Exerd
0
- Joined
- Jan 2, 2010
- Messages
- 448
- Points
- 28
Hi fellow LPF members,
I have been faced with a small challenge lately. That is, finding a large positive FL lens, of aspherical type, that is 88mm total OD (about 80mm minus its mounting flange), and back plane surface focal point of anywhere between 53-62mm. 60mm back focal point would be about perfect (FL from lens plano surface, not lens center).
I would like to use a quality lens, so I was looking past price, for something maybe CNC ground, glass (or other hard substance, with a high light transmission in the 4500K range for daylight-white LEDs).
I seem to be stumbling across cast glass/plastic once I find a lens that big. I have a 75mm cast glass lens, and it has a lot of spherical abberation. Almost as if, where it is brightest in focus, is not where it is actually focused best for clarity of the chip image.
Does anyone know of a company who may custom produce one to spec, or have quality lenses already of this size?
Thanks a lot. I'll keep digging myself. I've made a few orders now from Edmund, but their 80mm aspheric has been sold out it appears for a while now.
I have been faced with a small challenge lately. That is, finding a large positive FL lens, of aspherical type, that is 88mm total OD (about 80mm minus its mounting flange), and back plane surface focal point of anywhere between 53-62mm. 60mm back focal point would be about perfect (FL from lens plano surface, not lens center).
I would like to use a quality lens, so I was looking past price, for something maybe CNC ground, glass (or other hard substance, with a high light transmission in the 4500K range for daylight-white LEDs).
I seem to be stumbling across cast glass/plastic once I find a lens that big. I have a 75mm cast glass lens, and it has a lot of spherical abberation. Almost as if, where it is brightest in focus, is not where it is actually focused best for clarity of the chip image.
Does anyone know of a company who may custom produce one to spec, or have quality lenses already of this size?
Thanks a lot. I'll keep digging myself. I've made a few orders now from Edmund, but their 80mm aspheric has been sold out it appears for a while now.