In-camera diffraction correction with 645Z?

jwoodland · 09-26-2014, 02:56 AM

<<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.>>

**Digitalis** · 09-26-2014, 04:56 AM

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.

jwoodland · 09-26-2014, 05:30 AM

Originally posted by Digitalis

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.

**Digitalis** · 09-26-2014, 05:39 AM

Originally posted by jwoodland

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.

rawr · 09-26-2014, 06:26 AM

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.

**Rondec** · 09-26-2014, 07:04 AM

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

jwoodland · 09-26-2014, 09:45 AM

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.

09-26-2014, 02:56 AM	#1
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96	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.>>

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 & K-3 II	40	07-25-2014 10:41 PM
Rumoured K-3 f/w update: diffraction correction and mirror flap improvement	JPT	Pentax K-3 & K-3 II	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 & K-5 II	3	03-14-2011 02:21 AM

09-26-2014, 04:56 AM	#2
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	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
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96 Original Poster	Originally posted by Digitalis 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
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by jwoodland 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
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	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
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,652	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
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96 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.