BUILDING A LENS... PERISKOP? DOUBLE ACHROMAT?

[ruilourosa]

Hello

I am trying to build a lens... a simple lens... i would like to have a 750 to 1000mm i would prefer to have a simple construction, but a positive meniscus have a lot of difusion... would a steinhel periskop be any better? built out of 2 positive meniscus around a diafragm? or an achromat doublet? or an achromat doublet on either side of a diafragm...

also where can i buy lenses to make a photo lens of this type (cheap)


THanks


Rui Lourosa

 

[Someonenameddavid]

Hello

I am trying to build a lens... a simple lens... i would like to have a 750 to 1000mm i would prefer to have a simple construction, but a positive meniscus have a lot of difusion... would a steinhel periskop be any better? built out of 2 positive meniscus around a diafragm? or an achromat doublet? or an achromat doublet on either side of a diafragm...

also where can i buy lenses to make a photo lens of this type (cheap)


THanks


Rui Lourosa

You should look at www.surplusshed.com

David

 

[eclarke]

Or, check with Reinhold..He's making a reasonable priced 1000mm now.

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

 

[Mark Fisher]

I believe his lenses are single element lenses. If you actually want something reasonably sharp and not hard to build,consider a symmetric lens using simple lenses or achromats around a central aperture. If you haven't already, look at Alan Greene's book Primitive Photography. I have a couple of examples of a 300mm symmetric stopped to f64 onto 8x10 in this flickr set.