Help ID'ing Gundlach Optical Co. Lens

[ArchersTest]

When my grandfather passed he left quite a lot of LF gear with us. Due to having rather severe Alzheimers I never had the chance to ask him about most of it while we were storing it at our house. We recently unpacked some boxes that we hadn't touched in a while. This lens and a few cameras were in there.

For the past two years I have been learning how to shoot 4x5 on his old Speed Graphic and have been having an awesome time. But in coming across this lens I am curious if I might be able to adapt it for use on the Speed Graphic.

Ok so on to the lens in question. There are no name badges on it other than the stamped identification on the lens barrels that read "GUNDLACH OPTICAL CO." on the top line and "5x7SYM" on the second. It was mounted to what I believe is a Korona Long-Focus Series VI camera. The camera itself is in rough shape and in need of some bellows repair and some replaced woodwork that has split in storage. Attached are photos of the lens. I would like to know as much as I can about it as far as design and specifications and also how to best go about cleaning the glass and not damage it in the process.

Thank you for all your help in advance.

Duncan

 

[E. von Hoegh]

It's likely a Rapid Rectilinear of around 8" focal length, as such it will cover 4x5 with room to spare... if the shutter works. You'll need to mount it on a lensboard for the Speeder.

 

[Barry S]

It looks like you have a rapid rectilinear lens that covers 5x7. It should be fine to use on your Speed Graphic. You can unscrew the front and rear cells and clean the surfaces with some lens cleaning fluid and lens tissue.

 

[ArchersTest]

Any idea where I could find specific info as far as min focus distance or how much bellows I need to get to infinity? Judging from what it was mounted to originally the speed will have nowhere near enough extension to make use of it.

 

[Barry S]

If it's an 8" lens, you'd need 8" of distance between the aperture and the film plane to focus at infinity and 16" to get to 1:1. The Speed should give you about 13" of extension, so it should be fine.