Coverage on used/older lenses

**Dick Clark** · 5-Jan-2000, 01:05

Thanks for all of you how have given me advice in the past. It has been very he lpful, e.g., I bought a Rodenstock 4X lupe after respondants advised that my 10X lupe was not the best; the 4X makes focusing much easier.

Another question: I read a lot about used lenses in this forum. Most comments relate to sharpness and generic coverage attributes. However, regarding specifi c coverage info, I don't see a lot. While I realize measurements of light and s harpness falloff in regards to "adequate" coverage are subjective, it would help to know if you're dealing with 200mm vs 300mm of coverage.

So when buying an older used lense for which no readily available specs exist, i s there any way to get an idea of the coverage before buying?

Thx in advance.

T

**Kevin Kemner** · 5-Jan-2000, 11:31

If you look through the lens commentary section of this site you will find several pages with older lens information. It is fairly well documented.

**Ron Shaw** · 5-Jan-2000, 11:55

These sources of info may be of some help. http://www.graflex.org/lenses/lens-spec.html http://www.graflex.org/speed-graphic/lenses.html http://www.hevanet.com/cperez/testing.html http://www.hevanet.com/cperez/results.html

**Alan Gibson** · 5-Jan-2000, 13:04

You can get a rough idea of coverage by holding a sheet of paper in the focal plane and pointing the lens towards an outside window. Rotate the lens and paper together to place the image of the window on different parts of the paper get an idea of the coverage. Practice this at home first!