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Forum: Film SLRs and Compact Film Cameras
10-30-2017, 06:40 PM
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Unfortunately it isn't that fast or well corrected, the Kodak Ektar 50mm f/1.9 from 1941 even with its triplet of cemented groups, desperately needed coatings in order to produce reasonable contrast at its widest aperture.
The need for faster lenses pushed the industry towards improved multi-coatings. Sticking with the design philosophies of the past simply didn't cut it for 35mm photography. The lenses we work with today would have been inconceivable in the 1950s.
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Forum: Film SLRs and Compact Film Cameras
10-30-2017, 05:36 PM
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This was for optics designed for military applications, single coating started to appear in the consumer market until the late 1940s when 35mm photography was in its early stages. Multi coating started to appear in 1950s along with the first retro-focus wide angle lenses for SLRS.
The Leica Elmar 5cm f/3.5 is a very simple optical design, the fact that there isn't much difference between the coated/uncoated versions isn't hugely surprising. Lower element count means fewer air/glass interfaces where internal reflections can propogate and foul up image contrast. Older uncoated/single coated lenses with apertures of f/2.8 and faster show a more dramatic change in imaging characteristics.
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Forum: Film SLRs and Compact Film Cameras
10-29-2017, 04:51 AM
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Some Uncoated lenses post WWII were still in production, as there were still adherents who held that uncoated optics had a "look" that was lost as soon as coatings were used on lenses*. It was only until the 1960s and the progressive rise of Japanese mass manufacturing that lens coatings technology really took off.
*Uncoated lenses have a glowing, unsharp look, this was very popular during the early hollywood days for actors headshots. Presumably this was because editing out blemishes was difficult to do at the time and time consuming, Lightsources used for portraiture were primitive compared to today. For photography in those days light output levels had to be very high and often produced very hard and contrasty light.
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Forum: Film SLRs and Compact Film Cameras
10-29-2017, 12:20 AM
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There are examples of old uncoated* Voiugtalnder, Zeiss,Schneider and Leica lenses - Some of them are so popular they are updated and made with current optical coatings.
*or lenses with single coatings, magnesium fluoride was common AR coating used on early mass produced lenses . However MgF2 coating was fragile, simply rubbing it with a coarse material was sufficient to remove it, Its performance was also variable depending on which glass type it was applied to.
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Forum: Film SLRs and Compact Film Cameras
10-28-2017, 06:28 PM
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Not really. Voigtlander make uncoated and uncoated lenses: they are by necessity simple optical designs and the difference between them is an improvement in contrast but resolution is fundamentally identical.
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Forum: Film SLRs and Compact Film Cameras
10-27-2017, 12:55 AM
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The film may have had a resolution of about 60Mpix* - but the lenses at the time struggled to produce anywhere near this kind of resolution. My personal exemplar of this is the SMCP-K 50mm f/1.2 - it is not the sharpest 50mm lens pentax has ever made, at f/1.2 its resolution characteristic is abysmal, stop it down a bit, circa f/3.5~4 and it gets this soft-sharpness that was considered the holy grail of portrait photography in the 1960s - the kind of sharpness you get when you stretch a black stocking over a Carl Zeiss Sonnar 150mm f/4 C** on a Hasselblad 501C. Stopped down f/5.6~f/11 the 50mm f/1.2 really hits its stride, and performs admirably.
Don't get me wrong old lenses can produce phenomenal images on whatever medium they are used on. But if you're expecting the level of performance offered by new computer designed fully apochromatic primes that are showing up these days, you will be disappointed. In the end, If the artist is happy with the results that is good enough for me.
*I take these kind of statements with a hefty grain of salt - these numbers are nowhere near accurate when taken outside of the lab from which they were derived. 60Mega pixels at 1000:1 contrast perhaps, However, at 50:1 contrast you would only see probably 1/5th of that resolution. I have said before and it bears repeating: Film resolution is heavily dependent upon the photographers technique and ability, camera support systems used,Lenses, film flatness at the rails, film batch, the chemistry used to develop the film, the incantation used while you pour in the fixer, phase of the moon.etc etc
**some photographers would also go so far as to slightly de-focus the lens because for such a simple optical design, it was outrageously sharp.
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