View single post by Robert

Posted: Wed Feb 24th, 2016 07:27

Joined:	Sun Apr 1st, 2012
Location:	South Lakeland, UK
Posts:	4066
Status:	Offline

I can't find mention of an AA filter on the D500 but all DSLR's need some sort of protective glass in front of the sensor. Otherwise the image suffers distortion and focus issues. The question is whether the glass is clear or not, dipped in acid to produce a very slightly rippled surface sufficient to prevent aliasing of repetitive lines in an image.

https://en.wikipedia.org/wiki/Anti-aliasing_filter

There also of course needs to be a low pass filter which restricts the wavelengths of light able to reach the sensor to the visible range, filtering out anything below about 400nm or above 680-700nm. Otherwise you just get a blurred mess with focus shift and IR-UV contamination.

My understanding with these higher resolution sensors is that the frequencies involved are less susceptible to the problem of aliasing in real life use but I think Nikon have recognised they need to be light handed in this department now, I doubt they would go back to the strength of filters used in the D200 for example.

I think now this particular aspect of imaging design is better understood and better catered for. If there is some AA effect filter in the D500 I doubt it will be detrimental. There is a far greater mission to create the ultimate resolution image now rather than trying to minimise perceived issues which rarely existed.

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Robert.