[Winder]

Huh? Perhaps a different calculator? The image circle (diameter to provide minimum coverage) would be sqrt(24^2 + 36^2) = 43.3mm. Good design would indicate a little larger to accommodate variance in manufacturing tolerance.


Steve

What he is calculating is the radius of the image circle which is 21.633. 21.633 x 2 yields an image circle of 43.266mm. The Sony FF sensor measures 23.9 x 35.8mm which requires an image circle of 43.044mm. You have a tolerance of 0.222mm. Plenty....

[Winder]

A very interesting find. Thanks!

Is the distance behind the rear element consistent with K-mount? It seems to me that previous patents showed a greater distance but I find it difficult to judge the scale. Why would it need image stabilisation when all K-mount bodies have SR?

Because there is reason to believe that Pentax wont use In-body SR on its full frame unit.

[Alizarine]

Nice find. I do hope they make one.

The lens project with the model they displayed at CP+ last year ...if the Photokina interview in the Russian site was true, was abandoned (remember this?


If they have any plans to build a 70-200 f2.8, by all means should they make it a go. Even if it isn't on the roadmap!

Because there is reason to believe that Pentax wont use In-body SR on its full frame unit.

I also believe in the possibility of this, if they want to keep the body size down, close to the K-7/K-5.
But that would mean a whole new line of lenses, if not DFA's. And of course, what will happen to DA* lenses if they will?

[Winder]

Funny....Pentax had a lot of patents for lenses, but 99% of this lenses are never produced.

If this were Nikon/Canon/Sony I would agree, but this lens was designed by Pentax under Hoya. Why would a company with basically no R&D budget spend a dime developing a lens for a body it has no intention of ever building? Why would Hoya even consider it? It may never get built, but is an indication that Hoya/Pentax were investing resources into the development of a full frame system. No reason to even think about this lens if you're not moving in that direction.

[mecrox]

I'd have thought that trying to patent everything you have in your research lab is a way of crystallizing the company's value when you come to sell it. At the time, this is exactly what Hoya were trying to do. Patents are what Ricoh emphasized they were after when they acquired Pentax, and given how cynical Hoya were it's surprising they didn't try to patent the tea lady. I wouldn't read too much into this. Until facts are produced, It's just another crazy FF rumour.

[Clavius]

It's just another crazy FF rumour.

It's not even that. The DFA 100 and DFA 50 didn't result in an FF camera either, so why would a DFA 70-200 do?

[Kunzite]

Patents are what Ricoh emphasized they were after when they acquired Pentax

I thought Pentax was what Ricoh were after when they acquired Pentax

This patent confirms what Pentax said in their interview: they are working on "full frame" technologies, in background; and it seems they did it even under Hoya.

[froeschle]

Sigma 70-200/2,8 EX DG OS HSM
22 lenses in 17 groups
l = 197.6mm

Tamron 70-200/2.8 Di LD
18 elements in 13 groups
l = 194.3mm

Pentax 80-200/2.8 ED [IF]
16 elements in 13 groups
l = 195mm

70-200/2.8
17 elements in 14 groups
L = 296.16 (?!)

Canon patents for 600mm f/4 and 400mm f/2.8 lenses | Photo Rumors
For both those lenses, the “image height” is… 21.64mm – and don’t tell me they are almost full-frame…

[Effect of the Invention]
According to the present invention, focusing movement magnitude is made small, quick focusing is possible, structure is easy, and is low cost, and the electronic imaging device provided with a zoom lens system and this with the more outstanding optical performance is obtained.

[0002]
As a zoom lens system which aimed at a miniaturization and highly efficient-ization, 4 group zoom lens system which comprised the 1st lens group with positive refracting power, the 2nd lens group with negative refracting power, the 3rd lens group with positive refracting power, and the 4th lens group with positive refracting power is known sequentially from the object side (Patent document 1-3).

[0003]
These 4 group zoom lens systems mainly performed variable power by the 2nd lens group, and compensated the image surface fluctuation accompanying this variable power with the 3rd lens group, and the inner focus system which divides the 1st lens group into a pre-group and a rear group, and makes this rear group a focus lens group is used for them. Thereby, optical length cannot change in the case of zooming and focusing, but an optical system with little change of the f number can be acquired.

