Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-21-2013, 08:14 AM   #1
Loyal Site Supporter
RockvilleBob's Avatar

Join Date: Dec 2011
Location: Lewes DE USA
Photos: Albums
Posts: 1,675
Focus Calibration

I ordered a KatzEye screen and was able to order the shims yesterday and look forward to getting my Pentax K-5 focus calibrated.

I have a question about procedure - specifically about the focus indicator when using a manual lens on the K-5. Does the AF Fine Adjustment alter when the green indicator light and beep activate on a K-5 using a manual lens?

Two images are attached using a manual focus 85mm f2 lens.
  • lensalighn.jpg is the result when I use my K-5 with the existing shim and KatzEye - significant front focus - it looks like around 22-24 in the jpeg
  • lensalighn autofocus is mis-titled - it is the result of getting the same manual lens to light up the focus indicator in the K-5 - there is a slight front focus error - it looks around 6 on the jpeg lensalighn image
My questions are these:
Does changing the AF lens fine adjustment for "all lenses" also change when the indicator light is activated using manual focus?
If so should I then adjust the AF adjustment for "all lenses" to achieve proper focus, as indicated by the green light and beep, before changing shims and then change the shims so that manual focus is on target?

I can now see why my manual focus images were not that crisp.

Attached Images
   
05-21-2013, 08:30 AM   #2
Pentaxian
johnyates's Avatar

Join Date: Aug 2011
Location: Saskatoon, SK
Posts: 1,189
QuoteOriginally posted by RockvilleBob Quote
Does changing the AF lens fine adjustment for "all lenses" also change when the indicator light is activated using manual focus?
Yes.

QuoteOriginally posted by RockvilleBob Quote
If so should I then adjust the AF adjustment for "all lenses" to achieve proper focus, as indicated by the green light and beep, before changing shims and then change the shims so that manual focus is on target?
The visual focus and the auto focus are two separate systems. You want to adjust your shims so that when your subject appears in focus in the viewfinder, it is actually in focus on the sensor.

The auto focus system is adjusted separately using the AF Adjustment feature on the camera. It is less accurate--depending on the lens, there is a range of focus that will light up the green octagon. You may find it helpful to use CIF to determine whether your AF Adjustment is set correctly.
05-21-2013, 08:31 AM   #3
Loyal Site Supporter
RockvilleBob's Avatar

Join Date: Dec 2011
Location: Lewes DE USA
Photos: Albums
Posts: 1,675
Original Poster
I received this reply from Rachel Katz at KatzEye, she is very helpful

Your camera shows a fairly typical front focus error, for those cameras that have the problem. I think this particular type of test makes the error look a little larger than it actually is, particularly on MF, but still seems pretty much in character with the ones we’ve had to service. The indicator dot is triggered by the AF system, so your other test really is an AF test. Your AF is actually seems closer than most, although it could do with a little adjustment. That also is in line with what we have seen – cameras with MF calibration issues usually have AF calibration problems as well.

The two calibrations (AF/dot and MF) are entirely separate and don’t interact, so you can make the adjustments in whatever order you prefer. The menu adjustment for AF is simple enough, so you might as well make that one while you’re waiting for the shims. Even if you get the AF/dot dialed in though, I would still ignore the dot when doing the MF calibration. The indicator dot lights over a fairly wide range, which means that one can only calibrate it to an approximation. Your MF calibration, on the other hand, can be as precise as the difference between shim thicknesses will allow.
05-21-2013, 08:32 AM   #4
Loyal Site Supporter
RockvilleBob's Avatar

Join Date: Dec 2011
Location: Lewes DE USA
Photos: Albums
Posts: 1,675
Original Poster
QuoteOriginally posted by johnyates Quote
Yes.



The visual focus and the auto focus are two separate systems. You want to adjust your shims so that when your subject appears in focus in the viewfinder, it is actually in focus on the sensor.

The auto focus system is adjusted separately using the AF Adjustment feature on the camera. It is less accurate--depending on the lens, there is a range of focus that will light up the green octagon. You may find it helpful to use CIF to determine whether your AF Adjustment is set correctly.
Great help - thank you very much John

05-21-2013, 08:34 AM   #5
Loyal Site Supporter
RockvilleBob's Avatar

Join Date: Dec 2011
Location: Lewes DE USA
Photos: Albums
Posts: 1,675
Original Poster
QuoteOriginally posted by johnyates Quote
Yes.



The visual focus and the auto focus are two separate systems. You want to adjust your shims so that when your subject appears in focus in the viewfinder, it is actually in focus on the sensor.

The auto focus system is adjusted separately using the AF Adjustment feature on the camera. It is less accurate--depending on the lens, there is a range of focus that will light up the green octagon. You may find it helpful to use CIF to determine whether your AF Adjustment is set correctly.
What is CIF John?
05-21-2013, 08:47 AM   #6
Pentaxian
johnyates's Avatar

Join Date: Aug 2011
Location: Saskatoon, SK
Posts: 1,189
Catch in Focus.

Check the menu on your camera--it's in there somewhere.

Once you have it set up, you can use the AF system to trigger the shutter when using a manual lens.

Check your camera's manual and do a search here on the forums.
05-21-2013, 08:55 AM   #7
Loyal Site Supporter
RockvilleBob's Avatar

Join Date: Dec 2011
Location: Lewes DE USA
Photos: Albums
Posts: 1,675
Original Poster
QuoteOriginally posted by johnyates Quote
Catch in Focus.

Check the menu on your camera--it's in there somewhere.

Once you have it set up, you can use the AF system to trigger the shutter when using a manual lens.

Check your camera's manual and do a search here on the forums.
Thanks again John. Yes I know about Catch In Focus and that would be a better way to check the autofocus calibration than the method I used.
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!
adjustment, af, focus, indicator, jpeg, k-5, lens, light, pentax help, shims
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-5 Focus Calibration - Sigma lenses johnbachel Pentax K-5 9 05-09-2013 09:41 PM
pentax k-r focus calibration Enkhbayar Troubleshooting and Beginner Help 11 12-04-2012 05:50 AM
Katzeye focus screen and K5 calibration hoanpham Pentax K-5 3 09-16-2011 08:07 PM
Front back focus calibration on K20D AKum8 Pentax SLR Lens Discussion 2 08-01-2010 09:06 PM
Front back focus calibration - K20D AKum8 Pentax SLR Lens Discussion 2 08-01-2010 11:20 AM



All times are GMT -7. The time now is 01:27 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