There were some hot discussions about the AA filter characteristic in the recent K5 thread.
I've prepared a few images taken with an AA-less Olympus E-520 - please evaluate the full size images and not the thumbnails, of course.
http://photozone.smugmug.com/Reviews/AA-less/
The images were now converted via ACR 6 so the previously posted sample looks different now.
Please vote what you think about the technical quality of these images especially with respect to sharpness vs moiree & color artifacts. Compositon, color rendering and such is meaningless for this purpose.
Thanks!
PS: an AA filter is a low-pass filter mounted in front of a camera's sensor. It serves the purpose to eliminate moirees (color artifacts). The filter is not lossless.
I voted "acceptable". The last image (grill at the bottom of the tram) clearly shows unpleasant moires. In the end, it depends on the motif whether you need an AA filter or not.
I am mainly interested in trekking/landscape and, therefore, do not miss a strong AA filter (have replaced my Canon DSLR with an EPL1). I could probably live without any AA filter at all.
[quote name='Tiz' timestamp='1290965447' post='4530']
I voted "acceptable". The last image (grill at the bottom of the tram) clearly shows unpleasant moires. In the end, it depends on the motif whether you need an AA filter or not.[/quote]
Thanks for pointing this out. I looked and couldn't find any traces of moire. Now that I look close enough (30 cm from the screen, displaying this image at 100% magnification) I see it, but if anything I'm more convinced that this is a non-issue (at least in these images). The only thing that leaves some doubt in my mind is whether other lenses/apertures/cameras combinations would display more evident moire under the same conditions.
This poll is a bit pointless, since to judge things properly, it would take the images twice ...
from the same camera model, once with AA removed, once with its standard AA.
As it is now, you can see images that are quite sharp, but contain a lot of
traces of moire (albeit this sort of images usually does not bring them up
too much) ... most can be repaired in PP, but as well could an image from
a camera with AA be sharpened.
EDIT: By the way ... I voted "acceptable" as well, so one acceptable vote was obviously lost.
The problem with AA-less (be it from Leica, Sigma, or whomever) is that it does not only make moire patterns and aliasing stair stepping, it also just records detail that is not there. Some people seem to like it, and interpret that as being sharper, giving more detail (just hang around Sigma forums to notice that). But in reality, it is not better than over-sharpening your images in software.
Both I find ugly and silly, and both have nothing to do with real resolution or detail.
Reality is: subjects are not perfect to be broken down into hard edged squares of the size determined by pixel pitch. Details in a scene do not have edges that coincide magically at borders between square pixels. At least in the computer graphics industry the last decade or two anti aliasing is universally used to increase the quality of graphics.
AA-filterless (no matter what kind of sensor, bayer CFA, sigma/foveon, gray scale or other) will always record false detail. And like some people love over-sharpened images, or failed HDR conversions, or other oddities, there will always be people that like AA-less cameras producing false detail. In that sense, it is a matter of taste. What is not a matter for discussion is that an AA-filter actually has a reason based on solid science, and is a valuable part in a camera to capture a scene as faithfully as possible.
[quote name='Rainer' timestamp='1290972852' post='4536']
This poll is a bit pointless, since to judge things properly, it would take the images twice ...
from the same camera model, once with AA removed, once with its standard AA.
As it is now, you can see images that are quite sharp, but contain a lot of
traces of moire (albeit this sort of images usually does not bring them up
too much) ... most can be repaired in PP, but as well could an image from
a camera with AA be sharpened.
EDIT: By the way ... I voted "acceptable" as well, so one acceptable vote was obviously lost.
[/quote]
I agree with this. My first thought was that the shots are not super-sharp, i.e. you could obtain a similar sharpness with a camera with AA filter, plus great lens and good PP. However if you were to tell me that these hadnt been sharpened in PP then I would be more impressed. Side by side images are required ;-)
As it has a lot to do with the type of photography chosen, I think we as consumers should have the option to buy the DSLR bodies with or without AA filter. These images are very sharp and moire is visible as expected. I'd rather have a weak AA filtered body for city-scape photos like those... And for landscape, a body with no AA filter...
Serkan
[quote name='Klaus' timestamp='1290961447' post='4527']
There were some hot discussions about the AA filter characteristic in the recent K5 thread.
I've prepared a few images taken with an AA-less Olympus E-520 - please evaluate the full size images and not the thumbnails, of course.
[/quote]
I can see my house!
[quote name='dave9t5' timestamp='1290983406' post='4543']
I can see my house!
[/quote]
This bit of extra sharpness surely would allow slightly larger prints. From any kind of sensible viewing distance no moire would be visible. Especially not in the very dark grill of the tram. AA filters make most sense for fashion Photographers, because fabric is with few exceptions (fences maybe)the only subject which contains such high frequency regular pattern capable of causing visible moire. Note that the fences in your pics contain no visible moire at all. For landscape and portrait shooters removal AA-filters makes some sense. I just wonder if people do really print that big for the resolution advantage to become visible. I guess there is reason why AA filterless cameras are only availabe as medium format pro bodies.
[quote name='dave9t5' timestamp='1290983406' post='4543']
I can see my house!
[/quote]
I didn't vote; not sure where the poll is <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
![Wink Wink](https://forum.opticallimits.com/images/smilies/wink.png)
' /> but these images are biting sharp and nice colour/details <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt=':blink:' />