Removing the anti alias filter from a 40D

jgoetz4

Morning Folks
I believe that if this filter is removed from the camera, the images are quite a bit sharper. On the down side, moire is also increased. What additional benefits/down falls can be expected if this filter is removed ? Just curious.
Thanks and have a good day
Jim...

Robinivich

I think moire vs sharpness are the only real concerns, you might also consider looking at the Leica M8 for reference, it doesn't have an AA filter. I'm not sure if Leica explains that decision anywhere, I believe they have a blurb mentioning that it's intended to maximize use of lens resolution.

Now, whether you actually CAN remove it that easily from a 40D, is another question entirely

Also, I have to wonder if it's related to the IR cut filter, if removing one means removing the other (or if they're both the same piece of glass), then you'd have similar issues to the M8's infrared sensitivity, resulting in unnatural tones for some subjects.

ziggy53

MaxMax is one of a very few places that will perform that conversion and they have a nice page explaining the process and benefits.

http://www.maxmax.com/hot_rod_visible.htm

Besides moire you may also see odd artifacts in straight lines especially those lines with high contrast. Spider webs, boat rigging and some suspension bridges are common examples. The artifacts resemble high-compression JPG artifacts and highly compressed JPGs make the problem worse.

I used to shoot a Kodak DCS 460 (from 1995, 6 megapixel, $16,000 camera) and it did not come standard with an Anti-Aliasing (AA) filter. We wound up installing the filter because the problems offset the benefits.

While PhotoShop can reduce the effects of not having an AA filter, you can also tilt the camera a bit during the shot and straighten in post.

My recommendation is not to remove the filter for a general purpose camera (certainly not if it is your only camera) but I have been tempted to purchase an older Canon 5D for the conversion just for certain vista landscapes.

Unless you use the very best lenses and practice good focus technique, you may not even readily see the benefits of the conversion. (I would estimate that removing the AA filter on many cameras will increase resolution by about 15 percent.)

BTW, Foveon sensor cameras don't require an AA filter which does help those sensors somewhat since they lack as much luminance detail as a comparable Bayer imager (by photosite size). (More recent Foveon designs use staggered micro-lenses which do act as an AA filter with regard to luminance moire.)

jgoetz4

ziggy53 wrote:

MaxMax is one of a very few places that will perform that conversion and they have a nice page explaining the process and benefits.

http://www.maxmax.com/hot_rod_visible.htm

Besides moire you may also see odd artifacts in straight lines especially those lines with high contrast. Spider webs, boat rigging and some suspension bridges are common examples. The artifacts resemble high-compression JPG artifacts and highly compressed JPGs make the problem worse.

I used to shoot a Kodak DCS 460 (from 1995, 6 megapixel, $16,000 camera) and it did not come standard with an Anti-Aliasing (AA) filter. We wound up installing the filter because the problems offset the benefits.

While PhotoShop can reduce the effects of not having an AA filter, you can also tilt the camera a bit during the shot and straighten in post.

My recommendation is not to remove the filter for a general purpose camera (certainly not if it is your only camera) but I have been tempted to purchase an older Canon 5D for the conversion just for certain vista landscapes.

Unless you use the very best lenses and practice good focus technique, you may not even readily see the benefits of the conversion. (I would estimate that removing the AA filter on many cameras will increase resolution by about 15 percent.)

BTW, Foveon sensor cameras don't require an AA filter which does help those sensors somewhat since they lack as much luminance detail as a comparable Bayer imager (by photosite size). (More recent Foveon designs use staggered micro-lenses which do act as an AA filter with regard to luminance moire.)

Good Evening Ziggy,
Thanks for your input. I was mainly curious as to what the benefits & down falls were without the aa filter.
Have a good evening
Jim...