[Klaus]

[quote name='Class A' timestamp='1291200911' post='4639']

Klaus, it is great that you could reach a consensus with Falk.





Yes, it would indeed, if you are serious about the wording "other DSLRs have a 'seemingly higher resolution' out of the box". But if you are then you might as well not have your K-5's AA filter removed? If the resolution is only "seemingly higher" why spend the money? Just playing the devil's advocate here, of course.



I believe it is not necessary/helpful to remove the AA filter. I understand Falk wouldn't remove it either. Why do you still want to do it?

[/quote]



*sigh*



I do well believe Falk's mathematical analysis that you can recover the maximum of details via sharpening but sharpening itself is lossy in terms of increased noise and sharpening artifacts - it will cost you probably something like one ISO step in terms of noise to do so just to point to the most obvious effect. Don't nail me on "one" - it could be less or (more likely) more - I haven't measured this.

The sharpening itself may not affect the validity of the MTF tests so I could leave the K5 as is - this is correct. However, it does diminish the field quality of the K5 -> for me<-. There's a use for the K5 beyond the sheer testing. And ... as discussed .... it is, of course, a matter of taste. :-) If you prefer to have a sharp output at ISO 400 with an equivalent ISO effect like at ISO 800 (after sharpening), well fine - just go on - but I prefer to have a similar sharp output at ISO 400 with an equivalent ISO effect like at ISO 200 (because I need to apply less sharpening). I reckon the trade-offs of either approach are well understood. As mentioned I would prefer to have a weak AA filter rather than none but this option is not available out there.

Regarding the tests - it is quite meaningless whether there's an AA filter in the camera or not. This will NOT CHANGE THE RANKING of the lenses nor the technical quality of a lens and THIS IS THE ULTIMATE ESSENCE of it all.

Readers do already put too much emphasis on the max. LW/PH values because they try to cross compare systems although we do always stress that this is invalid - here and elsewhere. In the very theory I could even use straight JPEGs from a factory K5 resulting in max. LW/PHs around 2000. It would be an obvious approach and also a technically valid one - finally this is "recommended by Pentax" (it wouldn't be the default otherwise, wouldn't it ?). I reckon there would be an outcry in the community if I did so though. So as always in life - the truth is always gray and neither black nor white.

[thxbb12]

[quote name='Lomskij' timestamp='1291202227' post='4642']

Is it me, or K-5 RAW looks rather soft here?



[url="http://snap-studio.co.uk/rokas/pentax.jpg"]http://snap-studio.co.uk/rokas/pentax.jpg[/url]

[/quote]



These pics are not comparable as they are subject to focus accuracy.

Check details at different depths and you'll see that the blurriness you're seeing is in fact due to different focusing points. Compare images at a different depth, where the K5 was focused, and you'll see the opposite result.



This totally invalidates the test IMO.

A proper test would be to take a picture of 2D stuff instead, as it eliminate DOF issues.

[thxbb12]

Klaus,



Did you happen to remove a couple of replies?

A few minutes ago I replied to someone who posted a screenshot taken from Dpreview's D7000 review showing how blurry the output of the K5 was in comparison.

I don't see my reply nor the message above.

What happened?



Thanks.

[Klaus]

[quote name='thxbb12' timestamp='1291209080' post='4647']

Klaus,



Did you happen to remove a couple of replies?

A few minutes ago I replied to someone who posted a screenshot taken from Dpreview's D7000 review showing how blurry the output of the K5 was in comparison.

I don't see my reply nor the message above.

What happened?



Thanks.

[/quote]



Sorry. Copyright concerns. This was dpreview image content which is protected. You can, of course, post links to external tests here.

[Brightcolours]

[quote name='Klaus' timestamp='1291204714' post='4643']

*sigh*



I do well believe Falk's mathematical analysis that you can recover the maximum of details via sharpening but sharpening itself is lossy in terms of increased noise and sharpening artifacts - it will cost you probably something like one ISO step in terms of noise to do so just to point to the most obvious effect. Don't nail me on "one" - it could be less or (more likely) more - I haven't measured this.

