Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-29-2020, 11:37 PM   #1
New Member
AmsAmt's Avatar

Join Date: May 2017
Location: Amsterdam
Posts: 23
M42 to K focus issues

Dear all
I took pictures with the super tak. 50 1.4 on my kp, and later on k10d, all pictures at infinity were out of focus. Most of the others too. I am using an original pentax converter.
Some pictures were giving me back focus.
What do you think is the problem?
I can add pictures later if that will help.
Thanks Yuval

03-30-2020, 12:17 AM   #2
Site Supporter
Site Supporter




Join Date: Sep 2018
Location: SW Bavaria
Posts: 146
Hi Yuval,
can you please provide some more information?


How did you set the focus?
What f-stop did you use?
Can you see, that the pictures are out of focus in 100% view only or also when looking at the pictures in whole?
Do you have this issue with other lenses? Do you have any other fast lenses?

Having problems to focus to infinity might occour, when the stop of the lens at infinity is set wrongly.
But this would not affect the focus point on other distances.

A lens with 1.4 widest aperture is always difficult to focus. The through the lens autofocus is not designed to handel these lenses well. Use a tripod and liveview with magnification and extra edge focus to set the focus point. If your subject is still out of focus, there might be an issue with the lens, which i think is very unlikely.

Did you have backfocus on the KP as well as on the K10D? Backfocus is a known issue of the K10D and might worsen over time.

Greetings
Joerg
03-30-2020, 06:22 AM   #3
Pentaxian
D1N0's Avatar

Join Date: May 2012
Location: ---
Photos: Gallery
Posts: 6,087
Use live view zoomed in on the subject to focus. Infinity mark often overshoots infinity a bit in old lenses so you can't rely on it. The optical viewfinder in digital camera's is often not calibrated well enough for critical focus at wide apertures. The longer the focussing distance the harder it gets en the bigger the discrepancy between what you see in focus in the viewfinder and what is actually in focus gets. In live view you always see what is actually in focus. Focus peaking helps but is not accurate enough unless you can judge where the middle of the DOF lies by a surface surrounding your subject. I always move the zoom area to where I want my subject in the composition. Then zoom in and adjust focus.
03-30-2020, 08:00 AM   #4
Pentaxian
35mmfilmfan's Avatar

Join Date: Oct 2016
Location: Norfolk, UK
Posts: 1,235
You may find using an eyepiece magnifier (either Pentax or third-party) helps with MF lenses, as the eyepieces on digital cameras are not optimised for MF lenses. Is the focus indicator (green hexagon) confirming your focus point ? And this may be a daft suggestion, but is your shutter speed high enough ? IOW, could the lack of sharpness be camera shake ?

03-30-2020, 10:43 AM   #5
New Member
AmsAmt's Avatar

Join Date: May 2017
Location: Amsterdam
Posts: 23
Original Poster
QuoteOriginally posted by Papa_Joe Quote
Hi Yuval,

can you please provide some more information?

How did you set the focus?

as a manual focus lens used spot focus

What f-stop did you use?
can not check as it does not show on the exif file.

Can you see, that the pictures are out of focus in 100% view only or also when looking at the pictures in whole?
the pictures are 100 % out of focus

Do you have this issue with other lenses? Do you have any other fast lenses?
this is the first time i used m42 lens on k with k lenses , manual as auto i did not had an issue . this issue is far less noticeable when i close up on subjects.
Having problems to focus to infinity might occour, when the stop of the lens at infinity is set wrongly.
But this would not affect the focus point on other distances.

A lens with 1.4 widest aperture is always difficult to focus. The through the lens autofocus is not designed to handel these lenses well. Use a tripod and liveview with magnification and extra edge focus to set the focus point. If your subject is still out of focus, there might be an issue with the lens, which i think is very unlikely.
I can try live view next time on going out , (whenever that will be)
Did you have backfocus on the KP as well as on the K10D? Backfocus is a known issue of the K10D and might worsen over time.
it is on both , i do suspect the kp have a focus issue , since i dropped it , but this looks different.
Greetings
Joerg
thank you

(details are in bold)


---------- Post added 03-30-20 at 10:48 AM ----------

QuoteOriginally posted by D1N0 Quote
Use live view zoomed in on the subject to focus. Infinity mark often overshoots infinity a bit in old lenses so you can't rely on it. The optical viewfinder in digital camera's is often not calibrated well enough for critical focus at wide apertures. The longer the focussing distance the harder it gets en the bigger the discrepancy between what you see in focus in the viewfinder and what is actually in focus gets. In live view you always see what is actually in focus. Focus peaking helps but is not accurate enough unless you can judge where the middle of the DOF lies by a surface surrounding your subject. I always move the zoom area to where I want my subject in the composition. Then zoom in and adjust focus.
thanks

ill try live view and see how it works
03-30-2020, 03:28 PM   #6
Moderator
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 6,914
The K10D doesn't have Live View.
03-30-2020, 10:43 PM   #7
New Member
AmsAmt's Avatar

Join Date: May 2017
Location: Amsterdam
Posts: 23
Original Poster
QuoteOriginally posted by Not a Number Quote
The K10D doesn't have Live View.
I know
kp does ��
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, focus, infinity, lens, lenses, pentax help, photography, pictures, subject, time, troubleshooting, view, viewfinder
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Focus issues with old M42 lenses BerndM Troubleshooting and Beginner Help 11 12-26-2018 06:21 AM
For Sale - Sold: 3rd Pty M42, Helios-40-2, 28, 35, 85, 135, 200 and 450mm, M42-EF & M42-Nikon MightyMike Sold Items 80 12-29-2017 02:58 PM
Manual focus lenses with infinity focus issues - anyone else encountering them? kiwi_jono Pentax SLR Lens Discussion 8 10-18-2017 01:19 PM
For Sale - Sold: 3rd Pty M42, 70-150mm, 135mm F2.8, 200mm F3.5 M42-K, M42-EF & M42-Nikon Adapters MightyMike Sold Items 72 12-26-2016 09:37 AM
Focus, Focus, Focus (or the usefulness of focus charts) GoremanX Pentax DSLR Discussion 31 12-21-2014 11:49 AM



All times are GMT -7. The time now is 03:14 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