K-5 IIs -- The Pros and Cons of Omitting an AA-Filter

timcatn · 10-24-2012, 05:38 AM

Originally posted by Class A

Pixel-density is the relevant parameter to consider when comparing sensors of different sizes when you compare images taken with the same lens from the same distance. Then indeed, sensors with the same pixel density (e.g., Nikon D800 and Pentax K-5 IIs) will show moiré under the same circumstances.

However, note that in the above scenario the FOV will be different, i.e., the larger sensor will capture more of the scene around the crop that the smaller sensor shows.

When you compare equivalent images, i.e., images taken from the same distance, same DOF, same exposure then only the total amount of pixels matters. The sensor with the higher amount of pixels captures the same images just with more resolution (completely independently from sensor size).

Hence, the sensor with the higher amount of pixels requires finer detail for moiré to be created, i.e., will exhibit it fewer times than the sensor with the lower amount of pixels.

Of course.......I should have thought of that. It is of course the detail you shoot, relative to the amount of pixels used on that detail that is important. Thanks for clarifying.

**Pål Jensen** · 10-24-2012, 07:17 AM

Originally posted by Class A

"For most photographers, we recommend using cameras with antialiasing filters. Antialiasing substantially reduces the risk and severity of demosaicing artefacts and moire. Apparent softness can be effectively overcome with Photo Ninja's excellent sharpening filter, which uses deblurring technology that can effectively compensate for antialiasing blur."

Statement made by the creators of the Photo Ninja RAW converter (of Noise Ninja fame).

Why do we have these two clear pro AA-filter positions?
.

Won't you loose details when applying softening to an image with a filter?

ironlionzion · 10-24-2012, 07:40 AM

Originally posted by beholder3

Moire does not give a damn about pixel density or pixel count at all (if using a perfect lens). It wholly is based on the interaction of structures on the subject and the sensor.

False.

A sensor with higher mp will need finer and finer detail to produce moire...which means the moire will only show up at greater enlargements.

falconeye · 10-25-2012, 04:07 AM

The funny thing is ... at all FoV except wide angle and with high enough MP (like 40MP) the moiré-creating patterns are invisible to the naked eye (e.g., fabrics which look uniform). So, everytime you get it it is a complete surprise. And everytime you hunt for moiré you won't get it. This is why some testers will say that moiré is no issue - because they hunt for it.

Class A · 10-25-2012, 05:12 AM

Originally posted by falconeye

This is why some testers will say that moiré is no issue - because they hunt for it.

And this is why a good theory is so practical. One can predict that moiré will occur, so if it doesn't in practice, you know that you have to try harder.

While empirical results always trump theory, this is only true for thoroughly created and hence reliable results. And boy, are the latter hard to produce.

Blue · 10-25-2012, 05:15 AM

My interest in this camera is from an insect macro standpoint. I am looking forward to see it compared to the K-5 II and K-5 in that regard.

falconeye · 10-25-2012, 05:54 AM

Originally posted by Blue

My interest in this camera is from an insect macro standpoint. I am looking forward to see it compared to the K-5 II and K-5 in that regard.

Insect macros are an interesting special case. Because of DoF issues, you may want to shoot at f/14+ anyway and then the Bayer-AA filter would just create unnecessary extra blur. Diffraction alone then removes the risk of color moiré.

audiobomber · 10-25-2012, 06:24 AM

Moire is pretty unlikely to occur in nature photography; landscape, birding, etc.

normhead · 10-25-2012, 07:29 AM

Having said that, I got quite a few images with color moiré patterns with my D800E (maybe 1% and it is more than twice the MP) but only one made me loose a keeper (an otherwise very nice portrait shot).

From PentaxForums.com: https://www.pentaxforums.com/forums/pentax-dslr-discussion/203117-k-5-iis-pro...#ixzz2AJxMQHH9

Isn't that pretty much all you need to know? I'm not planning to sell my K-5 when I get my K-5 IIs. I'm assuming when I am doing portrait work I'll be using the k-5 as much as possible. I might be the only one who remembers this, but portraits used to be shot with lenses that were intentionally made softer than landscape and technical lenses. Going for absolute shaarpness in a phto used to be ano-no. I'm not sure what happened between now and then, but it ain't pretty. I lose more than 1% of my photos to a focusing and exposure problems. I'm a little unclear on why the AA filter would be less of a benefit on K-5, since the D800 and K-5 have almost identical pixel pitch. IN a purely physical sense, you're dealing with almost the same mechanics.

