"Swift and Son London, Universal Paragon No.2 f:5,65"
Hello,
I just bought this ( Petzval ) lens and would like to know more about it...
Best
Peter
"Swift and Son London, Universal Paragon No.2 f:5,65"
Hello,
I just bought this ( Petzval ) lens and would like to know more about it...
Best
Peter
Hello Peter
Unless I'm way off, I'm pretty sure that this isn't a Petzval, sorry - Steven Tribe is the one who will confirm, I'm sure
Andrew
http://www.largeformatphotography.in...-Lens-question
I did make a long reply here which wasn't auto saved! I think it is a Petzval, although the rear cell appears to be "sealed" which makes for really difficult cleaning.
In the 1890's, slower/lighter Petzvals were popular for home portraiture.
Later Petzvals are most often without brass sleeves.
Here is one with similar proportions to yours from Roussel et Berteau.
Later: The OP has mentioned an air gap between the two lenses in the rear cell in a PM which excludes a RR/Aplanat!
Looking at the Swift catalogue in the previous thread about the Paragon, I am amazed he was able to offer this is quite enormous sizes - lenses up to 7" inches in diameter.
Obviously not of Swift manufacture, so probably from one of the few makers in Paris who could manage the manufacture without huge investment in production facilities? I'll check some french makers to see if there is a Petzval series which matches up to the Swift list.
Just to put this into some kind of perspective.
Dallmeyer's D series (F6) corresponds very closely with data for the Swift list (F6 Petzval compared with F5.56 for Swift). They stopped at the 6" lens size!
I have only found Gasc et Charconnet making a 7" lens (listed as a standard product) at the moment - and only as a simple achromat, although they used the same achromat production in their Petzval series.
I'm very happy that I was wrong.................
Andrew
But the OP (and other owners of the Universal Paragon) are even happier!
Looking at details in the 2015 thread, I can see a marking that suggest a screw thread between what looks like two separate sections in the rear cell. A system to ensure the air space between the two lenses is correct?
Yes, I know. But I also deduced that the achromat used in their landscape series is exactly the same lens that is the front achromat in one of their Petzval series. All lens diameters match! I also have a french landscape and petzval from another maker (Lerebours, I think) with a similar complete match.
Well done - It looks like we now have found where Swift got his Universal lens from!
Later: Although this seems like a source/match with the Swift Universal Petzval, there are some problems! The Gasc et Charconnet/Laverne series 2 Petzvals are much faster and have the so-called "cone" arrangement - where the rear lenses have a larger diameter than the front achromat. But they would crtainly have experience in making Petzvals of this size and had sources for the chunks of optical glass.
Last edited by Steven Tribe; 29-Dec-2017 at 14:09.
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