Oops! Bad link below. Should be.
<http://www.moosemystic.net/Gallery/tech/AA_Filter/D200_AA.htm>
On 7/27/2011 9:03 PM, Moose wrote:
> On 7/27/2011 6:08 PM, Brian Swale wrote:
>> It looks as though for landscape photography anyway, it would be an
>> advantage to remove any anti-aliasing filter from the camera.
>>
>> See here
>>
>> http://www.maxmax.com/nikon_d200hr.htm.
> This is not as simple as you might imagine. Look at the vertical moiré
> patterns. Assume you have shot something without
> an AA filter, and such patterns afflict it. How are you going to fix it? A
> whole lot of hand work will improve it, but .
> . .
>
> Then how about the circular one? How will the details of your feathery
> foliage look with no AA filter? Obviously,
> different makers make different compromises. I'm guessing Oly shots of those
> tests would show no visible moiré.
> Anywhere, including foliage, where fine lines run parallel, even for a short
> distance, moiré can rear its head.
>
> But wait, there's more! Instead of looking only at the things he points to,
> look at the whole images.
>
> Look closely at the letters below the first moiré test pattern. I can see it
> , but you may need a glass or to enlarge
> it. The AA letters are softer edged, but the others have little busy
> artifacts around them that are hardly visible in
> the AA version. It would appear that the AA filter is also covering up pixel
> level failings of the sensor and/or
> demosaicing algorithms.
>
> So a weaker or non-existent AA filter is going to be a mixed blessing, no?
> Also, deconvolution algorithms are
> specifically designed to deal with the kind of OOF that AA filters cause -
> not by intent, perhaps, but by nature. So
> take a look at this.<cid:part1.04030301.06010407@gmail.com>
>
> Deconvolution, in this case in the form of Focus Magic, has at least leveled
> the playing field, if not given the AA
> image a slight edge in sharpness/detail definition. But look at the thin
> black on white lines of letters and scale. FM
> has also enhanced the artifacts around them to about the level of the non AA
> image.
>
> If this were a really important image to me, I could do some masking and use
> other tools to get the best of both worlds,
> but it admittedly takes time. But I sure prefer dealing with the AA softening
> to trying to correct moiré problems.
>
> So think before you leap; is there a fire outside the frying pan? I know you
> want images direct from the camera that are
> as close to finished as possible. In this case, I think you are better off
> with the AA filter than without. Yes, there
> are cameras with weaker and/or different AA filters and/or sensor systems
> that may hit a better compromise, but that's
> another story.
>
> I'd stick with the camera you have, and learn to correct the problem is those
> cases where it is necessary. If that
> doesn't do what you need, then it's time to consider a different camera or
> camera system. There are real reasons why
> some of us decades long OM shooters went with other digital systems.
>
> I'm afraid that my advice may run you into a different problem. Deconvolution
> is computation intensive. Assuming you are
> still running computer equipment of modest power, memory, etc., you may find
> it tediously slow. No free lunch. :-(
>
> Moose
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