grandaddy of dagors

[robert_4927]

A 30" Dagor just went up for auction on the famous auction site. I have never seen one of these . I thought they were just a myth. Now talk about coverage...Wow!

[Walt Calahan]

So you don't have to do a search:

http://cgi.ebay.com/HUGE-30-inch-Goerz-Dagor-Massive-coverage_W0QQitemZ7572938791QQcategoryZ30076QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Terence McDonagh]

I love the lens board that appears to be more of a lens plank than a lens board.

Alas, I would have LOVED to have seen Dagor77's ad for this had it been his. "There I was, deep in the primordial forest when I came upon a team of sherpas carrying the lens in a ceremonial sedan chair and a contingent of gurkhas defending it . . . "

[medform-norm]

Terence,
are you his ghostwriter, by any chance?
I see you do the job as well as Dagor77 himself would have done. Please continue. I wanna know what happens with the ghurkas.

[tim atherton]

"I love the lens board that appears to be more of a lens plank than a lens board. "

that's great - it looks like it was once mounted in the side of a Man O' War

[John_4185]

What is to keep us from grinding our own lenses to copy the Dagor in question? ..besides, possibly, knowing the lens material forumula.

(Hey, it's a stupid question but I'm stupid!)

[robert_4927]

I'm curious to see what it sells for. It will probably require a second mortgage.

[John Z.]

I bought a large huge and heavy Zeiss 750mm lens once, mounted in a shutter--I think it weighed in at about 10 pounds total. The problem with large heavy lenses like this is that you never use them. I would always leave the lens behind, because it made my gear seem so much more heavy, and eventually realized that a lens that you don't use has no value. I ended up selling it for something more compact.

[Ole Tjugen]

jj,
The lens formula for the Dagor is well known. And the materials.

What's stopping us is the sheer immensity of the task: A Dagor consists of two groups, each containing three lens elements.

Each of those three elements must be ground and polished on both sides to very narrow tolerances, and some of the surfaces can't be done efficiently on machines (they must be made "one to a block").

Then one element must be centered and adjusted to another before cementing. Then the third element gets put in place (even more carefully), and only then can you grind the eges to the final size.

And next you'll have to match a front group to a rear group, adjust the centering and spacing, and mount them in a barrel.

This may seem complicated, but it's really a lot more difficult than it seems!

[Richard Ide]

This thread made me weigh my 1200mm Apo Tessar. At 21 lbs I won't be taking it out into the field very often. Apart from that it made a great enlarging lens.

Richard