newbie needs help

Hello,

Can someone please explain me why the sensor of the DP1 can detect 14.1 million pixels while the effective pixels are only 4.6 million? (On Sigma France's website, it says 2652×1768×3 layers.) I'm really confused here. Is the goal to have a better dynamic range?

The Nikon D300 has 13.1 (sensor) 12.3(effective) million pixels, does it mean the DP1 does a better job with landscape pictures than the D300?

Another thing: according to dpreview, the DP1 was annouced in Sept, 2006, why is everybody getting it now? (Delayed by UPS?) And is there an early version of DP1 which has silver buttons on the back?

THanks in advance! Sorry if the questions are stupid.

Best Regards,
Tony

Some how this link wasn't intended for you. Sorry, I have no idea how this happened.

On MPs, I suggest you read more about the DP1 and its Foveon sensor in the catalog you can download here http://www.sigma-photo.co.jp/english/support/catalogue/index.htm also see http://www.foveon.com

The DP1 was 'announced' as a prototype at Photokina, Cologne, Germany, late September 2006. Several differnent prototypes (and then beta) cameras have been pictured in press releases and thus on retailers' sites and other online articles since then. Thus you will see slightly different images, depending upon how current or accurate to the released model. I've noticed some retailers' sites still show an older version (ie silver buttons) rather than the updated body version (ie black buttons) and other changes, ie hotshoe, different appearance in front etc. The first retail DP1 were available for sale in Asia on March 3, 2008. They are now making their way around the world ;-)

See the DP1 special site at Sigma website http://www.sigma-photo.co/jp/english for more info too. Be sure to view the DP1 sample gallery, direct link here http://www.sigma-dp1.com/sample-photo/index.html and many users' photos on http://www.pbase.com/cameras/sigma and the flickr DP1 photo pool here http://www.flickr.com/groups/sigma-dp1/pool/ Carl Rytterfalk's website http://www.rytterfalk.com is a good source for in-use videos and further commentary.
Best regards, Sandy
[email protected]
http://www.pbase.com/sandyfleischman (SD14 & DP1 galleries)
http://www.flickr.com/photos/sandyfleischmann (more)

ulrichvonlich said:

Hello,

Can someone please explain me why the sensor of the DP1 can detect
14.1 million pixels while the effective pixels are only 4.6 million?
(On Sigma France's website, it says 2652×1768×3 layers.) I'm really
confused here. Is the goal to have a better dynamic range?

The Nikon D300 has 13.1 (sensor) 12.3(effective) million pixels, does
it mean the DP1 does a better job with landscape pictures than the
D300?

Another thing: according to dpreview, the DP1 was annouced in Sept,
2006, why is everybody getting it now? (Delayed by UPS?) And is there
an early version of DP1 which has silver buttons on the back?

THanks in advance! Sorry if the questions are stupid.

Click to expand...

Its actually quite simple...A 14mp Foveon X3 sensor produces as image of 4.7mp in size and with a true 4.7mp of resolution, irrespective of the colour being captured.

A 14mp Bayer sensor on the other hand produces an image 14mp in size but with a true resolution of only somewhere between 3.5mp and 7mp, depending on the predominant colours of the subject being captured.
The resolution of a Bayer sensor is entirely colour dependant.

Take a 10mp Bayer sensor for instance...If it registers a subject that is is predominantly red then the minimum resolution can drop to the sum of its red photosites...2.5mp. The same goes for subjects that are predominantly blue.

For subjects that are predominantly green the maximum resolution can rise to 5mp but no more.

So the actual resolution of a 10mp Bayer sensor is somwhere between 2.5mp-5mp...Now your probably going to ask how can that be the case when the final image is 10mp in size?...Well the reason is the rest of the image data that makes up a Bayer image is made up from the averaged outputs of adjacent photosites (interpolation) with "made up" being the operative words as none of that additional data is actually real (it does'nt add to the resolution, it merely increases the final output image size).

...Its one of the main reasons why images from Bayer sensors look so soft and plasticy when viewed full size and its why the SD14 and DP1 (which has the same sensor) can match the resolution of good quality 12mp Bayer sensor cameras like the Canon 5D and Nikon D300.

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DSG
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http://sigmasd10.fotopic.net/

A direct comparison of the SD14 with the D300:

http://forums.dpreview.com/forums/read.asp?forum=1027&message=25836119

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http://www.pbase.com/hught

ulrichvonlich said:

Hello,

Can someone please explain me why the sensor of the DP1 can detect
14.1 million pixels while the effective pixels are only 4.6 million?

Click to expand...

The 14.1 MP number is the number of photodiodes, which are what are conventionally counted as pixels by camera makers. It's not what it detects, but what it has, hardware wise.

I don't know where you got the "effective" number. The CIPA standard for effective megapixels say it should not be applied to this type of sensor, but if it was applied, they would all be counted. If they've revised it again so that for Foveon sensors only the green pixels (for example) should be counted, then the number would be 4.7 M.

ulrichvonlich said:

The Nikon D300 has 13.1 (sensor) 12.3(effective) million pixels, does
it mean the DP1 does a better job with landscape pictures than the
D300?

Click to expand...

No, the MP number says nothing about how good a job a camera will do.

j

Thanks a lot! I've learned lots of stuff from you guys.

Best Regards,
Tony

Btw, the effective pixel is quoted from dpreview's camera database. Later I was told by a member that it should be the number of output pixel not effective pixel, which is, as you said, all of them.