Hey guys,
I need a 50mm pancake lens dirty cheap to use with my Isco Ultra anamorphic so that I get no vignette at 50mm (I'm at S35 sensor and EF mount). I already have a 50mm Zeiss ZF that I love but it vignettes, so I want to try a pancake lens. Any suggestion for a good one? Nikon 1.8?
Thanks!
Thread: Budget 50mm pancake
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12-28-2020 11:54 AM
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12-28-2020 12:00 PM
Just wondering...why does it vignette and how would a pancake make a difference?
The Nikon pancake is said to be a nice, sharp lens.
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12-28-2020 01:45 PM
The Isco is quite a long anamorphic scope and the path from the sensor of my Ursa Mini to the diopter becomes too long for it not to vignette at 50mm. A pancake would keep everything closer because of its short entrance pupil distance to the sensor.
The Nikon 50 1.8 does look promising.
Thanks
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12-28-2020 02:24 PM
From my testing (and I could be wrong) it's mainly the front element diameter that helps to determine vignetting. A pancake lens is normally going to have a smaller diameter front element anyways, but I wouldn't just go based on the thickness of the lens, especially because it is hard to know where the entrance pupil actually is.
I also go based off how near the front element is to the front threads, so that there can be as little clearance as possible between the lens and anamorphic.
When I am trying to figure out if something is going to vignette, I have also calculated the angle of the light from the front element outwards, in order to figure out if the path will clear the front element of the anamorphic.
You may also want to try something slightly longer, like a used Tamron 60mm F2. It's also completely internally focusing.
You could also try to put a wide angle adapter on the front of the anamorphic to go slightly wider (it would need to be zoom through, though.)
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