Well, looking at the difference in the images of the std d200 and hr
modified the moiré effects have been reduced in the std d200 but not
eliminated. What is really needed is a sensor where the pixels aren't on a
regular grid - something like film.
...Wayne
> -----Original Message-----
> From: Moose [mailto:olymoose@xxxxxxxxx]
> Sent: Thursday, 28 July 2011 2:03 PM
> To: Olympus Camera Discussion
> Subject: Re: [OM] (OM) digital imaging and anti-aliasing filters
>
> 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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