The sharpening itself may not affect the validity of the MTF tests so I could leave the K5 as is - this is correct. However, it does diminish the field quality of the K5 -> for me<-. There's a use for the K5 beyond the sheer testing. And ... as discussed .... it is, of course, a matter of taste. :-) If you prefer to have a sharp output at ISO 400 with an equivalent ISO effect like at ISO 800 (after sharpening), well fine - just go on - but I prefer to have a similar sharp output at ISO 400 with an equivalent ISO effect like at ISO 200 (because I need to apply less sharpening). I reckon the trade-offs of either approach are well understood. As mentioned I would prefer to have a weak AA filter rather than none but this option is not available out there.

Regarding the tests - it is quite meaningless whether there's an AA filter in the camera or not. This will NOT CHANGE THE RANKING of the lenses nor the technical quality of a lens and THIS IS THE ULTIMATE ESSENCE of it all.

Readers do already put too much emphasis on the max. LW/PH values because they try to cross compare systems although we do always stress that this is invalid - here and elsewhere. In the very theory I could even use straight JPEGs from a factory K5 resulting in max. LW/PHs around 2000. It would be an obvious approach and also a technically valid one - finally this is "recommended by Pentax" (it wouldn't be the default otherwise, wouldn't it ?). I reckon there would be an outcry in the community if I did so though. So as always in life - the truth is always gray and neither black nor white.

[/quote]

You can avoid sharpening most noise (as noise, unless "filtered", appears as coloured specs), when you apply sharpening.

In Photoshop (a usual suspect for sharpening), go from RGB to Lab-mode. Select the lightness layer and apply sharpening only on that layer. The coloured specs will not be as affected by the sharpening as you would see in RGB mode.

[Class A]

[quote name='Klaus' timestamp='1291204714' post='4643']

*sigh*

[/quote]

?

Is it my fault that it took you so long to arrive at your current position?



[quote name='Klaus' timestamp='1291204714' post='4643']

The sharpening itself may not affect the validity of the MTF tests so I could leave the K5 as is - this is correct. However, it does diminish the field quality of the K5 -> for me<-.

[/quote]

I'm happy for you to have whatever personal preferences for using the K-5 in the field.



Note, however, that you initially said that the removal of the AA filter were necessary because the "strong" AA made it pointless to replace the K10D with the K-5 for your lab tests. You specifically said that the K-5 issue only is an issue for your lab testing and that your concerns wouldn't apply to normal shooters. You even disrecommended the removal of the AA filter for non-lab users.



In the light of your new understanding, do you think you need to revise your earlier K10D = 2350 LW/PH vs K-5 = 2500 LW/PH assessment? Or was/is it an apples to oranges comparison? I'm assuming that you are now agreeing that the AA filter doesn't destroy resolution, that detail can be fully recovered by appropriate capture sharpening. If you agree then it seems that your LW/PH comparison was incorrect.



Regarding sharpening artifacts: I prefer to set my sharpening in a way so that I don't see artifacts. A choice I don't have with moiré.



Regarding sharpening noise: Even standard USM filters allow you to confine sharpening to high detail areas. This will not increase the noise in other areas. More elaborate methods (such as creating luminance / high frequency masks) are available if necessary.



[quote name='Klaus' timestamp='1291204714' post='4643']

Regarding the tests - it is quite meaningless whether there's an AA filter in the camera or not. This will NOT CHANGE THE RANKING of the lenses nor the technical quality of a lens and THIS IS THE ULTIMATE ESSENCE of it all.

[/quote]

I always understood that and that results are not comparable across different systems. No need for shouting. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt=':unsure:' />



[quote name='Klaus' timestamp='1291204714' post='4643']

So as always in life - the truth is always gray and neither black nor white.

