filters on a threadless lens? Gundlach Radar

[Daniel_Buck]

Hello! I have a Gundlach 12" Radar 8x10 that I just had CLA done on the Betax #5 shutter, and have it mounted on a board. I'm curious about using filters on this lens, since I shoot a relatively fast film (Tri-X 320) and the fastest shutterspeed on the shutter is 1/50th. I like the quality of blur that I see in out of focus areas in the image, so I'm planning on using this lens at f4.5 quite a bit on my 8x10. I'm guessing that I'm going to need an ND filter for times that there is just to much light. How would I go about doing that for a lens with no threads?

There are threads on the rear element, my 77mm filter is just slightly to small, so I assume the rear threads might be 78mm? I don't think I've ever seen filters in that size before.

Anyway, what's the best/easiest way do have an ND (or even a color filter) on a lens like this? The front element is roughly 80mm wide. If I had a square gel filter, I suppose I could just tape it (or hold it) up to the lens, I don't think I'd like to always do this though.

Any thoughts?



And on a side note, anyone know anything about this lens? Gundlach 12" Radar 8x10 I can take a few pictures of it if that would help anyone remember anything about the lens, like when they were manufactured? Just curious really :-)

[lenser]

Hi, Daniel.

Calumet has a gel filter holder (Xenophon) that can be mounted in front or behind the lens. It mounts to the board and should be the solution you need. There is also a clip on (spring mounted) holder with built in barn doors. It holds 3" gels. ND filters are available in gel form.

Cokin also has a mount that attaches by means of adjustable screws and their standard filter holder slides onto that. Then use whatever of their filters you want including polarizer, colored, ND, etc. This one is made for oversize diameter lenses or those without threads. I use mine for several different large format lenses.

Good luck.

Tim

[John Schneider]

S. K. Grimes makes a ring for just this purpose that is held in place by the friction of an o-ring:
http://www.skgrimes.com/slipon/index.htm

[Daniel_Buck]

looks like this might do the trick!

http://www.calumetphoto.com/item/LE5002/

I don't quite see how the SK grimes ring works? I mean, I don't understand how it stays attached to the lens? Maybe I should read it over again later :-)

[wfwhitaker]

...And on a side note, anyone know anything about this lens? Gundlach 12" Radar 8x10 I can take a few pictures of it if that would help anyone remember anything about the lens, like when they were manufactured? Just curious really :-)

You can look at a Gundlach catalog at cameraeccentric.com. Info on the Radar is here and here.

[Daniel_Buck]

Thanks Will! Yes, I found those two pages in my searching. Any idea when the lens was manufactured? Or what most people used it for? It's got plenty of coverage at infinity on 8x10, I plan on using it for closer up things though, and possibly portraits. Just curious, because my searching didn't bring up very many accounts of this lens.

[wfwhitaker]

Any idea when the lens was manufactured? Or what most people used it for?

My guess is that it's from the twenties. But I have little more information to go on than the Gundlach catalog pages. It was probably intended as a general purpose lens or a "commercial" lens, one which was flattering for portraits wide open, but reasonably sharp stopped down for commercial work. It was a studio lens. Its weight will tell you that much. Don't drop it on your foot!

The Lens Vademecum offers little about it, but does suggest that it's "essentially a Q15, but with a three-glass rear component." Q15 refers to the lens design diagram and is notably that of the Tessar. The implication, then, is that the Radar is basically a Tessar design. The three element rear cell may have been to avoid patent infringement. This last bit is speculation on my part, but this seems to be a fairly common modus operandi throughout the history of lens design. I have this same lens, also in a Betax. I've not yet had a chance to use it, but I look forward to doing so.

[Atul Mohidekar]

This is may be another option for threadless lenses - Cokin "P" Series Universal Adapter

http://www.bhphotovideo.com/c/produc...l_Adapter.html


// Atul

[Daniel_Buck]

Thanks Will! I was guessing 1930's just from the look of it. I'm always curious about when things were manufactured, don't know why :-)

Atul, that looks perfect! I think I'll pick one of them up and see how it fits! It looks like it will just barely fit!

[mikec]

no one mentioned the lee gel snap which is available in 4x4. I was thinking about getting one for the same purpose. any reason not to?