Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-26-2014, 02:56 AM   #1
Forum Member




Join Date: Dec 2011
Posts: 90
In-camera diffraction correction with 645Z?

<<Diffraction that occur when stopping down the lens during shooting are effectively corrected on the PENTAX 645Z.>>

Can anyone comment if this actually works, i.e., shooting stopped down being "corrected" as Ricoh states on their 645z feature list?

<<Newly equipped with diffraction and color fringe correctionLens compensation function
The PENTAX 645Z is equipped with full-featured lens correction functionality. Together with distortion and magnification chromatic aberration, peripheral illumination correction and diffraction correction are newly added. Diffraction that occur when stopping down the lens during shooting are effectively corrected on the PENTAX 645Z. Additionally, it is equipped with fringe correction for use in processing RAW images. This camera will support the higher quality finish.>>

09-26-2014, 04:56 AM   #2
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
It is variable unsharp masking - the more you stop your lens down the more sharpening is applied. The processing requirements for high precision deconvolution sharpening is astronomical. It is applied to raw files as well as jpg. so be careful with how you use it.
09-26-2014, 05:30 AM   #3
Forum Member




Join Date: Dec 2011
Posts: 90
Original Poster
QuoteOriginally posted by Digitalis Quote
It is variable unsharp masking - the more you stop your lens down the more sharpening is applied. The processing requirements for high precision deconvolution sharpening is astronomical. It is applied to raw files as well as jpg. so be careful with how you use it.
Thanks for that note. So you are saying that the sharpening is applied to the RAW file at capture and before it is written to the memory card, and cannot be undone? I guess that would be a good thing if it actually worked and did not cause problems that could not be undone.
09-26-2014, 05:39 AM   #4
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by jwoodland Quote
Thanks for that note. So you are saying that the sharpening is applied to the RAW file at capture and before it is written to the memory card, and cannot be undone?
No, it cannot be undone. Personally I would advise that if diffraction correction is desirable proper computer software should be the used. Especially if a large number of files are needed to be corrected as most computers these days have more processing power than what you will find in the Pentax Prime image processing engine.

09-26-2014, 06:26 AM   #5
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,581
For info, diffraction correction is a function built-into the Fujitsu MB86S22AA chip, the 'seventh-generation M-7M series of Milbeaut® image processors', which resides in both the K-3 and the 645Z.

It's a service the Fujitsu chip is designed to provide, along with noise filtering, purple fringing correction, lens distortion correction, full-HD H.264/AVC video compression/decompression etc. All Pentax are doing is flicking a software switch to enable it.
09-26-2014, 07:04 AM   #6
Loyal Site Supporter




Join Date: Mar 2009
Location: Southern Indiana
Photos: Gallery
Posts: 14,951
There were some comparisons on the K3. I didn't think it did that much, but I guess it could be helpful if you hate post processing and shoot above the diffraction limit a lot.

https://www.pentaxforums.com/forums/172-pentax-k-3/268253-more-details-about-...orrection.html
09-26-2014, 09:45 AM   #7
Forum Member




Join Date: Dec 2011
Posts: 90
Original Poster
Looks like that other thread linked to above turned into a pissing match like so many others, with little valuable info. But now that I know a little bit about the feature, and found the easy on/off button on the Z, I can make some tests for my different lenses and see what it does.THANKS for all your help guys!

Last edited by jwoodland; 09-26-2014 at 07:24 PM.
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, medium format
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
645Z no card in camera problem elsdad Pentax Medium Format 2 09-06-2014 02:45 PM
More details about diffraction correction JPT Pentax K-3 40 07-25-2014 10:41 PM
Rumoured K-3 f/w update: diffraction correction and mirror flap improvement JPT Pentax K-3 42 07-11-2014 10:34 AM
K5ii diffraction correction climit Pentax DSLR Discussion 2 11-17-2012 10:20 AM
In Camera Lens correction? Arbalist Pentax K-5 3 03-14-2011 02:21 AM



All times are GMT -7. The time now is 04:05 PM. | 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