[/quote]

Yes, of course (except for the "always" part, should have been "often"). Unfortunately, that doesn't prevent one from being wrong at times. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> I'm including myself in this, of course!

[Klaus]

Assuming that 100%, 0.5px sharpening is acceptable then it's valid to state that my initial assessment on the K10D vs K5 was wrong. I give you that by now after the discussions with Falk.



:-)



However, this does still not negate the statement that the K5 has a comparatively strong AA filter vs the rest of the gang (inc. the K10D).



;-)

[AlbertoM]

Hi Klaus,



I hate the AA filter and I dream a camera without filter... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />

I'm going to purchase a Pentax K5 and I am very sorry to hear that the AA filter is (maybe) strong...



But why Pentax wanted to put a strong filter in a sensor with smaller pixel??

I can understand that a 6Mpix camera is prone to moirè, but a 16MPix camera? Which lens, which f/number, which situation can generate moirè?



Anyway, for example, in this image, I definitely prefer retouch the little moirè instead of use a complex technique of unsharpening

http://photozone.smugmug.com/photos/5517...wNJs-O.jpg



I am also very curious to know how your K5 modified is in term of autofocus, focus at infinite and IR cutting



I don't care if the filter generates a colour shift, because I make myself profiles for camera raw, but if the IR are not filtered, a profile can not correct the shift



Which is the "company" that has removed the filter for you?

maxmax?



I've sent them a mail but they did not reply.....



Thanks

Alberto

[Klaus]

The camera is on the way to "Optik Makario" here in Germany ( [url="http://www.h-maccario.de/wordpress/"]http://www.h-maccario.de/wordpress/[/url] ) - the website is presented in German only. My K5 will be the first for the transformation. He has done so for numerous models (Nikon, Canon, etc. pp) including the K7. They started back in 2005 so they've got some experience here.



I will report back, of course. However, this will take a while now. The expected turnaround time is 2-3 weeks. Regarding the recent discussion I postponed the package till today actually.







[quote name='AlbertoM' timestamp='1291293708' post='4697']

Hi Klaus,



I hate the AA filter and I dream a camera without filter... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />

I'm going to purchase a Pentax K5 and I am very sorry to hear that the AA filter is (maybe) strong...



But why Pentax wanted to put a strong filter in a sensor with smaller pixel??

I can understand that a 6Mpix camera is prone to moirè, but a 16MPix camera? Which lens, which f/number, which situation can generate moirè?



Anyway, for example, in this image, I definitely prefer retouch the little moirè instead of use a complex technique of unsharpening

[url="http://photozone.smugmug.com/photos/551754081_WwNJs-O.jpg"]http://photozone.smu...081_WwNJs-O.jpg[/url]



I am also very curious to know how your K5 modified is in term of autofocus, focus at infinite and IR cutting



I don't care if the filter generates a colour shift, because I make myself profiles for camera raw, but if the IR are not filtered, a profile can not correct the shift



Which is the "company" that has removed the filter for you?

maxmax?



I've sent them a mail but they did not reply.....



Thanks

Alberto

[/quote]

[thxbb12]

[quote name='Klaus' timestamp='1291295034' post='4699']

The camera is on the way to "Optik Makario" here in Germany ( [url="http://www.h-maccario.de/wordpress/"]http://www.h-maccario.de/wordpress/[/url] ) - the website is presented in German only. My K5 will be the first for the transformation. He has done so for numerous models (Nikon, Canon, etc. pp) including the K7. They started back in 2005 so they've got some experience here.



I will report back, of course. However, this will take a while now. The expected turnaround time is 2-3 weeks. Regarding the recent discussion I postponed the package till today actually.

[/quote]



I suppose you'll be testing the DA 18-135 after you get the camera back?

Or did you happen to perform the test already?



What are your preliminary thoughts regarding the IQ of this lens? Does it seem better or worse than the Nikkor 18-135?



Thanks!