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06-15-2009, 03:50 AM   #46
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QuoteOriginally posted by nanhi Quote
f) use Av mode with the aperture between f27 & f8. Have been using P - mode - new to DSLR and slow to experiment.
For maximum sharpness, stay around f8. If you close down to much the pictures will be soft again.

06-15-2009, 04:23 AM   #47
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QuoteOriginally posted by blende8 Quote
The best way to get sharper images is to remove the AA filter.
How do you remove the AA filter?
06-15-2009, 12:00 PM   #48
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QuoteOriginally posted by jfsavage Quote
How do you remove the AA filter?
You don't - it's an integral part of the camera, and it serves a very real and necessary purpose in terms of reducing moire. It's just that there is a tradeoff between avoiding moire and introducing softness that is a very subjective one that different people will disagree on.

I assume the suggestion to remove it was meant as a joke.
06-15-2009, 06:08 PM   #49
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QuoteOriginally posted by Marc Sabatella Quote
You don't - it's an integral part of the camera, and it serves a very real and necessary purpose in terms of reducing moire. It's just that there is a tradeoff between avoiding moire and introducing softness that is a very subjective one that different people will disagree on.

I assume the suggestion to remove it was meant as a joke.
I wondered if someone had found a hack to modify the AA functionality. Now I think of it though, shouldn't the AA function be done as part of RAW processing?

06-15-2009, 07:01 PM   #50
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An AA filter is not software - it's a physical piece of hardware (a sort of lens) that it is attached to the front of the sensor. The basic idea is to blur away details that are too small for the sensor to record anyhow, to prevent them from introducing artifiants into the image.

I *have* heard of people disassembling cameras to remove it, but this is more slong the line of science experiment than something one would normally expect to do. So this discussion is kind of like if you complained about your car getting low gas mileage, and someone replied, "so convert it to run on cow dung instead". Technically possible, but not realistic for most people in any practical sense.
06-16-2009, 03:46 AM   #51
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QuoteOriginally posted by Marc Sabatella Quote
The basic idea is to blur away details that are too small for the sensor to record anyhow, to prevent them from introducing artifiants into the image.
Well, without an AA filter, you get false colors. The K-7 video function "picks" data from the sensor and its AA filter is made for still, not video. As a result, you are going to see some false color in video footage from the K-7 (or probably any other dSLR not expensive enough to offer supersampling the video from still images).

It is easy to understand: Assume you photograph a star with a very sharp lens. Without an AA filter, you'll hit a single sensor cell only, meaning, you'll record the color as red, green, or blue. A false color. No raw converter can recover from this situation as the information is lost.

With an AA filter, some light reaches the neighboring pixels and color information from all three channels is there. But you would always slightly sharpen the raw images for optimum results.
06-16-2009, 04:28 AM   #52
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It was meant as a joke, yes.
But seriously, it is possible and several repair shops offer it.
I have seen images "before/after" in the forums and the results look impressive.
I don't think that color artifacts are much of a problem.
At least this was never discussed.
The Leica M8 has no AA filter.
06-16-2009, 09:13 AM   #53
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Interesting results here: Nikon D200HR

06-16-2009, 09:30 AM   #54
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QuoteOriginally posted by falconeye Quote
It is easy to understand: Assume you photograph a star with a very sharp lens. Without an AA filter, you'll hit a single sensor cell only, meaning, you'll record the color as red, green, or blue. A false color. No raw converter can recover from this situation as the information is lost.

With an AA filter, some light reaches the neighboring pixels and color information from all three channels is there. But you would always slightly sharpen the raw images for optimum results.
That's probably the best / simplest explanation of the phenomenon I've ever seen - thanks for that. Not sure exactly how it relates to moire, but it does nicely illustrate one type of artifact that an AA filter is designed to improve, and why it has to be done optically before the sensor, not in processing on the resulting signal.

BTW, when I've seen discussions involving people who *have* played with cameras that have had their AA filters surgically removed, there is by no means agreement that the results are better. Depending on the type of scene and the type of artifacts you happen to be sensitive to, some shots have some people proclaiming the non-AA version better, and others proclaiming the opposite. And in any case, we're talking very small pixel-peeping sorts of differences (at least, when comparing non-AA versions to appropriately sharpened AA versions).

Bottom line: before even *thinking* about miniscule things like this, get a handle on the stuff that really matters in day-to-day photography - accurate focus, a solid tripod or else fast enough shutter speeds to handhold well, good quality lenses with hoods, and banish UV filters from your kit. Any of these things makes a *far* bigger difference.
06-16-2009, 04:08 PM   #55
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There is no need to do any pixel peeping if you look at the above link. In case of D200 there is large detail advantage to be had when removing the stock AA-filter. Similar results with the D300 as well. Too bad there wasn't anything about modified Pentax-cameras.
06-16-2009, 08:14 PM   #56
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i think the moral of this thread is to take pictures and try different settings to see what you like. Also, it seems to me through my research that cameras are not the limiting factor, its lenses. Many, if not all, lenses will produce great results when used properly.

If sharpness is your optimal need and you have a k20d, change the program line (in the custom shooting menu) to "MTF", it utilizes the MTF data which is held by the lens to pick the "best" settings. I generally shoot in program mode and have my program line at MTF and enjoy it thoroughly.

Seriously though, take pictures and try different things, its not like you pay by the shot!
06-17-2009, 07:42 AM   #57
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QuoteOriginally posted by Marc Sabatella Quote
That's probably the best / simplest explanation of the phenomenon I've ever seen - thanks for that. Not sure exactly how it relates to moire, but it does nicely illustrate one type of artifact that an AA filter is designed to improve...
Falk's nice explanation only refers to chroma aliasing. There is also luminance aliasing which may occur even in the absence of a Bayer matrix (e.g., with a Foveon sensor).
06-17-2009, 01:06 PM   #58
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QuoteOriginally posted by Maffer Quote
There is no need to do any pixel peeping if you look at the above link. In case of D200 there is large detail advantage to be had when removing the stock AA-filter.
Yes, but that's one camera only, tested using only one RAW converter, and who knows what sharpening settings were used. Results may be different if you change any of those variables. Like I said, I've seen other tests where one could legitimately prefer either way - except for moire test, where the AA filter always wins.
06-19-2009, 12:18 AM   #59
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QuoteOriginally posted by falconeye Quote
Well, without an AA filter, you get false colors.

It is easy to understand: Assume you photograph a star with a very sharp lens. Without an AA filter,
Thanks for that extremely good and easy to understand explanation!
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