[Guest]

$10K? “Medium format”? Ok come on…

So much for the hopes of real competition <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/unsure.gif' class='bbc_emoticon' alt=':unsure:' />

[Brightcolours]

They are drowning in their own hype ("45mp"), and low volume making it actually very expensive to produce.



Their foveon cameras do not capture more detail because of the lack of bayer array, but because they do not use any AA-filters... making the cameras actually capture false detail, not more real detail.



ANd that is ok, of course, many people seem to like the higher perceived sharpness on pixel level with AA-filterless cameras...



But that is what it is.. AA-filterless, not foveon magic. And yes... 9700USD for what is basically a Canon EOS 50D without live view, that is a tad steep.



Especially when that camera has a limited lens line up.



The high price will keep it very low volume, and the very low volume with keep the price high.

[Alessandro]

I'm very courious to see image samples taken with this camera.



Maybe I'm wrong, but I think that an APSC camera, even with 45 Mpixel Foveon sensor (that produces a 15 Megapixel-resulting image) is a bit different than a medium format sensor.



I guess that the tridimensional-look of the picture and the depth of field control are very different...



The comparison with "medium format" or saying that an APSC camera can be a valid alternative for medium format user is a rash statement.... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/rolleyes.gif' class='bbc_emoticon' alt='' />

[Guest]

[quote name='Alessandro' timestamp='1305884818' post='8678']

I'm very courious to see image samples taken with this camera.

[/quote]



http://www.sigma-sd.com/SD1/sample-photo/index.html

[popo]

While doing away with the AA filter may be a little questionable, this 15x3 foveon would need a weaker one than a 15MP bayer. I note Sigma are saying they don't need AA to prevent colour moire effects, implying they think moire is ok if it's equal between channels. I can kinda see where they're going, if we draw parallels colour noise is generally considered ugly, but luminance noise isn't so.



The price certainly does kill it as far as I'm concerned.

[Brightcolours]

[quote name='popo' timestamp='1305892577' post='8682']

While doing away with the AA filter may be a little questionable, this 15x3 foveon would need a weaker one than a 15MP bayer. I note Sigma are saying they don't need AA to prevent colour moire effects, implying they think moire is ok if it's equal between channels. I can kinda see where they're going, if we draw parallels colour noise is generally considered ugly, but luminance noise isn't so.



The price certainly does kill it as far as I'm concerned.

[/quote]

They do not need a weaker one, they need an exact same one as with a bayer CFA. Optimal strength of AA filters has nothing to do with the CFA filter below it, only with the fact that details in the real world do not start and end on pixel borders.



Foveon sensors have the SAME aliasing problems as Bayer CFA sensors.

Foveon sensors have the SAME luminance moire problems as Bayer CFA sensors.

Foven sensors do not have the same chromatic moire problems as CFA sensors.



Manufacturers who use AA-filters do not do that to prevent chromatic moire problems, but to prevent the false detail to be recorded. That that also prevents chromatic moire effects is a bonus.



Moire patterns are considered very ugly, also from foveon sensors.

Aliasing is considered ugly too.



It is fine to make the choice to not use AA-filters (same as Leica does), but I do not like their bogus marketing speak nonsense,

[youpii]

[quote name='Brightcolours' timestamp='1305894242' post='8685']

They do not need a weaker one, they need an exact same one as with a bayer CFA. Optimal strength of AA filters has nothing to do with the CFA filter below it, only with the fact that details in the real world do not start and end on pixel borders.



Foveon sensors have the SAME aliasing problems as Bayer CFA sensors.

Foveon sensors have the SAME luminance moire problems as Bayer CFA sensors.

Foven sensors do not have the same chromatic moire problems as CFA sensors.



Manufacturers who use AA-filters do not do that to prevent chromatic moire problems, but to prevent the false detail to be recorded. That that also prevents chromatic moire effects is a bonus.



Moire patterns are considered very ugly, also from foveon sensors.

Aliasing is considered ugly too.



It is fine to make the choice to not use AA-filters (same as Leica does), but I do not like their bogus marketing speak nonsense,

[/quote]



Conceptually, they should have better chrominance resolution than classical Bayer sensors.

But I'd like to see a proof that it works in real life. For example MTF curves when shooting Red/Green/Blue test charts instead of black charts.

[Brightcolours]

[quote name='youpii' timestamp='1305904856' post='8689']

Conceptually, they should have better chrominance resolution than classical Bayer sensors.

But I'd like to see a proof that it works in real life. For example MTF curves when shooting Red/Green/Blue test charts instead of black charts.

[/quote]

Yes, they should. Can you see that? No, but you can probably measure it... Detail sits in the luminance, not the chrominance...

Bayer CFA colour "deduction" is pretty successful in recreating colours.



The biggest problem for foveon sensors (if you do not mind AA-filter-less results) is the light loss compared to Bayer CFA sensors, making them potentially more noisy.

[popo]

[quote name='Brightcolours' timestamp='1305894242' post='8685']

They do not need a weaker one, they need an exact same one as with a bayer CFA. Optimal strength of AA filters has nothing to do with the CFA filter below it, only with the fact that details in the real world do not start and end on pixel borders.

[/quote]

In the case of bayer sensor, wouldn't the "strength" of AA filter be some two photosites of blur to allow for the sparse "chroma" detectors to work effectively. Foveon would need about one photosite strength. And before you go there, I know you can still extract some RGB info from all photosites, but let's say the "non-native" colour data is limited in value.

Manufacturers who use AA-filters do not do that to prevent chromatic moire problems, but to prevent the false detail to be recorded. That that also prevents chromatic moire effects is a bonus.

I'd consider moire in this case a manifestation of aliasing, so I wouldn't consider that a separate category, but more a subset.



Side note: when I converted the 300D to IR by removing the existing filter assembly, I didn't realise at the time I also removed the AA filter which was in the same module. I thought it looked sharper afterwards. Very rarely do I see something resembling moire or aliasing on it, although the longer wavelengths of IR do cause more diffraction blurring so may offset that itself.

It is fine to make the choice to not use AA-filters (same as Leica does), but I do not like their bogus marketing speak nonsense,

I agree there, but that is the way of marketing.

[Guest]

[quote name='Lomskij' timestamp='1305880804' post='8675']

$10K?[/quote]



Surely a crazy price but I must admit the SD1 samples look very good to me.