[0004]
[Patent document 1] JP,2002-6215,A
[Patent document 2] JP,2008-70450,A
[Patent document 3] JP,2002-162564,A

[0005]
However, since the zoom lens system of a Patent document 1 has too little lens number of sheets of each lens group (especially the 4th lens group), its chromatic-aberration-of-magnification change at the time of focusing is large. Since the Patent document 2 and the zoom lens system of 3 are made into the image blur correcting lens group (vibration proof lens group) which moves a part of 4th lens group in a direction orthogonal to an optic axis, there is much lens number of sheets, and their structure is complicated, and they are a high cost.

[Patent document 1] Sigma Corp.
[Patent document 2] Canon Inc
[Patent document 3] Canon Inc

[Mistral75]

Sigma 70-200/2,8 EX DG OS HSM
22 lenses in 17 groups
l = 197.6mm

Tamron 70-200/2.8 Di LD
18 elements in 13 groups
l = 194.3mm

Pentax 80-200/2.8 ED [IF]
16 elements in 13 groups
l = 195mm

70-200/2.8
17 elements in 14 groups
L = 296.16 (?!)

L = 296.16mm is the optical length (the patent is not linked to any particular mount). You have to subtract the flange-to-sensor distance to get the lens's length, i.e. 296.16 - 45.46 = 250.7mm. Still lengthier than competition.

[eurostar]

I don't see why it should be a proof a FF is coming.

A 70-200/2,8 is just a 100-300/2,8 scaled down for APS-C.

[thibs]

I don't see why it should be a proof a FF is coming.

A 70-200/2,8 is just a 100-300/2,8 scaled down for APS-C.

LOL

Still, AFAIK Pentax never designed FF lenses but when obvious (a 55 prime for APS wouldn't bring much would it?, so the 55 was an FF).
Zoom are a different story. It doesn't anything but that Pentax has (and probably still is) looking into the matter.
That is encouraging. But the excitement should be contained, folks.

[RonHendriks1966]

I don't see why it should be a proof a FF is coming.

A 70-200/2,8 is just a 100-300/2,8 scaled down for APS-C.

Well this can also be made for aps-c indeed.

I would buy it and sell my sigma!

I still prefer DA*135-270mm/f2.8 since that lens does make sence in creating a new lens that no competition has in it's portfolio and delevering on performance for a wide range of users. For sports it is good and with a TC it will deliver for nature photographers.

[maxfield_photo]

I don't see why it should be a proof a FF is coming. A 70-200/2,8 is just a 100-300/2,8 scaled down for APS-C.

I have to agree. As others are quick to point out, one major obstacle to Pentax releasing a full frame camera is that they've let their line of 35mm glass lapse, particularly in the area of zooms. Basically any time they design a lens they have one of two options, to fill a 36x24 frame, or to only fill a 24x16 frame. Obviously the first option adds unnecessary bulk to the lens if it will only ever be mounted on an APS-C body (of course it does let APS-C shooters take advantage of the sharpest part of the image circle), but this design philosophy has left Pentax in a position of being unable to offer lenses to go with a full frame DSLR should they choose to release one.

And hey, what about some love for us film shooters? Canon and Nikon never abandoned their film users. I may be wrong, but I believe both companies still make a film body, and of course all their Fx/EF lenses can be used on film.

I view this 70-200 f/2.8, if indeed it ever sees the light of production, as a way of getting back to a path from which Pentax never should have strayed rather than the herald of an imminent full frame. And in keeping with that theme, I hope they include an aperture ring.

[RuiC]

[/COLOR][/LEFT]

look a 70-200mm f2.8!!!!!

FF on the horizon right? right?

I can't read Japanese, but are you sure the filing date isn't March 10, 2011? That would still be interesting, since it's pre-Ricoh. And it wouldn't have contradicted any of Hoya's claims that it wasn't working on FF, since it's a bit cropped.

Image circle needed for 24*36 = sqrt (12*12 + 18 * 18) = 21,633 mm precisely
The patent is for a lens with an image circle of 21,64 mm so it fits;
I can't read Japanese but I don't see a patent for a lens giving image dimensions by its width and its height. It is the image circle that is specified here

You can read it in english here, filed by Pentax-Ricoh :

United States Patent Application: 0120229689

[Dr_who]

Pentax 100mm WR is Film/FF compatable, and that came out a long time ago and still no FF so I don't see why this would indicate ones in the horizon.