Dead ON!!! There are a number of "cracks" in this article ... one in that he assumes that every lamp merely radiates in all directions - the last time I looked, the EYA Halogen lamp in my D5500 has a built-in parabolic reflector. That serves to "directionalize" - collimate to some extent - the output from the filament. *After* this "raw" light (from either system) passes through the enlarging lens the rays (see "ray trace") follow the same paths anyway ... otherwise there would be no definite focal plane.Originally Posted by MichaelBriggs
The REAL reason to collimate is not to affect "sharpness"; it is to provide even illumination across the focal plane.
I've worked with optical systems with adjustable collimation. To set these up, one removes the projection lens and works the adjusting screws (or whatever) until the lamp filament projected to the focal plane is *centered* and in the best possible focus. That will insure the most even illumination possible over the plane of focus.
A system with condensing lenses - IMHO - n.b. - is NOT clearly and absolutely superior. It is more complex, heavier, more expensive - "feistier" in many ways - and possibly delivers "brighter" light (tad more efficient).
While I doubt the "superiority" I don't think there is an "inferiority" either. It is a matter of ... aesthetics, tastes, superstition ... whatever... a LOT like everything else in photography.