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02-15-2010, 08:03 AM   #166
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QuoteOriginally posted by ogl Quote
Possibility 2: 34 x 45 mm (4:3).
[...]
645 film size 41.5 x 56 mm. I doubt in such sensor size as "Possibility 1". It's bigger than 645 film.
I agree.

I just didn't want to jump to conclusions in my post. So, I prefered to list the possible implications of what "1.7x the size of 35mm" could mean.

If Possibility 2 4:3 holds true, then this would a 645 crop factor of 1.3 (1.26 actually).


Unfortunately, I see a third possibility now: That a marketing jack ass just compared the diagonals of 24x36 and 45x60 (which are a factor of 1.73 apart ...)


Last edited by falconeye; 02-15-2010 at 08:09 AM.
02-15-2010, 08:15 AM   #167
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You think that 3:2 sensor could be real in 645D?
Anyway, it seems to me - the sensor will be not less than 37.5 MP.

By the way, S2's JPEG size is 106.6 MB. RAW is 72.5 MB.

But... I think Pentax will be classical - 4:3, 39-40 MP.

Last edited by ogl; 02-15-2010 at 08:44 AM.
02-15-2010, 09:03 AM   #168
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45*35 mm. 40 MP.
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02-15-2010, 09:30 AM   #169
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QuoteOriginally posted by ogl Quote
45*35 mm. 40 MP.
What is this from?

This is in line with Possibility 2, 4:3. If the real deal, it would be great specs.

It actually is more like 46x35mm and the exact 645 crop factor would be
- 1.21 if using the displayed image area
- 1.27 if using the displayed image diagonal
(image area and diagonal as displayed are inconsistent ...)

4 Outputs at 18 MHz would mean burst rate <1.78 fps.

13 e- read noise is not a stellar figure. 69 dB linear dynamic range is 11.5 EV which isn't stellar for a medium format either. We'll see after first lab tests are published. Quantum efficiency is ok but some better CMOS chips now go up to 60%.

Where is this table from? Vendors normally don't publish such figures, because of people like me


On the other hand, 40 MP requiring only a lp/mm line resolution like the K10D did for its 10 MP promises for ultra sharp crisp images ...


Last edited by falconeye; 02-15-2010 at 09:37 AM.
02-15-2010, 09:39 AM   #170
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QuoteOriginally posted by falconeye Quote
What is this from?
it's from new Kodak sensor's pdf data. Sensor is developed in 2009.
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Last edited by ogl; 02-15-2010 at 09:47 AM.
02-15-2010, 09:43 AM   #171
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QuoteOriginally posted by ogl Quote
it's from new Kodak sensor's pdf data. Sensor is developed in 2009.
It's certainly not the only MF 40Mpx sensor of the market (I've seen at least another brand)


So I guess we'll have to wait a month patiently to see what is really displayed (and 40Mpx is just a rumor so far)

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02-15-2010, 09:51 AM   #172
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QuoteOriginally posted by ogl Quote
it's from new Kodak sensor's pdf data. Sensor is developed in 2009.
Ok, so the current info provided by Pentax doesn't rule out the Kodak KAF-40000 sensor. That's all we know which isn't more than before

I would appreciate, ogl, if you could be more precise in your communication


Nevertheless, I found this speculative post, so ogl is not alone in his assumptions
02-15-2010, 10:07 AM   #173
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It's just my guess. And nothing else.

02-15-2010, 11:21 AM   #174
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There are two 33.1 x 44.2 mm sensors (1.7 time the surface of a 24x36 sensor) manufactured by Kodak and currently used by Hasselblad: a 31MPx (H3D-31 and H3DII-31) and a 40MPx (the brand new H4D-40).

I guess the 645D's sensor could be one of them.
02-15-2010, 12:27 PM   #175
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Which sensor?

It's fun to speculate... better than waiting.

Assuming Kodak sensors, there are four in approximately 645 size: KAF-31600, KAF-39000, KAF-40000, KAF-50100, with sensor diameters of 55.1, 61.3, 54.8 and 61.3mm. I would prefer the one with best ISO and closest to 645 normal (i.e. the 39000 or 50100). While I would be happy with 39 or 40M pixels, I'd really prefer that my 645 wide angle remain 21mm (35mm equivalent).

That said, the price probably matters the most to having a viable product. I wonder if Kodak's 6.0 micron (newer) or 6.8 micron has the cheapest production. I notice that Leica is using the 6.0 micron sensors in the M9 and S2, likewise Hasselblad.

Kodak mentions that the KAF-40000 and 501000 both have the same pin connections, which makes a lot of sense for a company offering both systems.
02-15-2010, 05:05 PM   #176
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Why 645D?

I've been trying to answer for myself the question often asked in this thread: "Why do we need a 645D?"

(1) Print Size.

35mm digital is now at 18-24M pixels, which gives you excellent 12x18 prints, which can be pushed somewhat higher with upscaling. You only need 39M f you want to print high quality larger than 18x24 inches (0.50 x 0.75 meters). This is the realm of fashion, landscape, glossy magazines, calendars, and posters.

Professionals in fashion or publishing probably can already afford Hasselblad, PhaseOne and Leica. A 645D under $10,000 might be a sweet spot for the serious amateur landscape niche. I think wedding photographers are happy with the lenses, portability and ISO performance of Nikon or Canon.

