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mythguy9 · 07-05-2013, 03:35 AM

Hi guys, a question pops up in my mind while the market is hot with cameras without AA filter.

Can pentax/ricoh build a camera with removable AA filter like the built-in ND filter in many compacts?

If so, we don't have to worry about the cost of moire while enjoying the extra resolution due to removed AA filter in our cameras. Then when moire is a problem (like shooting at clothings) the user can simply activate the AA filter!

Is this achievable by today's technology (or more specifically Ricoh's technology???)

Na Horuk · 07-05-2013, 03:39 AM

I think the Q has an ND filter like that. Its actually not a bad idea. The only problem is that DSLRs have a much bigger sensor than compacts, but it might still be feasible

Anvh · 07-05-2013, 03:43 AM

I don't think they can do that, the blur is snak and precise.
Beside that cameras without aa filter are also specialised cameras.
It's a bit like suggesting a build in infrared filter for the 1% that use it

mythguy9 · 07-05-2013, 03:44 AM

Originally posted by Na Horuk

I think the Q has an ND filter like that. Its actually not a bad idea. The only problem is that DSLRs have a much bigger sensor than compacts, but it might still be feasible

Maybe, instead of a electronically-operated AA filter, build a mechanically-operated AA filter. For example the user can slide in the AA filter with a lever. I think this feature will give future Pentax-Ricoh DSLR an edge over the big two.

mythguy9 · 07-05-2013, 03:45 AM

Originally posted by Anvh

I don't think they can do that, the blur is snak and precise.
Beside that cameras without aa filter are also specialised cameras.
It's a bit like suggesting a build in infrared filter for the 1% that use it

I think you have a point there. If a camera is optimise to its AA filter then it probably can perform at its best.

Clavius · 07-05-2013, 03:48 AM

What about a screw-on AA filter for in front of the lens? Why wouldn't that work?

Anvh · 07-05-2013, 05:03 AM

Originally posted by Clavius

What about a screw-on AA filter for in front of the lens? Why wouldn't that work?

AA filter has 2 pieces of glass, 1 blurs it 1 or 2 pixels horizontal and the other blurs it vertically.
There is quite a bit of optimization in it.

It's not a simple "blur all" filter.

Clavius · 07-05-2013, 05:14 AM

Originally posted by Anvh

AA filter has 2 pieces of glass, 1 blurs it 1 or 2 pixels horizontal and the other blurs it vertically.
There is quite a bit of optimization in it.

It's not a simple "blur all" filter.

Clear, thanks. I was just thinking out loud.

I don't see the problem with moiré anyway, it's so easily corrected in PP.

asp1880 · 07-05-2013, 05:38 AM

It's been suggested elsewhere to use the Shake Reduction mechanism to do the AA-blurring. Just wiggle the sensor the right amount during exposure.

I don't know if it's theoretically or technically possible though.

Regards,
--Anders.

Eulogy · 07-05-2013, 05:49 AM

Originally posted by mythguy9

Maybe, instead of a electronically-operated AA filter, build a mechanically-operated AA filter. For example the user can slide in the AA filter with a lever. I think this feature will give future Pentax-Ricoh DSLR an edge over the big two.

Big 3 Actually. Sony is outselling Nikon at this point.

I like the idea, though, I see it being hard to execute. A small sensor mirrorless can have room for such things, but have you seen the internals of a K-5? There's no room!

JinDesu · 07-05-2013, 06:06 AM

Why not just soften the image slightly? Use a crappy UV filter?

**JimJohnson** · 07-05-2013, 06:14 AM

I am guessing the best course of action for someone who wanted AA filtration only sometimes, would be to have a camera with no AA filtration and deal with moire, when it is objectionable, in post processing.

I have read that the K-30 has 'lighter' AA filtration than the original K-5. I really don't know if that is true or not, but I can say that my K-30 images have much finer detail than my previous K-r. I'm sure part of that is also the jump in sensor density (12mp versus 16mp).

falconeye · 07-05-2013, 06:21 AM

There is a blur-type AA filter available for a few bodies optimized to remove edge flckering due to line skipping in movie mode. It is mounted manually into the mirror box with the mirror locked up.

Other than this, it is not doable. The Bayer-AA filter must sit right in front of the sensor and forms a sealed package with it to minimize reflections etc. Also, it is as large as the sensor and there would be no room where to flip it. Eventually, it alters the optical path length, so focus wouldn't work correctly anymore.

The sensor shake method is feasible. Might or might not need a revised sensor shift motor though.

Anvh · 07-05-2013, 10:29 AM

Originally posted by falconeye

The sensor shake method is feasible. Might or might not need a revised sensor shift motor though.

I would then suggest to do the oppisite.
So have a sensor with AA filter standard, when using the camera on a trippod where you get the best sharpness they could move the sensor around to take multiple photos and then stack them into 1 big photo 4 times the resolution for example.

falconeye · 07-05-2013, 11:36 AM

Originally posted by Anvh

move the sensor around to take multiple photos

superresolution requires deconvolution. it's not as straight-forward as you may think.

btw, doing a burst of half a dozen free hand shots normally does the same. The software is good enough at aligning them to subpixel accuracy.

07-05-2013, 03:35 AM	#1
mythguy9 Senior Member Join Date: Jun 2012 Photos: Albums Posts: 276	Built-in AA filter like ND filter??? Hi guys, a question pops up in my mind while the market is hot with cameras without AA filter. Can pentax/ricoh build a camera with removable AA filter like the built-in ND filter in many compacts? If so, we don't have to worry about the cost of moire while enjoying the extra resolution due to removed AA filter in our cameras. Then when moire is a problem (like shooting at clothings) the user can simply activate the AA filter! Is this achievable by today's technology (or more specifically Ricoh's technology???)

