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View Full Version : Does anyone know this "different" Petzval soft lens type?



Steven Tribe
28-Apr-2010, 15:15
Maker Emil Busch. Made from the Preussian period up to the ROIA period. Seems to be a Petzval with tangential adjustment of the FRONT cemented pair. Looks odd with a tangental focussing drive on the sleeve and a radial drive on the barrel. I enclose documentation from the European "glamour" auction site that sold the grubby one in 2007 and has the cleaner, late version, in an auction in May. I have no connection with the auction house - and probably never will have - as the 20% fee ires me! Could the Nicola Perscheid adventure be based on previous interest? Can't find a catalogue that has it.

CCHarrison
28-Apr-2010, 16:16
Hi Steven,

Cool lens. I would have guessed its an "after-market" addition to the lens given the different drive mechanisms..Also, its far more common to find tangent drives on (early) US made lenses and fairly rare to find them on European lenses...so it adds to the mystery. However, seeing two of them that are the same makes me doubt they are after-market....

Also, the tangent drive mount would impede the travel of the barrel by the rack-in-pinion (it will hit the outer barrel)...and it does look like the waterhouse stop slot window has been reduced due to this - but its hard to tell from the photo. Having the lens in hand would reveal a lot about the lens...


Dan

Steven Tribe
28-Apr-2010, 16:24
This is the very unhelpful engraving (only to be expected from Emil Busch!).

seven
28-Apr-2010, 22:38
Steven, what looks like like an odd tangental focussing device is used to disassemble the lens into two halfs. The same mechanism is implemented on the famous Darlot Cone Centralisateur.

Steven Tribe
29-Apr-2010, 00:27
Yes I have seen something like it on some Darlot CC's. But why continue until around 1900. Westlicht (the Auction House) can't make up their minds about it. Now they write:

" Fine brass lens with Waterhouse stops, approximately 36cm length (eqf or physical?)rack and pinion focusing, mounting ring".

But in 2007 they wrote:

"very early Busch soft-focus lens with a slot for Waterhouse stops, brass bound with rack and pinion focussing, engraved: "EMIL BUSCH. Rathenow. Preussen.", 20cm long, 12cm diameter, focal length approx. 35cm, compared with lenses of a similar design this model has an extra adjustment to soften the image by unscrewing the front lens, the metal parts have unsightly stains, but the lenses are clear and undamaged, the lens comes with the original brass cap which is usually missing. A rare and interesting lens. (c.1865, condition B/C)".

They must have turned the radial drive to see what happens? But perhaps "unscrewing" really means "removing". Then the Comb in the engraving means combination - which would be a good description for an objective which functions la Darlot CC?

Steven Tribe
29-Apr-2010, 03:32
I have just compared the Busch with a selection of Darlot CC. Looks like the same system - I can just make out the extra rim on the Busch which looks like the Darlot solution.