Traditional · 10-25-2012, 07:34 AM

Interesting discussion this, to say the least!

JinDesu · 10-25-2012, 07:35 AM

I understand the thread, but is the consensus at this point:

"The k-5IIs is probably not going to show moire in most subjects, and the deciding factor for people is whether or not they care if it does pop up."?

Winder · 10-25-2012, 07:50 AM

Originally posted by audiobomber

Moire is pretty unlikely fto occur in nature photography; landscape, birding, etc.

Bird feathers and insect eyes (Macro) are two of the more common places to fine moire.

Winder · 10-25-2012, 07:56 AM - **1 Like**

Originally posted by JinDesu

I understand the thread, but is the consensus at this point:

"The k-5IIs is probably not going to show moire in most subjects, and the deciding factor for people is whether or not they care if it does pop up."?

We will needs to see some wedding dress tests. Wedding photography is a huge segment and the wedding dress shot is a standard "must have" for the bride. If the K-5II Super gets a reputation for producing moire in wedding dresses it will have a hard time selling just because of the sheer number of togs work or plan to work in the wedding/portrait segment.

I hope it sells really well and we see a K-3 24MP APS-C without the AA filter this Spring.

normhead · 10-25-2012, 08:04 AM

The thought of using a K-5 for weddings somehow makes me shudder. My cousin used to have a wedding business and always shot with hasseys, that's just what good wedding photographers used to do. What is this world coming to?

audiobomber · 10-25-2012, 08:13 AM

Originally posted by Winder

Bird feathers and insect eyes (Macro) are two of the more common places to fine moire.

I know insect eyes have a pattern that could trigger moire, but as Falk pointed out, you will likely be into diffraction aperture range for extreme macros, so your lens will break up the moire.

I initially thought bird feathers may be a problem, but I read somewhere that they weren't. Have you experienced this?

10-24-2012, 07:17 AM	#17
Pål Jensen Site Supporter Join Date: Dec 2007 Location: Norway Photos: Albums Posts: 4,371	Originally posted by Class A "For most photographers, we recommend using cameras with antialiasing filters. Antialiasing substantially reduces the risk and severity of demosaicing artefacts and moire. Apparent softness can be effectively overcome with Photo Ninja's excellent sharpening filter, which uses deblurring technology that can effectively compensate for antialiasing blur." Statement made by the creators of the Photo Ninja RAW converter (of Noise Ninja fame). Why do we have these two clear pro AA-filter positions? . Won't you loose details when applying softening to an image with a filter?

10-25-2012, 06:24 AM	#23
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Moire is pretty unlikely to occur in nature photography; landscape, birding, etc. Last edited by audiobomber; 10-25-2012 at 08:09 AM.

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10-24-2012, 05:38 AM	#16
timcatn Senior Member Join Date: Jul 2012 Location: Trondheim Posts: 237	Originally posted by Class A Pixel-density is the relevant parameter to consider when comparing sensors of different sizes when you compare images taken with the same lens from the same distance. Then indeed, sensors with the same pixel density (e.g., Nikon D800 and Pentax K-5 IIs) will show moiré under the same circumstances. However, note that in the above scenario the FOV will be different, i.e., the larger sensor will capture more of the scene around the crop that the smaller sensor shows. When you compare equivalent images, i.e., images taken from the same distance, same DOF, same exposure then only the total amount of pixels matters. The sensor with the higher amount of pixels captures the same images just with more resolution (completely independently from sensor size). Hence, the sensor with the higher amount of pixels requires finer detail for moiré to be created, i.e., will exhibit it fewer times than the sensor with the lower amount of pixels. Of course.......I should have thought of that. It is of course the detail you shoot, relative to the amount of pixels used on that detail that is important. Thanks for clarifying.

10-24-2012, 07:40 AM	#18
ironlionzion Veteran Member Join Date: Dec 2010 Location: Dallas, TX Posts: 409	Originally posted by beholder3 Moire does not give a damn about pixel density or pixel count at all (if using a perfect lens). It wholly is based on the interaction of structures on the subject and the sensor. False. A sensor with higher mp will need finer and finer detail to produce moire...which means the moire will only show up at greater enlargements.

