AF Micro-Adjustment tool

[Isaac Burdeinick]

Thanks Bart:

Here are some Samples:

At Minus 5:

At Zero:

Plus 5:

I dont see much difference? they all are at 100%

 

[Bart_van_der_Wolf]

I dont see much difference? they all are at 100%

Hi Isaac,

First of all, did you use the recommended target I made available in post #1 for checking the focus on your camera LCD, or did you use this alternative one? With this alternative one, it looks like you need to increase the shooting distance to get some more moiré in the actual image, maybe that will help with picking a winner by looking at the actual image output. Maximizing the moiré, both on the camera LCD and in the final image, is the key to determining optimal focus.

Secondly, it is very likely that your widest f/6.3 aperture at 270mm focal length is generating enough DOF to not make much difference between -20 and +20 adjustment. Wider apertures have significantly more shallow DOF, making accurate focusing more critical and easier to check.

If you use the intended target, making sure you display it at 100% zoom (actual size, pixel per pixel) on your computer, do you get moiré at any focus position on the Live View camera LCD? If not, can you try different focus distance towards the target? The distance needs to be large enough to generate moiré in the actual image, but it may appear sooner on the camera LCD.

As a final resort you may try shorter focal lengths which allow a wider aperture, which should be okay if f/6.3 gives enough DOF to mask focus bias anyway.

Cheers,
Bart

 

[Isaac Burdeinick]

Thank You Bart

I Will go on and do it with the suggested target and more far away.
Ill post them after...

Thanks!

 

[Bob Latham]

I thought I'd bring an update to the Micro-Adjustment discussion as I've been performing some beta testing on an automatic calibration system written by a guy in the UK.

The software was developed using Canon's SDK utility and attempts to find the correct MA value for each lens. The code controls the camera via its USB port and takes a series of upto 40 images of a test chart (at all MA values from -20 to +20) and then performs an analysis of the contrast. The information is presnted in graphical format and the derived MA value is written (if required) to the camera body.

The initial release covered the 7D and 5DMkII with the 50D and 1DsMkIII now being tested. The 1DMkIII and 1DMkIV will follow shortly. I have just completed calibration of my 1DsMkIII with 7 primes (14, 24, 35, 50, 85, 100 and 135mm) with a solitary zoom (70-200) and the results look good. The values differ from the ones I obtained using a Lens Align Pro but not greatly so and all cases bar one have agreed with my previous direction (front or back focus). I'll be trying the telephotos and remaining zooms in the next day or so.

More can be read here at the developer's website. http://www.reikan.co.uk/focal/

Bob

 

[Bart_van_der_Wolf]

I thought I'd bring an update to the Micro-Adjustment discussion as I've been performing some beta testing on an automatic calibration system written by a guy in the UK.

Hi Bob,

Thanks for bringing this to our attention. I have to read up on this new tool, or try it, before I can comment.

It remains to be seen if and how this tool can be used on other cameras than the currently supported ones, including other brands, and including manual focus lenses. I anticipate some discussions and feature requests to accommodate a larger audience.

There is a risk of drawing too much attention away from my free solution in this thread which even works with other camera brands. In fact, the thread is already so long that I frequently received requests for summaries, also by PM and email). I've therefore created a new thread (here) dedicated to FoCal. The initiative deserves it's own space, especially since it presumably will become a commercial product.

Cheers,
Bart

 

[nicolas claris]

Hi Bart and all
This tool is still working great!
Over the past three years I couldn't use it because the Pentax 645D had no live view…
This is why I used the Micheal Tapes tool (see my post here).
For some peace of mind, i got used to verify quite oftenly (before every important shoot, those which cannot be redone) the AFMA with 'natural' targets (pedestrian cross road stripes, trees etc.) while on the fields…
So today was the day to adjust all my lens to the brand new 645Z, and forgetting Bart's tool, i adjusted all my lens:
25 mm - 8
55 mm - 6
80/160 - 2
90 mm - 3
120 mm - 5
300 mm = - 7
And suddenly, poking my head, I remembered that I could use the 645Z' live view and Bart's target…
Bang! all settings confirmed!
When AFMA is good, one can see the small circles and some purple area around.

Nice : )

Thanks again Bart!

 

[Asher Kelman]

Bravo on getting the 645Z and also on being smart, optimizing this gem of a camera.

Did those first adjustments come from natural targets or using Michael Tapes tools? BTW, which version do you have?

This is an exciting upgrade!

Except for not having a fast flash synch speed, you're pretty well set. I find no practical limitation in only having low shutter speed synch on the A7R, as I hardly every use flash to overwhelm daylight and so darken the background and sky.

Asher

 

[nicolas claris]

Hi Asher
The first adjustments came from natural targets, Michael Tapes does not recognize yet the 645Z files.
Flash sync is 1/125 fairly enough for me when I use it (mainly for some macros).

Yes this body is a great upgrade!

 

[Asher Kelman]

Hi Asher
The first adjustments came from natural targets, Michael Tapes does not recognize yet the 645Z files.
Flash sync is 1/125 fairly enough for me when I use it (mainly for some macros).

Yes this body is a great upgrade!

Nicolas,

I would hope that Michael updates his software. Have you let him know your needs?

Asher