Regarding Contax N digital and Leica digital back

[fotografz]

John and Richard, that Canon passed on the Foven chip is easy to understand. They are a maker of their own chips. Contax's vision was a full frame 35mm capture, which as we know from the Kodak 14n, is no easy task. Full frame is so difficult and expensive, that whole new approaches to camera and lens design are revolving around smaller chips.

I wonder, since the Foveon chip relies on multiple layers, does the problem with light angle become even more severe for full frame capture? IMO, full frame is the frontier for all digital capture. The first full frame under $2,000. wins all the marbles.

 

[jkohl]

Marc,

Have you read the Shutterbug August issue? The author sort of indicates that Foveon is not the only producer of that type of chip, that some of the medium format backs use similar technologies. The article sort of really opened my eyes to the possibilities. I give credit to Sigma to being brave to use this chip and maybe I might consider the camera if it doesn't go the way that Contax did with it's poor marketing. I still would like some of the experts to comment on the chip. Thanks Marc and Richard.
John

 

[jkohl]

Richard,

My impression of the Foveon chip also comes from the galleries from other websites too. The photos are very impressive. This is what really peaked my interest, such as www.pbase.com/sigmasd9/root and www.sd9.org this is where I've been looking.
John

 

[afranklin]

Hi Marc,

> I wonder, since the Foveon chip relies on multiple layers, does the > problem with light angle become even more severe for full frame > capture?

I'm not sure, but one would think so. I don't know what the well depth of the Foveon sensor is, and since they aren't used in any "full frame" use, no one has reported on this issue.

> IMO, full frame is the frontier for all digital capture. The > first full frame under $2,000. wins all the marbles.

I agree with that, but I'm not sure that is important to most...as most new camera sales don't care about image format. Keep in mind, that it is only our relating to the lense focal length that format matter.

Regards,

Austin

 

[afranklin]

Hi John,

With regards to the Foveon... The "idea" of the Foveon is one that has been around for a long time, long before Foveon developed what they developed. The Foveon is a decent implementation, but it does have it's problems. The two most apparent ones I've seen are long exposure issues, and second color. If you look at some of the pictures from it that were done in low light, you will see a lot of color fringing and blown out highlights. Standard pictures have funny color. So, at this point in time, I don't believe these sensors are high end.

One of the issues that I have questioned about this architecture is the ability to retain color fidelity...simply because the color "filtering" may not be able to be very accurate, unlike Bayer pattern sensors, where the actual optical color filters, and are very very accurate.

A question I have had with the Foveon architecture is the depth of the sensor wells...though in fact, they may be shallower than other sensors, unfortunately, I have not been able to find this information, and no full-frame camera exists that this can be tested on. If anything, the vignetting will not happen uniformly, due to the different depths of the different colors.

Contax probably didn't pick the Foveon probably because it wasn't full frame, and it wasn't very high pixel count available at the time. I also am glad they did not, simply for the color distortion issues seemingly inherent in the Foveon design.

I have hopes that this technology can develop further, but I'm not suitably impressed with their first go-round. Time will tell. I also don't see the current sensor, for both resolution and color distortion, as being able to "take advantage" of the Zeiss lenses...so the Sigma lenses may be just fine...and I have heard that Sigma does make some pretty decent lenses, though I have no first hand experience with them.

www.dpreview.com has a good message board for Foveon users, and this is where I have seen most of the images I've seen, and found out about people's complaints.

Regards,

Austin

 

[narrbl]

Mike, yes, thought about the possibility you mention a while after posting. But then I thought again.

How many levels can we represent on the best of printing processes, vs. 65,000 from a 16-bit capable photo electronics? More important perhaps, how many levels are left in the underexposed 'thin negative' (or its thick cousin) you are trying to recover in scan?

In fact, if I were trying to recover that thin negative, my 'best bits' to use in the sensor system would be those 'crowded' more towards the top of the signal range, thus avoiding any in-system noise. That's what Epson 3200 has actually done, according to your observation, to recover the greyscale that's possible.

You'd have to have far better than a 16-bit-capable analog portion of the system to do better by smearing its range in turning up the gain - gets costly because it runs into physics everywhere.

Back then to asking what the remains of the underexposed negative itself can resolve - and the output screen or paper, which both seem a lot more like the 8-bit plus some at best range, isn't it? I am sure someone has some quick numbers on that to throw.

Same as the wet darkroom, I think: the paper characteristics could give soft _input_ range, capturing differentials that it could find, but its output range, probably not so far at all.

Anyway, the above fits with my small ex&les of negative recovery I've thought quite successful on the 3200.

Regards, Clive