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Regarding Contax N digital and Leica digital back

Austin, I don't think Shu-Hsien is always communicating on a purely literal level the way you are taking it. For ex&le, lens tests using flat patterns are suspect in many circles because they can, and probable are, used as a marketing tool. So, you could say that component of the camera is being optimized for test charts (ie, designed to excell in these types of resolution, and distortion tests. For ex&le Mamiya 645 glass often fairs a tad better than similar Zeiss 645 glass, yet other characteristics that are apparent in the final result make the Zeiss offering more desireable to some photographers. And isn't it possible that the same process could be done in the design and processing phase of digital capture? That is, optimize the default contrast, sharpening, etc to show maximum performance for these tests?

I believe this was a creative triumph for Contax with the ND, and a marketing blunder at the same time. Setting all the other functional issues aside, one main issue with the camera is the relatively flat images you get from it initially. This really bummed me out at first, having been used to a Nikon D1X and Canon D30 files. It took a long time before I realized the advantage of how the camera was
designed and set up. Just a thought based on practical application of all these different cameras.
 
Hi Marc,

I have made a couple of shots with a Contax ND at my dealer. The images are dull right out of the box exactly as you described. Could you give us a hint how your working flow is to achieve fast and easy above average results with it?

DJ already started with its own workflow in this thread:

http://www.contaxinfo.com/discus/board-auth.cgi?lm=1055211787&file=/14047/103913.html

So it would be great if you or any other ND owner could describe their way to get the most out of it in color and B&W in the same thread there.

Thanks

Dirk
 
Hello Marc,

I just remembered it was you as well as Shu-Hsien who had remarked on the limited raw utility from Canon on S-50.

I wonder if my comments in just-posted message to him about Breeze Browser abilities might fit for your work as well?

Many thanks for all you've done to try to draw out on these two cameras/systems - a great help, and probably a question or two before long.

Regards, Clive
 
Hello Howard, and again, just a very brief comment today.

G2 is a sweet camera, and it would be very nice to anticipate a digital back for it or Leica M . But I think all evidence is that the optics compact rangefinders will mitigate against ever seeing one - the compactness itself drove a compact optical path design which took advantage of film's insensitivity to incidence angle.

Dirk himself recently posted notice in another forum of a live chat for Leica technicians - it's rough to read but very appreciated for the real information it contains. This can be found through http://www.leicainfo.com/seiten/downloads.html, and the actual text is in a PDF (small to download).

Looking at the collimating array that is part of the back of the new Olympus E-1 digital-design lenses, I can make a slight imagination that there could be a digital back which encorporated such an optical assist - but seems not so likely for lots of possible reasons, including that it would also extend the depth of the camera considerably.

Yet one doesn't know - a Foveon without microlenses, or some development none of us has background to think of in alternative sensors with less of the angle problem, who can say. In the mean time, a very nice camera to use with a nice scanner ;), and for the sense of time in its feel.

Regards, Clive
 
Austin, it seems basic semiconductor physics will say that temperature is always a direct factor determining sensor - or other analog channel - noise, at a given set of other conditions.

I find myself thinking also of those 'literal fact' books that drove the original semiconductor industry - SEEC series.

The best and the most mathematical of them made me feel entirely right with the world in that day, with its evocative note at the end that all enclosed was, in reality, a fiction.

Art in thoughtfulness, again, composing better than any single line ever could, of its 'facts'.

Regards, Clive
 
Dear all,

The following is from Finney. The first thing I would like to say is I won't answer any comments on this post, especially those challenging the credential issue:

Just came back from Lassen National Park. Beautiful place! Took some nice photos with TVSD there.

First I will have to thank many people who had tried to defend me, but please, stop doing so for now as this will not do this board any good. I was very amused by seeing words such as "sad" or "punishment" showing up here. Do we really have to be so serious? This website is fairly new. It is natural that the webmaster would over-eagerly try to protect his babe. Things may change along the time, anyway, right?

Some said that the dialogs had turned to be too technical. Well, in reality, nothing has really reached the technical level yet. It's only crosscheck on basic concepts at best.

One basic concept I kept stressing is that the conversion process (commonly termed as AFE, Analog Front End) from image sensor signals to raw image file is not done just through an A/D converter. You can check the block diagrams in the webpages listed below:

Philips Semiconductor:

http://www.semiconductors.philips.com/pip/TDA9962.html

Texas Instruments:

http://www.ti.com/sc/docs/products/msp/videoimg/ccd/blckdiag.htm

Analog Devices:

http://www.analog.com/UploadedFiles/Data_Sheets/78682628AD9821_0.pdf, first page.

National Semiconductor:

http://cache.national.com/ds/LM/LM98501.pdf, second page.

In the diagrams, PGA stands for programmable gain &lifier, and VGA is variable gain &lifer. They are used mostly for basic noise reduction, black level calibration, and white balance, etc, at the analog stage. As you can see, most or less, they all have similar structures, there is some sort of loop around the ADC, analog to digital converter. You will let you be the judge this time, and I am sure your brain will tell you what is true and what is not.

AFE chip is a very hot market now. Many digicams, probably include the ones you have, have already used the chips listed above. I used Nu Core's design as an ex&le simply because its website had more information available to the public. Again, I will have to emphasis, even with the same image sensor, different AFEs will give you different quality of raw image data.

