View Full Version : Turner Reich 12/21/28" triple: extension!

16-Jan-2008, 21:34
I picked up this lens several months ago for my 8x10 project camera, which is still a project rather than a usable camera (though it's pretty damned close now).


I finally got around to cleaning it up and mounting it on a lens board (thanks to a flange I finally got my hands on). The glass on this thing is beautiful! Almost totally clean! I thought it was somewhat yellowed and marked but there are only a couple of very tiny scratches and spots; almost like-new.



This matte paint is prone to fingernail scratches, but that's of little consequence.

What a sexy lens:


I can't wait to get some film and try it (could shoot as-is, believe it or not the bellows only have a few tiny pinholes which won't matter for wider aperture exposures).

But I wasn't just going to brag about how nicely this lens cleaned up and show off my lens board, which as a non-woodworker I'm actually kind of proud of - I have a question about it (and other convertibles). It seemed I needed way more bellows extension than I would have anticipated for the 21" component. I couldn't even use the 28" component. I guess this is partly because the lens is mounted on the back of the shutter; but is there some other feature to the design of these that puts the nodal point way back from them? Are the single elements like a retrofocus lens?

I also recently got my hands on a 150/265 symmar convertible for 4x5 and the 265 configuration requires about 310mm of bellows for infinity focus. Surprised the hell out of me.

What's the deal here?

Ole Tjugen
16-Jan-2008, 23:27
You got it in one - single elements of convertibles have the nodal point way out on the other side of the aperture from where the glass is sitting. It's the same with single-cell landscape lenses.

So in case of emergency (bellows too short), mount the single cell on the front of the shutter instead. Less bellows needed, but you may be able to see why it's always recommended to have the single cell behind! :)

16-Jan-2008, 23:44
So in case of emergency (bellows too short), mount the single cell on the front of the shutter instead. Less bellows needed, but you may be able to see why it's always recommended to have the single cell behind! :)

Now I'm curious. Will have to try it out.

Gene McCluney
17-Jan-2008, 00:47
The camera depicted in your photos should have a rear extension rail, which when mounted, would give you more length. If you still don't have enough bellows draw to focus the lens, you could make a top-hat lensboard that protrudes out in front of the camera for a few inches. I did this for one lens I have. Went to a hobby shop, Hobby Lobby and purchased a small wooden box, and glued that (without the lid) to a flat lensboard, and drilled a hole for the lens in the end of the box.

17-Jan-2008, 00:50
Yeah, I meant with the extension rail which gives about 30" total extension. Of course it's fine for even up to close work with both elements (12" configuration).

Thanks for the suggestion for the pre-fab'd box. I hadn't thought of that and figured I'd not want to mess with even simple joinery at the moment.

17-Jan-2008, 23:43
I've got a 12/21/28 too! Generally speaking, the use of the 28" element on pretty much any camera is limited to landscape work when you're trying to isolate particular elements. I can really only think of 2 cameras made that will meaningfully focus closer than infinity, a Canham and a Lotus, both offering about 36" of extension. Everybody else clocks in at about 30", give or take an inch or two, which is not enough to bring the focus very close at all.

The idea is basically the same as a long lens on a 35mm camera: they're not for close-ups, but for isolating and compressing.