10-25-2012, 04:07 AM	#19
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	The funny thing is ... at all FoV except wide angle and with high enough MP (like 40MP) the moiré-creating patterns are invisible to the naked eye (e.g., fabrics which look uniform). So, everytime you get it it is a complete surprise. And everytime you hunt for moiré you won't get it. This is why some testers will say that moiré is no issue - because they hunt for it.

10-25-2012, 05:12 AM	#20
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251 Original Poster	Originally posted by falconeye This is why some testers will say that moiré is no issue - because they hunt for it. And this is why a good theory is so practical. One can predict that moiré will occur, so if it doesn't in practice, you know that you have to try harder. While empirical results always trump theory, this is only true for thoroughly created and hence reliable results. And boy, are the latter hard to produce.

10-25-2012, 05:15 AM	#21
Blue Moderator Site Supporter Join Date: Jun 2008 Location: Florida Hill Country Photos: Gallery \| Albums Posts: 17,377	My interest in this camera is from an insect macro standpoint. I am looking forward to see it compared to the K-5 II and K-5 in that regard.

10-25-2012, 05:54 AM	#22
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by Blue My interest in this camera is from an insect macro standpoint. I am looking forward to see it compared to the K-5 II and K-5 in that regard. Insect macros are an interesting special case. Because of DoF issues, you may want to shoot at f/14+ anyway and then the Bayer-AA filter would just create unnecessary extra blur. Diffraction alone then removes the risk of color moiré.

10-25-2012, 07:29 AM	#24
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Having said that, I got quite a few images with color moiré patterns with my D800E (maybe 1% and it is more than twice the MP) but only one made me loose a keeper (an otherwise very nice portrait shot). From PentaxForums.com: https://www.pentaxforums.com/forums/pentax-dslr-discussion/203117-k-5-iis-pro...#ixzz2AJxMQHH9 Isn't that pretty much all you need to know? I'm not planning to sell my K-5 when I get my K-5 IIs. I'm assuming when I am doing portrait work I'll be using the k-5 as much as possible. I might be the only one who remembers this, but portraits used to be shot with lenses that were intentionally made softer than landscape and technical lenses. Going for absolute shaarpness in a phto used to be ano-no. I'm not sure what happened between now and then, but it ain't pretty. I lose more than 1% of my photos to a focusing and exposure problems. I'm a little unclear on why the AA filter would be less of a benefit on K-5, since the D800 and K-5 have almost identical pixel pitch. IN a purely physical sense, you're dealing with almost the same mechanics.

10-25-2012, 07:34 AM	#25
Traditional Forum Member Join Date: Aug 2012 Posts: 57	Interesting discussion this, to say the least!

10-25-2012, 07:35 AM	#26
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	I understand the thread, but is the consensus at this point: "The k-5IIs is probably not going to show moire in most subjects, and the deciding factor for people is whether or not they care if it does pop up."?

10-25-2012, 07:50 AM	#27
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	Originally posted by audiobomber Moire is pretty unlikely fto occur in nature photography; landscape, birding, etc. Bird feathers and insect eyes (Macro) are two of the more common places to fine moire.

10-25-2012, 07:56 AM - 1 Like	#28
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	Originally posted by JinDesu I understand the thread, but is the consensus at this point: "The k-5IIs is probably not going to show moire in most subjects, and the deciding factor for people is whether or not they care if it does pop up."? We will needs to see some wedding dress tests. Wedding photography is a huge segment and the wedding dress shot is a standard "must have" for the bride. If the K-5II Super gets a reputation for producing moire in wedding dresses it will have a hard time selling just because of the sheer number of togs work or plan to work in the wedding/portrait segment. I hope it sells really well and we see a K-3 24MP APS-C without the AA filter this Spring.

10-25-2012, 08:04 AM	#29
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	The thought of using a K-5 for weddings somehow makes me shudder. My cousin used to have a wedding business and always shot with hasseys, that's just what good wedding photographers used to do. What is this world coming to?

10-25-2012, 08:13 AM	#30
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by Winder Bird feathers and insect eyes (Macro) are two of the more common places to fine moire. I know insect eyes have a pattern that could trigger moire, but as Falk pointed out, you will likely be into diffraction aperture range for extreme macros, so your lens will break up the moire. I initially thought bird feathers may be a problem, but I read somewhere that they weren't. Have you experienced this?