Tominon 105/4.5 in Copal shutter: what to do?

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

Dear friends,
today I salvaged an old Polaroid camera that was being thrown away in the university where I work. It has a Tominon 105/4.5 in Copal shutter activated by a sort of gun. "Tominon" started a ring in my head, according to the classical lens name pattern.
First thing I did was to understand what the heck a Copal shutter is Smile

. Now I know. Second, I looked inside to understand how the lens is mounted to the body.
Third, and please help me, how can I use this thing: I see that results can be good. I suppose the shutter is integral part of the lens. However, the front lens block seems to be freely rotating. As far as I see, without pushing the shutter button, shutter is closed, unless there is some trick I do not know. I will unmount from the camera body, mount on bellows, and then? Should I leave the shutter cable there and blocked in some way in B position?

Focus distance seems to be around 10-20cm (putting my eyes in place of film).

Thanks.

ludoo · Expire: 2011-12-05

Mount it on an old Polaroid Land Camera tha uses packfilm, still produced by Fuji. You will probably need to adjust the rangefinder on the camera, but other than that it might work great. It's one of the favourite lenses for a conversion. Please don't butcher it. Smile

Conversion instructions

http://www.instantoptions.com/conversions/250/250.2.php

ps - se sei a Milano fammi un fischio, che ho una macchina da usare per la conversione se vuoi (oppure vendimi l'obiettivo). Smile

jjphoto · Joined: 17 Mar 2009 Posts: 406

You can unscrew the lens from the shutter so that the lens can be used on it's own, on a bellows or helicoid.

exaklaus · Expire: 2011-12-02

Had two of them, one sold at Ebay.
Have a look at this already ended auction to see some large and detailed photos.
Click here to see on Ebay.de

Klaus

jjphoto · Joined: 17 Mar 2009 Posts: 406

exaklaus · Expire: 2011-12-02

I don't know, what will be normal. The two I had/have, show that rear part.
Never made any picture with that lenses, but holding it with and without rear element in front of a white surface, will show that the image with rear element is bigger than without it.
Klaus

jjphoto · Joined: 17 Mar 2009 Posts: 406

thanks
jj

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

Thank you all.
As soon as I'm back home I'll try to understand better what I have. And no, Ludoo, I will not butcher it Smile

. I'm not in Milan, so we could not try a conversion on your camera. However, I would like to use it on digital, in some way.
JJ: something puzzling is that the front part seems to be freely rotating on the shutter.

iangreenhalgh1 · Expire: 2014-01-07

If you just want to use the lens on your EOS, I could put that Copal shutter to very good use on the panoramic camera I have made from an old box camera.

I sent you a PM.

Congrats on your lucky find, silly university!

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

So, I unmounted it from the camera. It seems slightly different from those linked until now: it seems shutter and lens are integrated, i.e., I can unscrew the front part but a lens remains on the back, which in turn can be unscrewed but what connectes the two parts is the shutter. By the way, the shutter part includes aperture too (so, Ian, I would be glad to send you the shutter, but unfortunately at the moment I do not know what else to do).
I also already found a way for adapting in a non destructive way: a 39-42mm step up ring can be put on the back below the flange, and stays centered and well fixed. Now I have to understand how to maintain the shutter open.
Apologies for the picture quality: I did them in a hurry, I have to go running in some minutes.

iangreenhalgh1 · Expire: 2014-01-07

I have some approx 100mm enlarger lenses that are in M39 so easy to mount on EOS with bellows, a Rodenstock Rogonar-S 90mm, a Schneider Componon-S 100mm and an Industar 110mm. Maybe one of those would be of more use to you than a lens in a shutter?

ludoo · Expire: 2011-12-05

To keep the shutter open, just screw an old fashioned cable release, set the shutter on B, then press the release and lock it in place.

luisalegria · Expire: 2018-01-18

That is the normal way to mount a large format lens on a shutter.

That is why (in English anyway) such a lens is referred to as being "in shutter". A lens that has all its optical elements outside the shutter is called "In barrel".

The shutter/aperture mechanism is best placed inside the optical formula to make it easier to preserve coverage.

How to use on digital ?
I suggest extension rings or bellows plus a body cap, drilled with a hole about the size of the rear mounting screw. Like this -

http://forum.mflenses.com/bauschandlomb-kodak-5-inch-f-8-rapid-rectilinear-t25908,highlight,%2Brectilinear.html

Alternately you can use that lens on an old 6x9 (120 film) folder with a lousy 10.5cm lens and shutter. Many old folders were made to be cheap, and the place where savings were made were the lens and shutter, which often had one or two elements (meniscus type) and only one "Instant" speed. However the bellows and film transport had to be the same as any 120-film camera.

Something like this - http://camerapedia.wikia.com/wiki/Foldex_20

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

The quick hack was ok and solid (mounted on extension tubes, just to try):

With 61mm extension tubes, and walk-focus, this is the FoV (and low contrast):

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

Luis: thank you for the extra info. In the meantime I found a way for mounting it easily and without damages. The thread size is 32mm diameter, and the lens was fixed to the body with a retaining ring, by chance large slightly less than 42mm. I've just put a 39-42mm ring in the middle, with some care.

Ian: let me play a little Smile

(you know better than me that is not the easy way the most fun).

Ludoo: right, perhaps I have still one from Zenit times. Perhaps even a long screw may do it.

luisalegria · Expire: 2018-01-18

There you go ! Even better !
Congratulations !
The only way to make these adaptations is to think like an inventor.

jjphoto · Joined: 17 Mar 2009 Posts: 406

Thanks for posting pics of it.

JJ

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

iangreenhalgh1 · Expire: 2014-01-07

Bravo Enzo, great to see you got it working!

I love bellows with old lenses, a lot of fun!

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

Playing with bellows, this evening (f/8, 0.8s, ISO200). Only unpractical thing: the tripod mount is on the lens end, so to focus I have to move the camera. I suppose my wife does not allow me to post a 100% crop of dust in the bottom part Laughing

jjphoto · Joined: 17 Mar 2009 Posts: 406

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

Another attempt, on bellows.

iangreenhalgh1 · Expire: 2014-01-07

Belissimo!

Obviously a very good lens, well done!