triplet closeup lens

[Simon Clement]

Hi

I am trying to find closeup lens, with the following specifications. EFL 350+/-20 mm, F#5, preferably a cooke triplet or tessar. Any help would be appreciated

cheers

simon

[Dan Fromm]

I take it that when you write "closeup lens" you mean lens that will perform well around 1:1.

If you can live with f/7.7 - f/10 maximum aperture, there are many decent 360 mm or 14" process lenses around. If you must have f/5, you're in trouble.

Why must you have a triplet or a tessar? There are process lenses in both designs, but 14" dialytes and 6/4 plasmats are a little easier to find. If you must have a tessar type, look for Apo Tessars, Apo Germinars, Cooke Apotals.

Good luck, have fun,

[Simon Clement]

Hi

thanks for the prompt reply. This would be to fit onto the front of a zoom lens that we have.

[Tony Lakin]

Seems like a little knowledge is a dangerous thing!!!

[Dan Fromm]

Oh. You mean a 2.87 diopter. Oh. Ask Century Precision Optics what they can do for you.