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07-05-2013, 03:39 AM	#2
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	I think the Q has an ND filter like that. Its actually not a bad idea. The only problem is that DSLRs have a much bigger sensor than compacts, but it might still be feasible

07-05-2013, 03:43 AM	#3
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	I don't think they can do that, the blur is snak and precise. Beside that cameras without aa filter are also specialised cameras. It's a bit like suggesting a build in infrared filter for the 1% that use it

07-05-2013, 03:44 AM	#4
mythguy9 Senior Member Join Date: Jun 2012 Photos: Albums Posts: 276 Original Poster	Originally posted by Na Horuk I think the Q has an ND filter like that. Its actually not a bad idea. The only problem is that DSLRs have a much bigger sensor than compacts, but it might still be feasible Maybe, instead of a electronically-operated AA filter, build a mechanically-operated AA filter. For example the user can slide in the AA filter with a lever. I think this feature will give future Pentax-Ricoh DSLR an edge over the big two.

07-05-2013, 03:45 AM	#5
mythguy9 Senior Member Join Date: Jun 2012 Photos: Albums Posts: 276 Original Poster	Originally posted by Anvh I don't think they can do that, the blur is snak and precise. Beside that cameras without aa filter are also specialised cameras. It's a bit like suggesting a build in infrared filter for the 1% that use it I think you have a point there. If a camera is optimise to its AA filter then it probably can perform at its best.

07-05-2013, 03:48 AM	#6
Clavius Veteran Member Join Date: Feb 2011 Location: De Klundert Photos: Gallery Posts: 4,150	What about a screw-on AA filter for in front of the lens? Why wouldn't that work?

07-05-2013, 05:03 AM	#7
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by Clavius What about a screw-on AA filter for in front of the lens? Why wouldn't that work? AA filter has 2 pieces of glass, 1 blurs it 1 or 2 pixels horizontal and the other blurs it vertically. There is quite a bit of optimization in it. It's not a simple "blur all" filter.

07-05-2013, 05:14 AM	#8
Clavius Veteran Member Join Date: Feb 2011 Location: De Klundert Photos: Gallery Posts: 4,150	Originally posted by Anvh AA filter has 2 pieces of glass, 1 blurs it 1 or 2 pixels horizontal and the other blurs it vertically. There is quite a bit of optimization in it. It's not a simple "blur all" filter. Clear, thanks. I was just thinking out loud. I don't see the problem with moiré anyway, it's so easily corrected in PP.

07-05-2013, 05:38 AM	#9
asp1880 Veteran Member Join Date: Jul 2010 Location: Lyngby, Copenhagen Photos: Albums Posts: 742	It's been suggested elsewhere to use the Shake Reduction mechanism to do the AA-blurring. Just wiggle the sensor the right amount during exposure. I don't know if it's theoretically or technically possible though. Regards, --Anders.

07-05-2013, 05:49 AM	#10
Eulogy Veteran Member Join Date: Feb 2012 Location: Fredericton, New Brunswick Photos: Gallery Posts: 632	Originally posted by mythguy9 Maybe, instead of a electronically-operated AA filter, build a mechanically-operated AA filter. For example the user can slide in the AA filter with a lever. I think this feature will give future Pentax-Ricoh DSLR an edge over the big two. Big 3 Actually. Sony is outselling Nikon at this point. I like the idea, though, I see it being hard to execute. A small sensor mirrorless can have room for such things, but have you seen the internals of a K-5? There's no room!

07-05-2013, 06:06 AM	#11
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Why not just soften the image slightly? Use a crappy UV filter?

07-05-2013, 06:14 AM	#12
JimJohnson Loyal Site Supporter Join Date: Jan 2012 Location: Summer:Lake Superior - Michigan Winter:Texas Hill Country Photos: Gallery Posts: 2,774	I am guessing the best course of action for someone who wanted AA filtration only sometimes, would be to have a camera with no AA filtration and deal with moire, when it is objectionable, in post processing. I have read that the K-30 has 'lighter' AA filtration than the original K-5. I really don't know if that is true or not, but I can say that my K-30 images have much finer detail than my previous K-r. I'm sure part of that is also the jump in sensor density (12mp versus 16mp).

07-05-2013, 06:21 AM	#13
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	There is a blur-type AA filter available for a few bodies optimized to remove edge flckering due to line skipping in movie mode. It is mounted manually into the mirror box with the mirror locked up. Other than this, it is not doable. The Bayer-AA filter must sit right in front of the sensor and forms a sealed package with it to minimize reflections etc. Also, it is as large as the sensor and there would be no room where to flip it. Eventually, it alters the optical path length, so focus wouldn't work correctly anymore. The sensor shake method is feasible. Might or might not need a revised sensor shift motor though.

07-05-2013, 10:29 AM	#14
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by falconeye The sensor shake method is feasible. Might or might not need a revised sensor shift motor though. I would then suggest to do the oppisite. So have a sensor with AA filter standard, when using the camera on a trippod where you get the best sharpness they could move the sensor around to take multiple photos and then stack them into 1 big photo 4 times the resolution for example.

07-05-2013, 11:36 AM	#15
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by Anvh move the sensor around to take multiple photos superresolution requires deconvolution. it's not as straight-forward as you may think. btw, doing a burst of half a dozen free hand shots normally does the same. The software is good enough at aligning them to subpixel accuracy.

Built-in AA filter like ND filter???

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