[MouLaG Ôfr]

Let's hold our breath and hope this will happen.
@Mistral : incredible, this was not only a mock-up !
The menus though, look like of an overaged ergonomy.

Certainly not, it was an early prototype destined to be marketed.
But Pentax decided not to do so (and it's difficult to blame them, Contax, with the same sensor, tried to do it but it ended with a cessation of activities in 2005 ! This was to early for the digital market to release a FF camera.)

I can see some differences between the two models of MZ-D (and with better photos it will be easier to trace these), for example, there is an AF on the AF button on the back of the K-1 but not on the same button on the back of the earlier prototype !

[MouLaG Ôfr]

Thanks to remember me this sentence.
K-01 was more of a style experience than of the serious camera Ricoh is supposed to produce ...

It was not Ricoh, but Hoya !

[Zygonyx]

It was not Ricoh, but Hoya !

Hence my remark stating Ricoh, indeed... being convinced that Ricoh takes more seriously the photo business than Hoya did.

Mistral's reported pictures :
Of course the "K-1" was the prime testimony of Pentax commitment to FF, this early tentative having eschued because of Philips semiconductors failure.
Though it it true that publishing such other pictures taken in july 2011, just after the announcement ot Ricoh takeover, and having renamed this body K-1 ; can adress the dream of many of us.
But this hasn't been Ricoh's act.

[txsbluesguy]

Anyone ponder the possibility that if Ricoh did do a full frame it would most likely be a sony sensor and just to speed things up FF lens development wise they might license the sony A-series lens system too ??? Just throwing fuel onto the fire ....

[Kunzite]

Great, more nonsense. Pentax would adopt a competitor's mount which offers absolutely no advantage over their own, just because.

[Cambo]

From left to right:

• Q
• K-5
• K-1 (similar to MR-52/MZ-D)
• made-up 645D
• 645J (limited edition only distributed in Japan)
• 67

And that K1 is STILL beautiful, 12 years on...they should re-do that camera...the sloped top makes complete ergonomics sense...what a shame...is there anybody here who doesn't think it's absolutely gorgeous?

But I just got the grip for my K5 finally...what camera...

Cheers,
Cameron

[Pentaxosaurus]

If Pentax/Ricoh decide to go for FF they basically have two options – either reuse the K mount and do SR in the lens (as they did for the 645D), or keep in-body SR as a primary selling point and develop a new mount.

I doubt that the K mount accomodates the 43mm FF image circle plus 1.5 to 2 mm leeway for sensor movement on either side, i.e. a minimum of 45 to 46mm image circle. Most of the existing K lenses wouldn't be suitable for IBSR anyway as they don't cover a sufficient image circle (except for the 28/3.5 Shift …), thus it wouldn't make sense to relaunch the old lenses. There could be adapters for K lenses on a new (“A”?) mount giving the user the choice of turning SR off or shooting with a crop factor of, say, 1.2 instead, but only with a smaller register. How does a FF mirror fit in then?

This looks like Ricoh have a choice between a mirrorless new mount with IBSR and adapters for old lenses (with the option of a redesigned focusing and aperture control), and a fully compatible K mount with no IBSR and mechanical aperture control etc. Anyone see a third way??

Considering these alternatives I feel I understand why they still can't make up their minds … :-o

[Kunzite]

If Pentax/Ricoh decide to go for FF they basically have two options – either reuse the K mount and do SR in the lens (as they did for the 645D), or keep in-body SR as a primary selling point and develop a new mount.

Yet Sony made their A-mount work, with in-body stabilization and old lenses...
Yes, there is the third - actually a first and most logical - choice: just use the K-mount, with in-body stabilization.
If some old lenses won't give optimal performance up to the extreme corners, it's not an issue; they will just have to launch lenses which works well. Yes, the K-mount supports it.

The reason they couldn't "made up their minds" are more about money, than our endless speculations.

[Mistral75]

(...)

I doubt that the K mount accomodates the 43mm FF image circle plus 1.5 to 2 mm leeway for sensor movement on either side, i.e. a minimum of 45 to 46mm image circle.
(...)

Where does that urban legend come from???

Do you realize that the Asahiflex mount had an EXTERNAL diameter of 37mm whilst being a 24x36 mount?

[dankoBanana]

Where does that urban legend come from???

Do you realize that the Asahiflex mount had an EXTERNAL diameter of 37mm whilst being a 24x36 mount?

