A.F. Fine Tuning.

HELP!!!. I've just been checking for fine focus on my K5iis and my K3. Most of my lenes including an old Takumar 135 K mount are all within 1-2 increments. Hardly worth bothering about. However one of my favorite lenses, my Sigma 24-60 f2.8 EX DG is way off. It is focusing close to me (front focusing) I believe. I've taken it to the full 10 increments and it is still out. this is at f2.8 and also still at f11. Is there any way to get more adjustment? Or is it a job for Sigma. I've had this lens 4 or 5 years. I bought it just before they brought out the 24-70 version.
CHEERS Vic.

I've just thought of something else. Even on Live View when it is sharp when I take the picture it is out of focus???? CHEERS Vic.

How can it be your favourite lens if it's always OOF!

You can add more in DEBUG mode though PK-Tether but it throws
all lenses out. Still worth trying.

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Live view is through the sensor so assuming the focus doesn't change from viewing live to pressing the shutter button it should be in focus.

Live view is WYSIWYG

Algi. When using it for "wide" shots with f11 or f16 focused 1/3rd of the way in then obviously all is OK. All is sharp with a big depth of field. It's just when I try anything closer with f2.8
Smeggy. Sorry, I made a mistake there. I meant when I use manual focus through the viewfinder not live view.
I was doing it all on a tripod with SR OFF and using the 2sec. delay timer.
I used cards which I had downloaded with the black and white oval and lots of lines, set up at 45 degrees so the oval looks like a circle and the camera at the same height so it was straight on to the card.
So still HELP!!!!!
CHEERS Vic

You need to focus on something vertical with a sloping
ruler at the side..... something like the DIY GhettoCal

LINKY

Simplified paper only version.....

LINKY

OR an easier way...

http://ricehigh.blogspot.com/2012/01/focus-adjust-k-5-and-pentax-af-lenses.html






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+1 on the ricehigh method.

To see if this can help anyone to help me. This is the set up and method I used to check the focus on my 24-60 f2.8 Sigma lens. It is focusing close to me (Front focusing)?.











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1) The set up in my light tent showing the cards with one turned a little to show they are at 45 degrees
2) As they are set.
3-4) Solid UniLok tripod and bubble level.
5) No adjustment.
6) Plus 10.
7) minus 10.
Back to no adjustment.
All are front focusing. IS IT ME?
Once again HELP!!! CHEERS Vic.

EDIT. They seem to have come out all in the wrong order to what I put them in but basics still apply it is front focusing. Also all photos have been reduced to 1000 pixels across the top for easy uploading. Vic.

EDIT (2) They were all taken at f2.8. 100iso. 125th sec. 2sec delay. vic.
EDIT (2)

The problem might be (a) the lens itself needs a workshop visit for calibration, and/or (b) because it's a Sigma lens, by which I mean that since Sigma avoid licensing costs by reverse engineering, etc, the lens id might be shared with another of your lenses. If (b), when the Sigma is mounted the camera sets up the lens AF the same as the other lens. If the Sigma is already 'out', then the AF adjustment applied to it would/could make it worse.

Does it focus correctly in LV?

Testing should be done with the lens wide open, and being a zoom it is likely to change through the zoom range, so test (a) only at your preferred focal length and put up with any oof at other points in the zoom range, or (b) at both ends and the middle of the zoom range, then average.

Given the possibility of lens id sharing, one thing you could try is reset/cancel all existing lens adjustments (after making a note of them per lens) and then just try setting up the Sigma.

If there is no other lens data in the camera that could cause confusion with the Sigma, and it is still 'out', this I think would point to the Sigma needing re-calibration by Sigma.

John. On LV and Manual focus it is good. Smeggy mentioned this earlier but I had done manual focus through the view finder and it was out.
All other fine focusing settings are at zero. I did this to make sure there was no possibility of any errors.
CHEERS Vic.

Does it ever focus correctly at infinity ?

Looks to be front focussing by a large amount..... probably
a lens fault.

It also looks like there's some camera shake. You could try
flash with the lens wide open to stop any shake also don't
have any room lights on..... daylight only test.

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KH. I've never actually focused it manually at infinity? Why?.
Algi. Yes to your first sentence. A lot.
If you read my last comment you will see there is NO camera shake. Big strong heavy tripod.
NO lights on. Just my light diffusing box set up in the conservatory. I've now talked to a man at Sigma and he has told me something else to try.
I'll now try this.
CHEERS Vic.

Just an update folks. I've sent it off to Sigma. They should get it today before 1pm. I'll let you all know the outcome and if they do a good job.
CHEERS Vic.

Up date. Sigma UK said my lens was approx. 10yrs old and would need a complete new circuitry fitted. £89.00'ish. So they also said I could P/X it for a new lens so I decided to have one of their "NEW" 17-70 f2.8-f4 DC lenses. (Wider zoom and only one stop more at 70mm). Serial number 013. How new is that. It's an HSM AF motorised lens and I new they were supposed to be fast and silent but "WOW" and "WOW" again. I didn't expect it to be as fast or as silent as it is. Also the focus is spot on.
CHEERS Vic.