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Message: <blockquote data-quote="Surveyor" data-source="post: 3174893" data-attributes="member: 50720">David, this was about 8 years ago and my memory has gone elsewhere, have not found it yet. Thinking about this, about that time frame I had a couple of other cameras that had the same pixel size or close to it but only an 8x6 mm sensor instead of the 6.6 mm height. I think it may have been an Olympus of some type. I have never used picture height for any sort of use so I am unfamiliar with it.The old Imatest I had, I think it just had a check box for anti-aliasing. The current one I am using has 0, .2 or .4x anti-aliasing for the custom portion but I think the ISO function is preset but I don't remember if it is off or 2x.There may be some aliasing going on but I doubt if it is much. Using the ISO default and checking from one program to the next with the same images I got very much the same results.I found an image of a reduction of the same image data in the folder with the one posted but I think I may have done this with a demo version of something I bought later. I have no notes on it but it looks very similar with the exception of showing all the channels.The way SFR works is the slant is set up along a chosen axis so that the way it is sampled you sample 10 pixels in one direction for 1 pixal perpendicular. This gives a 0.1 pixel (assuming 5°) level detection for each pixal along the other axis. I have looked the equations up at one point and can honestly say I have no idea of what they are doing, a lot like the Roddier reduction of star tests.</blockquote>

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