New Foveon 4.5MP chip

[Gints Klimanis]

http://www.dpreview.com/news/0308/03080803foveonx3_5m.asp

The Foveon X3 5M is a 1/1.8-inch CMOS image sensor ...

Check it out. Hmmm. There is no mention of light sensitivity.

[Ron Johnson]

Interesting that Foveon believes digital video happens at a resolution of 640x480. There is little info here (or at Foveon's site), but there seems to be no provision for 16:9 nor HD.

[Gints Klimanis]

Yeah, I'm with you about the video resolution. The Foveon processor seems to be catering to digital camera Motion JPEG video resolutions: 640 x 480 and probably 320 x 240.

[Matt Betea]

All these marketing schemes with numbers is getting tiring. The chip might have 4.5mp in 3 layers. But 4.5mp of resolution it does not have. For video this could turn out nice, but they would need to pump up the actual pixel location count to contend in the still world.

[Nathan Gifford]

It is still early in its development. When cost/performance reachs the right level it will probably takeoff.

[Jeff Donald]

They are behind the 8-ball. Cameras are already at 6MP and higher. It's a hard sell, consumers are looking for higher numbers.

[Ken Tanaka]

Once a numeric basis has been established in a market, as it has in the digital photo market, everyone is forced to chase that basis. As many of us know, the image acquisition and processing system of digital cameras is more important to the end results for most consumers than the sheer quantity of pixels. But such qualitative values are very hard to sell against "the number".

"Behind the 8-ball", indeed.

[Gints Klimanis]

It's important to consider what they're offering: higher quality pixels. They claim that one of their pixels is equivalent to two of the typical pixel. So, even with a 3MPixel chip, they're at 6 effective MPixels and no processing overhead. They are offering the equivalent of 3 CCD color and recording full color level instead the "mosaic" color levels of 50% of green, 25% of blue, 25% of red. So, since the missing information need not be interpolated, the pictures snap faster and with less power. This is a big deal.

[Imran Zaidi]

Having looked very closely at the pixel level at the quality of some sample images from a reviewer of the 3MP version, I do have to say that not only is the higher color resolution apparent, but the actual color levels available to you in photoshop are a strong suggestion that there's something distinctly different and better going on with this chip than other chips.

From the reviews I've read, the problems associated with these cameras seem to have to do with the speed of focusing in low light, and the general speed of picture taking in general. But I haven't had one in my hands so I can't say.

[Gints Klimanis]

The processsing speed I'm referring to is the interpolation required to "de- mosaic color planes." JPG compression will still be applied to the image, although with fewer pixels, the process should be faster. What's the RAW format available in most cameras. Since Canon provides a RAW conversion utility, I suspect that the RAW format is the mosaiced image.

With the Foveon, you get something like 3 Million uninterpolated pixels. With the other cameras, you get, say, 6 million pixels with a fair degree of interpolation.
So, it's a bit unfair to compare the Foveon to the typical CCD/CMOS pixel.

[Jeff Donald]

All of which is a tough sell to a market place that is conditioned by every other manufacture (except, maybe Fuji and their Super CCD) to believe more is better. Is any company even using the Foveon chips? I heard Sigma dropped the use of Foveon chips.

The RAW data is the data off the chip, before most, if not all, processing. No, WB, sharpening, contrast, brightness etc have been applied.

[Imran Zaidi]

Seems to be alive and kicking with a 10.2 million pixel sensor (2268 x 1512 x 3 layers) chip...

http://www.sigma-photo.com/Html/Cameras_sd9.htm

http://www.foveon.com/SD9_info.html

(Neat... I didn't know you could do firmware updates with this cam. That makes for a more promising future...)

[Matt Betea]

On a regular CCD color is interpolated. Not resolution. Looking at the SD9, there is obviously a problem using this chip at high sensitivity settings (400 ISO equivalent is as high as it can go). It also has problems with long exposures.

The idea is good. But it's going to take a lot more development to get it to compete. Until they can pump the resolution up, fix the sensitivity and exposure problems I'll be quite happy with my 6mp traditional CCD and interpolated color.

[Gints Klimanis]

Color interpolation is spatial resolution interpolation. For images with many sharp features, the actual resolution of interpolated CCDs is lower than the advertised # of megapixels. I would agree that the resolution is about half, as described on the Foveon web site.

[Jeff Donald]

I thought I had heard that Sigma had announced that it was not using Foveon chips in their next camera, I may certainly be wrong. In any event, you're severely limited in your choice of lenses. While Sigma makes some interesting lenses, they aren't in the same league as Canon or Nikon. Unless a major camera manufacture (Nikon or Canon) or electronics company (Sony or Panasonic) picks them up they are destined to be just a footnote, I'm afraid.