austin.grant wrote:
Just a follow up to my post: Astronomik has just released EOS XL clip-in filters for full frame Canon cameras. Without a doubt the way to go!
I would rather go my way I have developed 4 years ago for my infrared crop DSLR camera: Infrared-Clip filter in front of shutter - behind the mirror. So I have easy exchangeable filter, and a bright viewfinder - I love the optical viewfinder.
That's great for IR ONLY photography, where you are blocking out much/all of the visible light. Your mod is necessary to use the viewfinder at all.
In the discussion above, I'm talking about removing the AA filtration. It also removes the IR blocking filter, so you need to replace that to get the benefits of increased sharpness without the "enhanced" IR passthrough. The viewfinder still works fine. It's getting all the light it gets as stock.
Sneakyracer wrote:
When viewing at 100% or pixel peeping
These guys explain it well and with sample images: HERE
How is sharp at the pixel level, then, different from plain old sharp?
Something I notice on the linked page takes me back to a point I made earlier in this thread - and perhaps in a few other places recently. Different cameras and lenses (and apparently removing the AA filter adds another variable) require different amounts of sharpening in post. In the examples, the non-AA filter images look sort of like over sharpened images at 100% in some cases, complete with halos. On the other hand, the AA filter images at 100% look softer... but I'll wager that that they have not yet been sharpened.
So a more interesting comparison would be between end results - the non-AA filter version with whatever minimal sharpening one might apply (and perhaps sometimes some blur to deal with moire?) and the sharpened image from the camera with the AA filter - with both examples optimized in the ways that a talented post-processor might use.
Basically the detail you get on the file obviously depends on the system resolution, that is the lens/sensor (and technique/settings). After that you can sharpen obviously but you can't beat detail that is recorded, specially when resizing (up) images for print. Can you just cancel out the blurring effect by sharpening? I don't know. I guess it might be possible to reduce the blur effect by using a sharpening algorithm that has the data of the specific aa filter used in the sensor that outputted the image you want to sharpen. Trial and error might work and some people have made some nice sharpening recipes. Software like GeniuneFractals / Perfect Resize works well for resizing.
Not all sensors have the same AA filtering obviously. Some have slight filtering resulting in not much difference when you remove it others have stronger filtering. Unfortunately camera manufacturers do not specify the strength of the AA filter on camera models.
Bottom line the purpose of the AA filter is to blur images to reduce aliasing. The things is it blurs the whole image, it is not selective of course. Using a lens that is not as sharp will have the same effect.
If you see halos around edges in an image then there is something else going on. I have seen plenty of files from sensors without an AA filter and have not seen that in raw files. If the file comes out too sharp for your taste it is quite easy to blur it a bit.
I am thinking of having the hot rod mod (AA filter removal) on my 1DS3 done, It has a high enough pixel density that aliasing should not be a huge problem. I can do before and after shots and compare it to my 5D3.
Basically the detail you get on the file obviously depends on the system resolution, that is the lens/sensor (and technique/settings). After that you can sharpen obviously but you can't beat detail that is recorded, specially when resizing (up) images for print. Can you just cancel out the blurring effect by sharpening? I don't know. I guess it might be possible to reduce the blur effect by using a sharpening algorithm that has the data of the specific aa filter used in the sensor that outputted the image you want to sharpen. Trial and error might work and some people have made some nice sharpening recipes. Software like GeniuneFractals / Perfect Resize works well for resizing.
Not all sensors have the same AA filtering obviously. Some have slight filtering resulting in not much difference when you remove it others have stronger filtering. Unfortunately camera manufacturers do not specify the strength of the AA filter on camera models.
Bottom line the purpose of the AA filter is to blur images to reduce aliasing. The things is it blurs the whole image, it is not selective of course. Using a lens that is not as sharp will have the same effect.
If you see halos around edges in an image then there is something else going on. I have seen plenty of files from sensors without an AA filter and have not seen that in raw files. If the file comes out too sharp for your taste it is quite easy to blur it a bit.
I am thinking of having the hot rod mod (AA filter removal) on my 1DS3 done, It has a high enough pixel density that aliasing should not be a huge problem. I can do before and after shots and compare it to my 5D3....Show more →
I wouldn't make it that complicated. I'd simply have a skillful photographer/post-processor take both files and optimize them in whatever ways produce the best result for each file, make high quality prints, and compare. You would obviously use less sharpening in post with the AA-filterless source file.
I'm betting that there would be little or no visible difference, or at least not one that would consistently favor one result over the other.
That said, I do think that there will come a time when sensors are so much higher resolution than what we have today that anti-aliasing filters will simply become unnecessary. We aren't there now for the most part, though some feel that the D800e gets close - but even there it depends a bit on the subject that the photographer focuses on. (For example, landscape photographers like the D800e while certain other photographers might be happier with the D800.)
gdanmitchell wrote:
I wouldn't make it that complicated. I'd simply have a skillful photographer/post-processor take both files and optimize them in whatever ways produce the best result for each file, make high quality prints, and compare. You would obviously use less sharpening in post with the AA-filterless source file.
I'm betting that there would be little or no visible difference, or at least not one that would consistently favor one result over the other.
That said, I do think that there will come a time when sensors are so much higher resolution than what we have today that anti-aliasing filters will simply become unnecessary. We aren't there now for the most part, though some feel that the D800e gets close - but even there it depends a bit on the subject that the photographer focuses on. (For example, landscape photographers like the D800e while certain other photographers might be happier with the D800.)
The pixels density of the D800 is high enough that the AA filter starts to become almost unnecessary. Same with some of the APS-C sensor cameras although the smaller the sensor the higher magnification of any visible flaws.
Also the increase in detail gained by removing the AA is not huge, it might be the equivalent of adding a few megapixels (depending on the strength of the filter) given equally good glass and technique.
I mean, would you notice in the end result from a 16 mp camera to a 20 mp camera given that everything else is equal? It's tough in print. But in scenes with lot's of small detail in the frame, like landscapes, the difference will probably be noticeable. Not as much as using a better sensor with 200% the megapixels but still there will be a difference. It is optimizing what pixels you got. People pay a lot of money by getting a lens that is just a wee bit sharper. So to some the extra detail is important.
Also of note: In Nikons D800E and D7100 did not remove the OLPF but instead added another filter to counteract the blur effect. Here are the results compared to the D800 and D7000:
Good points made by Sneakyracer and Dan above - there is nothing else to add to it from my side other than agreeing that I don't need to sharpen anything in post processing in my IR photos taken with my IR-converted MkII camera (without AA filter). With my regular light MkII camera, I need to resharpen often a bit in post-processing.
My next regular light camera hopefully will have no AA filter (similar to A7R or D800E).
