D-FA 50mm f/1.0 SDM

[cousinsane]

Sure. Nevermind that it's a Leica M mount.

Originally Posted by Buddha Jones

Nothing is impossible Voigtlander 50/1.1 Nokton

[RawheaD]

Originally Posted by cousinsane

Sure. Nevermind that it's a Leica M mount.

Thank you for pointing that out. Saved me a post. Wait, I just wasted a post thanking you



Like it was discussed in the 30/1.0??? Thread, F1.0 and even faster lenses are very possible to make for rangefinder systems that generally have register distances that are much shorter than mount diameters. It doesn't take a Leica to make a lens faster than F1.0; just look at Schneider Kreuznach's Xenon 25mm f0.95 for C-mount (cine lens). Or Angenieux 25mm f0.95 (c-mount), all possible because C-mount has much shorter register than it's mount diameter. But even IF there was an F1.1 lens for the PK mount, which, even according to my thought is theoretically possible, it doesn't prove anything beyond that an F1.1 is possible; it has nothing to do with whether or not F1.0 is possible. Like I challenged in the 30/1.0 thread, show me just one example of an F1.0 lens for a mount that has a smaller mount diameter than its register. Answer: it doesn't exists (outside of macro-only lenses).

[ajuett]

I like all these blurry "spy shots" they remind me of the 70's blurred shots of the Sasquatch. SR and fast Af should be helping us see these secrets of the world more clearly. Shouldn't they?

[EricT]

Originally Posted by Digitalis

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.

Because all the other limiteds are compact? I would think an f/2 lens would be pretty big. An 135mm ltd would be great, though, I find it a lot more interesting than a 50mm f/1.0.

[Digitalis]

Originally Posted by Miserere

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.

.

but it would be possible, take a look at the rear element of my Pentax K 50mm f/1.2

[ibk]

Originally Posted by pcarfan

How do you know this....I am pretty sure Pentax doesn't consider 400mm to be 'super' telephoto, but do you have an internal source?

I can't share more info but no one on this forums guessed the exact length of the lens so far.

[drerka]

Hi All,

As most of you, I don't know whether these images are fake or not. And I don't know whether a 50mm 1.0 is technically possible on K-mount.

Pentax, as I see it, is a company that cares very much about technical excellence and therefore is more willing than other companies to introduce showcase products, such as a fast prime.

A new product has two goals imho: to be sold and to make a statement about the brand itself. In some products the focus is on selling a lot of items, in other products the focus is on establishing or reinforcing brand image. Top quality primes will absolutely do the latter and will sell too, if the price is right.
And combined with the previous point, my take on it is that a fast FF prime doesn't sound impossible.

And an FF future for Pentax? Well, that's a debate that will go on for quite a while I think. Imho an FF body is inevitable, not on technical grounds only, but again because of prestige and brand image, a factor that weighs heavily in Asian / Japanese culture.

And think about it: is it really that hard for Pentax to introduce an FF body? The technology exists (My Z1 from 1991 has 1/8000 shutter and I believe it has 1/250 flash sync) The sensors are becoming more and more usable and getting cheaper.
The lens line has to be upgraded, but Pentax also was able to introduce one of the finest lens lines for APS-C. And still we call it a small company with limited resources... Factor in Hoya and I think you'll see why I don't dismiss the rumors in this thread as implausible.

Roger.

[Asahiflex]

If I've read right then someone here mentioned that the M42 mount could not accept a 55mm f/1.2 lens. Wrong, Tomioka made one, albeit at the expense of some hacking in the back element to accommodate the auto diaphragm pin.

[robjmitchell]

What madness! A 50/f1.0 would sell like moldy steak in a Japanese fish market
How about we speculate on the two new lenses that have been hinted at by a couple of posters.
#1 will be a super telephoto. My guess is a zoom, I was thinking a 80-400 like tokina but maybe not, it could be longer
#2 would most likely be a 30/35, since we need a fast normal, also dreaming of a DA*11-16/2.8.
we will have to wait and see!

[muustuus]

I too think that 1.0 could be possible with cutting a piece from the rear element or with some other tricks. Lever for the aperture is needed when using it with LX. :P

[nulla]

For you techos

What shutter speed would be required to enable the use of f 1.0 under full daylight conditions.



Neil

[thibs]

A couple days ago I've been limited to use f/2.4 with my Sigma 28/1.8 because the K10D was already at 1/4000.

Of course that was in very sunny afternoon.

[janneman]

DFA 50/1.0??? What is the use of that? DOF will be so shallow at f1.0 I doubt many cameras, even anything other than Pentax won't have any FF/BF probs. 400/4? sweet but not onmy wish list...
DFA 20/2.8? Don't we have that covered with the DA*16-50/2.8?? DA135/2.8 limted. Nice addition to the line up but not my kind of thing...
Now, where are the two lenses that I would like to see?? The fairly wide fast sealed prime (30/1.4) and the medium ranged sealed walkaround zoom??

Those are the lenses on the top of my list, and many other listst as well.
This is by far the most useless roadmap update I have ever seen by Pentax

[Prognathous]

I'm curious. If Pentax modified the current SMCP-A 50mm f/1.2 front elements to gather more light (e.g. make them twice to three times as large), while keeping the rear element as is, will such a lens not pass more light to the sensor?

Prog.

Edit: The 50/1.2 has a filter thread of 52mm, which means that it's front element is not very large. Elements that are twice as large won't neceserily cost that much. Many wide-angle adapters (e.g. the Olympus WCON-07C) have a glass elements that are about this big, and their MSRP is typically no more than $150.

[miriya]

I can do - like this crude shit in 10 minute.

stop cheating and stop cheated.