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04-15-2014, 11:00 PM   #76
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QuoteOriginally posted by Mistral75 Quote
It certainly is not. Just consider the M42 mount, the L39 mount of older Leica cameras or the M37 mount of Asahiflex, all 24x36 cameras with a "sensor" diagonal of 43mm.
Technically you could just have a pinhole in front of the sensor and project an image of infinite size, but like I said, having a smaller mount diameter makes things more complicated for lens and body designers, particularly for large aperture or telephoto lenses.


Last edited by Cannikin; 04-15-2014 at 11:11 PM.
04-15-2014, 11:01 PM - 4 Likes   #77
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I'm not sure what the arguments over the 645Z price are all about. This camera is a low volume product, the R&D for which has to be paid for. It isn't just a matter of adding up what you can buy the components for, or guess what the labour and other manufacturing costs might be. Re-using some of your other higher-volume lines obviously helps, but you still have to spend time integrating them into a coherent design, building design prototypes, pre-production prototypes etc, and then re-working things until you get a satisfactory result. How many of these do you think Ricoh will sell every year?

Ricoh has also said they will be providing support for professionals using this camera. Where do people suggest that support will be paid for? Some of it no doubt will come from a subscription service, but some of it will be built into the selling price. The building of an in-country professional support network is perhaps the most interesting thing to come out of the 645Z launch, in terms of the possible 35FF camera and maybe even in terms of the present and future APS-C bodies.
04-15-2014, 11:27 PM   #78
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What is the zoom or crop factor vs 35mm?
04-15-2014, 11:32 PM   #79
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@WerTicus -- following the above post... also... if you have an older 645 lens from film days, what is the crop factor for the 645Z?

04-15-2014, 11:58 PM   #80
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QuoteOriginally posted by RobA_Oz Quote
How many of these do you think Ricoh will sell every year?
No ideea, but the initial production volume is a mere 400 units per month (100 lower than for the 645D)
04-16-2014, 12:07 AM   #81
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QuoteOriginally posted by WerTicus Quote
What is the zoom or crop factor vs 35mm?
0.79.
Not huge, but that's only part of the story of course.
04-16-2014, 01:41 AM   #82
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QuoteOriginally posted by Sandy Hancock Quote
0.79.
Not huge, but that's only part of the story of course.
FF -> 645Z 0.79

645 film -> 645 digital 1.26

645 digital -> FF film/digital 1.27
645 digital -> APS-C 1.94

FF -> APS-C 1,52
04-16-2014, 03:08 AM   #83
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Some History

And I quote from Pentax 645N - photo.net

"Paal Jensen
Pentax goal with the 645n was to to make a Medium Format camera that works like a 35mm slr. This should be taken into consideration when judging the camera."


Who is he?

Change tenses and substitute z for n and we might be there
Too bad that it costs more than my car is worth and any that lens would cost me at least more than my monthly salary!

Trevor

04-16-2014, 04:08 AM   #84
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QuoteOriginally posted by Aristophanes Quote
While the 645z is a tripod camera, the goal of a medium format mirrorless should be to make a handheld beast. It would still cost at least what the 645z costs now. I still say the Mamiya 6/7 series is what can be emulated. .
Actually, it is the format size, not camera size, that makes the 645 a tripod camera. This is because in order to get enough DOF AND being able to use the camera to its best advantage, ie lowest possible ISO, you end up by using a slower shutterspeed. A mirrorless won't change that. In fact, a larger heavy camera is easier to held still due to its larger inertia.....
04-16-2014, 04:40 AM   #85
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QuoteOriginally posted by Pål Jensen Quote
Actually, it is the format size, not camera size, that makes the 645 a tripod camera. This is because in order to get enough DOF AND being able to use the camera to its best advantage, ie lowest possible ISO, you end up by using a slower shutterspeed.
I agree the 645Z is as much a tripod camera as the K-3.

However, there is no difference whatsoever in enabling/disabling handholding between various sensor formats (that's one of the nicer corrolars of the equivalence theorem).

You would determine image quality on acceptable noise level, DoF based on the subject, shutter speed based on FoV and subject motion, none of them being dependent on the sensor format. Then you'd choose your (35mm-equivalent) setting which is whatever it is for the camera size you use. It wil lbe this invariable 35mm-equivalent settingwhich will determine if you can handhold or not.

Of course, 50MP resolution in the field handheld is difficult to master or impossible to achieve. But this will hold true whatever be the sensor format.

---------- Post added 16-04-14 at 13:03 ----------

QuoteOriginally posted by climit Quote
well is it really medium format
It is a common size, 44x33mm, commonly referred to as cropped MF.
You can buy it from at least Pentax, Hasselblad, PhaseOne, Leica, Mamiya Leaf.

QuoteOriginally posted by romeck Quote
FF -> 645Z 0.79
FF -> APS-C 1,52
Thanks.

Well, MF is 56 × 41.5mm: C_mf = 1.

