Meniscus Lens to cover 16x20

**AuditorOne** · 8-Jul-2014, 19:59

I am in the process of building a ULF Pinhole camera that will use up a bunch of old 16x20 paper I inherited. But I would also like to try a meniscus lens with it as well. An interchangeable lens pinhole if you will.

I am doing some internet research but I know there are people here who probably have thoughts on this, and experience as well. I certainly welcome any ideas in this arena.

Moderators, there may be a better place for this. Feel free to move it.

**Andrew O'Neill** · 8-Jul-2014, 20:57

Some of Reinhold's meniscus lenses will cover 16x20.

http://www.re-inventedphotoequip.com...gurations.html

**Jim Galli** · 8-Jul-2014, 23:25

What is your focal length?

**Jim Jones** · 9-Jul-2014, 05:56

A +2 close-up filter is readily available and has a focal length of about 20 inches. This would be equivalent to the popular 127mm lens on many 4x5 press cameras. Designing a pinhole camera to use one of these would provide slightly wide angle coverage. Basic cameras have used simple meniscus lenses for a hundred years. At small apertures they can record fairly sharp images. Using an appropriate filter for focusing and shooting restricts the range of color and reduces chromatic aberration. Two element achromatic +2 close-up filters are also available, but are expensive. They would improve performance when using the full visual color spectrum. Mounting close-up filters may be easier than using unmounted lenses. A cheap additional filter ring with the glass removed can be used as a retaining ring in a thin lens board.