TeamSK jay wrote:
Anybody know of any companies out there that will remove the AA filter and replace it with something appropriately transparent?
Hutech will do that for you. They make camera modifications for astro and IR photography.
I own a modified 20D, where the original UV/IR + AA filters have been removed.
The images are definitely sharper when viewed at 100%, but in two cases ( out of several thousands of shots) I also had heavy moire.
Besides doing astrophotography I shoot mostly landscapes and can live with the permanent moire 'threat'
I checked Hutech out but am somewhat confused. Are the AA and UV/IR filters the same physical unit? I'd like to retain all other filter capabilities, just lose the AA. They didn't seem to have an option for that.
GB_10D wrote:
Hutech will do that for you. They make camera modifications for astro and IR photography.
I own a modified 20D, where the original UV/IR + AA filters have been removed.
The images are definitely sharper when viewed at 100%, but in two cases ( out of several thousands of shots) I also had heavy moire.
Besides doing astrophotography I shoot mostly landscapes and can live with the permanent moire 'threat' :)
Gerhard
Anyone who wants to remove the aa filter should think about the take home message in this post. Gerhard reports two instances out of several thousand shots in which there was "heavy" moire. Well ... this means there was less heavy Moire in the all other shots. It doesn't mean there was none; it just means that Gerhard accepted the result and wasn't troubled by it. I will state again, that high frequency information (technically known as fine details :-) ) passed by the lens that exceeeds the Nyquist frequency does not just disappear. Either it gets attenuated by the aa filter, or absent that, it gets put in the wrong place in the image. Everyone is free to judge what works best for them, but removing the aa filter violates the "no free lunch theorem."
bill vann wrote:
I attribute it solely to the lack of an AA filter as the only cameras that give the same superior results are the leica (no AA) and the medium format backs, most of which come without or are user optional and can be used or not.
bill
Could I point out that the difference could equaly be attributed to the sensor type - CMOS vs CCD.
From what I understand the Sigma doesn't have an AA filter because it uses the foveon senser. Maybe I am just completely ignorant but it just seems like a far better way of doing things to me. I am pretty excited to find out more about the SD14 this week.
