View Full Version : Air Ministry Lenses and Dallmeyer

sun of sand
4-Mar-2010, 08:14
I just noticed this so I have to hurry up

I picked up this UU 14in f/5.6 in bad cosmetic shape only cause it went for nothing
Dallmeyer Serrac from what I've read on these forums and elsewhere

It is a tessar like the Serrac
It is not f4.5 like the Serrac
The iris is not "held back" wide open in any way
This lens only travels to f16

Others "AM 14A/3140" only travel to f11 and maybe some to f32
Official Dallmeyer Serracs travel/are marked to f32

This auction has an AM 14A/827
Branded as both Dallmeyer Serrac as well as Air Ministry with the crown compared to simple AM arrow symbol
Only marked to F11

my question is
What's up with all these variations on supposedly the same lens?
were some used as enlarging lenses on 9x9 film or something
9x12 film ever used in aerial imaging? 355mm is kinda long I'd think for 9x9 enlarging

My lens cleaned up very well btw
It has the most advanced tarnish/bloom of any uncoated lens I've seen front and rear element
Haze cleared right up
only few very minor scratches/cleaning marks

I sprayed it black w/ shellac and then buffed it
Machined the iris to close down all the way
my first reinstall of 20 aperture blades was easy simple ..large diameter barrel, though.
pretty decent for $20 lol

Dan Fromm
4-Mar-2010, 09:44
If UU 429465 fits the normal Dallmeyer s/n sequence, it was made in the early '50s. Big if. Similarly, 231497 was made between '33 and '36.

FWIW, the MoD contract numbers you quoted decode like this:

AM = Air Ministry
14A = photographic equipment
3140 and 827 are contract numbers. They support my belief that 231497 is much the older lens.

What are you going to use for a shutter?

sun of sand
4-Mar-2010, 19:22
The lens is much too large for my 4x5 tachihara so may be put on a box camera sometime in the future for fun
Shutter is a Kangol or peanut butter lid

Did Dallmeyer even build this lens -my lens? Is it a Serrac ..an f/5.6 Serrac
I think someone -you or someone else- mentioned it could have been built by Ross or someone else for Dallmeyer
It seems strange to me that so many variations in aperture of the same lens? would be made
f5.6 marked to f16 but closes down fully, f5.6 marked to f32, f5.6 only to F16, f5.6 but only f11, f4.5 but only f11, f4.5 to f32
Why would you keep a lens from stopping down? I don't understand limiting an f4.5 to 5.6 much either

Seems the same lens was being used 5 different ways or a couple ways throughout the decades with ..
seems strange to me

The bloom is nice, though. The other AM Serrac listed looks to have an equally nice tarnish

Ernest Purdum
5-Mar-2010, 09:20
My understanding is that these AM lenses were made by whoever had the production capacity at the time. (And probably the low bid in some cases.)

9X9 inches is an aerial camera size and 14" would be a useful focal length for the format. A 14" Tessar would more than cover.

The diaphragm is restricted on some aerial camera lenses so that it won't be accidentally set so that vibration would ruin the image even if the exposure was adequate. Aerial photographers are frequently wearing heavy gloves and need all the help they can get regarding settings.

sun of sand
5-Mar-2010, 17:12
my bad


mine is 429465

Those seem very close for an outside company ross or wray etc to have built mine
Don't know how the codes are broken down whether literally 5 lenses earlier or 5 weeks earlier etc but seems very close for separate companies to be keeping No's in check
but I don't know about that stuff

That one seems coated while mine is tarnished
I'll attach a picture of the bloom lol


I shouldn't have missed that thread

then this early AM Dallmeyer lens

seemingly the serracs and anastigmats were in existence together during roughly the same time periods ..early and late
You have AM serracs and AM anastigmats
Serracs and Anastigmats with roughly the same production #s
all different kinds of apertures

Makes sense some uses would require easier setting of the lens
but so many variations

Dan Fromm
5-Mar-2010, 17:43
According to the VM, "Dallmeyer WW2 lenses can turn up with 'JHD' stamped on them in white paint but no other makers name and the serial numbers are often begun with UU or VV if original Dallmeyer." Dallmeyer made your UU 429465.

