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05-25-2009, 03:22 PM   #136
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I don't think we have enough information to believe these pictures, as clearly they could be a hoax (an easier thing to fake than all those K7 mock-ups for example). The smart money is on skepticism at this point.

Still, if all Pentax was to do was release all the lenses mentioned that aren't the DFA* 50 f/1.0 -- which I don't think would be too surprising-- then we still will have some promising lenses to look for in the next year. It would be an excellent way to keep excitement going after the K-7 fervor wears off.

05-25-2009, 03:39 PM   #137
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Nothing is impossible Voigtlander 50/1.1 Nokton
05-25-2009, 03:59 PM   #138
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If you've seen the back element on the Canon 85mm 1.2 you've seen that it's so large that it takes up the whole usable space in the mount opening. They even have the electronic contacts for the lens on the element. Since the EF mount has the widest mount opening this seems like it would mean that an 85mm 1.2 would not be possible for K-mount. I'm not an optical engineer or anything so I'm not sure if this is completely correct, but the rear element of the Canon 85mm 1.2, ans the comparative sizes of the mounts makes it seem like Pentax would be out of luck.

QuoteOriginally posted by illdefined Quote
remember, they do still have the 77 Ltd. 1.8 so they may figure they have time to work on 85/1.2. in fact they even promote it on the last K-7 ad. a clue?
05-25-2009, 04:44 PM   #139
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QuoteOriginally posted by claude21 Quote
When all K7 specs were still rumors, a guy in a french forum give the specs and the fact is they were all true. This person also said that K200D sucessor will come near september 2009 AND that a Full Frame Pentax camera will come in 2010.
I have this in my book as well. First source to leak "K7" name!

As for the 50/1.0. My money is on hoax as well.

If true, it would announce the forthcoming FF lens roadmap. But then where is the 24-70 kit lens? And DFA* 24-70/2.8; DFA* 70-200/2.8 pro zooms?

05-25-2009, 04:50 PM   #140
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QuoteOriginally posted by mutedphotos Quote
But isn't it known that Hoya was mainly interested in the medical optics side of Pentax, and as such wouldn't be inclined to shell out exorbitant amounts of R&D funds for the camera side?
Err no.

In the 2008 interview, Ned Bunnell said this:

QuoteQuote:
[...] The good news is that the recent acquisition by Hoya is very positive for the Pentax brand. There were lots of rumors of Hoya wanting to acquire Pentax solely for our medical business. However, Hoya spent $980million for Pentax, and most of that value was for our camera business. With this kind of investment, Hoya is very committed to maintaining and growing the Pentax camera brand. [...]
read the rest here
05-25-2009, 04:51 PM   #141
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QuoteOriginally posted by Buddha Jones Quote
Nothing is impossible Voigtlander 50/1.1 Nokton
let's just see if Voigtlander can pull it off...they were lucky with the 35mm f/1.2, though the other Voigtlander RF lenses aren't quite as good as their leica counterparts. though the 35mm f/1.2 is as close to Leica I have ever seen voigtlander get. though zeiss RF lenses are superb, bitingly sharp lenses I own the Biogon T*21 f/2.8 and that lens is friggin spectacular...though my M3 or M6 doesn't have the proper framelines damn it all...sometimes I wish I had a bessa RF.

Last edited by Digitalis; 05-25-2009 at 04:58 PM.
05-25-2009, 05:04 PM   #142
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QuoteOriginally posted by mutedphotos Quote
Hm...real or not I couldn't afford a single one of those lenses.

New DFA lenses would seem to suggest they're prepping a lens lineup for a future FF model, but a 20/2.8 and 50/1.0 seem like an odd place to start, especially since they already have the 50mm covered with the f/1.4. If they're really prepping the lineup wouldn't they start by covering standard ranges they don't already have?

And FWIW, wouldn't a 25/2.8 645 lens (if even possible) be in the neighborhood of $8000?
I would say the same, and it's a good time to improve on Pentax's older FA lens line up and make the lenses as good as they can get. though Pentax making a 50mm f/1.0 lens would be very interesting indeed, either pentax are breaking a few laws of physics or they have found a way to get over the limitation of the K lens mount. I can think of one way they can do it...and it involves FREE.

a 135mm f/2.8 limited...why not f/2? I would like that! I have been itching for a longer limited.
05-25-2009, 05:22 PM   #143
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QuoteOriginally posted by Buddha Jones Quote
Nothing is impossible Voigtlander 50/1.1 Nokton
Anything is Possible!!!

