"Thanks all, I don't have the D'Agostini book but have seen diagrams of the Derogy lens which looks as if it can be assembled in many different combinations. There is a letter in an early British Journal of Photography which mentions the…"
"Photographic Lenses of the 1800's in France by Corrado D'Augustini mentions a Derogy convertible lens of 1858. Perhaps you have this book?
On p347 the author wrote that "Gasc & Charconnet built an Objectif…"
"Stephen I bought a copy of the British volume. I have some comments about it. I can provide details of the imprint. Frederic Hoch was holding copies of all three on his table, but said that eBay was the place to buy. "
At the Photographica 22 event, which took place yesterday, on one of the dealers’ tables I saw three thick books listing, respectively, French, British and German lenses. These volumes seemed to be privately published and well…"
I have come across a lens by Gasc & Charconnet it is an ordinary Petzval design with the addition of a third lens placed between the other two. The extra lens is a cemented achromat. The third lens and the front element are both mounted in a tube which slides relative to the rear lens group.With the third lens removed and the tube retracted the back focus of the lens is 6". With the third lens in place and the tube extended the focal length is reduced and gives a smaller image with a back…See More
"A good manual is "Directions for obtaining both positive and negative pictures upon glass by means of the collodion process, and for printing from the negative glasses on to paper" by T. H. Hennah. This is online at archive.org.
"Hello, I think we are looking at the back of the tent so the little flap or door would be a 'red window' the tall object on top of the tent to the left is probably a water tank.
There is a modern description of an old tent…"
"Early bellows were commonly finished in leather but cloth and paper were also used even as early as the wet-plate period.
Sometimes the leather was coated in shellac or similar which gives a very shiny synthetic look. Advertisements sometimes…"
"Hopefully two files are attached showing adverts for the Royal from 1907 and 1908.
The shutter is probably set in two parts – by setting the spring tension which controls the rate at which the blinds move and by changing the gap between the…"
"This looks like the Royal sold/made by Staley in the 1900s. The large focusing hood was introduced in 1908. Sands & Hunter would have been the retailer either new or second hand. I'll add some photos that show adverts for…"