The Ministry of Defense had other companies make Dallmeyer designs (the 14"/5.6 and 8"/2.9 Pentac and the 36"/6.3 tele) under contract. Same prescription and mechanical design, different factory. USAF did the same with, e.g., Metrogons.

To add to the fun, MoD also bought 14"/5.6 TTH Anastigmats that are in fact Aviars. The ones that TTH made have serial numbers that begin with TT. That lens at m-camera could well be one.

Dallmeyer and, AFAIK, all of the other major UK lens manufacturers assigned serial numbers in sequence.

Don't get hung up on trade names. Dallmeyer made tessar types at different speeds, each speed seems to have had its own trade name. f/3.5 tessar, Dalmac; f/4.5, Serrac and Dalrac (slightly different prescription); f/6.3, Perfac. All tessars are anastigmats and anastigmat is another trade name. Many many lens makers used it.

Now stop torturing yourself about just which dog you bought, also about dogs in general, and tell us how you're going to use your little bow-wow of nothing at all. I don't want to know what you intend to shoot, would like to know what you're going to use for a shutter. Hat or jar lid really won't do with ISO 100 in broad daylight. Especially since the lens won't stop down very far.

Steve Hamley
5-Mar-2010, 18:19
Well, if you think the lens is worth the money for a trip to S.K. Grimes, wonderful things can be done. 36cm Heliars never came in a shutter AFAIK, but attached is a picture of mine in Compound #5 after the trip. I think most 360mm/14" f:4.5 tessar-types will fit into a Compound #5 and reach full aperture as my Heliar does.

So using a 2-stop polarizer (set to 0 polarization if you don't want polarization) at 1/25th second is equal to shooting 100 speed film at "sunny f:16". It's an elegant but expensive solution. Certainly the 14" f:5.6 would fit in an Ilex #5, or possibly even a Compound #4.

FWIW, my 14" f:5.6 Dallmeyer referenced in the link above has a considerably smaller rear cell than front, where the f:4.5 lenses seem the same fore and aft, as does a 14" f:6.3 Commercial Ektar. I've wondered why the rear cell is smaller.

Cheers, Steve

sun of sand
5-Mar-2010, 20:27
I'm not saying the lens is a major find
I don't care if I have a "Dallmeyer" lens or not lol
I was just interested in the history
It was nearly free and with it cleaning up so well I'm already pleased with the lens regardless if I ever use it or not

If I were to use it one day on a larger camera/box I can use any film I choose
I machined/dremeled out the barrel ..easy job
It closes down to about f40 maybe the full f45 ..f32 feels safer as the blades begin to pop
I have 4 and 6 stop wratten density filters I use with a 275 Celor to make it usable at f5

I did forget about the Heliar possibility
I'll have to look up those AM heliars to see if the barrel styling is the same etc
the anastigmat labeled lenses look to have a closer in appearance barrel/aperture ring design than the serrac labeled ones

my front back cells are equal
about 63.5mm in element diameter
no beauty plate on the back so the front of barrel is larger
the flange on my celor is a close enough fit for the "serrac" to be usable I just found out

thanks for the help, man

Dan Fromm
6-Mar-2010, 04:35
My, we all speak loosely. Dallmeyer patented the Pentac. It is in the same design family as Voiglaender's patented Heliar but isn't a Heliar. Or a Dynar, for that matter. It is a Pentac, and at f/2.9 a bit faster than Voigtlaender's own.

For all I know MoD bought lenses from Voigtlaender before the war started and after it ended, but while the hostilities were on there was very little trade between the UK and Germany.

