Leica S2's Kodak CCD sensor

[leica007]

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quoted from Kodak's press release:

 

"The LEICA S2 camera, powered by the new KODAK KAF-37500 Image Sensor, [....] With an imaging area of 45mm x 30mm, the 37.5 million pixel KAF-37500 represents a new optical format for photography, providing an image capture area over 50% larger than traditional 35mm film.

 

The sensor also includes specific design features that optimize its use in the S2 camera, such as the use of microlenses to increase the overall light sensitivity of the device, enabling improved image quality under low light conditions. In addition, an infra-red absorbing optic was incorporated directly into the sensor’s packaging, enabling the development of a thinner camera design by eliminating the need to include this IR-absorbing function as a separate camera component."

[john_f]

According to a video of Leica reps shot at Photokina (see Photokina 2008 Live Tradeshow Coverage - Video Clips), the Kodak designed CCD is the first "medium-format" sensor to include on-board image processing (this feature is now common on most high-end "24x36" format DSLR cameras), courtesy of Fuji - another partner with Leica in the development of the S2.

 

For more info on the KODAK TRUESENSE 6.0 micron Full Frame KAF-37500 CCD, click on:

- News Release

- Kodak: Investor Center: News Release

- KODAK CCD Image Sensors Power New Cameras for Professional Photography

- News Release

 

Also, the full list of "full frame" (as opposed to interline) CCD sensors from Kodak:

Kodak Image Sensor Solutions - Full Frame CCD (KAF-37500 to be added later)

 

The KAF-37500 includes a specially designed extra-thin and very effective UV filter (might be used in a future M9 ... who knows), but no word yet on anti-alias filter. With some luck, we might soon find out that Leica and Kodak decided to stay the course with their "no AA filter" approach.

 

John F.

[georg]

It has no AA-filter!

[wildlightphoto]

The sensor also uses an RGBI pattern rather than Bayer pattern which gives additional sensitivity (less noise).

[luigi bertolotti]

The sensor also uses an RGBI pattern rather than Bayer pattern which gives additional sensitivity (less noise).

 

RGBI pattern ? Sorry for my ignorance... how is it ref. to the typical Bayer ?

[wildlightphoto]

RGBI pattern ? Sorry for my ignorance... how is it ref. to the typical Bayer ?

 

Instead of the RGBG pattern used by all other sensors aside from Foveon, the S2's sensor uses a Red Green Blue Intensity (RGBI) pattern. Color resolution is a bit less, sensitivity in low light is greater (= less noise). I suspect the smaller pixel pitch compared with the DMR's sensor was chosen to compensate for the lower color resolution without sacrificing much of the improved sensitivity/noise performance.

[Knorp]

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Any thoughts anyone why CCD and not CMOS ?

[mjh]

Any thoughts anyone why CCD and not CMOS ?

Medium format sensors from Kodak or Dalsa are invariably of the CCD variety. Camera vendors tend to prefer CCDs because of their superior fill factor.

[stevelap]

The sensor also uses an RGBI pattern rather than Bayer pattern which gives additional sensitivity (less noise).

I'm sorry Doug, I haven't sen any evidence to support that statement. Do you have a source?

[lars_bergquist]

The KAF-37500 includes a specially designed extra-thin and very effective UV filter (might be used in a future M9 ... who knows) ...John F.

No way. The S2 is an SLR camera, meaning that the flange-to-sensor register is MUCH longer relative to the sensor diagonal (54mm in the case of the S2) than in the case of the short-register M cameras. This means that rays hitting the peripheral parts of the sensor will impinge at a much less acute angle. This is critical for a sensor that relies on interference, not on plain IR absorption, which would demand a much thicker filter layer, probably impermissible just because of the acute angle. So a FF M will need a different solution, which is probably quite a long way off.

 

The relevance to a coming R10 is obvious, however. And now we know that the R10 is the next project on the Leica to-do list. With the same pixel density, this would mean something like 24 mpx, as against 37.5 for the S2.

 

The old man from the Age of Tri-X

[carstenw]

I am not sure if it is really so impossible. The M8 sensor has a separate IR filter, to my knowledge, but the S2 sensor sounds like it uses the sensor glass to do the IR filtering as well, so this would mean a significant savings in thickness. With this technology, it might be possible to get that bit of extra filtering required for an M.

[mjh]

The M8 sensor has a separate IR filter, to my knowledge, but the S2 sensor sounds like it uses the sensor glass to do the IR filtering as well, so this would mean a significant savings in thickness.

The IR absorbing filter of the M8’s KAF-10500 replaces the cover glass of other Kodak CCDs (or rather, it is the cover glass), so this is actually quite similar to the design of the KAF-37500. The KAF-37500’s filter may not be an absorption filter, though.

[t024484]

The sensor also uses an RGBI pattern rather than Bayer pattern which gives additional sensitivity (less noise).

Kodak recently announced the KAF50100 and the KAF37500 as using the same new technology, in which "holes" or positive loaded atoms are used as content carriers instead of electrons as in the KAF10500.

Although the KAF37500 is not on Kodak's website, the KAF50100 is.

In the KAF50100 specifications one can read that is has a Bayer RGB layout, which makes it very unlikely that the KAF37500 for the S2 is using a different RGBI technology.

