Lens Configuration

**Jim Fitzgerald** · 15-Jul-2014, 12:41

Somehow I'm drawing a blank on this lens. I'm thinking it is a triplet design but I don't recall seeing this before. Two bright three small dim and two bright. Any help would be appreciated.

Jim

**Dan Fromm** · 15-Jul-2014, 13:02

Jim, does the lens have a name?

The dim reflections come from glass-cement-glass interfaces. The bright come from air-glass interfaces.

If you can, please count reflections for each cell. Close the diaphragm as far as it will go or take one cell out of the barrel or shutter. And check that you're not missing a bright reflection from an outer surface. I've done that more than once.

**Jim Fitzgerald** · 15-Jul-2014, 17:26

Dan, the lens is a New York Lens Company 14x17 to 16x20 Group portrait lens. Looks like some type of RR as the reflections are the same front and back. Sorry for the small cell phone pics.
Jim

**Dan Fromm** · 15-Jul-2014, 18:26

Thanks, Jim.

**Jim Fitzgerald** · 15-Jul-2014, 18:33

Any ideas?

**Dan Fromm** · 16-Jul-2014, 07:03

Jim, how many light sources are you using? I ask because I see what looks like several in y'r shots. I always use just one, makes counting easier.

**Jim Fitzgerald** · 16-Jul-2014, 07:11

Dan, that is a good question and most likely mystery solved. There were three!!! Duh!! Sorry about that.

**Jim Fitzgerald** · 16-Jul-2014, 07:18

Well it is a RR as I thought. One light told the story. Thanks for pointing that out Dan.

**goamules** · 16-Jul-2014, 07:52

If it's long, brass, and American, from approximately the late 1800s, it's almost always a RR, or Petzval. If the rear has any separation, you can instantly eliminate a Petzval. These RRs were very common, and are really pretty nice lenses.