Weird Heliar 42 cm

[Dan Fromm]

Papi, if you can live with f/9 maximum aperture, get an Apo-Saphir.

[lungovw]

Thanks everybody for the useful information. And yes, the ,5 is almost gone but it is there. It is a f/4,5. The serial number is 108353, not so sure about the 8 as it is almost gone too. Maybe it was fitted to an equipment with special needs in terms of geometry as Steven suggested. I am saying that because although apparently assembled in a wrong way, if I put it the way the flange is normally placed, outside camera body, I get a nice image from a building in front of my window at more or less 42 cm from iris. I think that if somebody would have assembled it in a wrong way probably the optical elements would no work properly. I have to study it carefully and decide what to do about it. The glass seems to be simply dusty and dirty, but there is no separation or prominent scratches over the elements.

[Louis Pacilla]

If this is the correct orientaion then your shooting it backwards or your iris is in the wrong position UNLESS your iris system is a complex iris where the ring for setting the stop is pushed forward while the iris is nearer the rear of the lens.

I know because I own a TRUE factory correct countersunk 1911 48cm Heliar and it DOES have the compex iris with the blade in the correct Heliar position where the iris ring is in front as is the Voigtlander script and all other information is on the front rim of the front cell. It should look EXACTLY like all other countersunk Heliars only scaled way up to the 48cm size. If I find time today/tomorrow I'll post photos of my beautiful countersunk 48CM f4.5 Heliar. BTW it has the same screw in tabs/post on the iris ring of my counter sunk 48cm Heliar as the Universal Heliar uses on the SF rind.

[lungovw]

Doing a quick & dirty test: when lens hood is facing the scene, image is OK, but in fact iris is not in the right place for a Heliar, it is close to the front element. But it focus about 42 cm as expected. If I reverse the lens and let the iris on the back, the lens hood facing the image, and flange in wrong position, the image is clearly worse and focus is about 35 cm.

Looking now to the front and back pictures, it is strange to me that there is no branding/info on none of them. On the opposite side, the one having a lens hood, the mounting doesn't look at all like a front element.

[Nodda Duma]

The focus will still work out to be sort of 42cm because focal length in that design is more dependant on the elements themselves rather than relative position, but aberration correction would be wonky.

Reversing it and getting something different makes sense since focal length is measured from the exit pupil position (by convention for object at infinity) and not the physical back of the lens.

[Louis Pacilla]

Hey lungovw
I'll really try to get photos made of my 48cm Heliar in factory countersunk mount and I'll try to figure out how to post them later today/tomorrow so you will get the idea of a true & proper factory countersunk set up is. It is very much just a scaled up version of a Voigtlander smaller sized countersunk mount. All lens information is on front rim with a nicely made rear portion of the outer barrel that protects the linkages for the iris the iris ring has a pair of tabs for making changing f stop easier and they are the same as those used on the Universal Heliar SF ring. The center element is attached to the front group like on normal Heliar but there is an inner barrel of sorts that holds the rear group & iris setup as well as the front/center groups screw into this barrel too.
The lens actually looks like a GIANT eye on my 8a.I made a unique set up so the that I could mount it on a 10x10 board w/ a 9x9 box built ooff the back of the 10x10 board and on the back of the box I have a large #8 Packard mounted w/ the two tubes coming out of the front 10x10 lens board. So all the countersunk part w/ front cell iris control + 2 tubes bellow and the Packard & rear portion of lens barrel are inside the camera w/ only the part meant to be exposed exposed.

[Pere Casals]

Papi, if you can live with f/9 maximum aperture, get an Apo-Saphir.

Dan, thanks for the suggestion, I've just learned that's a heliar design. It looks it has a harder bokeh than voigts, but it's an impressive glass !