Poll: AF Accuracy Adjustments

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Lenses for Pentax CamerasLenses for Pentax Ca...

7650 posts
19 years
Totana,
Spain.

Posted 23/10/2012 - 07:17 Link

Following on from some replies in another thread, I'd be interested to know how many of us here have had to make fine tuning adjustments in-camera for AF inaccuracies to correct either back or front focussing issues.

Peter E Smith - flickr Photostream

Joe S Joe S

341 posts
16 years
Denmark .. or somewhere else

Posted 23/10/2012 - 07:36 Link

My previous K7 needed massive correction (edit: -9 and clearly noticeable). "Fortunately" aomebody stole that body and my K5 is spot on or -1 on the lenses I have tested. So I am actually not sure correction is needed.

Hi. My name is Joel and I'm a travelholic.
Stolen kit: Pentax K7 #3428965 and Pentax FA 43mm #0028350

Edited by Joe S: 23/10/2012 - 07:37

MattMatic MattMatic

5866 posts
21 years
Sussex,
UK

Posted 23/10/2012 - 07:38 Link

All of my lenses, but only really noticeable because I regularly shoot f/2.8 and brighter where DoF and focussing is critical.

FWIW, I've found the chart approach only gets you so far - I still have to fine tune a couple of steps for portraiture.

Matt

http://www.mattmatic.co.uk
(For gallery, tips and links)

Mannesty Mannesty

7650 posts
19 years
Totana,
Spain.

Posted 23/10/2012 - 07:46 Link

MattMatic wrote:
All of my lenses, . . .

Thanks Matt, did you vote in the poll?

ilovesaabs ilovesaabs

1386 posts
11 years
Richmond/Denbigh

Posted 23/10/2012 - 09:27 Link

Both 16-50 and 60-250 were ok on K20D before SDM failure....Repaired lenses focus perfectly without correction. No such issues with DA*300. All spot on on the K-5

MattMatic MattMatic

5866 posts
21 years
Sussex,
UK

Posted 23/10/2012 - 10:10 Link

Quote:
Thanks Matt, did you vote in the poll?

Doh! Not enough sleep...

gartmore gartmore

6724 posts
18 years
Glasgow,
Scotland

Posted 23/10/2012 - 10:31 Link

All my lenses were fine on the K20 until one day when they all back-focused. There wasn't enough adjustment without hacking but a global adjustment sorted everything

DaveHolmes DaveHolmes

1174 posts
13 years
Bradford

Posted 23/10/2012 - 11:08 Link

I haven't really checked since moving to the K5... My lenses appear to be sharp and I'm a little nervous of fiddling round and making a hash of it to be honest...

simonkit simonkit

2106 posts
16 years
Mold,
North Wales

Posted 23/10/2012 - 12:38 Link

Never had a single issue/need to adjust with the K10D, K20D or now the K5

Simon

My website http://www.landscapephotographyuk.com

My Facebook page http://www.facebook.com/landscapephotographyuk

Find me on Google+ link

andrewk andrewk

828 posts
15 years
Oldham,
Lancashire,UK

Posted 23/10/2012 - 13:44 Link

I have a Sigma 28-70mm f3.5-4.5 Epsilon that back focusses a little, especially close to. If/when I upgrade from the K200D I use, maybe I'll be able to fix that and it'll get some more use. It's a shame really, as it's very solidly constructed and in perfect condition.

Andrew

Mike-P Mike-P

13615 posts
16 years
Hythe,
Hampshire UK

Posted 23/10/2012 - 13:59 Link

My Pentax lenses are all fine, my Sigma lenses need some adjustment, the MKI 70-200mm f2.8 needed it on the K-7 and K-5.

Interestingly my Canon lenses don't need adjustment on the 7D but the Sigma lenses do.

Which sort of tells you something about Sigma lenses I guess ...

rscoote rscoote

219 posts
14 years
Knaresborough

Posted 23/10/2012 - 15:49 Link

I hadn't made any adjustment but prompted by this thread I checked my new DA* 300 which needed +3 on my K-5, then checked my Sigma 70-200mm 2.8, which needed -5.

Interesting the pixel peeping to look at the focus point illustrated how the 300mm was noticeably sharper wide open (f4) than the Sigma at 200mm (f2.8 ).

My PPG link
K-3, K-5 + D-BG4 Grip, Pentax: FA 50 1.4, DA* 300, Sigma 70-200 2.8 Macro HSM II, Sigma 18-50 2.8 EX DC, Metz 58 AF-1

Edited by rscoote: 23/10/2012 - 15:50

Blythman Blythman

4248 posts
13 years
Blyth,
Northumberland

Posted 23/10/2012 - 15:56 Link

I looked at one of my lenses. Adjusted it. All seemed fine. Used it on a couple of outing and images weren't sharp. Adjusted it again. And I ended up back at zero. And it was spot on.

Go figure

Alan

PPG
Flickr

DaveHolmes DaveHolmes

1174 posts
13 years
Bradford

Posted 23/10/2012 - 15:57 Link

rscoote wrote:
I hadn't made any adjustment but prompted by this thread I checked my new DA* 300 which needed +3 on my K-5, then checked my Sigma 70-200mm 2.8, which needed -5

Is there a usable guide on how to do this (apart from the manual)?
Is a focus chart essential?

........................................................................
Digital:
Pentax K5- Vivitar 19mm 3.8; FA35mm f2; D-Xenon 100mm macro f2.8; DA50-200mm WR...
Flash:
Yongnuo YN-560; Vivitar 285HV; Cactus V4 triggers...
Film:
Pentax-MX & M50mm f1.4; Spottie & 55mm f1.8; MG & M40mm 2.8...

https://www.flickr.com/photos/daveholmesphotos/