micro adjustment using a computer screen?

I think I read a thread on here that talks about using a computer screen to do micro adjustments. The screen will display a circular pattern. Does anyone remember or know what I am talking about?

you want to do MFA in the type of light that you typically shoot under.

i'm assuming you don't typically shoot computer screens.




this thread show my set up (full frame in post 6) and i also talk a little about my feelings and experience with MFA:

https://photography-on-the.net …/showthread.php​?t=1446712

Canon's take on MFA. http://www.learn.usa.c​anon.com …oadjustment_art​icle.shtml

A thorough reading of this has convinced me that not bothering with MFA, unless I have a problem, is the way to go. I never 'test' lenses. I just use them. I've never felt the need for MFA.

Since gutting the 7D2 this is the first time I have ever needed to MFA. It is called the Moire Fringe technique.

https://tnonline.wordp​ress.com …justment-by-keith-cooper/

http://travelthroughpi​ctures.com/photo-items/mfa-moire-reikan/

http://www.komar.org/f​aq/camera/auto-focus-test/

However from this thread one of the the top birders MFA's at minimal focusing distance. I may try it to see how it compares to my dollar on the wall vs Dot Tune vs Reikan FoCal tests.

http://www.fredmiranda​.com …/topic/1398378/​1#13292444

As for shooting in the light you normally shoot in. When I do something I go all out. I had FoCal for over a year but never got into it. A few months ago I decided to bring it out of hibernation and upgraded to Pro so I could MFA over 400mm. I purchased the hard target and after a little research picked up some studio CFL's that are 5500K to more closely match the conditions I shoot in.

digital paradise wrote in post #17803117
Since gutting the 7D2...

Interesting turn of phrase....

There were days I wanted to

Bassat wrote in post #17803013
Canon's take on MFA. http://www.learn.usa.c​anon.com …oadjustment_art​icle.shtml

A thorough reading of this has convinced me that not bothering with MFA, unless I have a problem, is the way to go. I never 'test' lenses. I just use them. I've never felt the need for MFA.

From the article:

Summary:
This terrific Canon feature will surely be a benefit to very critical users, whose only option if they encountered a tendency for focus error in the past was to send equipment to a service technician for evaluation and adjustment. Especially since AF Microadjustment can be performed for individual lenses if needed, it's a great step forward in allowing users to fine-tune their cameras to their exact needs.

Personally, I try to MFA all my lenses that are 2.8 or wider and it does make a difference for me. Most require less than 5 steps of adjustment but my 50 1.4 is set to +16 and it looks like crap with no adjustment. YMMV.

digital paradise wrote in post #17803117
Since gutting the 7D2 this is the first time I have ever needed to MFA. It is called the Moire Fringe technique.

https://tnonline.wordp​ress.com …justment-by-keith-cooper/

http://travelthroughpi​ctures.com/photo-items/mfa-moire-reikan/

http://www.komar.org/f​aq/camera/auto-focus-test/

What does " gutting the 7D2" mean ??

Submariner wrote in post #17804920
What does " gutting the 7D2" mean ??

I meant to say getting but since it kinda became a bit of a joke I didn't correct it.

The fastest way to MFA is to use a target that gives you indication of where focus lies in relation to the target you aimed at. Just having a flat subject that you shoot at won't tell you if focus is before or after that subject, and you are left with a guessing game of where to go next with your values.

Something simple like a high contrast vertical target, and a yardstick laying next to it at the 1/2 way mark going toward you is a good way to do this, or make something like what I sell in my signature. Doing this will allow you to narrow to the needed value in just a couple of tries.