Radar 12" F6.3?

**Corran** · 26-May-2016, 08:32

It's clearly an amateur change to the original marked aperture on the lens cell, likely from an ignorant person who either replaced the shutter or found it as-is and decided to "fix" the mismatching numbers, but didn't understand how apertures and f/stop scales work. Probably saw that when set to f/6.3 it was wide-open and so changed the f/4.5 marking to that.

Post #3 surmised the shutter was from a 14" f/6.3. I don't know what else there is to add. It's obviously not a factory change, at least from what I can see on your blurry photo.

**koh303** · 26-May-2016, 09:19

The shutter is actually marked correctly for this lens - at F6.3, the aperture is closed and measures about right for that setting, and have enough travel left, and opening to be set at F4.5, so the above theory is not relevant for this case.

The aperture and shutter seem to be marked appropriately for each other in every respect...

My only guess is that this lens was marketed at a point in time when the F4.5 setting was no longer a viable or usable setting due to sharpness requirements.

**Corran** · 26-May-2016, 09:37

This is the first time you've explicitly stated that the marked f/6.3 aperture is stopped down and not at maximum.

Sounds like you have all the answers.

**domaz** · 26-May-2016, 09:39

Originally Posted by koh303

My only guess is that this lens was marketed at a point in time when the F4.5 setting was no longer a viable or usable setting due to sharpness requirements.

It seems like by making statements like this you are trying to make this lens somehow historically significant, when there's really no evidence it's anything other than someone re-labelling the lens incorrectly, out of confusion or for some other unknown reason. If we found two of these lenses with the aperture changed in a similar way, maybe you could have a case.

**koh303** · 26-May-2016, 09:50

Originally Posted by domaz

It seems like by making statements like this you are trying to make this lens somehow historically significant, when there's really no evidence it's anything other than someone re-labelling the lens incorrectly, out of confusion or for some other unknown reason. If we found two of these lenses with the aperture changed in a similar way, maybe you could have a case.

**Guess** not statement. The lens is marked correctly as is the shutter.

**Jim Galli** · 26-May-2016, 10:15

As long as we're all throwing our **guesses** into the pool of ignorance to see what floats to the top, I'll join in. My guess is that since Kodak was selling the h&ll out of their Commercial Ektar's Gundlach figured they'd jump on the band wagon.

**choiliefan** · 19-Mar-2018, 09:00

Resurrecting an old thread I just bought an 8X10 6.3 Radar lens not received yet. Hopefully this isn't a re-sell by the OP but a second example of this obvious rarity.