[Knorp]

Medium format sensors from Kodak or Dalsa are invariably of the CCD variety. Camera vendors tend to prefer CCDs because of their superior fill factor.

Thank you Michael for your reply, but really only for their superior fill factor ? Surely there must be other reasons as well ?

Kind regards.

[mjh]

Basically, a CCD sensor is an extremely simple analog device, devoting most of the available space on the chip to converting photons into electrons and then storing those electrons until the accumulated electrical charges are to be read out. With CMOS you can do all kinds of fancy stuff, but it detracts from what is a sensor main task, namely turning an image into a pattern of electric charges.

[sdai]

Most Japanese manufacturer adopted CMOS mainly because its relative simple architecture when compared to CCD so they can integrate a large amount of peripheral electronics on chip. This in the long run can dramatically bring down the manufacturing cost, standardize the development platform and shorten the product cycle.

 

I had a copy of the minutes of the annual meeting of CIPA back in 2003 - can't find it now, where I read the concept of "camera on a chip" for the first time, apparently, Nikon, Canon, Sony et al are doing exactly that just now.

[scott kirkpatrick]

Another factor in the CMOS/CCD debate is that the CMOS processing is much closer to the sequence of steps followed in making huge-volume products like semiconductor memory, so that the tooling costs are reduced by the larger volume of product over which they are shared. CCD's, on the other hand, are made on manufacturing lines that are no longer state of the art for high volume product, and have been repurposed for just this task. There may be some savings because the facilities have been depreciated, but the operating costs are applied to fewer, more specialized applications. Kodak, with a business devoted to perhaps hundreds of parts in the catalog, can do this, but a typical semiconductor manufacturer would be reluctant.

 

scott

[Guest guy_mancuso]

Bottom line for me is i will take a CCD sensor over a CMOS every time when making a purchase. I just like what i see better out of a CCD sensor. Not scientific but i see better color, tonal range, saturation and contrast. Most likely a personal choice but the best files I have had at least for me are CCD and Kodak. I just keep buying the same sensor although different in each camera it is the look i like from the DMR, M8 and now the Phase Back. If the S2 was CMOS i would not even consider it. My personal thing. I could go back in my files and pull all the camera's I just mentioned and the files all will have that look to them. I may have switched out a few camera's but always had a Kodak CCD sensor in each. One reason I am looking at the S2 along with others.

[LCL999]

Any thoughts anyone why CCD and not CMOS ?

 

Let me quote from a 17th October 2008 posting on The Economists's on-line site ( Digital photography | Me no Leica any more | The Economist but you may need to be a subscriber).

 

Apart from the arrival of less pricey full-frame digital SLRs, the other recent development that has impressed your correspondent is the way imaging chips are migrating from CCD (charge-coupled device) technology to CMOS (complementary metal-oxide semiconductor), used widely in the computer industry.

 

The best thing about CMOS is that, unlike CCD, chipmakers have poured billions into shrinking the components on such devices and making them run faster, cooler and smarter. Because the power consumption of a CMOS chip is so much lower to start with, full-frame sensors can be made that run cool, generate less noise and offer longer battery life.

 

Any comments?

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Look here: Interesting Leica gear

[Gentleman Villain]

 

Any comments?

 

Yeah, not a word about what the final image is actually gonna look like....It's a grocery list of techno-babble that could have been copy/pasted from the manufacturers site *no offense* My opinion is that CMOS is like Communism because it sounds great on paper but often disappoints in real world application.

 

Since the author is a die-hard analog (film) guy...then he will probably eventually notice that the CMOS sensor portrays everything with an over-smoothened plastic-like texture. Skin-tones look like plastic...human hair looks un-natural like a costume wig or toupe.....Clear blue skies render like the bottom of my 4 year old neice's blue plastic kiddie pool ... green foliage looks like it doesn't need water and won't ever die

 

To my eyes....CCD has a more film-like quality to it's texture. It's not really the kind of thing that is easily described.. Sometimes, attempting to explain it can be like taking a redneck to a wine tasting. Since the author has a lot of film experience he'll probably have a good enough eye to notice the difference in texture between CMOS and film. It might not bother him at first. There might be a honeymoon period with CMOS...could last a couple of years....but eventually....the author will probably start to miss some of the qualities of film especially when it comes to portraying texture.

 

Personally, I had a love/hate relationship with CMOS that lasted several years. It finally ended when I attempted to shoot a series of stock photographs of 1oz American Eagle Gold Coins. One particular shot had me stumped...I re-shot it 7 times...something was wrong...kept fiddling with the lighting...messing with the composition...couldn't figure out what was the problem. Finally it dawned on me that the coins didn't look like gold..they looked like plastic. That was the "final straw" for me.

 

....probably could also rant about dynamic range in CCD vs CMOS....could also mention the downside to working in the same color palette as millions of Canon/Nikon housewives...but just don't feel like it right now

 

The gearheads will argue this issue to death and they usually end up winning in forumland. They make their argument with a bunch of charts and diagrams and spec sheets. They talk about bit depth and pixel size and all of this stuff. But I'm just a photographer and know what I like...and CMOS looks like plastic to me...CCD is much more film-like IMHO...BTW I'm not the only self-employed photographer that thinks this way. Sorry for the strong opinions...but sometimes I just feel like being totally blunt...Whenever I think about CMOS it just makes me mad for all the years I wasted trying to make it work (in vain)