Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-06-2011, 08:05 AM   #1
Junior Member




Join Date: May 2011
Location: Melbourne
Posts: 44
AF inconsistency - need advice

Hi there. I recently upgraded to K-5 from a K10 and I have a problem. My main lens is a Tamron 17-50mm f2.8. The lens focuses spot on on my K10 but for some reason K-5 struggles to focus properly. There is a huge difference in AF adjustment between indoor light (-10) and outdoor light (+4). Also almost half of the pictures I'm taking outdoors are out of focus although I always get the focus confirmation before taking the picture. And by out of focus I mean really really blurry pictures from f2.8 to f8.

So far it seems that the camera is faulty but what puzzles me is that with my other lenses, Pentax 55-300 and Sigma 10-20, the K-5 has no problems focusing. I get really good focus with all 3 lenses on my K10 but somehow K-5 doesn't like my Tamron. I always use center focusing and upgraded to firmware 1.03 as soon as I got the camera (and I'm sorry now I didn't try the lens before the focusing adjustments that came with the firmwares...)

Any idea what the problem is? Should I send the camera back? Is there a way of downgrading the firmware? Any thoughts are appreciated. Thank you.

06-06-2011, 01:15 PM   #2
Pentaxian
RonHendriks1966's Avatar

Join Date: Jan 2009
Photos: Gallery
Posts: 8,556
Well if your camera works with two lenses then maybe it's time to say goodbye to the Tamron.
06-06-2011, 01:41 PM   #3
Ash
Community Manager
Loyal Site Supporter
Ash's Avatar

Join Date: Mar 2007
Location: Toowoomba, Queensland
Photos: Gallery | Albums
Posts: 22,679
3rd party lenses seem to have more issues with focusing on the K-5. The only way to resolve it is to have the lens and body calibrated by a service person.
06-06-2011, 04:52 PM   #4
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 8,939
RonHendriks1966, did you notice that the OP wrote that the Tamron focused just fine with his K10D?

Clearly there is a problem with the Tamron & K-5 combination and it is not easy to determine where the cause of the problem is.

However, given
  • the K-5's shoddy AF history (with at least one bug remaining),
  • the dependency of your results on light temperature, and
  • the fact that the Tamron worked fine on your K10D,
I'd start the trouble shooting with the K-5.

Third-party or not, a camera's AF should not behave like that. The Tamron lens is highly regarded, not only by members of this forum, it has worked with many, many Pentax DSLR models before.

06-06-2011, 06:37 PM   #5
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
The Tamron needs to be re-calibrated for focus. An issue that crops up with this lens even with other camera makes. The Tamron is a nice and sharp lens but build quality is nothing to shout about.
There is nothing overtly wrong with your K-5.
06-07-2011, 06:59 PM   #6
Veteran Member
Smeggypants's Avatar

Join Date: Sep 2010
Posts: 1,536
The K-5 does have inconsistent AF with V1.03. I beleive this is a side effect of them bodging up 1.03 in order to improve the Low light AF performance.


QuoteOriginally posted by Nicks Quote
Also almost half of the pictures I'm taking outdoors are out of focus although I always get the focus confirmation before taking the picture. And by out of focus I mean really really blurry pictures from f2.8 to f8.
Are you sure this is due to being out of focus? At f8 a bit of frotn or back focus should fall within the DOF

I've been getting some intermittant soft images in bright daylight even at 1/2000s and smaller apertures towards F8. It's a bit random and I'm wondering if it's due to the Anti-shake not latching quick enough. I normally leave the Anti-Shake on all the time but I'm purposely turning it off on my next shoot, unless I specifically need it.
06-07-2011, 07:48 PM   #7
Inactive Account




Join Date: Feb 2009
Location: Velence, Hungary
Posts: 664
QuoteOriginally posted by Smeggypants Quote
It's a bit random and I'm wondering if it's due to the Anti-shake not latching quick enough. I normally leave the Anti-Shake on all the time but I'm purposely turning it off on my next shoot, unless I specifically need it.
I've actualllly set up a "user" mode similar to the TAV mode-with SR off..and I have the impression that my focus accuracy improved during bright light shootings when SR has no real importance.

Andras
06-07-2011, 09:17 PM   #8
Brooke Meyer
Guest




I'm feeling guilty.

