At that point it is not clear which sensor will be deployed in the upcoming Pentax 645D medium format camera. My first guess few months ago was for the KAF-39000 from Kodak. Today ThePhoblographer reported on a newer Kodak sensor that is few millimeters smaller than KAF-39000.
The only problem is that neither of those sensors will give us the reported "1.7 times bigger than a regular full frame sensor" ratio (official information from Pentax).
- A regular full frame sensor is 36mm x 24mm, or 864 mm² with 43.3mm in diagonal.
- The older medium format KAF-39000 sensor is 49mm x 36.8mm, or 1803mm² with 61.3mm in diagonal.
- The new medium format KAF-40000 sensor is 45.76mm x 35.34mm, or 1617 mm² with 54.78mm in diagonal.
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Still considerably larger either way, and it opens the way for True MF digitals from pentax down the line once everyone has the investment in lenses. Fingers crossed folks.
Admin, I presume the sensor used in Pentax 645D will be either the 31 Mpx or the 40 Mpx Kodak sensor used for instance in Hasselblad H3DII-31 and H4D-40 respectively.
The size of these sensors, according to Hasselblad, is 33,1mm x 44,2 mm i.e. 1,463 mm² or 1,693 times the area of & 24×36 sensor. Hence the “1.7 times bigger than a 24×36 sensor” officially reported by Pentax.
See here http://www.hasselblad.fr/media/1342793/uk_h3dii31_datasheet_v4.pdf (bottom of page 3) and here http://www.hasselblad.fr/media/2231320/uk_h4d-40_datasheet_v2.pdf (top of page 6) for the size of these sensors.
You may have noticed The Photoblographer states in the end of his article that the 40 Mpx Kodak sensor he is reporting on “surely isn’t the sensor in the Hasselblad H4D-40″.
It’s highly unlikely Pentax would use the KAF-39000: It’s several years old and has substantially worse Quantum Efficiency than today’s chips. As you point out, it’s physically too large to be “1.7x.”
If you look at the specs for the KAP-40000 active pixel count (7304 x5478) and multiply that by 6.0 micron pixel pitch, you get 43.8 x 32.9 mm (1441 mm²). That’s pretty close to “1.7x.”
The discrepancy is that image sensors always have some light-masked and dummy pixels around the border of the usable image area.
The Phoblographer misunderstood the term “Full Frame.” It doesn’t refer to image area, but rather to the readout technology (i.e. as opposed to “interline”).
not knowing much about pentax nor MF, i can say that if it isnt the larger of the sensors being considered (and hopefully better??) i will not consider it in the future (not that i need it my D700 is a handful already).
lol im just saying. I really want to try MF though but everything is too costly right now and hopefully pentax will bring some good stuff to the poor market.
there is no replacement for displacement, true for cars, true for sensors, true for everything.
Although i cannot afford it, i can always dream