Enlarger height & magnification

Roughly where should the enlarger head sit for the print you want? Enter your negative, print size and lens to get the magnification and the negative-to-baseboard distance.

Distances come from the thin-lens conjugates. Real columns add a little for the head and easel, so treat this as a close starting height, then focus to finalise.

About this tool

This tool estimates where to set your enlarger head for a given print size. Enter the negative size, the print size and your enlarging lens, and it returns the magnification and the negative-to-baseboard distance as a close starting height for darkroom printing.

How to use it

  1. Choose your negative format.
  2. Enter the print long edge you want, in inches.
  3. Choose the enlarging lens focal length for your format.
  4. Read the magnification and set the head near the negative-to-baseboard distance, then focus.

FAQ

Is the height exact?

It comes from thin-lens conjugates, so treat it as a close starting point; real columns add a little, and you finalise by focusing.

Which lens should I use?

Match the lens to the format, roughly a normal focal length: 50mm for 35mm, 80mm for 6x6, 105mm for 6x7, 150mm for 4x5.