I'm wondering about this too. I see this statement often and wonder if it is true?

[monochrome]

I doubt that the K mount accomodates the 43mm FF image circle plus 1.5 to 2 mm leeway for sensor movement on either side, i.e. a minimum of 45 to 46mm image circle.

In for three. Let's see a source, or some scientifically repeatable published measurements to back up your "doubt".

I think you have a conclusion in mind seeking a question.

Pentax has always had the engineering and capability to release a K-mount FF camera. The only reason Pnetax has not released a FF camera is the economics of the inevitable low volume at their market share, coupled with their own lack of capital (and Hoya's unwillingness to supply capital) to finance losses while they build share.

Ricoh has the capital and the willingness. Full Frame K-mount camera is real, but not soon.

[Pentaxosaurus]

Where does that urban legend come from???

I'd call it a ruler

Do you realize that the Asahiflex mount had an EXTERNAL diameter of 37mm whilst being a 24x36 mount?

And what lenses did they have? Focal length, max aperture??

The inner diameter of the K mount is about 43mm. (I don't have the exact specs at hand, just took a lens and a ruler.) In most long telephoto lenses that I know of the rear lens is pretty deep inside the lens body; look at the L converters, they use this space and protrude into the lens barrel.

Now try to draw a lens diagram where the rear lens sends the light to a 47mm sensor through a 43mm mount and where the distance between lens and mount is larger than the register, the distance between mount and sensor. How large can that rear lens be? For a contrast look into the HD DA 560/5.6 – or at the lens diagram, like myself who doesn't have access to the real one .

[Fogel70]

II doubt that the K mount accomodates the 43mm FF image circle plus 1.5 to 2 mm leeway for sensor movement on either side, i.e. a minimum of 45 to 46mm image circle. Most of the existing K lenses wouldn't be suitable for IBSR anyway as they don't cover a sufficient image circle (except for the 28/3.5 Shift …), thus it wouldn't make sense to relaunch the old lenses. There could be adapters for K lenses on a new (“A”?) mount giving the user the choice of turning SR off or shooting with a crop factor of, say, 1.2 instead, but only with a smaller register. How does a FF mirror fit in then?

The only thing the size of the mount is limiting is maximum aperture size, not how much the image circle of the lens will cover.
FI there are FF lenses with rear lens element smaller than 10mm, and they still cover full FF image circle, and they probably also cover enough for SR.

And for normal image stabilization, +- 0.5 mm of sensor movement will be needed for FF.

[Pentaxosaurus]

The only thing the size of the mount is limiting is maximum aperture size, not how much the image circle of the lens will cover.
FI there are FF lenses with rear lens element smaller than 10mm, and they still cover full FF image circle, and they probably also cover enough for SR.

As I mentioned before, this is not true. Generally speaking, wide-angle lenses can be built with small rear lenses but telephoto lenses can't. BTW, there is a reason why camera systems with larger image formats do have larger mounts …

And for normal image stabilization, +- 0.5 mm of sensor movement will be needed for FF.

Don't know what you call “normal image stabilization”. The Pentax APS-C sensors can move by ± 1 to 1.5mm; a larger format needs larger movements as the same field of view is projected onto a larger area. Therefore the pixel movement is amplified by the crop factor and, accordingly, the sensor has to move more for the same effect: ± 1.5 to 2mm.

It's somewhat unfortunate that a larger sensor, which is heavier anyway, needs larger movements, and explains why there is no IBSR for the 645 format (although the lenses do cover a large image circle of about 75mm while the sensor only measures 55mm diagonally).

I really don't want to spoil the fun, but we shouldn't entertain any hopes that Pentax can do anything that is physically impossible. And whine if they don't.

[monochrome]

I really don't want to spoil the fun, but we shouldn't entertain any hopes that Pentax can do anything that is physically impossible. And whine if they don't.

I'm truly astonished that in all the years I've been a member of this Forum this is the first time any expert on IBIS has ever suggested the potential technological limitation. I should think by now someone Like Falk Lumo would have written a paper and posted here frequently if you are correct.

I have read that the size of the magnets required to move the sensor assembly was limiting, and that the current required to drive the magnets would require too large a battery but this is the first time I've read that typical K-mount lenses would not throw a large enough image circle to allow IBIS to work.

I'm calling . . . . serious doubt that you are correct. Let's ee science, not just supposition and assertions.