retrofocus wrote:
I am aware that most DSLRs use a so called anti alias (AA) filter in front of the sensor to avoid formation of Moire patterns in the original image. The AA filter is made from clear crystalline lithium niobate with different thickness depending on the use in many kind of digital cameras.
Now my question: Why do manufacturers (e.g. Canon) really use this AA filter? It lowers the resolution of the sensor up to 30% - is it just to make sure that nobody sees a bit of a moire pattern when the cameras are tested professionally later? The moire pattern can be removed easily in post processing software, too. Is anybody aware of another reason why AA filters are used? It does not make a lot of sense to me that such kind of filters are added as standard in most digital cameras and which is not providing the best of digital resolution outcome especially when consumers try the best and sharp lenses! Medium format cameras and also Leica\'s digital M8/M9 cameras do not use AA filters.
Nikon might have realized that this is an issue because they offer now the D800e without anti aliasing. This will increase the resolution and makes most out of the 36 MPixel sensor.
I am also aware that the AA filters are coated to reflect infrared. But the infrared reflection can also be achieved without using an AA filter in the first place. If anybody has some insight especially from the camera manufacturers, please post!
it\'s not that easy to remove in post and when you do you get blurring away anyway, it\'s worse than real AA filter
the 5D3 has only 20D pixel pitch I don\'t think it\'s nearly close enough to start doing away with AA filter, even the D800e seems borderline, it\'s not even 7D pixel pitch
retrofocus wrote:
I am aware that most DSLRs use a so called anti alias (AA) filter in front of the sensor to avoid formation of Moire patterns in the original image. The AA filter is made from clear crystalline lithium niobate with different thickness depending on the use in many kind of digital cameras.
Now my question: Why do manufacturers (e.g. Canon) really use this AA filter? It lowers the resolution of the sensor up to 30% - is it just to make sure that nobody sees a bit of a moire pattern when the cameras are tested professionally later? The moire pattern can be removed easily in post processing software, too. Is anybody aware of another reason why AA filters are used? It does not make a lot of sense to me that such kind of filters are added as standard in most digital cameras and which is not providing the best of digital resolution outcome especially when consumers try the best and sharp lenses! Medium format cameras and also Leica\'s digital M8/M9 cameras do not use AA filters.
Nikon might have realized that this is an issue because they offer now the D800e without anti aliasing. This will increase the resolution and makes most out of the 36 MPixel sensor.
I am also aware that the AA filters are coated to reflect infrared. But the infrared reflection can also be achieved without using an AA filter in the first place. If anybody has some insight especially from the camera manufacturers, please post!
it\'s not that easy to remove in post and when you do you get blurring away anyway, it\'s worse than real AA filter
the 5D3 has only 20D pixel pitch I don\'t think it\'s nearly close enough to start doing away with AA filter, even the D800e seems a bit borderline
retrofocus wrote:
I am aware that most DSLRs use a so called anti alias (AA) filter in front of the sensor to avoid formation of Moire patterns in the original image. The AA filter is made from clear crystalline lithium niobate with different thickness depending on the use in many kind of digital cameras.
Now my question: Why do manufacturers (e.g. Canon) really use this AA filter? It lowers the resolution of the sensor up to 30% - is it just to make sure that nobody sees a bit of a moire pattern when the cameras are tested professionally later? The moire pattern can be removed easily in post processing software, too. Is anybody aware of another reason why AA filters are used? It does not make a lot of sense to me that such kind of filters are added as standard in most digital cameras and which is not providing the best of digital resolution outcome especially when consumers try the best and sharp lenses! Medium format cameras and also Leica\'s digital M8/M9 cameras do not use AA filters.
Nikon might have realized that this is an issue because they offer now the D800e without anti aliasing. This will increase the resolution and makes most out of the 36 MPixel sensor.
I am also aware that the AA filters are coated to reflect infrared. But the infrared reflection can also be achieved without using an AA filter in the first place. If anybody has some insight especially from the camera manufacturers, please post!
it\'s not that easy to remove in post and when you do you get blurring away anyway
the 5D3 has only 20D pixel pitch I don\'t think it\'s nearly close enough to start doing away with AA filter, even the D800e seems a bit borderline
Apr 11, 2012 at 07:45 PM
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