Sigma Digital SLR Cameras.

If you are the real GP welcome

If not, sod off troll

Please forgive me if it really is you George but I believe your identity has
been hijacked on several occasions

This may be one too

Arts

"Georgette Preddy" wrote in message
om...
Andy Fraser wrote in message
...
In rec.photo.digital, Georgette Preddy uttered these immortal words:

foveon is 2250 x 1500 pixels.
that is only 3 mp.

A 2230 x 1500 image requires exactly 2250 x 1500 x 3 sensors.
Obviously.

Don't you realize there are 3 color channels?

I'm hoping someone can help me understand this better. I went to the
Sigma
website and looked at the specs of the SD10 and sure enough they say
this
camera produces images that are 2268 x 1512 x 3 layers.

Here's where I get confused, please bare with me. If I take a picture
taken
with my Kodak 5MP camera (I'm not about to attempt to compare these 2
cameras BTW) and save it as a bitmap I get a file that's 14,953,734
bytes
in size. That's what I'd expect given the resolution of 2580 x 1932 x 3
bytes per pixel, 1 each for the red, green and blue values of each
pixel.
The fact that that picture was arrived at by applying an algorithm to
the
data from the Bayer mosaic filter CCD jobbie is irrelevant to what I'm
getting at. AIUI my camera produces a photograph with nearly 5 million
true
colour pixels in it while the Foveon X3 method used by the SD10 produces
a
3.4MP true colour image.

If you drew a 5M pixel image by hand with Microsoft Paint, then saved
it as a TIF it would be the same size too. That doesn't make it an
optical photograph. All that matters is the optical quality of the
optical data, the number of pixels are irrelevant, any image can be
upscaled to consume any number of pixels.

A 6MP Bayer has 6M monochrome sensors, a 3.4MP (output is 13.72MP)
Foveon has 3.4M full color sensors. It would take a 13.72MP Bayer to
equaly the quality of Foveon data, if such an enormous sensor existed.

I suggest reading Phil Askey on the subject...

"The Foveon X3 sensor captures full color for each pixel location and
thus requires no demosaic processing, a single individual pixel has
its own distinct color without influence from neighbouring pixels.
This leads me to the term 'Single Pixel Resolution', the X3 sensor's
striking ability to capture image detail down to a single pixel level,
such as a wire which in the image is just one pixel across.

You can of course produce similar results from a Bayer sensor camera
by downsampling an image by 50% [meaning 25% of the original image
area], this is (approximately) the same as combining two green, one
red and one blue pixel together. To achieve this and be left with an
image of the same size as the SD10 you would need 4536 x 3024 (13.7
megapixel) input image."

If you are the real GP welcome

If not, sod off troll

Please forgive me if it really is you George but I believe your identity has
been hijacked on several occasions

This may be one too

Arts

"Georgette Preddy" wrote in message
om...
Andy Fraser wrote in message
...
In rec.photo.digital, Georgette Preddy uttered these immortal words:

foveon is 2250 x 1500 pixels.
that is only 3 mp.

A 2230 x 1500 image requires exactly 2250 x 1500 x 3 sensors.
Obviously.

Don't you realize there are 3 color channels?

I'm hoping someone can help me understand this better. I went to the
Sigma
website and looked at the specs of the SD10 and sure enough they say
this
camera produces images that are 2268 x 1512 x 3 layers.

Here's where I get confused, please bare with me. If I take a picture
taken
with my Kodak 5MP camera (I'm not about to attempt to compare these 2
cameras BTW) and save it as a bitmap I get a file that's 14,953,734
bytes
in size. That's what I'd expect given the resolution of 2580 x 1932 x 3
bytes per pixel, 1 each for the red, green and blue values of each
pixel.
The fact that that picture was arrived at by applying an algorithm to
the
data from the Bayer mosaic filter CCD jobbie is irrelevant to what I'm
getting at. AIUI my camera produces a photograph with nearly 5 million
true
colour pixels in it while the Foveon X3 method used by the SD10 produces
a
3.4MP true colour image.

If you drew a 5M pixel image by hand with Microsoft Paint, then saved
it as a TIF it would be the same size too. That doesn't make it an
optical photograph. All that matters is the optical quality of the
optical data, the number of pixels are irrelevant, any image can be
upscaled to consume any number of pixels.

A 6MP Bayer has 6M monochrome sensors, a 3.4MP (output is 13.72MP)
Foveon has 3.4M full color sensors. It would take a 13.72MP Bayer to
equaly the quality of Foveon data, if such an enormous sensor existed.

I suggest reading Phil Askey on the subject...

