 50x the focal length, LensAlign at 25x the focal length (e.g., 5m/16' or 2.5m/8', respectively, for a 100mm lens).  The reason for that is if you calibrate at the MFD, the optimal adjustment is usually not applicable across the broader focal range, whereas calibrating from a greater distance gives a result that's more applicable across the range of subject distances. The only lenses where you might want to be calibrating at such short distances are UWA lenses.

Viggo, I see the phenomenon you're describing, with the LensAlign at 25x focal length, but it's less pronounced. I generally find that as I step through the images, when approaching the best adjustment, the shots with focus starting from infinity will be off, then at the best adjustment they’ll all be spot on, then as I move away the shots with focus starting from the MFD will be off (or vice versa).
EOS 1D X, EOS M, and lots of lenses
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wickidwombat

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Re: What's wrong with the microadjustment?!
« Reply #17 on: February 09, 2012, 09:06:49 PM »
1m (where my LensCal is)

I micro adjust all my lenses at MFD

This is really not a good idea, unless you'll always be shooting at the MFD.  Canon recommends setting the AFMA at 50x the focal length, LensAlign at 25x the focal length (e.g., 5m/16' or 2.5m/8', respectively, for a 100mm lens).  The reason for that is if you calibrate at the MFD, the optimal adjustment is usually not applicable across the broader focal range, whereas calibrating from a greater distance gives a result that's more applicable across the range of subject distances. The only lenses where you might want to be calibrating at such short distances are UWA lenses.

I dont use any of those systems, I posted the chart I print out and shoot. I usually set it at the MFd and then move the tripod back a little keeping it at approx 45 degrees usually try and have the width of the page fill the width of the frame and check that the camera is square to the page.
this way the shot is as close as possible so easy to see and change in sharpness when zooming in to check
set AF to lock onto the thick black line but check the sharpness againt the numbers down each side.
if you move too far back the angle of the lens to the page flattens significantly and the shot is smaller in the frame making it harder to see changes in clarity.
then once my calibration is set i'll take some ditance sots of the tripod then remove the camera from the tripod and take a variety of variable range shots making sure i am happy with the focus

This method seems to work for all my lenses so far.

soo many different recomendations around for micro adjust calibration though.
I wouldnt mind giveing that calibration software a try though
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Viggo

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Re: What's wrong with the microadjustment?!
« Reply #18 on: February 10, 2012, 05:51:37 AM »
1m (where my LensCal is)


I micro adjust all my lenses at MFD


This is really not a good idea, unless you'll always be shooting at the MFD.  Canon recommends setting the AFMA at 50x the focal length, LensAlign at 25x the focal length (e.g., 5m/16' or 2.5m/8', respectively, for a 100mm lens).  The reason for that is if you calibrate at the MFD, the optimal adjustment is usually not applicable across the broader focal range, whereas calibrating from a greater distance gives a result that's more applicable across the range of subject distances. The only lenses where you might want to be calibrating at such short distances are UWA lenses.

Viggo, I see the phenomenon you're describing, with the LensAlign at 25x focal length, but it's less pronounced. I generally find that as I step through the images, when approaching the best adjustment, the shots with focus starting from infinity will be off, then at the best adjustment they’ll all be spot on, then as I move away the shots with focus starting from the MFD will be off (or vice versa).


Did another test with the other 5d, and it's the same crap there... Jesus Christ... 4500 usd camera and lens-kit, and it can't focus from more than one distance, fantastic Canon, just fantastic.

At least this explains why I have every other shot tack sharp and the other either non-usable or "keep because it's a good picture, although it isn't sharp"

So that's what 21 megapixels does, shows you all the  F A I L  in autofocus and lenses. And this isn't nitpicking, it's one good and one oof image. I'll try to post an example....

*EDIT*

Here's the example, and keep in mind, this is very close, about 1,2 meters, shooting near infinity and this misfocusing are tens of meters.....

« Last Edit: February 10, 2012, 06:19:37 AM by Viggo »
1dx, 17-40 L, 24-70 L II, 85 L II, 200 f2.0 L

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Re: What's wrong with the microadjustment?!
« Reply #18 on: February 10, 2012, 05:51:37 AM »