(2) Is 35mm a dead end?

The other question might be whether 35mm sensors will continue to improve. OGL's chart the other day indicates that 35mm at 24M pixels is starting to run into optical limits, specifically diffraction at smaller f-stops. In other words, 6 micron pixel size might be close to the physical limits given diffraction and DOF needs.

Just as in the age of film size matters, and landscape photographers, want to use f-11 or f-16 for depth of field, while resolving 40 or 50M pixels. Maybe Pentax would create a new market by offering a couple tilt & shift 645 lens?

(3) Physical and mechanical limitations.

With 6 micron pixel sensors, it looks like extraordinary lens quality, fine mechanical precision and pro-hardened design is necessary. This interesting article by Joseph Holmes, a top-end landscape photographer (see his gallery), talks about just how much care you need.

quote:
QuoteQuote:
"...the design properties of the cameras which can use the various medium-format and scanning back sensor options have, generally speaking, not fully caught up with the reality of the sensors. Most of the existing cameras were designed for either 645 film or 56 x 84 mm (6x9) film. The optical demands of 37 x 49 (or 36 x 48) mm sensors are vastly higher (four to six times higher in my estimation). So the precision required in the camera system is a huge issue and this includes not merely manufacturing precision, but also the things which allow the photographer to get a picture into focus in the first place, including the view through a viewfinder, the fineness of the focussing mechanism, the fineness of a tilt mechanism, where present, etc. The sheer size of the cameras also tends to be overly large, given the smaller size of the sensors."
In other words, 40-50M pixels on 645 sized sensors (not to mention 35mm at 18-24M pixels ) requires pro-quality bodies, lenses and focussing. I have some 645 Pentax lenses so I'd like to believe Pentax can compete with Leica and Zeiss lenses.
02-15-2010, 06:06 PM   #177
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2010, February 16 at 10:00 Tokyo time News release

QuoteOriginally posted by falconeye Quote
It is 2010, February 16 at 10:00 Tokyo time and the link I gave earlier today does work now.

It says:

Vol.1 NEWS

- 1.7x ****** (can a native Japanese speaker please translate exactly? )

- The amount of data in one image per sheet from 100MB to be too, I think you understand your unique sense of sensor resolution overwhelmingly large at first glance.

So, there is nothing new which has been published at 10:00, which wasn't in my earlier post.
02-15-2010, 06:25 PM   #178
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Ok, nothing new in the Vol.1 News installment (and http://www.camera-pentax.jp/new/news02/index.html doesn't exist yet

But I had time to think about it.

1. The 1.7x surface 35mm crop allows for the KAF-40000 sensor or some other similiar-sized sensor.

2. The leaked 645D user manual cover mentions DNG as raw format.

3. Uncompressed DNG from Pentax are (so far) about 13 Bit per Pixel, compressed ones are about 60% as large.

Taking the 100 MB quote from Pentax, this would imply
- 17 MP (16 Bit TIFF / linear DNG encoding)
- 52 MP (16 Bit Bayer encoding)
- 65 MP (13 Bit Bayer encoding)
- 100 MP (13 Bit Bayer encoding compressed)

I don't think they mean the first interpretation as a K-7 does already produce 87 MB uncompressed 48bpp TIFF files ...

I don't think they have taken Kodak's 50MP sensor. It has a poor quantum efficiency (a full stop less than their 40MP sensor!!).


Therefore, I actually start to think that the KAF-40000 is the most plausible candidate in a list of few.
02-15-2010, 07:15 PM   #179
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QuoteOriginally posted by falconeye Quote
Ok, nothing new in the Vol.1 News installment (and http://www.camera-pentax.jp/new/news02/index.html doesn't exist yet

But I had time to think about it.

1. The 1.7x surface 35mm crop allows for the KAF-40000 sensor or some other similiar-sized sensor.

2. The leaked 645D user manual cover mentions DNG as raw format.

3. Uncompressed DNG from Pentax are (so far) about 13 Bit per Pixel, compressed ones are about 60% as large.

Taking the 100 MB quote from Pentax, this would imply
- 17 MP (16 Bit TIFF / linear DNG encoding)
- 52 MP (16 Bit Bayer encoding)
- 65 MP (13 Bit Bayer encoding)
- 100 MP (13 Bit Bayer encoding compressed)

I don't think they mean the first interpretation as a K-7 does already produce 87 MB uncompressed 48bpp TIFF files ...

I don't think they have taken Kodak's 50MP sensor. It has a poor quantum efficiency (a full stop less than their 40MP sensor!!).


Therefore, I actually start to think that the KAF-40000 is the most plausible candidate in a list of few.
I haven't seen Radu's comment on DPReview linked here yet, which supports your supposition - if so, my apologies for duplicating,
02-15-2010, 08:25 PM   #180
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QuoteOriginally posted by MetaD Quote
I've been trying to answer for myself the question often asked in this thread: "Why do we need a 645D?"

(2) Is 35mm a dead end?

The other question might be whether 35mm sensors will continue to improve. OGL's chart the other day indicates that 35mm at 24M pixels is starting to run into optical limits, specifically diffraction at smaller f-stops. In other words, 6 micron pixel size might be close to the physical limits given diffraction and DOF needs.
24 MP is no problem.
30 MP at 35 mm is not bad too. But it's close to limit.
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