"The Foveon X3 sensor captures full color for each pixel location and
thus requires no demosaic processing, a single individual pixel has
its own distinct color without influence from neighbouring pixels.
This leads me to the term 'Single Pixel Resolution', the X3 sensor's
striking ability to capture image detail down to a single pixel level,
such as a wire which in the image is just one pixel across.

You can of course produce similar results from a Bayer sensor camera
by downsampling an image by 50% [meaning 25% of the original image
area], this is (approximately) the same as combining two green, one
red and one blue pixel together. To achieve this and be left with an
image of the same size as the SD10 you would need 4536 x 3024 (13.7
megapixel) input image."

If you are the real GP welcome

If not, sod off troll

Please forgive me if it really is you George but I believe your identity has
been hijacked on several occasions

This may be one too

Arts

"Georgette Preddy" wrote in message
om...
Andy Fraser wrote in message
...
In rec.photo.digital, Georgette Preddy uttered these immortal words:

foveon is 2250 x 1500 pixels.
that is only 3 mp.

A 2230 x 1500 image requires exactly 2250 x 1500 x 3 sensors.
Obviously.

Don't you realize there are 3 color channels?

I'm hoping someone can help me understand this better. I went to the
Sigma
website and looked at the specs of the SD10 and sure enough they say
this
camera produces images that are 2268 x 1512 x 3 layers.

Here's where I get confused, please bare with me. If I take a picture
taken
with my Kodak 5MP camera (I'm not about to attempt to compare these 2
cameras BTW) and save it as a bitmap I get a file that's 14,953,734
bytes
in size. That's what I'd expect given the resolution of 2580 x 1932 x 3
bytes per pixel, 1 each for the red, green and blue values of each
pixel.
The fact that that picture was arrived at by applying an algorithm to
the
data from the Bayer mosaic filter CCD jobbie is irrelevant to what I'm
getting at. AIUI my camera produces a photograph with nearly 5 million
true
colour pixels in it while the Foveon X3 method used by the SD10 produces
a
3.4MP true colour image.

If you drew a 5M pixel image by hand with Microsoft Paint, then saved
it as a TIF it would be the same size too. That doesn't make it an
optical photograph. All that matters is the optical quality of the
optical data, the number of pixels are irrelevant, any image can be
upscaled to consume any number of pixels.

A 6MP Bayer has 6M monochrome sensors, a 3.4MP (output is 13.72MP)
Foveon has 3.4M full color sensors. It would take a 13.72MP Bayer to
equaly the quality of Foveon data, if such an enormous sensor existed.

I suggest reading Phil Askey on the subject...

"The Foveon X3 sensor captures full color for each pixel location and
thus requires no demosaic processing, a single individual pixel has
its own distinct color without influence from neighbouring pixels.
This leads me to the term 'Single Pixel Resolution', the X3 sensor's
striking ability to capture image detail down to a single pixel level,
such as a wire which in the image is just one pixel across.

You can of course produce similar results from a Bayer sensor camera
by downsampling an image by 50% [meaning 25% of the original image
area], this is (approximately) the same as combining two green, one
red and one blue pixel together. To achieve this and be left with an
image of the same size as the SD10 you would need 4536 x 3024 (13.7
megapixel) input image."

"Bart van der Wolf" wrote in message ...
"Georgette Preddy" wrote in message
om...
SNIP
A 6MP Bayer has 6M monochrome sensors, a 3.4MP (output is 13.72MP)
Foveon has 3.4M full color sensors.

Nonsense, as usual. Sensors are not monochrome, nor are they full
color.

All Bayer MP ratings are strictly monochrome. Color is digitally
interpolated after the shutter closes at an expense of -75% of the
monochrome resolution. When a Bayer DSLR maker says 6MP, they mean 6M
monochrome sensors, not full color. That is why you'll never see a
color resolution test image used by on a site that is sponsored with
big money from Bayer camera manufactures, like dpreview.com and
imaging-resource.com.

"Bart van der Wolf" wrote in message ...
"Georgette Preddy" wrote in message
om...
SNIP
A 6MP Bayer has 6M monochrome sensors, a 3.4MP (output is 13.72MP)
Foveon has 3.4M full color sensors.

Nonsense, as usual. Sensors are not monochrome, nor are they full
color.

All Bayer MP ratings are strictly monochrome. Color is digitally
interpolated after the shutter closes at an expense of -75% of the
monochrome resolution. When a Bayer DSLR maker says 6MP, they mean 6M
monochrome sensors, not full color. That is why you'll never see a
color resolution test image used by on a site that is sponsored with
big money from Bayer camera manufactures, like dpreview.com and
imaging-resource.com.