Therefore, all current MF digital cameras have crop factors

Hasselblad H5D-60 53.7 x 40.2mm: C_mf = 0.96
PhaseOne IQ280 53.7 x 40.4mm: C_mf = 0.96
Pentax 645Z 43.8 x 32.8mm: C_mf = 0.79
Common "cropped" MF 44 x 33mm: C_mf = 0.79

35mm full frame FF 36 x 24mm: C_mf = 0.62 = 0.79^2


Therefore, "cropped MF" sits right in the middle between FF and MF which may explain why 44x33 is so popular (all MF vendors have at least one camera in this segment).

It isn't unlike APSC which sits right in the middle between FT and FF. However, the step from FT to FF (x2.0) is much bigger than the step from FF to MF (x1.6). Therefore, the step from FF to cropped MF is the smallest of all increments in the sensor size ladder, smaller even than the step from 1"/CX to FT.

Last edited by falconeye; 04-16-2014 at 05:17 AM.
04-16-2014, 05:08 AM   #86
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QuoteOriginally posted by falconeye Quote
I agree the 645Z is as much a tripod camera as the K-3.

However, there is no difference whatsoever in enabling/disabling handholding between various sensor formats (that's one of the nicer corrolars of the equivalence theorem).

You would determine image quality on acceptable noise level, DoF based on the subject, shutter speed based on FoV and subject motion, none of them being dependent on the sensor format. Then you'd choose your (35mm-equivalent) setting which is whatever it is for the camera size you use. It wil lbe this invariable 35mm-equivalent settingwhich will determine if you can handhold or not.

Of course, 50MP resolution in the field handheld is difficult to master or impossible to achieve. But this will hold true whatever be the sensor format.
Yes, there is a difference between cameras handholdability based on formats because of the fact how people actually use their cameras. They do not buy or use cameras after the "theorem of equivalence"; they make they choices because they are not equivalent.
In addition, the image quality standards are not equivalent either; ie a person who buy a 645z is doing it because his standards are higher than what smaller formats can achieve. And you want to have that advantage every time you can.

Ie when I shoot a landscape with the camera on a tripod I'm not going to boost the ISO on the 645z in order to making it equivalent to an APS body; I want that image quality advantage. Hence, I end up with a slower shutterspeed for the same DOF.

If you look at images published with various format where the exposure detals are published as well, like Pentax Photo Annual, you'll see that larger format images are shot with slower shutterspeeds as a trend than images shot with smaller formats. Eg most Pentax 6X7 images are shot at F:22 in order to get enough DOF, but no one is using 3200ISO film (or whatever) in order to make it equivalent to a 35mm image (whats the point?) Hence, larger format cameras are to larger extent as tripod cameras....
04-16-2014, 05:33 AM   #87
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QuoteOriginally posted by climit Quote
well is it really medium format? Just a litle bigger than full frame, more like a four thirds full frame, I suspect some 20% more horizontal resolution than full frame. Hopefully the new Sony sensor shall be super capable in dr, noise etc. I supose this format works well in the sweetspot of legacy 645 lenses.
It's the exact same sensor size (33x44mm) as the old medium format 645D but with 50mp instead of 40mp and 204800 iso max instead of 1600 iso max.
Pentax 645D - Pentax Medium Format DSLRs - Pentax Camera Reviews and Specifications
Pentax 645Z - Pentax Medium Format DSLRs - Pentax Camera Reviews and Specifications
04-16-2014, 05:53 AM - 2 Likes   #88
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Should output pretty good facebook photos.
04-16-2014, 05:56 AM   #89
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QuoteOriginally posted by Pål Jensen Quote
Actually, it is the format size, not camera size, that makes the 645 a tripod camera. This is because in order to get enough DOF AND being able to use the camera to its best advantage, ie lowest possible ISO, you end up by using a slower shutterspeed. A mirrorless won't change that. In fact, a larger heavy camera is easier to held still due to its larger inertia.....
The ability to handhold any camera depends largely on the camera's mass and size.

One of the advantages of the film era medium format rangefinders was their much smaller size compared to a Pentax 67.

Size factors in where the camera can go be it into a bag or into a stadium. And that translates into sales.
04-16-2014, 05:58 AM   #90
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QuoteOriginally posted by falconeye Quote
I agree the 645Z is as much a tripod camera as the K-3.
No, it's twice of a tripod camera as the K-3: it has two tripod sockets

QuoteOriginally posted by falconeye Quote
You would determine image quality on acceptable noise level, DoF based on the subject, shutter speed based on FoV and subject motion, none of them being dependent on the sensor format. Then you'd choose your (35mm-equivalent) setting which is whatever it is for the camera size you use. It wil lbe this invariable 35mm-equivalent settingwhich will determine if you can handhold or not.
Why "35mm-equivalent"? Why would I have to think to a format I'm not using?
And why do we have to talk about "35mm" on a topic dedicated to the brand new Pentax medium format DSLR?

By the way, the reasons I would buy a 35mm Pentax DSLRs are not included in this "equivalence" nonsense. Neither are the reasons I would buy a 645Z, if I were to win the lottery (amazing camera, can we talk more about it?)

Aristophanes, if you're saying that a smaller and lighter camera is easier to hand hold, I strongly disagree. The camera's shape and weight distribution are very important, and I found the 645D body to be surprisingly comfortable to hold despite its size and weight. Similarly, many small cameras are "slippery", with little grip.

Last edited by Kunzite; 04-16-2014 at 06:04 AM.
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