Re: Double vs Single Condenser Lens

Peter <w2tga@[EMAIL PROTECTED]
> wrote:

> On Apr 13, 4:55 pm, news*NOSP...@[EMAIL PROTECTED]
 (A R)
> wrote:

> > Now, I have a pair of spherical condenser lenses but unfortunately I
> > have no cell to mount them in. A single lens on its own fits snuggly
in
> > the enlarger head and seems (by eyeball) to give a uniform
illumination
> > across the easel.
> >
> > I know some enlargers use single apsherical lenses but what
> > advantage/disadvantage do I have using a single spherical lens?

> > I need more time!
> 
> Broadly, I think the objective of a condenser system is to (i) as you
> said evenly illuminate the negative, (ii) pass as much of the light
> through the negative as is practical and (iii) pass it through as
> nearly colimated as possible.
> 
> With one lens, if the convex side is toward the negative, objective
> (i) would likely be fulfilled.  I have doubts about (ii) and (iii).


But what if the lens was turned flat side towards the negative?


-- 

I need more time!