From my in-house darkroom experience many years ago, I discovered that the lens system required to image a flat plane to another flat plane (i.e. film to paper) was very different from the lens system required to image a 3-d scene to a flat plane (i.e. real world to film). Check out process camera lense systems.
Donald.
----- Original Message -----
> From: "jeff.heiss@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Monday, February 20, 2017 2:46:58 PM
> Subject: Re: [Homebrew_PCBs] reducing mask image with lens
>
> This is very interesting info, thanks guys. Testing a current day HP laser
> printer at 600dpi and 1200dpi did not show appreciable resolution increase
> between 600 and 1200. Traces 5mil to 8mil were more gaussian in appearance
> instead of a desired sharp edge. I envisioned using 35mm film enlarger in
> reverse to reduce the mask size but it occurs to me that 35mm is the largest
> possible board size.
> This guy experimented with a microscope for reduction. Not feasible for
> PCBs but neat.
> https://www.allaboutcircuits.com/projects/diy-pcb-photolithography-microfeature-fabrication/
>