PDA

View Full Version : Can I trouble you for some lens info about this lens?



Sid Ceaser
14-Sep-2015, 13:30
Hi all,

I've been looking for a brass lens that I could use on my Toyo 4x5 field camera. Finally by chance last weekend I came across this little brass jewel at a flea market surrounded by much larger brass lenses:

139613

On the lens it says:

Heliograph
4x5
Geneva Optical Co.
Chicago

On the bottom brass part with the mounting holes it says "Made in France"

It came with a home-made waterhouse stop, but the seller wasn't sure what the aperture was for the plate, or for the lens wide open. The front element unscrews/removes.

I did a little Googling and it looks like it's a Rapid Rectilinear lens, but aside from that, I have no other information.

I took the lens mount off my Toyo, and removed the lens that was attached to it, and this lens seems a tiny bit larger so it won't fit in the hole.

I did some measurements:

40.8mm back end circumference (where the mounts are)
44.5mm front circumference
51.8mm in length.

Does anyone know if this will work with 4x5? Does the 4x5 designation on the lens indicate it's for use with that size camera?

I'm not very educated when it comes to old brass lenses, but I hadn't seen one this small before, so I grabbed it.

Could anyone ballpark me as to what size of a lens mounting board I would need? Any algorithms I can do to estimate what the aperture is wide open? Any good sources for push-on caps for the front?

Thanks everyone. I hope you don't mind my questions.

Mark Sawyer
15-Sep-2015, 10:53
To determine focal length, point the lens out a window and focus an image of a distant object on a wall. Measure the distance from the Waterhouse slot to the image. That's the focal length.

Measure the diameter of the opening through the front lens. That's the aperture.

Divide the focal length by the aperture. That's the f/stop. (Most Rapid Rectilinears are f/8.)

Since it says "4x5" on the lens, it was made for the 4x5 format.

And, trying not to be snarky, but you're offering photography workshops on using the camera manually, and you don't know what focal length, aperture, and f/stops are? :confused:

Sid Ceaser
15-Sep-2015, 11:47
To determine focal length, point the lens out a window and focus an image of a distant object on a wall. Measure the distance from the Waterhouse slot to the image. That's the focal length.

Measure the diameter of the opening through the front lens. That's the aperture.

Divide the focal length by the aperture. That's the f/stop. (Most Rapid Rectilinears are f/8.)

Since it says "4x5" on the lens, it was made for the 4x5 format.

And, trying not to be snarky, but you're offering photography workshops on using the camera manually, and you don't know what focal length, aperture, and f/stops are? :confused:

Thanks!

I know nothing about brass lenses - especially when I buy one from someone that couldn't tell me the first thing about it. I have no experience using brass lenses. I have no history with them. I bought a brass tube with some glass in it from someone that said "hey, that glass looks in good condition, eh?" but couldn't tell me *anything* about it.

I know plenty when it comes to lenses and gear that I use. When it comes to an old lens with no information that I don't have any history with? That's when I try to ask those in the know.

Please note: I don't teach a workshop about brass lenses or how to determine finding their apertures.

But otherwise thanks for the info!

DrTang
15-Sep-2015, 11:58
HOLD ON

"surrounded by MUCH LARGER BRASS LENSES" you say??????


hook me up.. I'd like a nice 15-17" please

Sid Ceaser
15-Sep-2015, 12:05
HOLD ON

"surrounded by MUCH LARGER BRASS LENSES" you say??????


hook me up.. I'd like a nice 15-17" please

No joke: A few weeks ago at a local Flea Market I was browsing one of those sellers that buys out estates and then tosses things in boxes and brings them to the Flea. There was a guy two boxes ahead of me poking through stuff, and then I heard a quiet gasp come from him, and he pulls out this, I don't even know the size - maybe it was for a 11x14 camera, maybe larger, brass lens. It was huge. The guy had to wrap both hands around the tube to hold it. He quickly walks over to the seller, asks him "how much for this old brass tube" (knowing exactly what it was but underplaying it's value) and the guy selling all this stuff looks at it and says "That? Gimme $10 for it"

My jaw hit the ground. Dude zipped the 10 into the guys hands and tore out of there as fast as he could. I just stood there amazed at what I had just saw.

If I had only been five minutes earlier!

Mark Sawyer
15-Sep-2015, 12:35
Thanks!

I know nothing about brass lenses - especially when I buy one from someone that couldn't tell me the first thing about it. I have no experience using brass lenses. I have no history with them. I bought a brass tube with some glass in it from someone that said "hey, that glass looks in good condition, eh?" but couldn't tell me *anything* about it.

I know plenty when it comes to lenses and gear that I use. When it comes to an old lens with no information that I don't have any history with? That's when I try to ask those in the know.

Please note: I don't teach a workshop about brass lenses or how to determine finding their apertures.

But otherwise thanks for the info!


Determining the aperture is the same for all lenses, brass or not. Just get a ruler and measure it.

IanG
16-Sep-2015, 01:53
Going by the measurements it's similar in size to my 8"/8" f8 RR lenses. While Dallmeyer's 5x4 f8 RR was a 6" lens it's not uncommon for slightly longer FL's to be used, my Wray marked 8x5 lens is 12" - Dallmeyer state 10" for 8x5.

I'm assuming the OP means diameter not circumference otherwise it would be far too small to cover 5x4 :D

Ian