09-23-2010, 12:30 AM
[quote name='popo' timestamp='1285198592' post='3113']
I look at it a slightly different way. A foveon stack gives what I consider a true output pixel. The way bayer type sensors are sold are a marketing trick to make the numbers sound higher than they really are. But because it is what almost everyone uses, it sticks. The required interpolation means it can never be pixel perfect sharp other than using sharpening tricks.[/quote]
Agreed <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
It doesn't really matter. A lot was written on this here and there, but some of it was patently wrong. The thing is that a lens resolves much more than any current sensor, so it really is a moot point. Higher MPs will give us images with more details, and the larger details will still be there too. A diffraction limit only means that you can't resolve more for a specific spatial frequency, but what nobody seems to ever mention is that that spatial frequency on a high MP sensor is much higher than on a lower MP frequency, and that that is really only the reason that you reach the sensor diffraction limit.
It is like saying that a lens is diffraction limited at F/4 (which good, fast lenses often are). That actually means the lens can resolve at least the same spatial frequency as is possible for the diffraction limit according to the Rayleigh criterion (9% contrast if I am not mistaken), and that amounts to a resolution of 400 lp/mm. This would amounts to a very small pixel size, if you'd want to capture this resolution. However, there always is the formula for maximum resolution of a system, so it will always be less than the lowest common denominator in a chain, as the inverse total resolution of a system is equal to the sum of the inverse part resolutions in the system (if not limited by an AA-filter, though, as this has an interesting side effect in lower MP sensors).
And, BTW, at F/8 the diffraction limit, f.e., is about 200 lp/mm, so even that is not nearly reached by any sensor yet (that would be approximately 140 MP).
Yep, it should be better. Let's hope we will be able to see some images soon <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
Ok, and now I ended up commenting on diffraction after all <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' /> <ROFL>. Ah well <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
Kind regards, Wim
I look at it a slightly different way. A foveon stack gives what I consider a true output pixel. The way bayer type sensors are sold are a marketing trick to make the numbers sound higher than they really are. But because it is what almost everyone uses, it sticks. The required interpolation means it can never be pixel perfect sharp other than using sharpening tricks.[/quote]
Agreed <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.Quote:And personally I'm not bothered with diffraction other than just another law of physics to get in the way. It is there when it is there. But in the specific case of this new sensor, I think it is a worthy consideration when people start pixel peeping. Will the sensor deliver the theoretical benefit or not? To answer that, you need to avoid possible scenarios where the limit is elsewhere. Because it isn't a bayer pattern sensor, we need to consider the differences.
It doesn't really matter. A lot was written on this here and there, but some of it was patently wrong. The thing is that a lens resolves much more than any current sensor, so it really is a moot point. Higher MPs will give us images with more details, and the larger details will still be there too. A diffraction limit only means that you can't resolve more for a specific spatial frequency, but what nobody seems to ever mention is that that spatial frequency on a high MP sensor is much higher than on a lower MP frequency, and that that is really only the reason that you reach the sensor diffraction limit.
It is like saying that a lens is diffraction limited at F/4 (which good, fast lenses often are). That actually means the lens can resolve at least the same spatial frequency as is possible for the diffraction limit according to the Rayleigh criterion (9% contrast if I am not mistaken), and that amounts to a resolution of 400 lp/mm. This would amounts to a very small pixel size, if you'd want to capture this resolution. However, there always is the formula for maximum resolution of a system, so it will always be less than the lowest common denominator in a chain, as the inverse total resolution of a system is equal to the sum of the inverse part resolutions in the system (if not limited by an AA-filter, though, as this has an interesting side effect in lower MP sensors).
And, BTW, at F/8 the diffraction limit, f.e., is about 200 lp/mm, so even that is not nearly reached by any sensor yet (that would be approximately 140 MP).
Quote:At the end of the day, this could, and probably should, be better than a similar nominal bayer sensor. Like everyone else I'll have to be patient and wait for samples to see if it can deliver.
Yep, it should be better. Let's hope we will be able to see some images soon <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.Ok, and now I ended up commenting on diffraction after all <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' /> <ROFL>. Ah well <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....