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Forum: Pentax SLR Lens Discussion
06-10-2011, 08:25 PM
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that was actually my point really. For instance Leica used elements from the old Leica-M 50mm f/1.2 Noctilux ASPH in the Leica-M 50mm f/1.0 Noctilux they made in 1975 - though the glass they were using was incredibly hard to make and wasn't available from the catalogues of known glass manufacturer at the time*.
*the glass Leica used in the Noctilux 50mm /1.2 ASPH is called 900/1 - has a refractive index of 1.9005 (abbe index = 40.5) and it contains Lanathum oxide 55.5% 18.6%Tantalum oxide, 8% boron trioxide,5.30% Zirconum and other materials were used to raise the refractive index. The glass was made in platinum crucibles at 1,700K under stringent conditions, the glass blanks were made in batches of 900 and nearly 30% were thrown out because of defects.
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Forum: Pentax SLR Lens Discussion
06-08-2011, 08:26 AM
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yes.
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Forum: Pentax SLR Lens Discussion
06-07-2011, 09:50 PM
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true, anyone who has looked at the going price for aspherical Ai-S 58mm f/1.2 noct-nikkor these days - I paid a bit more than 3K for mine*, but mine was in its original box:D
*I paid $150 for a Pentax K 50mm f/1.2 a few years ago - which was(still is) in mint condition.
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Forum: Pentax SLR Lens Discussion
06-07-2011, 06:41 AM
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not entirely true, I have seen canon and nikon photographers using M42 takumar lenses from the '60s on their cameras and they produce impressive results
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Forum: Pentax SLR Lens Discussion
06-07-2011, 01:17 AM
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very true, Minolta (Sony) are the biggest culprit for this. The Rokkor 50mm f/1.7 was only transmitting 83% of the light while the Pentax 50mm f/1.7 - (a contemporary lens design) was transmitting close to 94% - these difference in transmission can be chalked up to the coatings used on the lenses.
from what I have seen the vignetting from the lenses is pretty consistent from the summilux 21mm f/1.4 to the 'lux 75mm f/1.4 which can be because of either the microlenses, or behind the scenes ISO bumping. The leica M9 has arguable the worst High ISO performance from a FF sensor I have worked with (my nikon D3s is the current High ISO prize winner for me) and if Leica was bumping the ISO values it would be pretty obvious - though I haven't checked my M9 for this...I'll get back to you on that.
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Forum: Pentax SLR Lens Discussion
06-06-2011, 05:00 PM
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not really, Kodak has developed offset microlenses to compensate for that - and I have been using my Leica M9 for some time and even with ultra fast lenses like the Noctilux 50mm f0.95 ASPH vignetting is very well controlled. The only reason leica M cameras are essentially limited to 135mm as their longest current focal length is the rangefinder baselength isn't long enough.
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Forum: Pentax SLR Lens Discussion
06-06-2011, 07:31 AM
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I think you are forgetting that they are still using exactly the same lens mount and flange distance as they have been using for to past 50+ years. The reason why Leica M cameras are able to have such fast lenses designed for them is because their short flange distance - which is 27.80mm the pentax flange is 45.46mm - almost twice that of the leica.
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Forum: Pentax SLR Lens Discussion
06-04-2011, 08:07 PM
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Three of the fastest pentax lenses I use these days. note that the front elements on all three of these lenses are very similar in size.
( I know the FA*85mm f/1.4 should be in there but I prefer the smaller FA77 f/1.8)
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Forum: Pentax SLR Lens Discussion
06-03-2011, 06:52 AM
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good point. For example the Leica noctilux 50mm f/1.2 - released in the 1966 was an aspherical design, and was optically superior to the Canon 50mm f/0.95 which didn't use any aspheric lenses in it's design. Curiously In 1976 Leica produced the Leica Noctilux 50mm f/1.0 - which like earlier canon lens did not use Aspherics. It is only in recent history when Leica announced the Leica noctilux 50mm f/0.95 ASPH when the Leica community sighed with relief that Leica was again producing cutting - edge lens designs. though strangely the Leica noctilux 50mm f/1.0 is actually still in pretty high demand these days because of the Leica "glow" it produced which was nothing more than carefully controlled spherical abberation.
I personally prefer the "classic" 50mm f/1.0 for my work on the Leica M9. The new 50mm f/0.95 ASPH is basically just a faster lens than the summilux 50mm f/1.4 ASPH - at f/2.8 they both render things identically - I like the character the classic noctilux has.
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Forum: Pentax SLR Lens Discussion
06-02-2011, 09:06 PM
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the canon 85mm f/1.2 gets it's rear element handed to it by the pentax FA*85mm f/1.4 - so if I were you I would stop using the Canon 85mm f/1.2L lens a some shining example of goodness. I use a Leica 80mm f/1.4 on my canon FF bodies because the Leica lens doesn't have the awful focus by wire mechanism that the Canon 85L does- and the Leica lens has better aberration control.
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Forum: Pentax SLR Lens Discussion
06-02-2011, 05:16 AM
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there are also lens mount constraints to take into consideration -E.g: Canon changed over from the FD to the EF mount which can support a 50mm f/1.0 lens, the FD mount was maxed out at 50mm f/1.2
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Forum: Pentax SLR Lens Discussion
06-02-2011, 03:36 AM
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The Canon lens got it's rear element handed to it by the Leica Noctilux-M 50mm f/1.0 - and now Leica have the Noctilux-M 50mm f/0.95 ASPH
I own a canon EF 200mm f/1.8L and yes it is very very good for sports, but lately I have been using my Nikkor AF-S 200mm f/2 VR on my D3s - the Nikkor being optically perfect to my eyes, The canon 200mm f/1.8L has some pretty nasty purple fringing at large apertures.
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