Sigma/Foveon Questions
in [Digital Cameras]
|
Prev: SI Facescape
Next: FF camera with mirrorless design
From: Savageduck on 23 Apr 2010 21:54 On 2010-04-23 18:21:50 -0700, Bubba <digitalrube(a)yahoo.com> said: > On Apr 21, 8:35�pm, Kennedy McEwen <r...(a)nospam.demon.co.uk> wrote: >> >> Mismatched spectral response is one of the reasons why the Foveon >> concept isn't as good as its supporters claim. �Whilst you do get full >> colour pixels, and hence increased resolution over a similar pixel count >> BFA camera, the response is a poor match to the eye. �Foveon's highest >> response is to blue, then green and then red. �With this major mismatch >> in spectral response between the sensor and what we perceive, the Foveon >> design requires significantly higher matrix manipulation to reproduce >> the visual image, with its consequential tendency to excess noise and >> colour balance errors across the human visual spectrum. �Sigma cameras >> are notorious for their inability to get consistent flesh tones. >> >> Kodak's proposed RGBW 2x2 matrix has similar problems, although it comes >> with the benefit of improved broadband luminance response, so it isn't >> all bad. �Colour purity in good light isn't as good as conventional >> Bayer, but low light sensitivity is much better. > > The thread has gone far beyond my ability to follow most of the > responses. I appreciate the time you took to make this passably > understandable by someone conversant neither in this specialized field > of technology nor, for that matter, in film-based photography (if > indeed any mathematical equations or matrices would pertain to film- > based photography). > > Today, I handled the Nikon P100 model I spoke about somewhere on this > thread. It's pretty lovely, but there's no review of it on dpreview, > and I want someone to tell me if the sensor size make the "CMOS" lure > (for laypeople such as myself) pathetic. Although nospam gave some > sort of formula for figuring out how effective a sensor will be, this > is Greek to me. > > So since I've left the Sigma possibility behind, if someone could tell > me if the P100 sensor is comparable to the Canon SX1 (which is > apparently very small), I'd appreciate it. I'd also appreciate knowing > how small is too small with a CMOS sensor (if it's possibly to say > that, i.e., below a certain size, I'd be better off, or just as good > with, a camera with a CCD). > > Thank you. Google is your friend, there are a few other review sites, dpreview isn't the only game in town; < http://www.digitalcamerareview.com/default.asp?newsID=4300&review=nikon+coolpix+p100 > < http://www.neutralday.com/nikon-coolpix-p100-in-depth-review/ > < http://www.photoxels.com/nikon-p100-review.html > < http://www.neocamera.com/review_nikon_p100_more.html > < http://www.pocket-lint.com/review/4682/nikon-coolpix-p100-camera-review > < http://www.infosyncworld.com/reviews/digital-cameras/nikon-coolpix-p100/10865.html > < http://www.photographybay.com/2010/02/23/nikon-p100-hands-on-review/ > -- Regards, Savageduck
From: David J Taylor on 24 Apr 2010 01:50 "nospam" <nospam(a)nospam.invalid> wrote in message news:230420101816005046%nospam(a)nospam.invalid... > In article <GNrux+C+mj0LFwHX(a)kennedym.demon.co.uk>, Kennedy McEwen > <rkm(a)nospam.demon.co.uk> wrote: > >> >>>It would also require interpolation to translate to the ubiquitous >> >>>retangular grid of displays and file formats. >> >>> >> >>Interpolation is inherent in all CFA formats >> > >> >Not spatial interpolation. >> > >> Yes, spatial interpolation - do you think the red and green content of >> the pure blue pixels are created by magic? > > it's not spatial. the number of pixels on the image and on the sensor > are the same. > > it's the toy cameras, such as the ones that advertise 640 x 480 but > really have a 320 x 240 sensor, where there's spatial interpolation. So how is the red and green content at the blue pixel location created, if not by spatial interpolation? David
From: nospam on 24 Apr 2010 02:23 In article <hqu0s2$4fu$1(a)news.eternal-september.org>, David J Taylor <david-taylor(a)blueyonder.co.uk.invalid> wrote: > So how is the red and green content at the blue pixel location created, if > not by spatial interpolation? it looks to its neighbors to calculate the missing components. it's not upsizing anything.
From: David J Taylor on 24 Apr 2010 03:53 "nospam" <nospam(a)nospam.invalid> wrote in message news:230420102323351152%nospam(a)nospam.invalid... > In article <hqu0s2$4fu$1(a)news.eternal-september.org>, David J Taylor > <david-taylor(a)blueyonder.co.uk.invalid> wrote: > >> So how is the red and green content at the blue pixel location created, >> if >> not by spatial interpolation? > > it looks to its neighbors to calculate the missing components. it's not > upsizing anything. "looking to its neighbours" /is/ spatial interpolation. You could regard it as upsizing 1 million red sensor pixels to the red component of a 4 million pixel RGB image, if that helps. Cheers, David
From: Alfred Molon on 24 Apr 2010 05:14
In article <etloZZDEnj0LFwmT(a)kennedym.demon.co.uk>, Kennedy McEwen says... > The only assumption I am making is that the laws of physics apply to the > Foveon device, and that determines the absorption depth of each colour > in the silicon and also the QE of each colour. A few years ago, people (let's call them "experts") in this NG were postulating that by the laws of physics sensors with live view would have higher noise levels than sensors without. How wrong they were. -- Alfred Molon ------------------------------ Olympus E-series DSLRs and micro 4/3 forum at http://tech.groups.yahoo.com/group/MyOlympus/ http://myolympus.org/ photo sharing site |