Will add to the list today.
Every early L et S that has survived Waterhouse slots and has the original front cup insert system is genuine miracle!
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Will add to the list today.
Every early L et S that has survived Waterhouse slots and has the original front cup insert system is genuine miracle!
Well this is new! I have just checked my identical lens 2113 and what I thought was a faint pencil/ink trace is, indeed, a very thin scratched text. So the missing rice marking was actually present on the edge.
The lettering is very shallow and about the width of a spider’s silk thread.
Post photo tomorrow.
Here are extracts from the edge achromat scratches. I will check a few later lenses.
There is a new JFS (J.F.Shew) import of Lerebours et Secretan glass in the early 1850’s fitted to UK brass.
This is an identical model to the 60mm lens Landscape meniscus we have in serial number register as #6425. It is #6431!
Unlike 6425, 6431 appears to have the front aperture system.
Will report more when it arrives.
6431 has arrived.
It has obviously been made (brass) in the same batch as 6425. The threads are hand cut, which means that parts from one lens “almost” fit perfectly on the other lens - but not quite! Note that the four mounting holes in the two sleeves are not the same size (later repair?) in both lenses and the gear cover/sleeve with marked with V and VI respectively.
The front aperture missing in 6425 is present here in the new 6431 and is very simple baffle - no obvious adjustment possible.
Lens diameter is 57mm which corresponds to the pill box achromat made by Lerebours from 1853. Focal length is 30cm so the F values are low for landscape achromat!
There two major differences between the two examples. This new 6431 glass has no scratch markings and is brass turned mounted rather than the screw-in ring of 6425. The screw-in system was dominant in France whilst the lathe turning mounting was the most usual (and quickest!) in the UK!
It has already been noted that the scratched serial numbers on English mounted lens are both larger and not so elegant as their Parisian counterparts. So perhaps the “scratching” took place in the UK and sometime between 6425 and 6431, the mounter reverted to “English” lens mounting traditions and gave up on the arduous scratching at the same time?
I have added considerably to the list of lenses (#110) and introduced a section on the pre serial number lenses of both “Lerebours” and “Lerebours et Secretan”. I appear never to have removed the first, earlier, list and I have sometimes (actually quite often!) added lens details there instead of at post #110. This is remedied.
I am now the owner of a non-serial number Lerebours et Secretan from just before 1845.
There are differences from the later versions. This is the smallest Petzval made at the time for the simple cameras 1/4 plate which L &S produced.
The differences are:-
Brass engraving goes along the barrel, rather than across. There are some other (more splendid) examples on page 10 of this thread.
Front achromat is “sealed in” through being turned in a lathe.
Edge of lenses almost devoid of marks and without the rice scratches.
Matching marks for gear cover and sleeve are pricks in the brass, rather than digits or Roman numbers.
Note the problem the engraver had with “Paris”.
Got round to and managed to re register for the forum after about 18 year absence. I have a serial number of a new arrival No.3173 landscape lens, provisionally 360mm with fixed barrel but missing front plate and aperture assembly.
Attachment 241592
I'll double check for rice writing in the morning. Also No 6072 re sold on ebay over the weekend.
Regards
Sven
I was the purchaser of the 1/2 plate Petzval 8334 EBay last week. This was a general antiques/curios lister, who had done some homework and discovered the serial number scratchings on the lens. The scratchings looked a little different from others, so I did a small sample check of some others.
The lenses are 2113 (the earliest we know of with the lens serial number), 6431 (JFShew import) and 8334.
The 8334 is a far better marking than the earlier ones - perhaps using an improved Technology! But it also shows that there is variation in the position of the “scratcher”. Some mark the edge away from where they are standing, whilst others “write” the serial numbe on the lens edge nearest to them.
Nr 10717 sold 9 Dec 2023 for 220 USD:
https://www.ebay.co.uk/itm/115997875473
https://i.ebayimg.com/images/g/lscAA...Q~/s-l1600.jpg