Anyone able to identify maker of early petzval radial drive lens

**rossn4** · 19-Jul-2016, 18:06

I have a large early petzval radial drive lens which is missing the outer housing that would have said who the maker the lens was. From looking at its construction is anyone able to indentify the maker? The two screws holding the radial gear track are distinctive and I was hoping someone might have a similar lens. It is not slotted. Thanks for any info anyone could provide.

**Steven Tribe** · 20-Jul-2016, 00:29

Originally Posted by rossn4

I have a large early petzval radial drive lens which is missing the outer housing that would have said who the maker the lens was. From looking at its construction is anyone able to indentify the maker? The two screws holding the radial gear track are distinctive and I was hoping someone might have a similar lens. It is not slotted. Thanks for any info anyone could provide.

Agreed, it could be a pre-1858 Cabinet sized Petzval. But, on the other hand, it could also be a much later Projection Petzval, as the radial system made a small comeback! It if is an American pre WHS Petzval, you may get some pointers from the collector/users here. However thay may need some convincing as removing the brass sleeve will be something of a risk with aged screw threads. I do have a Scottish radial drive made by Liddell of Edinburgh, who was a very small supplier to the band of photography interested in that area. Not a Petzval though, but an experimental double lens combination for Callitypes, I imagine. There is a very visible gear plate attached to the barrel, but with rather more holding screws than yours.

Early threads were mostly cut by hand, and because there is some variation, this were often identified as matching pairs with (usually) roman numerals close to the threads. If they are present, then I am sure it is pre-1858.
Looking at the individual lenses might help in giving clues.

**goamules** · 23-Jul-2016, 16:23

The knurling on the two lens element fixtures is not early American, which is angled and "rope like." Yours is straight cut knurling.

**Steven Tribe** · 30-Jul-2016, 04:27

I have taken a more careful look at the OP's photos and have come to the conclusion that it is an atypical tangential drive, rather than a radial drive. The small gear teeth appear to be in the same plane as the usual type which reach across the whole gap. The teeth are also considerably finer than others I have seen. I enclose a photo of mine which has a non-concealed view of the teeth.

**rossn4** · 31-Jul-2016, 20:00

Thank you for your comments. I'm still studying the lens. Here is another picture showing a better angle of the gear track. I'm pretty sure it is a normal radial drive. One feature I didn't mention is that the ring that separates the two real elements is split. I can't tell if its rusted through and split that way or if it was originally installed as a split ring.