B-A-C Posted January 18, 2017 Share #81 Posted January 18, 2017 Advertisement (gone after registration) Another question - will Leica ever make an APO Summicron 35? Quote Link to post Share on other sites More sharing options...
Advertisement Posted January 18, 2017 Posted January 18, 2017 Hi B-A-C, Take a look here Will we ever see a Noctilux 35mm?. I'm sure you'll find what you were looking for!
michaelwj Posted January 18, 2017 Share #82 Posted January 18, 2017 (edited) 60mm filter, really? Reminds me of the 90mm f1.0. Fits but just impossible to use... Yes really. But it would be possible to use, the lower right of your picture would just be a bit of a gamble. You'd block about the same as with the f/1 Noctilux (which also has 60mm filters), but it would have much more impact on the 35mm frame A 90mm f/1 would need a 90mm hole*, and likely 95mm filters, so no dice, the RF window would be blocked and you wouldn't be able to focus at any aperture. I don't mean to sound condescending, and this is for others who might read it, but have you ever thought of what "f/2" means? To make it so that a 2/90 lens lets the same amount of light in as a 2/35 (have you ever noticed that a 2/35 has a much smaller aperture than a 2/90 - it's collecting light from a larger area) the f-stop is the focal length divided by the size of the hole (and has no units). So a 50mm lens with a 25mm hole has an aperture of f/2. the "/" is literally dividing, and "f" is the focal length. A 90mm f/2 would have a hole 90mm/2=45mm, and the 50mm f/0.95 has a hole that is 50mm/0.95=52.63mm (and uses 60mm filters). The famous 35mm f/0.75 therefore has a hole that is 35mm/0.75=46.66mm, so yeah a 60mm filter would be fine**. *the hole often looks a different size because you're looking at it through magnifying lenses. Generally speaking, the front element must be at least this big. Wide angles generally need a bit more to collect light from a greater angle, and because most of them are a normal lens with a wide angle adapter on the front. **to account for the wide angle lens, I've given a bit extra to reduce potential vignetting. Edited January 18, 2017 by michaelwj Quote Link to post Share on other sites More sharing options...
michaelwj Posted January 18, 2017 Share #83 Posted January 18, 2017 Another question - will Leica ever make an APO Summicron 35? Not at what I would like to pay 1 Quote Link to post Share on other sites More sharing options...
NB23 Posted January 19, 2017 Share #84 Posted January 19, 2017 (edited) Yes really. But it would be possible to use, the lower right of your picture would just be a bit of a gamble. You'd block about the same as with the f/1 Noctilux (which also has 60mm filters), but it would have much more impact on the 35mm frame A 90mm f/1 would need a 90mm hole*, and likely 95mm filters, so no dice, the RF window would be blocked and you wouldn't be able to focus at any aperture. I don't mean to sound condescending, and this is for others who might read it, but have you ever thought of what "f/2" means? To make it so that a 2/90 lens lets the same amount of light in as a 2/35 (have you ever noticed that a 2/35 has a much smaller aperture than a 2/90 - it's collecting light from a larger area) the f-stop is the focal length divided by the size of the hole (and has no units). So a 50mm lens with a 25mm hole has an aperture of f/2. the "/" is literally dividing, and "f" is the focal length. A 90mm f/2 would have a hole 90mm/2=45mm, and the 50mm f/0.95 has a hole that is 50mm/0.95=52.63mm (and uses 60mm filters). The famous 35mm f/0.75 therefore has a hole that is 35mm/0.75=46.66mm, so yeah a 60mm filter would be fine**. *the hole often looks a different size because you're looking at it through magnifying lenses. Generally speaking, the front element must be at least this big. Wide angles generally need a bit more to collect light from a greater angle, and because most of them are a normal lens with a wide angle adapter on the front. **to account for the wide angle lens, I've given a bit extra to reduce potential vignetting. Dude, I know my maths around lenses. It is not rocket science. I doubt that a 35 f0.75 is feasible in M mount with a sufficient CoC. For a M8 or Dx? Doable. A Leica 90mm f1.0 does already exist. So it is doable. Edited January 19, 2017 by NB23 Quote Link to post Share on other sites More sharing options...
NB23 Posted January 19, 2017 Share #85 Posted January 19, 2017 Besides, the 90 f1.0's diameter looks to be in the 135mm region, a far cry from your 95mm cslculation. Quote Link to post Share on other sites More sharing options...
otho Posted January 19, 2017 Share #86 Posted January 19, 2017 (edited) Besides, the 90 f1.0's diameter looks to be in the 135mm region, a far cry from your 95mm cslculation. BTW, Elcan 90 f/1 have four distance rings ("4457" for infinity, "4149" for 100 m, "4149" for 50 m and "4149" for 20 m). Price - ca. $140K (only 10 pieces have been completed)... Edited January 19, 2017 by otho Quote Link to post Share on other sites More sharing options...
michaelwj Posted January 19, 2017 Share #87 Posted January 19, 2017 Advertisement (gone after registration) Dude, I know my maths around lenses. It is not rocket science. I doubt that a 35 f0.75 is feasible in M mount with a sufficient CoC. For a M8 or Dx? Doable. A Leica 90mm f1.0 does already exist. So it is doable. Sure you know it, but you don't seem to apply it. The 90mm ELCAN, has a big front element, lets say 135mm (all I've found is that it is larger than the 560mm telyt, which is 12.5cm). So at 135mm it is 1.5x the minimum required of 90mm, applying that to the 0.75/35mm we get a 65mm filter. Not far off my 60mm, and surely doable. While we're at it since you know so much feel free to explain how CoC will impact its size. 1 Quote Link to post Share on other sites More sharing options...
Paul J Posted January 24, 2017 Share #88 Posted January 24, 2017 I would find it very difficult to choose between a 35mm APO-Summicron and a 35mm Noctilux if they were offered at the same time, they are both lenses I would buy. Quote Link to post Share on other sites More sharing options...
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