Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-30-2012, 12:05 AM   #16
Veteran Member
TOUGEFC's Avatar

Join Date: Nov 2009
Location: Brisbane
Photos: Gallery
Posts: 3,561
QuoteOriginally posted by Abbazz Quote
Yes, it is called focus shift and it happens often with fast lenses, as a consequence of spherical aberration: What is Focus Shift?

Cheers!

Abbazz
The DA*55 doesnt suffer from focus shift.

04-30-2012, 01:16 AM   #17
Pentaxian
MegaPower's Avatar

Join Date: May 2010
Location: Hong Kong / Irvine, CA
Photos: Gallery | Albums
Posts: 565
I heard only Pentax can cal a few lenses on Kx
Otherwise, you have to open debug mode everytime you change lenses, like me.
The other solution is get a K5/K7, which I did.
04-30-2012, 03:48 AM   #18
Pentaxian
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,366
QuoteOriginally posted by DaveHolmes Quote
How often do most folk actually need to make adjustments in camera for front/back focusing?
I have to adjust my K5 with every AF lens. My k20 does not need to adjust anything. It just spot on 100%.
The K5 had been sent in for service and got replaced new AF block. It is now far more consistent AF, but still need adjustment.
04-30-2012, 04:32 AM   #19
Veteran Member
GabrielFFontes's Avatar

Join Date: Jul 2011
Location: Rio de Janeiro, Brazil
Posts: 647
But as you stop the lens down, the less critical the front focus will be...

04-30-2012, 06:28 AM   #20
Pentaxian
aurele's Avatar

Join Date: Jan 2011
Location: Paris, France
Photos: Albums
Posts: 2,975
Original Poster
QuoteOriginally posted by GabrielFFontes Quote
But as you stop the lens down, the less critical the front focus will be...
(made a mistake, it's back focus.)

It back focus so much that if i aim a 5m traget, the focus will be done around infinity ... So i just can't stop the lens enought to correct it. +180Ám is a HUGE correction, you know !
04-30-2012, 09:11 AM   #21
Veteran Member
Anvh's Avatar

Join Date: Sep 2011
Posts: 4,616
QuoteOriginally posted by aurele Quote
Can the K-5 handle a +180Ám in adjustments ?
+ and - 100Ám in normal software but more with the debug menu.
But your lenses will focus differently on another camera.
So if a lens focus perfectly on your camera now doesn't mean it also focus perfect on another camera.
04-30-2012, 09:26 AM   #22
Veteran Member
DaveHolmes's Avatar

Join Date: Jul 2010
Location: Yorkshire
Posts: 1,501
QuoteOriginally posted by MegaPower Quote
I heard only Pentax can cal a few lenses on Kx
Otherwise, you have to open debug mode everytime you change lenses, like me.
The other solution is get a K5/K7, which I did.
Like I said before... I think I'm just lucky... Need to make no adjustments on my K-x on any of my AF lenses, including the FA35 that arrived today... Shot an egg as a test subject at f2, f2.8, f4 & f5.6 and there're no FF/BF problems I can see...
05-01-2012, 02:03 AM   #23
Pentaxian
aurele's Avatar

Join Date: Jan 2011
Location: Paris, France
Photos: Albums
Posts: 2,975
Original Poster
QuoteOriginally posted by Anvh Quote
So if a lens focus perfectly on your camera now doesn't mean it also focus perfect on another camera.
i'll do a test with a K-r ASAP, to see if it's not a problem in my k-x.

05-01-2012, 02:22 AM   #24
Site Supporter
Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 5,815
At least yours focuses. Mine doesn't
I'm really looking forward to using once a get a winner.
05-01-2012, 02:43 AM   #25
Pentaxian
aurele's Avatar

Join Date: Jan 2011
Location: Paris, France
Photos: Albums
Posts: 2,975
Original Poster
QuoteOriginally posted by Sandy Hancock Quote
At least yours focuses. Mine doesn't
what do you mean ? your SDM is fried ?
05-01-2012, 02:49 AM   #26
Site Supporter
Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 5,815
Yep. Brand new out of the box. Nothing.
05-01-2012, 03:11 AM   #27
Pentaxian
aurele's Avatar

Join Date: Jan 2011
Location: Paris, France
Photos: Albums
Posts: 2,975
Original Poster
i guess you did everything to make it work, so send it back or send it to repair !
05-01-2012, 03:17 AM   #28
Site Supporter
Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 5,815
Depends what you mean by everything. Is there some magic trick?

I tried it on three bodies, all of which are fine with my DA*300 and my two Sigma HSM zooms.
I flicked the AF/MF switch on the lens several times, and tried AFS and AFC on my K-5.

Am I missing something??
05-01-2012, 05:48 AM   #29
Pentaxian
aurele's Avatar

Join Date: Jan 2011
Location: Paris, France
Photos: Albums
Posts: 2,975
Original Poster
cleaning the SDM contact of body and lens ?
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
af, k-mount, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K10D GX10 CCD Position Adjust (AF adjust) kevbirder Pentax DSLR Discussion 10 09-22-2011 02:35 PM
Architecture permanently erect..... dcmsox2004 Post Your Photos! 7 03-26-2011 07:07 AM
Setting ev comp +2 permanently possible on K-x? kbrede Photographic Technique 13 01-19-2011 04:19 PM
Attaching M42 adapter permanently to a lens Tim_R Pentax SLR Lens Discussion 9 10-07-2010 05:45 AM
Thinking of permanently attaching an adapter to a M42 lens - looking for advice countzero Pentax SLR Lens Discussion 5 01-21-2008 05:20 PM



All times are GMT -7. The time now is 11:56 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top