Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
08-01-2017, 01:43 PM   #1
Forum Member

Join Date: Jan 2012
Posts: 74
AF problems with da*16-50

Hi All,

I have some strange problems with AF reliability with da*16-50 (bought months ago) connected to K-3II. Depending on focus length (short or long end) and the distance to the subject I get either BF or FF. Micro adjustment can treat only part of problems (BF or FF).

Could you please check on your equipment (I mean da*16-50) if you have similar issue or maybe I've a bad luck? :-P

Another thing is field curvature on short end. Taking a photo on short distance e.g. 3-8m results with pictures sharp from corner to corner (even on f2.8!!!).
If I go closer to infinity the lens produces relatively soft edges with very sharp center (or sharp edges with soft center, depending on where focus is fixed).

Do you think that sending pair lens+body for proffesional adjustment could help or maybe I can throw the lens through the window? :-P A few years ago I had my the 1st sample of da*16-50 together with K200 and the K5 and I can't remember such a strange behaviour.

BTW mu K-3II works perfectly with da21, da40, da70, da*300 and Tammy 70-200. Da15 sometimes also seems to have bad days and then I need to use manual focus.


08-01-2017, 03:47 PM   #2
Veteran Member

Join Date: Aug 2010
Location: Houston, Texas
Posts: 824
Earlier, I did not have AF issues with my 16-50, but it was used with the original K5. It seemed to be a good performer at all focal lengths and apertures, though I did not pixel peep much, but I was very happy with the results. I've not checked it since it was returned from Precision Camera service as its zoom was frozen.
08-02-2017, 08:23 AM   #3
Veteran Member

Join Date: Dec 2013
Photos: Gallery
Posts: 603
I had exactly the same problem when it comes to focusing on my last copy of the lens. It unpredictably missed focus on the long end, regardless of the aperture value. I had it adjusted together with the body (K-3), but it did not eliminate the problem all together. This lens was the single most problematic piece of photographic equipment I had ever used.
Speaking about the sharpness, it was pretty much useless up to F4. The edge / corner sharpness was weak up to F8. I switched to Sigma 18-35 and have never looked back.

  • 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!
center, corner, da*16-50, distance, edges, ff, focus, k-3ii, 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
Pentax DA* 16-50 and DA*50-135mm Autofocus Problems shaolin panda Troubleshooting and Beginner Help 40 10-08-2019 01:46 AM
Quality issues of the 16-50 2.8 SDM Problems solved? 16-50 an K5 Discontinued? Celles Troubleshooting and Beginner Help 20 10-08-2016 11:24 AM
For Sale - Sold: DA 12-24, DA 35 , DA 40, DA 16-45, Sigma 18-250 - Only not sold -DA 16-45 now $150 TGaa Sold Items 11 05-04-2016 04:50 PM
Shootout #2 - DA 15 Ltd / Tamron 17-50 @17 / DA* 16-50 @16 / Sigma 10-20 @16 EarlVonTapia Pentax SLR Lens Discussion 4 06-23-2013 10:17 PM

All times are GMT -7. The time now is 11:48 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]