I agree that is the photo, the final product, which counts. But in film photography, won't you choose the right film to get the best result for a specific subject? Similarly, for digital photography, other than lens and image sensor, you may have to choose the right AFE, the right image processor, and the right software? Even when companies only provide you bundled solutions today, this does not mean you can not make a better choice among them? For a new product, it will take time for people to learn the truth then ask for better solutions. Remember when CD players just came out, many experts told you that this is the ultimate sound and all CD players should sound the same? Who would have expected that today we have products like CD transporter, box to kill jittering, D/A processor, and up-s&ler, etc? Will high end digicams become highly modulized? The coming Leica digi back may be a hint to what will come in the future?

BTW, I am 100% American. My real job is in the chip design business, actually, it is more like near the top of chip design chain. The specific field I am in allows me to have access to real design data as well as chip manufacturing issues. I have come across several image processors, AFEs, in the past. Right now I am invovled with big projects like the new Sony Play Station 3, a new 3D graphic chip, some super router core chip...etc. The issue is that I have never talked about those (do I really care? probably some people care, but I don't) with Shu-Hsien. With his MD background, he thought everything related to computer and chip was called IT.

After reading some call for real answers here, I am thinking of starting a loosely coupled discussion group to focus more on the technology side of photography. I will not mind sharing industry news and whisper there. The membership will be selective, most likely through referral only. It will be email based and everybody has to use her/his real identity. Some may warn this kind of discussion group will lead to a cult like status but I believe when someone is already interested in technologies to this level, she/he should possess the poweress to do independent thinking. Not intend to replace the role of contaxinfo, quite on the contrary, the list will be a supplement to it. We all know that open forums will run into certain problems sooner or later, and we need a new kind of disscusion group. Please share your thought and see where we can go from here.

Since the talk has turned to a bit philosophical, let me also post a quote from a famous Chinese philosopher/writer in the early 20th century:

Who care about million of critics!! Yet I will tender those still willing to learn!



So, keep smiling and do not forget about taking great pictures!
happy.gif


-finney
 
John,

> Hi think you will find a full size ccd sensor is imposible with any > current SLR or range finder camera as the lens throuts are to narrow > to permit light to reach the cornors of the sensor at an angle usable > to the sensor.

In general, you are correct, more so for wide angle lense use. That is why Contax claims to have redesigned their lense mount, to reduce this issue, as well as to add electronic contacts. As far as G or Leica M series full frame digital, that is one major factor, the other is the proximity of the lense to the film plane.

The Canon lense mount seems to do OK, but I have seen reports of degredation with wide angle lenses. Kodak bases their DSLR cameras on a Nikon body, and again, I've heard the same issue with that with the new full frame Kodak.

Regards,

Austin
 
Hi Marc,

> For ex&le, lens tests using > flat patterns are suspect in many circles because they can, and > probable are, used as a marketing tool. So, you could say that > component of the camera is being optimized for test charts (ie, > designed to excell in these types of resolution, and distortion tests.

Honestly, I have never heard this before, and I'm in touch with quite a few optical experts. I'll ask and see what they say.

> For ex&le Mamiya 645 glass often fairs a tad better than similar > Zeiss 645 glass, yet other factors that are apparent in the final > result make the Zeiss offering more desireable to some photographers.

Yes, same with Fuji...but the lense tests only show particular characteristics, not all, and, at least for me, I know I don't like the bokeh from Fuji MF lenses, so better MTF or not, I like the Zeiss lenses over the Fuji lenses.

> And isn't it possible that the same process could be done in the > processing phase of digital capture. That is, optimize the default > contrast, sharpening, etc to show maximum performance for these tests?

Contrast certainly can be changed...but resolution really can't be. What resolution the sensor sees, is what it sees. It certainly would depend on the test, but doing a sensor "test" would really involve different things than doing a lense test...and another issue, as far as sensor "testing", it is difficult to separate the lense from the sensor, unless you have a bench set-up to test the sensor with the same lense...so you really have to test the "system". This really gets into a very amorphous and subjective area of testing. Recently, the ISO defined a scanner test, which was very good...one that would put all scanners on equal footing, as far as dynaimc range claims.

Regards,

Austin
 
Hi Clive,

> Austin, it seems basic semiconductor physics will say that temperature > is always a direct factor determining sensor - or other analog channel > - noise, at a given set of other conditions.

Thermal conditions are always important in electronics. I do a lot of thermal testing, and have a thermal chamber to do so. I've also tested quite a few imaging devices in the thermal chamber. It is true that thermal characteristics are important, but it is the significance of the effect that is important. The thermal effect may be far below other issues as well, so it's certainly not a stretch to believe that thermal issues may be responsible for the noise in the sensor, but it is not the only factor that might be. If you'd like a very good paper on CCD noise characteristics I'd be happy to email it to you off list.

Regards,

Austin
 
>=20 >=20 >=20 > [Thanks, a small correction to make, the dynasty to close all the harbors= and > foreign connection was Ming Dynasty, the very first ruler of Ming so it w= as > about 700 years ago. It was pretty much a time that Chinese scientific a= nd > technology developed started to fall far beyond the Western world due to = lack > of exploration and exchange, except Zheng-He=B9s voyage. Chin Dynasty, as a > contrary, was among the best dynasty in Chinese history, although it was = ruled > by Manchurian. Given the credit to a lot of ancient thinkers, many belie= ved > that Chinese got matured too early in its development to its own good. > Brgds/Kaisern ] >=20 >=20 >=20
 
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