Info wanted: Aldis Triplet 20in 5.6 W↑D

[thegreatcornholio]

Hi everyone,

I did some research in the net, but did not find any info about that lens. The label says Aldis Triplet W↑D 20in. 5.6. What I know is that W↑D is for War Department.
Does anyone know the year of production? This would be a good portrait lens for 8x10, has anyone experiences with that?

Thanks in advance, Max

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[Oren Grad]

Per Forum Guidelines, no valuation requests please.

[thegreatcornholio]

Anyone with some information?

[IanG]

The only information I can find is the lens was for Aerial photography, it seems the same lens was later sold as a Portrait lens for 10x8 presumably in a different barrel. It's listed in my 1921 BJP Almanac. If it's WWI I assume it's before the Air Ministry was set up which was early 1918, but of course it may be a much later version of the same lens,

Ian

[Steven Tribe]

I am sure Ian is correct. During the first world war, the airforce was still a part of the ground forces. They were called the Royal Flying Corps (RFC) and were mostly active with recon. and anti-Zeppelin actions. I can't imagine why they would have chosen this sort of lens, so a later use in the army/navy is possible. It may have been used like the well known camera/lens sets that were issued by the RAF for airfield/personnel use.

There is a specialist on line who is concerned with these UK military lenses, but I don't have information here.

[IanG]

Interestingly Aldis dropped this lens from their adverts in 1923, however a pre-WWI BJP 1910 Almanac shows them offering Photo-Surveying equipment so this maybe an important clue.

Also WD lenses carried their makers name, The Saleroom has a Dallmeyer 2B WD lens for sale with the engraving Iris added by TTH Feb 1919 so WWI military lenses are marked WD. There was a major problem with specialist optical glass during WWI as it was imported from Schott in Germany until the war began. A Triplet would be quite cheap easy to make and the coverage for the 20" f5.6 is given as 10x8 for the portrait version. The Royal Flying Corps were using photo surveying of battlefields in Frnace & Belgium etc.

Ian

[angusparker]

See here: http://www.allenrumme.com/lensdb/Portrait.html


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[Paul Ewins]

Quoted from the Vade Mecum:
"They (Aldis) did make some aerial survey lenses in 1917 for the RAF, like others finding the
glass available prevented the direct copying of the f4.8 20in AeroTessar type requested and making a triplet
type instead. The first compromise was in aperture, which was reduced to f5.6 owing to the non-availability of
larger glass slabs. Secondly, they used a triplet design, and claimed it fully equalled the German original.
Production was from early 1918. Later bigger glass slabs allowed the production of similar f4.0 20in and f6.0
36in lenses, the latter for 10x8in. These were long focus lenses used over narrow angles, and the curves are
very "shallow" and the corrections can be amazingly good as a result. (The Photographic Journal of R.P.S.,
04/1919, p122)"