The Computar dL 50mm F2.8 enlarger or enlarging lens is described below.
 

Computar dL brochures
 
The Burleigh Brooks Optics Inc. brochure for the Computar dL line of enlarger or enlarging lenses is partially reproduced below. See the full brochure here Computar dL Enlarging Lenses

	Burleigh Brooks Optics Inc. Computar brochure published 1977[1]

This pamphlet below is from KYVYX Corp. See full pamphlet here Computar dL Enlarging Lenses

	High res file of the above (opens in a new window)