I have two K-5s, both on 1.03. My DA12-24, Tamron 28-75, DA 50-135 and Sigma 100-300 all work fine. This is from last Sat. with my new used open box K-5 and 4 year old Tamron. Th 1/160 sec shutter speed is an attempt to offset the florescent lights color flicker. In late afternoon, it really is that bright.


Last edited by Brooke Meyer; 08-31-2011 at 11:05 PM.
06-08-2011, 01:34 AM   #9
Junior Member




Join Date: May 2011
Location: Melbourne
Posts: 44
Original Poster
Thank you all for your comments.

"The only way to resolve it is to have the lens and body calibrated by a service person."

If I send the body to be calibrated with one lens, is this going to affect the focus with my other lenses?

"The Tamron needs to be re-calibrated for focus."
"Are you sure this is due to being out of focus? At f8 a bit of frotn or back focus should fall within the DOF"

The lens is working really well on my K10, as my other lenses. I really don't think it needs calibration. Also FF and BF is only part of the problem. K-5 really struggles acquiring focus with this lens. Sometimes I focus on a close object <3m, I take the picture then focus on a distant object >50m and I get the focus confirmation with no actual focusing action happening?! I check the second picture and I can clearly see the same close object in focus at the bottom of the picture but not the distant object I actually focused on. I have to release and press the shutter one more time to get the correct focus in this situation....And I always use center spot focus so there's no room for mistakes here.

I'll have to see what happens with the SR off...
06-08-2011, 02:41 AM   #10
gtl
Veteran Member




Join Date: Feb 2010
Posts: 349
Dumb question but is your K5 is perfect with other lenses?

QuoteOriginally posted by Nicks Quote
Thank you all for your comments.

"The only way to resolve it is to have the lens and body calibrated by a service person."

If I send the body to be calibrated with one lens, is this going to affect the focus with my other lenses?

"The Tamron needs to be re-calibrated for focus."
"Are you sure this is due to being out of focus? At f8 a bit of frotn or back focus should fall within the DOF"

The lens is working really well on my K10, as my other lenses. I really don't think it needs calibration. Also FF and BF is only part of the problem. K-5 really struggles acquiring focus with this lens. Sometimes I focus on a close object <3m, I take the picture then focus on a distant object >50m and I get the focus confirmation with no actual focusing action happening?! I check the second picture and I can clearly see the same close object in focus at the bottom of the picture but not the distant object I actually focused on. I have to release and press the shutter one more time to get the correct focus in this situation....And I always use center spot focus so there's no room for mistakes here.

I'll have to see what happens with the SR off...
06-08-2011, 03:46 AM   #11
Veteran Member
Tommot1965's Avatar

Join Date: Sep 2010
Location: Perth Western Australia
Photos: Gallery | Albums
Posts: 1,026
my K5 had inconsistent Af with differing lenses..so your not alone ...and it wasn't Af fine adjust either..but shifting focus as the FOV widened .. with a screw drive prime it was spot on...pentax/sigma HSM/SDM...not too good in low light ....
06-08-2011, 05:40 AM   #12
Junior Member




Join Date: May 2011
Location: Melbourne
Posts: 44
Original Poster
"Dumb question but is your K5 is perfect with other lenses?"

Yes, as I said, my K-5 is ok with all my other lenses. And my Tamron lens and my other lenses are all perfect with my K10D body.........The problem is only with the K-5+Tamron 17-50 combination.
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!
camera, dslr, firmware, focus, k-5, k-5 ii, k-5 iis, k5, lens, lenses, pentax k-5, tamron
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Suggestion layout inconsistency sterretje Site Suggestions and Help 2 03-05-2011 01:17 PM
Autofocus Inconsistency with K20D NeverSatisfied Pentax DSLR Discussion 24 03-13-2009 05:43 PM
Did not buy K200d Today because of focus inconsistency. Sitting Bull Troubleshooting and Beginner Help 7 02-02-2009 08:01 AM
k20d AWB inconsistency qksilver Pentax DSLR Discussion 20 04-21-2008 02:25 AM
Urgent problem: Inconsistency in noise level with K10D Cannon-S2 Pentax DSLR Discussion 33 01-23-2008 12:02 PM



All times are GMT -7. The time now is 02:22 AM. | See also: NikonForums.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