Help with Super Topcor 5,6/120?

[Nelari]

I have a 90mm lens (Angulon) for my homemade 4x5 camera and thought a 120mm one would be a nice addition. So I bought the one in the title off Ebay.

It was clearly advertised as being mounted on a Horseman board. But, uninformed as I am, I didn't think this would be a problem.

Well, it is. First of all, the flash connector is on the board, not the (Seiko) shutter. There is a miniature cable coming from the shutter that leads to the connector - I really would not want to mess with it.

Second, I had this bright idea of just removing the lens (with the shutter, of course) from the Horseman board and transferring it to another homemade board of mine. I went as far as removing the rear element, which led to almost removing the front element (almost because it is still connected to the flash socket on the Horseman board).

Next, what fell out was a loose brass ring that was between the front and rear elements. No, I didn't lose it, but I didn't catch how the small opening on the ring was oriented, and this seems critical. I mean, when I put the parts back together, the lever for focusing didn't work anymore, and I think it did before.

So, would anyone have any advice on how to proceed? Should I just forget about the flash sync and do without it (which I wouldn't like)? Does the brass ring have something to do with the focusing lever?

[Havoc]

I'm not following.

Apart from the flash socket being on the lens board and wired to the shutter, this is a normal rear element-shutter-front element construction. So if you removed the rear element, then how can the front element be attached to the flash socket? I also can't see what this brass ring would be. You said it was between the front and rear element, but the only thing between the front and rear element is the whole shutter. Not just a ring. There can be brass shims under an element, but those are just very thin flat rings. And the whole shutter is fixed to the lens board with a retaining ring just like any other LF lens.

What I guess happened is that you took one of the elements apart. I do have a 90mm super topcor, and the rear element just unscrews from the shutter. But the front element is screwed so hard into the shutter that it comes apart when I whan to screw the front element out.

[Tom Monego]

This sounds like a lens from a 2 1/4 Horseman technical camera a 980 or similar, a small board. You built a camera, can you build an adapter board for the Horseman board and lens. If I remember from when I had a Horseman 980, this lens would cover 4x5 but just cover.

[Dan Fromm]

It could also be on a board for a 4x5 Horseman. 160 mm claimed coverage, though.

OP, if you want a not too expensive 120 mm +/- lens that covers 4x5, consider a 125/5.6 Fujinon-W.

[B.S.Kumar]

The Super Topcor 120mm f/5.6 lens has an image circle of 160mm, as marked on the bezel around the lens. If the flash sync port is on the board it means the lens is mounted on a Horseman 80mm lens board for Horseman 6x9 and 4x5 field cameras. The port isn't very easy to remove from the board, so unless you are willing to forego flash sync, it isn't very easy to remove the shutter from the board.

Adapters are available for other cameras - Toyo Field and View, Linhof Technika and Rittreck come to mind. If you're using a home made board, it is a simple matter to drill four holes in the corners and use screws to attach the Horseman board to your board. Or make your own adapter.

Kumar

[ic-racer]

That 120mm has the biggest image circle of the Horseman 6x9cm lenses and can be used with the 4x5in step-up back. I used mine on my 4x5 Horseman FA for a while, until I got a lens allowing movements. Depending on the lensboard and Seiko shutter, the lens cells may, or may not, be transferrable to any other Seiko shutter.

For example the lens cells on these two 75mm Topcors can't swap shutters. (Inside vs outside lettering).

[Nelari]

I'm not following.

Apart from the flash socket being on the lens board and wired to the shutter, this is a normal rear element-shutter-front element construction. So if you removed the rear element, then how can the front element be attached to the flash socket?

Sorry for the confusion. The front element is attached to the shutter, and both the shutter and the flash socket are attached to the Horseman board, and the flash socket is electrically connected to the shutter by means of a very short wire.

So both the flash socket and the front element are connected to the shutter, but they are not really attached to each other. I shall try to be more precise the next time I write about this.

I also can't see what this brass ring would be. You said it was between the front and rear element, but the only thing between the front and rear element is the whole shutter. Not just a ring. There can be brass shims under an element, but those are just very thin flat rings.

There is a circular hole in the shutter. The brass ring fits that hole. It is very thin and flat. I don't know what it is for, but it certainly was between the front and rear elements.

What I guess happened is that you took one of the elements apart. I do have a 90mm super topcor, and the rear element just unscrews from the shutter. But the front element is screwed so hard into the shutter that it comes apart when I whan to screw the front element out.

The front element is still screwed into the shutter - which explains the confusion I caused by referring to "front element" when I should have referred to the "front element that is, at this moment in time, screwed into the shutter".

[Oren Grad]

Sorry for the confusion. The front element is attached to the shutter, and both the shutter and the flash socket are attached to the Horseman board, and the flash socket is electrically connected to the shutter by means of a very short wire.

So both the flash socket and the front element are connected to the shutter, but they are not really attached to each other. I shall try to be more precise the next time I write about this.

There is a circular hole in the shutter. The brass ring fits that hole. It is very thin and flat. I don't know what it is for, but it certainly was between the front and rear elements.

The front element is still screwed into the shutter - which explains the confusion I caused by referring to "front element" when I should have referred to the "front element that is, at this moment in time, screwed into the shutter".

OK, so for precision, what you're talking about is the front cell, not the front element. "Element" refers to each of the individual pieces of glass - the simple lenses - that are mounted together in a cylindrical or conical barrel to give you a "cell"; the "cell" is what gets mounted in the shutter.

[Havoc]

OK, so for precision, what you're talking about is the front cell, not the front element. "Element" refers to each of the individual pieces of glass - the simple lenses - that are mounted together in a cylindrical or conical barrel to give you a "cell"; the "cell" is what gets mounted in the shutter.

Sorry, that is my mistake. Not a native english speaker.

[Nelari]

Sorry, that is my mistake. Not a native english speaker.

I did forum searches with combinations of front/rear and element/cell:

"front element" 83 pages (of hits)
"front cell" 30 pages
"rear element" 77 pages
"rear cell" 32 pages

Interesting. But, getting back to the subject in the title: continuing to peer at the Super Topcor, I finally became aware of a small screw on the shutter. It really looks like the gap on the thin flat brass ring that I have mentioned is meant for that screw. Then, there is a tiny hole on the Horseman board that, if positioned just right, will allow you to work the screw.

All three – screw, gap, and hole – are now aligned. But the lever for focusing just won't budge.