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11-30-2009, 12:51 AM   #46
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QuoteOriginally posted by RuiC Quote
My guess for one of the buttons is to switch to FX format, using D/FA lenses via a fully auto up-converter, so fulfilling the needs of the vast FF fans.
Rui
That would be impossible, the register distance is longer than the one for 35mm lenses.

11-30-2009, 12:56 AM   #47
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QuoteOriginally posted by eurostar Quote
That would be impossible, the register distance is longer than the one for 35mm lenses.
But he mentioned an "up-converter", which will take care of that. But personally I don't believe in such a solution. Not because it isn't feasible, but because I don't like the idea of a converter which will degrade the quality of my lenses.
11-30-2009, 01:32 AM   #48
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QuoteOriginally posted by gazonk Quote
Are you sure? That would make it more-than-full-frame MF (the 645 film size is smaller at 56 x 41.5). It would also make 76 mm the normal lens focal length, i.e. the 55mm on the road map would then be a WA lens.
Yep, looked at the wrong line in my post, the numbers I posted in another previous post are correct though https://www.pentaxforums.com/forums/826629-post23.html

Quoted post, updated with S2 numbers:
Normal 645 (at least following Pentax specs) is 56 × 41.5 mm (from 120 film - Wikipedia, the free encyclopedia) or 69.7mm diagonal.

This 39MP Kodak sensor would be 36.7*49mm and 61.2mm diagonal. Indeed a 1.1X crop (based on diagonal calculation).

The Leica S2 is 30x45mm or 54mm diagonal.

In terms of area:

1798,3mm˛ for the Kodak sensor
1350mm˛ for the Leica S2 sensor
2324mm˛ for the original 645 format.
On area based calculation: 1.3X crop (if didn't make any mistake).

For comparison:
FF is 864mm˛
APS-C is about 375mm˛ (thought there are a couple differences following sensors)
4/3 is 243mm˛.

There's the same area difference between FF and S2 than between S2 and cropped Kodak 645 sensor. The cropped 645 is more than two times as big as FF. And the original 645 one of the smallest legacy MF formats.

Really, the S2 isn't MF IMO. Bigger than FF, but no MF either. Please not that previous 'MF' sensors from Kodak were quite more cropped, so I wouldn't have called those 'MF' either. I can't go against Leica and not others equivalent.
11-30-2009, 02:51 AM   #49
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S2's sensor is in the 3:2 aspect ratio, which is the same as 35mm film, rather than the 4:3 ratio of 645 medium format.

11-30-2009, 04:23 AM   #50
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QuoteOriginally posted by Asahiflex Quote
But he mentioned an "up-converter", which will take care of that. But personally I don't believe in such a solution. Not because it isn't feasible, but because I don't like the idea of a converter which will degrade the quality of my lenses.

Sorry, I meant to write Adapter NOT converter. So your lens quality will prevail.

Rui
11-30-2009, 05:00 AM   #51
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QuoteOriginally posted by RuiC Quote
Sorry, I meant to write Adapter NOT converter. So your lens quality will prevail.
Rui
And will work only as a macro lens.
11-30-2009, 06:28 AM   #52
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QuoteOriginally posted by thibs Quote
There's the same area difference between FF and S2 than between S2 and cropped Kodak 645 sensor. The cropped 645 is more than two times as big as FF. And the original 645 one of the smallest legacy MF formats.
Hmm, if the 645D uses a sensor as close to 645-fullframe as that, it would be really cool. A 55 mm lens still makes sense, though, it would correspond to a 39 mm on FF or 25 mm on an APS-C (K-7 with 1.53 crop), i.e. just slightly on the wide side. It would also keep the existing lenses approximately within their current usage range (e.g. it will make the FA 33-55mm equivalent to a 23-39 on 35mm - with 645 film it's equivalent to 20-34).
11-30-2009, 10:34 AM   #53
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QuoteOriginally posted by RuiC Quote
Sorry, I meant to write Adapter NOT converter. So your lens quality will prevail.
Rui
Mmm in theory, since the 'hole' of the mount is a lot bigger on 645 than on FF, an adapter may be made so the lens would get recessed into the 645mount at the proper register distance.
I doubt it, though, specially, on a practical usage point of view. But why not..

11-30-2009, 01:19 PM   #54
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The Mirror

Wouldn't the K Mount lens rear element interfere with 645D Mirror and its function?

Now if there were no mirror then I think you could stuff an adapted K Mount lens into bigger 645D lensmount hole, though controlling manual aperture on lens would be next obstacle.






QuoteOriginally posted by thibs Quote
Mmm in theory, since the 'hole' of the mount is a lot bigger on 645 than on FF, an adapter may be made so the lens would get recessed into the 645mount at the proper register distance.
I doubt it, though, specially, on a practical usage point of view. But why not..
11-30-2009, 02:41 PM   #55
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QuoteOriginally posted by Samsungian Quote
Wouldn't the K Mount lens rear element interfere with 645D Mirror and its function?
Now if there were no mirror then I think you could stuff an adapted K Mount lens into bigger 645D lensmount hole, though controlling manual aperture on lens would be next obstacle.
It may very well be. I have no possibility to make any measurement but your point is pretty good one.
11-30-2009, 03:08 PM   #56
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QuoteOriginally posted by thibs Quote
It may very well be. I have no possibility to make any measurement but your point is pretty good one.
Well, the FF lenses would need a mirror at least large as an LX one, but a 645 lens, even on a cropped 44x33 sensor, would need a larger mirror, and thus no space for the register of 35mm lenses.
11-30-2009, 03:17 PM   #57
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QuoteOriginally posted by eurostar Quote
Well, the FF lenses would need a mirror at least large as an LX one, but a 645 lens, even on a cropped 44x33 sensor, would need a larger mirror, and thus no space for the register of 35mm lenses.
lens would have to extend into the body about a full inch.
25.41mm
mounts.htm
11-30-2009, 03:42 PM   #58
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If they have told to include a way to replace future sensors, the sensor assembly is most likely not exactly hardwired, because you just cant take and resolder sensor with different pinout (unless they tend to replace the whole camera electronics)...

Well the point was, why not shift the sensor closer to the lens after rising the mirror, to make FF register distance. There have already been ton of moving stuff - mirrors, shutters, SR.. it would be just a slightly different design to this whole moving mess.

The only thing i could not instantly think of a solution was register distance and focusing screen. Maybe 2 part mirror, there in FF mode one just stays up, while the other part is left 45degrees at FF reg. dist.

Crazy thoughts...
If going completely MAD you could design lenses not by register distance but for best optical performance and signal the register distance for each lens digitally, same way like focal length and other stuff is being sent. Then the camera would position sensor after rising mirror.
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Last edited by ytterbium; 11-30-2009 at 03:56 PM.
11-30-2009, 03:53 PM   #59
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Ytterbium, you have just proposed a new AF system
11-30-2009, 05:40 PM   #60
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QuoteOriginally posted by jeffkrol Quote
lens would have to extend into the body about a full inch.
25.41mm
mounts.htm
Or the mirror would be flipped up and use LV. Well let's not turn it complicated. Anyway the question was about the two taped buttons on the left side of the body.
What are they for?

Rui
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