Do I need a retaining ring on my Goerz Dagor 12 inch?

[wallpaperviking]

Hi,
I have a 12 inch Goerz Dagor 6.8 and it has the retaining ring to attach to a Copal 3 lens.

Is the retaining ring purely there to make the front and rear elements "grip" to the lens board?

Am looking to attach this lens to a bit of a DIY camera and the width of the retaining ring is getting in the way. If I was to screw the rear element into the shutter as far as it would go, would this still make the lens work? It seems when doing this that there is a small amount of space left for where the retaining ring would normally sit...

Sorry, probably bit of a basic question. Any help would be much appreciated! :)

[Tin Can]

I have trouble understanding the problem

Maybe others are also

Pics would help

There are usually TWO Copal 3 rings, one is threaded and the other thick one is not, as it's a spacer to allow the shutter to work, without being hung up

But your old lens may be different, are you using a Copal 3 shutter?

[Jim Noel]

I don't understand the problem either.

[David Lindquist]

I'm also having trouble understanding this. By any chance is the Dagor is in a barrel front mounted to a No. 3 Copal?

David

[Luis-F-S]

Why don't you post some photos so we can maybe figure out what you're asking? L

[Chuck Pere]

The retaining ring is used to hold the shutter on to the lens board. The front and rear lens elements would then be screwed into the shutter. The front and rear elements would not make contact with the lens board in any way that prevents them from being fully screwed into the shutter.

[wallpaperviking]

My apologies, I guess that was a pretty confusing question... I am playing around with a DIY camera that is loosely based off this one here...

https://www.newsshooter.com/2018/01/03/this-18-year-old-photographer-built-his-own-8x10-large-format-video-camera/

Mainly because I had most of the parts anyway and have always liked the look of a 8 x 10 portrait but could never quite justify $20 or so for a shot.



I guess I have two questions. One design has the large format front standard sitting directly above the digital taking lens and be able to move above it. This is done by an upside down front standard and rail, that is connected to the middle section of the camera design. (a)

The other has both the digital camera and front standard of the large format camera sharing a rail. (b)

a) I am looking to get the large format lens as close to the digital taking camera as possible, as in, sitting above it.. Is it easier enough to get a much thinner retaining ring, so that the lens/retaining ring combo can sit further down on the lensboard? (picture with included lens board)

b) Am still tinkering with the distances but if sharing a rail, the lens would need to be recessed back into the lens board to have infinity focus on the large format lens. As the digital camera and front standard share the same rail (as seen in the article), I was wondering if I could just have the front and rear elements of the lens screw into each other and place them behind a lens board somehow? This would give me much needed millimetres to try and reach that infinity focus. I just tried it and it seems to screw in all the way. By not having the "gap" that is created by the lens board and the retaining ring, does this affect the lens' optical performance? In the article above, you can see that is what he has done, as I don't think he had a retaining ring..

Thanks, hope that is a bit clearer :)

[Tin Can]

Ok we have seen these things before

Good luck

[John Kasaian]

It looks like a flange is on the back of the lens board instead of the front.
If it suits your purpose and works----is light tight and the shutter controls don't bind----I don't see an issue.
I would screw the flange to the lens board though:confused:
Using both a flange and a retainer ring is like wearing a belt and suspenders, IMHO