The MoD lenses that turn up with fair frequency tend not to be great prizes. Eric Beltrando's calculations (visit www.dioptrique.info) suggest that the Pentac just isn't a great lens.

sun of sand
6-Mar-2010, 10:22
I've always equated aviars with heliar
Perhaps one day after having bought either I'll make the distinction
Till then I don't care and probably wont care enough even then lol

One of those links was probably an Aviar.

How did Pentac get into the discussion? I know I don't have a F2.9 Pentac whether it's a heliar design or not
That seems loose as well
Cannot fault you for trying to straighten something out but really what is knowing the Pentac more intimately going to do for me?
calling a lens a dog is loose
I cant even navigate Dioptrique to find whatever you're showing me but him saying they aren't great lenses doesn't mean anything to me, either
Yeah, probably not the most perfect lens or best quality control with em rushing out the door as fast as possible but many of the lenses used here aren't
and that doesn't matter

and hell no I don't think a too big for me tessar is worth S.K. Grimes lol
I'm good with my L.C. Grimy

Dan Fromm
6-Mar-2010, 13:19
Well, you wrote "heliar." That's how the Pentac came in. The Aviar is in the dialyte family. Not at all like a tessar or a heliar. Another cult lens, though, whose virtues I've never seen. But then, I'm an ignorant barbarian.

About dogs, I don't have one in any fight. I do, though, have a fair number of Tessars (some made by Zeiss, others by B&L, even one Krauss) and tessar types, use some of 'em. At the moment one of my 85/6.3 B&L's is at Grimes having its little Compound overhauled.

About Eric, he says nothing on his site about whether a lens or good or bad. He just does ray-tracing calculations based on the prescriptions as published in patents or, in the case of some Boyer lenses, from the company's archives. The curves speak for themselves. The closest he comes to expressing an opinion is in his assessments of coverage, which are consistently smaller than manufacturers' claims.

About using good, bad, or indifferent lenses. Wide angle lenses possibly excepted, for most purposes a so-so lens is better than good enough. This is, though, no reason to choose lenses likely to be worse than so-so. To get back to Pentacs, someone, probably J. G. Motamedi, has reported finding most of a moderate-sized sample of wartime 8"/2.9 Pentacs unusable. And Eric's calculated curves for EKCo's heliar types are consistent with how the two I've had shot; not that sharp and not as much coverage as expected.

sun of sand
6-Mar-2010, 15:17
I did write heliar and I guess that was a mistake but you should have corrected the heliar/aviar not tell me about the pentac
Pentac has nothing to do with nothin
cant be mad with someone for what amounts to an education but
thats loose

For whatever reason I still equate Aviar with Heliar
probably not for the actual design but for a similar "signature look"

I don't know what a ray tracing is but it sounds boring
Curves? uh no

I saw a chart with "fast" lenses ..and most of em were only mediocre/crap in performance wide open
still good enough for many people to use em

Stopped down I expect tessars -most all lenses- to be pretty good no matter who built it
This 355mm is a chunk, though. I didn't expect it to be quite so large but with how well the glass has now cleaned up I consider it a fine purchase and really even if it had stayed a mess I still would have been ok with it

It was Motamedi

I have a sironar-N 150, grandagon 90 4.5, cooke 158mm, 275 celor that I like
It's not about buying cheap hoping to find a diamond
I have lenses already
I thought a 355 would be interesting to check out
210 to 275 was a big jump and the 355 is a nice jump, too
only it's clear that I'll have to buy a telephoto design
that's OK as I'll be able to go even longer and get something even more suitable
osaka 400mm or something

and I suspect anyone even using the word barbarian to be one themselves
Not in my vocabulary
just doesn't mean anything
to me

Dan Fromm
6-Mar-2010, 17:23
Friend, most people are barbarians by definition. Everyone who is not a native speaker of Greek is a barbarian. I'm a birthright barbarian and proud of it.

Re y'r whateverac, how could you possibly go wrong for $20?