18" Artar Cell Spacing

[Steve Hamley]

Folks,

O.K. this is a long shot, but does anyone have a factory-mount 18" (not the 16-1/2" or 19"). Apparently they didn't make a lot of them. I'd like to know the length shutter + cell adapters.

Did see one in shutter at Midwest at one time though.

Cheers and TIA, Steve

[E. von Hoegh]

There was a thread about the spacing of a 16 1/2" Artar last year. The upshot was at least three different lenths of the barrel, and no way to tell which to use by just having the cells in hand. A more useful measurement would be from the vertex of the front element to the vertex of the rear element, assuming the optics weren't tweaked along the way.

Edit: I've seen them marked 18" and 450 mm, back before I knew what to do with such a lens.

[Steve Hamley]

Thanks E.,

Yes, I think Andrew Glover (Dagor77) has stated that the spacing was "all over the place", but if you had a number, it would be a start.

I have noted that nearly all process lenses in barrel tend to be shorter than their shutter mounted counterparts, so at least there's an indication of the potential direction.

Cheers, Steve

[cdholden]

I have noted that nearly all process lenses in barrel tend to be shorter than their shutter mounted counterparts, so at least there's an indication of the potential direction.

Cheers, Steve

How about an exception? Don't forget the G-Clarons. Only the 150mm is different. The others in that series are equal.
http://www.largeformatphotography.info/forum/showthread.php?t=78834

[Steve Hamley]

Yep, but different design and unlike the barrel Artars, at least some thought was given to fitting the G-Clarons to a standard shutter.

Cheers, Steve

[E. von Hoegh]

Also, barrel Artars were spaced for copy ratios, while Artars that were factory mounted in shutters were spaced for wider ratios. Just to add one more variable.

[Steve Hamley]

Yes, that's why I want to know what a factory shutter mounted lens measures.

Cheers, Steve

[E. von Hoegh]

Just a thought, but wouldn't the dimensions scale?

[Steve Hamley]

Here's the summary measurements for the 16-1/2" Artars in shutter mentioned in Jim Fitzgerald's thread:

CD Ewen - 1.741
mine, (remeasured) 1.775
E. von Hoegh - 1.6800

my 19" - about 2.175 (can't get the rear cell all the way out, but close)

I think that Dagor77's comment about the cell spacing being "all over the place" likely means that they aren't that critical about cell spacing.

It may also mean they changed the cell design and so the spacing to keep the glass in the desired location to the iris.

Or they may have changed the actual optimization over the years.

Cheers, Steve

[E. von Hoegh]

Those numbers are the lengths of the barrels with cells removed. The actual spacing of the elements would depend on the dimensions of the cells; the actual spacing of the elements could have been identical in every example.

The front vertex to rear vertex of my 16 1/2" measures 2.1275", if that helps at all.

[c.d.ewen]

Steve:

How about some empirical testing? Slip them into a PVC pipe and see if they make a decent image.

Charley

[E. von Hoegh]

Steve:

How about some empirical testing? Slip them into a PVC pipe and see if they make a decent image.

Charley

Too simple.;)

[Steve Hamley]

Actually I thought of trying to get the barrel lens on something with a digital back then unscrewing the cells turn at a time, then half turn to fine tune while pixel peeping. Great use for a digital camera!

Cheers, Steve

[Steve Hamley]

The barrel lens arrived (marked 45cm) and the front cell screws into the shutter for my 19" Artar - can't get the rear one loose yet.

I thought maybe that the 45cm/18" was so uncommon they probably didn't make unique adapters for it.

Cheers, Steve

[CP Goerz]

Actually Goerz were NOT sloppy about spacing whatsoever, that comment should be reserved and used most often with another lens maker....Carl Zeiss, the kings of sloppy optical construction.


As many of you may have found you can't take the cells from one Artar and use the barrel for another, each lens was HAND TUNED to its own specific barrel, its quite rare and I've only had a perfect fit in one case over decades of trying. The focal length of the lens may be 455mm or 17 1/2" approx, does the barrel actually say 18"? If so it may have been a custom job, Goerz did that kinda thing from time to time. Good luck finding a barrel for the lens, all I can suggest is perhaps using a 19" barrel and adding tape to the threads for a fit then once proper sharpness is achieved to silicone the cells in place...kinda rough and ready but saves the expense of shutter mounting.

[E. von Hoegh]

The rear cell on my 16 1/2" will not screw into the barrel when it is just snugged into the flange. Loosen it in the flange, and the cell screws in perfectly freely. That's how closely Goerz fitted the threads.