Dallmeyer A.M. 14in 356mm f4 with handmade brass M42 adapter

[Dan Dozer]

Dan - When you get back from your trip, would you be able to take the equivalent photos of your lens (aperture ring, iris diaphragm wide open, and iris diaphragm fully stopped down)? With these three data points, this would let us make a good comparison of the differences between the Air Ministry and civilian versions.

Also, perhaps it is just me, but the aperture lever on your lens almost looks a little "homemade"? It looks quite thin & flimsy in comparison to the massive ruggedness of the lens... I also notice that your aperture ring has grooves machined into it, which would seem to indicate that it was intended to be grabbed by the hand... while my Air Ministry lens has a smooth ring, perhaps to save costs because it was coupled via that block and not operated directly? It also looks as though your aperture ring is flat on the top, whereas mine is somewhat "dished"...[/QUOTE]

Let me see what I can do about getting some photos of it. The aperature lever on my lens does look flimsy and in fact it is. I'm sure that it is factory made, but it clearly isn't strong enough for the size of this lens and it has been bent more times than once in it's past history.

[Scheimpflug]

That's the one I mentioned earlier, the 36".

It's a telephoto, ic of around 20" - 22" at infinity-
(I haven't measured properly yet-)
ff distance is around 50cm at infinity-

It covers 20x24 at around 0.8x magnification, so I'm tempted to try some portraits at some point...

My one doesn't have that tab, or any holes to mount it-
must have been used in a different camera...

It may be a bit hard to see when it isn't in your hands, but the tab/block isn't actually bolted through the aperture ring - it just has two parts which clamp on to it from the sides. The two screws are actually outside the ring.



Now that I think about it, I wonder if this block is the reason for the "dished" shape of the ring? If so, it might explain why Dan Dozer's civilian lens has a simpler "flat" ring. Otherwise, I would have expected the civilian version to be "fancier" than the military version.

Mine has the large arrow.
The flange is part of the barrel, it looks just like the ebay one.(except it doesn't say Dallmeyer) It also has a thread about 75mm, or 3 inches. Looking at yours again, it looks like perhaps your flange was machined off,(the bright metal ring on the barrel).
Here's a link to Jim's ad that I bought from, with the picture, (he may be having sellers remorse)
http://www.largeformatphotography.in...ad.php?t=63149

Interesting! I hadn't known that these had the flange built-in, and I was wondering why mine had the one polished part but everything else painted!

So if that is the case, what was the purpose for the rear threads?

[sun of sand]

The ones that don't stop down all the way can of course be machined out easily
if youre looking to use the lens
you get to f45 before the blades really tighten and tweak
replacing the blades after the mod is easy with the barrel being so large
could probably do the whole job in 25 minutes
mine needed the old grease changed as well with the aperture ring being very sticky

the threads on mine fit but perhaps not perfectly the flange for my 10.75in Celor

[Scheimpflug]

The ones that don't stop down all the way can of course be machined out easily
if youre looking to use the lens
you get to f45 before the blades really tighten and tweak
replacing the blades after the mod is easy with the barrel being so large
could probably do the whole job in 25 minutes
mine needed the old grease changed as well with the aperture ring being very sticky

the threads on mine fit but perhaps not perfectly the flange for my 10.75in Celor

Thanks for the tip! Do you have any suggestions or how-to guides for disassembling these lenses? Would I be best to start at the front or the back?

Even if I wasn't going to modify it, it would be interesting to open it up anyway, just to see if it has been modified in the past.

[Steven Tribe]

They were all made during wartime and Dallmeyer and others sub-contracted the manufacture to other establishmnets. If there is no Dallmeyer, JHD or VV - then someone else made it. The 36" is commonly termed "Big Bertha" and has trouble with colour correction. There were many surplus to requirements after 1945 - so were a special offer up to around 1950. They were typically adapted to be used for sport's photography - Cricket in the UK and New Zealand.

[Scheimpflug]

If there is no Dallmeyer, JHD or VV - then someone else made it.

"UU" as well.

They were typically adapted to be used for sport's photography - Cricket in the UK and New Zealand.

Hadn't heard that before! Do you have any more information about this usage? Was it amateur photographers / hobbyists who did this, or professionals? Do you know how they were typically adapted, or what camera formats were used?

Thanks.

[Steven Tribe]

Once again, Vade Mecum has a write-up! Production of the AM 14a wartime lenses was at a high level due to expanding no. of aircraft and plane losses! The market "collapsed" in 1945 and the unused and undamaged lenses were on offer up to around 1950. I think the UK producers were very unhappy about the further sale which reduced the demand for "new" lenses. I think the sports modification were generally professional whilst the bird watchers version was more likely to be home-made.

I seem to remember that UU (also on Dallmeyer designs) was an abreviation for manufacture at National Optical - a wartime assembly plant set up by T,T & H.

[sun of sand]

Thanks for the tip! Do you have any suggestions or how-to guides for disassembling these lenses? Would I be best to start at the front or the back?

Even if I wasn't going to modify it, it would be interesting to open it up anyway, just to see if it has been modified in the past.

the front element group on mine was tough to unxscrew -as they've been on others- but I eventually got it using a thick rubberband for extra grip
The elements all screw into place so it's an easy take apart/put together
just do it

My lens had a moderate amount of haze which cleared up completely


I don't have that thicker aperture handle thingy, though. I don't think that would complicate anything

I've never installed aperture blades before so I'm glad this lens was my first
very easy to do

if you want to modify it get a dremel/cutting disk
it doesn't change anything cosmetically
youll just be able to close down to f45

[Dan Dozer]

Sorry, it's taken a while for me to get photos of my Dallmeyer Serrac. Hope these show a little more on what the "user" lens has that may be different from the AM lens.

First two photos show lens at wide open at F4.5 and closed down at F11. Note that when I originally got the lens, the iris was stuck. I took it apart and fixed it and noted that if I wanted to enlarge the groove to allow the iris to close down more, it wouldn't have been difficult.

Third photo shows the apperature ring. It's somewhat hard to read because mine isn't as cosmetically nice looking as yours (it seems to have had a much harder life). Noted F-stops are F 4.5, 6, 8, and 11.

Fourth photo shows the lever that is screwed to the aperature ring that you can use to open/close the iris. It appears to be factory made, however, it clearly wasn't made strong enough as it has been bent a few times in it's past life.

I'm real curious that if this lens was intended for the general public rather than aerial cameras, why would they only make it to go down to F11?

[Richard Kaye]

I just got a very similar item from ebay. Mine is an AM 14" lens. Front and rear cells are both about 65mm in diameter. Total weight about 1.2kg. Rear cell unscrews easily and is obviously a doublet (no air space). Front cell is an air spaced pair, so I conclude it's tessar-style. Mine has the same A.M. code and a UU number, and is also stamped JHD10 so I am pretty sure its Dallmeyer. It's uncoated and in great condition. F stops 5.6,8,11 and 16 only.

I just discovered that it mounts on my sinar really really easily. The hole size required is exactly the size of the hole in a "top hat" panel when the central extension is removed, and the real element protrudes through the board just enough to get close to but not foul the old sinar copal shutter I have. (And the 65mm diameter is perfect for this too with no vignetting.) So I am happy - even if it is not the greatest lens in the world it will give me a new "look" to play with. Testing this weekend.