05-25-2009, 05:38 PM   #144
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Revisited: The limits of technical feasibility

Just to repeat a discussion we already had for the 30mm/1.0 ...


For a f/1.0 with an optical construction where entrance and exit pupil have the same diameter (this is the case normally -- even for tele or retro-focus lenses with a protuding rear element), the diameter of the mount hole must be the registration distance which is 45.46 or 45.50 mm. But it only is ~42mm. So, anything faster than f/1.1 should be extremely difficult to build.

Additionally, the PK mount was designed to be just big enough to enable the 50/1.2 (which was said to be impossible with the M42 thread mount).


Theoretically, Pentax could make a 50/1.0 and accept vignetting right up to the center (effectively making it slower than 1.0). Could still gather more light than a proper f/1.2 when considering the entire surface. And with electronic correction of vignetting you get the f/1.0 shutter values ... So, it could be a marketing trick

[ Ah ... and no single pixel would see the entire exit pupil. Could make for an interesting bokeh fully open ]


I think this pretty much sums up all technical aspects of the issue. I am still thinking it is a hoax, though

Last edited by falconeye; 05-25-2009 at 05:53 PM. Reason: Revisited: The limits of technical feasibility
05-25-2009, 05:47 PM   #145
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QuoteOriginally posted by Votesh Quote
If you've seen the back element on the Canon 85mm 1.2 you've seen that it's so large that it takes up the whole usable space in the mount opening. They even have the electronic contacts for the lens on the element. Since the EF mount has the widest mount opening this seems like it would mean that an 85mm 1.2 would not be possible for K-mount. I'm not an optical engineer or anything so I'm not sure if this is completely correct, but the rear element of the Canon 85mm 1.2, ans the comparative sizes of the mounts makes it seem like Pentax would be out of luck.
I'm not sure this has anything to do with pentax' ability to create an f1.2 or larger aperture lens, remember they were able to produce a 50mm f1.2. Now I could be wrong and the mount isn't able to have a f1.2 85mm lens because of constrants however it becomes increasingly easier to have a larger aperture as a lens gets down into the lower mm ranges. So a 30mm f1.0 lens may be doable. In the end I don't think that the size of the back eliment matters as much as that of the front. Most of what the back eliments job is is to cast a viewing circle large enuff to cover the sensor. this of course is a simplified description and there is more that it does. I don't think that it is quite that important in the creation of a lens with a large aperture because as far as light goes, a lens acts as a condenser. they take a large amount of light spread over a big area and condense into a smaller area a little larger than the thing that will be collecting the light, the exception to this being fish eye lenses in that they don't cover the whole censor; remember trying to burn things with a magnifying glass?

well that just what my physics class taught me any way, well that and my $0.02.

Ian
05-25-2009, 06:44 PM   #146
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A 50/1.2

A50/1.2 is not big lens, filter diameter 52 mm
05-25-2009, 06:45 PM   #147
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QuoteOriginally posted by and Quote
didnt say it wasnt useful, but if you were going to start building an ff lens lineup it would be a very strange place to start.
We have no FULL roadmap.
05-25-2009, 07:28 PM   #148
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Regarding an f/1.0 lens from Pentax: The 50mm f/1.4 has a rear element ~29mm in diameter, giving it an area of 660.5 sq.mm. The 50mm f/1.2 has a rear element diameter of ~35.5mm, giving it an area of 989.8 sq.mm. These numbers make sense: f/1.2 is 1/2 stop faster than f/1.4, so the area of its rear element should be 1.5 times larger; and it is.

A 50mm f/1.0 lens would have a rear element twice the area of the f/1.4, which would mean its diameter would have to be square root of 2 larger. That gives us ~41mm. Take any K mount lens and measure that width; you'll see that the aperture lever would have to be removed in order to have a rear element that large and the glass would be very near the edge of the mount.

.
05-25-2009, 08:28 PM   #149
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Oh c'mon, this has got to be a hoax.
05-25-2009, 08:42 PM   #150
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QuoteOriginally posted by Miserere Quote
you'll see that the aperture lever would have to be removed in order to have a rear element that large and the glass would be very near the edge of the mount.

.
So it would fit, if they axed the aperture lever? Perhaps it would used electronic controlled aperture. If it is really a D-FA* they could just say that some D-FA* lenses need electronic aperture control, just like some DA* lenses need SDM.

Edit: they could have a bit of the rear element missing to make room for the aperture lever, like the canon 85 f1.2 does with its electronics.

Last edited by nixcamic; 05-25-2009 at 09:05 PM.
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