View Full Version : Lens Identification Help Please

4-Oct-2013, 13:04
Hello everyone.

I could really use some help identifying a lens I found in my grandfather's store room. He had it wrapped up with a bunch of other stuff from the 1930's era. I don't know much about it and a friend recommended me to ask on this forum. I have taken some pictures of it and attached them below. I think it is a Ross but again I know nothing about these and could really use the advice. Here are the specific markings:

A M (with Crown Logo)

REF. No 14A/2320

20 IN F. 6.3

Serial No 154156

Made in England

F. , 6.3, 8, 11, 16, 22, 32

Any help at all would be appreciated.

Thank you.



Struan Gray
4-Oct-2013, 13:32
It is a British aerial photography lens, almost certainly from one of the Williamson aerial cameras. 20 inches focal length (500 mm), telephoto design, big and heavy. Not worth much, but worth enough that you can usually sell them and get the buyer to pay for shipping.

4-Oct-2013, 13:37
Thanks for the information Straun! Any idea where I could get more information?

Struan Gray
4-Oct-2013, 13:50
There are quite a few old recon squadrons with web pages about the Williamson cameras, so Google them first. There are also a couple of Wikipedia entries.

The lens collectors vade-mecum has some information about these cameras and lenses. It's available cheaply as a pdf.

There is a fair bit of info on this site about Air Ministry lenses in general (the A and M). They were made under contract by several optics companies, even if the design came from one of the more famous ones like Ross. If you can find a serial number, the first two letters are a code as to which optics house made the lens you have.

These lenses used to be popular post-war for 'Big Bertha' sports and photojournalism photography where you simply couldn't get close. They can be jury-rigged in front of almost any camera if you are handy, but they will need a shutter. It was common to use them with a focal-plane shutter like the ones found in Speed Graphic cameras, but they also work with things like the Sinar behind-the-lens shutter.

At least one member here has built a custom camera around the 36" big brother of your lens. Again, Google is your friend.

Steven Tribe
4-Oct-2013, 13:54
Lens Vade Mecum.
This is a Dallmeyer lens, I think.
Quite early in the use of these.
Described as:

"Telephoto f6.3 20in Probably often these are Dallon related, for 5x5in"

Dallon is the civil version.
AM means Air Ministry. The 14a is the War ministry's code for the RAF. The 4 digit number is the contract number - it is said that this numbering was used in RAF Station Stores system.

Sold for use in bird watching and sports photography after the war.
Often have identifying codes like VV and WW. Some were made by Dallmeyer - others at various shed factories (Luftwaffe!) with dubious quality control.

4-Oct-2013, 14:01
Wow! Thanks Straun and Steven. You guys are awesome.

Thank you so much for the information and for posting it so quickly!

I am very grateful and appreciate it!


4-Oct-2013, 17:54
I picked up a 14 inch f 5.6 AM Dallmeyer recently and have added a Packard shutter. Hope I don't run out of rail once I get baby mounted. I am expecting low contrast as aerial lenses are normally designed for fine resolution rather than crispness. Or so I was told years ago. Perhaps it is time to invade the digital camera safari folk with heavy weight glass.

Dan Fromm
4-Oct-2013, 19:26
Lens Vade Mecum.
The 14a is the War ministry's code for the RAF.

Are you sure? I ask because I always thought that 14a meant photographic equipment. I could be mistaken.

Steven Tribe
4-Oct-2013, 22:27
Could be - or perhaps for photo equipment to be mounted on planes. Now you mention it, I seem to recall that the code for an english field camera set issued for the boys in blue to take group photos at airfields had another code.

5-Oct-2013, 01:16
I picked up a similar coated 17" f5.6 telephoto at a flea market 2 months ago, so it's post WWII but no makers name and no aperture markings but it does stop down fully. The only identification is on the Lens cap - WIS. 8117 REF.3 17" f/5.6 it has an aluminium storage tube with the same ref (without the Fl & aperture).

Mine should fit a normal Speed Graphic, unfortunately my SG is a customised wide angle camera and has less extension.


5-Oct-2013, 06:44
LOSLOB, a few small tell-tale signs and other information indicate your lens was most likely made by Ross not Dallmeyer. In fact it's probably a special order 20" f6.3 Teleros

Dallmeyer's equivalent 20" lens is an f5.6 whereas Ross made two series - f5.5 and f6.3 Teleros lenses. The engravings also match this, Dallmeyer mark their Focal lengths as 17" & 20" etc and their speed as F/5.6 (before & after WWII), Ross on the other hand mark the FL as 17in, 20in and there's a small line under the "in", also under the o of the "No" by the serial number.

My own lens is a 17" Series VI f5.6 Dallon and looks lke other large Dallons.


5-Oct-2013, 10:54
Thanks to everyone who has contributed to identifying this lens for me.

@ IanG: Most of the research I have been conducting has led me to agree with you. I think it is a Ross as well. Thank you.