ALL digital cameras require an anti - aliasing filter, as do all analogue
cameras.
Where there is sufficient digicam budget, this will be a flat sheet of
glass, Most often, the anti - aliasing filter is a not - quite - pin - sharp
lens.
This is essential because once an image is captured with aliasing, there is
NO POSSIBILITY of removing it, since it is indistinguishable from the wanted
signal,
The analogue cameras need an anti aliasing filter (always formed by the
lens) to avoid base - fog increase. This has been one of the limits to 35mm
lens performance for decades, with cost being another. The
Julian
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxx>
Sent: Friday, September 19, 2003 8:49 PM
Subject: Re: [OM] Nope, It missed it by few hundred miles
> Just for the record, these are not filters in the sense that you mean.
> Nobody is trying to take away your spectrum. I have no idea how well or
> poorly digital sensors respond to IR or UV, but, whatever the effects of
> these filters on the transmission of IR or UV, they are secondary to the
> primary purpose of limiting light that oscillates between light and dark
> at a high enough frequency to cause aliasing effects. The aliasing is
> not something that can, at least so far, be eliminated in software. The
> particular characteristics needed vary with sensor type and spatial
> resolution. Thus the term 'low-pass' refers not to the
> frequency/wavelength of the light, but the level of detail it renders in
> spatial oscillations of light intensity.
>
> If, for example, the E-2 has a 10mp sensor, it would need a different
> low-pass filter than the E-1. At some level of sensor resolution that
> starts to exceed the resolution of the lenses, no filter would be needed.
>
> Moose
>
> Boris Grigorov wrote:
>
> ><snip> Something struck me when someone mentioned somepin about the low
pass filter. The camera has processing and I want complete control over
that processing power. Why do I need this low pass filter only? To me
photography is painting with light. I want to experiment and do not want no
steenkin infrared film&see where I am going?. Let me control the filtering,
I would like to experiment (not only in the infrared spectrum&). I really
doubt that this feature would be that expensive, or as expensive as at
least dozen more that I could think of &
> >
>
>
>
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