09-23-2010, 11:42 AM
(This post was last modified: 09-23-2010, 11:51 AM by Brightcolours.)
[quote name='popo' timestamp='1285241406' post='3152']
I am aware of the physics involved, but you've totally missed the point. I'm not the best at explaining stuff so let's try again. While diffraction "happens" at the lens, it still has to get detected by the sensor before we see it. Due to the softening effects of the bayer pattern and low pass filter, it should be noticeable at an output pixel level much "later" on a 15MP bayer sensor than a 15x3 foveon of same area for example.
I get a feeling we're all arguing for the same thing but expressed in totally different ways...
[/quote]
The bayer pattern does not actually soften the image... it is quite capable of recording luminance (where the detail lays) to a surprising degree.
The AA-filter is not bayer specific... one can also put an AA-filter in front of a foveon sensor for the same reasons (not wanting to record false details and moire effects).
There are two ways to look at diffraction softening. At pixel level (where it makes little sense) and at image level.
At pixel level you probably are correct, the AA-filter "softening" may slightly cover up diffraction softening, but it will not be much at all.
But the low resolution of Sigma sensors till now anyway covered up diffraction softness. So on pixel level, diffraction would be detectable on a 7D much sooner than on a SD14.
On image level (where diffraction actually does matter), there is/will be no difference between cameras with different types of sensors and different resolutions. Diffraction of the projected image will be the same with similar sized sensors. A lower resolution sensor merely will cover up diffraction softness due to its own lack of resolution.
A downside to the foveon sensor will again be the noisy nature of it, unless they have radically changed the light "absorption" layers in the new sensor (I am not sure if that actually would be possible).
Foveon sensors effectively record a smaller percentage of light compared to bayer RGB CFA array sensors. So... I do not expect the new sensor to deliver great higher ISO results, and I am curious if again they went for a low or no AA-filter approach.
I am aware of the physics involved, but you've totally missed the point. I'm not the best at explaining stuff so let's try again. While diffraction "happens" at the lens, it still has to get detected by the sensor before we see it. Due to the softening effects of the bayer pattern and low pass filter, it should be noticeable at an output pixel level much "later" on a 15MP bayer sensor than a 15x3 foveon of same area for example.
I get a feeling we're all arguing for the same thing but expressed in totally different ways...
[/quote]
The bayer pattern does not actually soften the image... it is quite capable of recording luminance (where the detail lays) to a surprising degree.
The AA-filter is not bayer specific... one can also put an AA-filter in front of a foveon sensor for the same reasons (not wanting to record false details and moire effects).
There are two ways to look at diffraction softening. At pixel level (where it makes little sense) and at image level.
At pixel level you probably are correct, the AA-filter "softening" may slightly cover up diffraction softening, but it will not be much at all.
But the low resolution of Sigma sensors till now anyway covered up diffraction softness. So on pixel level, diffraction would be detectable on a 7D much sooner than on a SD14.
On image level (where diffraction actually does matter), there is/will be no difference between cameras with different types of sensors and different resolutions. Diffraction of the projected image will be the same with similar sized sensors. A lower resolution sensor merely will cover up diffraction softness due to its own lack of resolution.
A downside to the foveon sensor will again be the noisy nature of it, unless they have radically changed the light "absorption" layers in the new sensor (I am not sure if that actually would be possible).
Foveon sensors effectively record a smaller percentage of light compared to bayer RGB CFA array sensors. So... I do not expect the new sensor to deliver great higher ISO results, and I am curious if again they went for a low or no AA-filter approach.