Advice on micro-adjusting a 300mm lens?

I pick up a new MkIII body tomorrow.

I would love to know everyones individual approaches to micro-adjusting a 300mm f/2.8 lens and how you would all go about it.

Obviously there will be a few differing methods but I'd love to hear them all.

Also would you use the same methods with converters on?

All help greatly appreciated.

Thanks for taking the time to read my post.

Here you are:
http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html

Essentially, use a laptop displaying the image at 50 X FL, or 15 m for the 300, and make the lens focus at maximum amount of interference patterns.

Offcially you need to do this on a tripod, but I do find I manage very well even when handheld.

Kind regards, Wim

It took me quite a long time ..but I tried 2 different ways .

http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html

http://photo.net/learn​/focustest/

And then after getting stable results indoor I confirmed results outdoor with a bottle of Vitel outside (30-40 meters far)
With my 5DMKII that's the type of adjustement I memorized
300L2.8 non IS -> +6
300L2.8 non IS + TC1.4X -> +6
300L2.8 non IS + TC2X -> +12
300L2.8 non IS + TC1.4X + TC2X +17
And nearly same adjustement with my 50D +6(no TC) +10 (TC1.4) +15(TC2.0)

You can try my free chart here as well.
https://photography-on-the.net …736&highlight=f​ree+adjust

wimg wrote in post #9060348
Here you are:
http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html

Essentially, use a laptop displaying the image at 50 X FL, or 15 m for the 300, and make the lens focus at maximum amount of interference patterns.

Offcially you need to do this on a tripod, but I do find I manage very well even when handheld.

Kind regards, Wim

Thanks I had seen this one and was definitely keen to try it

newworld666 wrote in post #9060377
It took me quite a long time ..but I tried 2 different ways .

http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html

http://photo.net/learn​/focustest/

And then after getting stable results indoor I confirmed results outdoor with a bottle of Vitel outside (30-40 meters far)
With my 5DMKII that's the type of adjustement I memorized
300L2.8 non IS -> +6
300L2.8 non IS + TC1.4X -> +6
300L2.8 non IS + TC2X -> +12
300L2.8 non IS + TC1.4X + TC2X +17
And nearly same adjustement with my 50D +6(no TC) +10 (TC1.4) +15(TC2.0)

Excellent. I'll try both tools, thanksfor sharing your experiences and the setting you happened to arrive at with your combo's too.

I's funny that almost everyone I see has + settings and very few minuses.

TeamSpeed wrote in post #9060489
You can try my free chart here as well.
https://photography-on-the.net …736&highlight=f​ree+adjust

Thanks for this I'd actually already red the post with your chart extensively and also have it printed out ready for tomorrow too!

butcha27 wrote in post #9061117
Thanks I had seen this one and was definitely keen to try it

I don't have a 300L, but I did calibrate my fast lenses this way, including 135L with extender. None required micro-adjustment, except the 85L. I will check the 100-400 this week, but I haven't noticed any problems yet.

Kind regards, Wim

Here's the link to how I did the MFA on my friend's MkIII and 300 2.8.

I feel your way can give some result..
but the most difficult part for me.. was to adjust in middle of the "dof", to do this it took me a rather long time and I tried with different distance till 30 meters to confirm the correct adjustement.
I don't know if I am clear, but if dof is 50cm I try to adjust at 25cm exactly in the middle

I used this calculator ->
http://www.dofmaster.c​om …000&distance=70​&units=1.0

to try to get the right position for 3 far bottles ...

wimg wrote in post #9060348
Here you are:
http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html

Essentially, use a laptop displaying the image at 50 X FL, or 15 m for the 300, and make the lens focus at maximum amount of interference patterns.

Offcially you need to do this on a tripod, but I do find I manage very well even when handheld.

Kind regards, Wim

I tried that method but found it rather insensitive, perhaps because of the low pixel density on my old laptop.

I found a high contrast subject was best and just looking to maximise sharpness.

The main problem with longer lenses is the distance needed, some lenses show a lot of random variation when close that disappears if you back off. Notably these tended to be the non-L lenses. I think this is why the 50X F suggestion is made.

I did a short note of this experience http://www.zen20934.ze​n.co.uk …phy/Microadjust​/index.htm, I found it a lot easier to use SRF software, but you can do it just by pixel peeping.

Hi Lester,

Lester Wareham wrote in post #9066245
I tried that method but found it rather insensitive, perhaps because of the low pixel density on my old laptop.

I found it very sensitive. Too sensitive for trying to adjust for MF on the TS-E 17 ...

That's another option. A whiteboard at 45 degrees with vertical black marker lines connected by a horizontal works quite well too, IME.

The 50X FL suggestion is made, AFAIK, because that is the distance at which Canon tests AF, and optimizes lenses for, generally speaking anyway. Canon has an AF test somewhere, and they do state that you should test at 50X FL in the accompanying document.

Resolution tests generally are also done at 50X or 100X the FL.

I did a short note of this experience http://www.zen20934.ze​n.co.uk …phy/Microadjust​/index.htm, I found it a lot easier to use SRF software, but you can do it just by pixel peeping.

Very interesting read, and congrats on the 7D, BTW .

I do think your results with the 50 F/1.4 may well indicate why this lens has problems focusing close to MFD, especially in not-so-good light conditions.

Kind regards, Wim