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A 12.5mm Cosmicar that needs no machining

V

Vivek

Guest
Nope.

This is the lens that Ranger9 posted about, a long time ago, in this forum. I have a sample of this (bought after Ranger's post). Its coverage is even less than that of the 12.5/f1.4's though the illumination is about the same.

The one I modified to have full coverage is a Fujinon-TV CF12.5A 12.5mm f/1.4 lens.

( I tried to make a post on that:http://forum.getdpi.com/forum/showthread.php?t=12689 never finished. Will get to it sometime.
 

hodad66

Member
Just got mine in but waiting for c mount adapter.......
just ordered rear "c mount" cap and am looking for
a front cap. Does 27mm sound right?
 

sangio

New member
I was looking at buying a 12.5 Cosmicar 1.4; the price seems reasonable. Could someone please explain what machining is necessary to mount this lens on a G1?

I assume a C-mount adapter is needed as well.

Many thanks
Santo
 

hodad66

Member
I was looking at buying a 12.5 Cosmicar 1.4; the price seems reasonable. Could someone please explain what machining is necessary to mount this lens on a G1?

I assume a C-mount adapter is needed as well.

Many thanks
Santo
From what I've read a bevel needs to be run around the
base so that it will screw further into the adapter
thereby allowing infinity focus......

See HERE
 
Last edited:

RichA

New member
I was looking at buying a 12.5 Cosmicar 1.4; the price seems reasonable. Could someone please explain what machining is necessary to mount this lens on a G1?

I assume a C-mount adapter is needed as well.

Many thanks
Santo
In case anyone is looking for one, Surplusshed.com is still offering that lens for only $25.00. The tricky part is that you have to carefully lathe or file the edge, taking care not to cut into the screw holes that hold the mount on the lens.
 

sangio

New member
In case anyone is looking for one, Surplusshed.com is still offering that lens for only $25.00. The tricky part is that you have to carefully lathe or file the edge, taking care not to cut into the screw holes that hold the mount on the lens.
Thanks Rich.

Can anyone tell me what the maximum distance this lens will focus to without machining? I would be using it mostly indoors so infinity focus isn't a big issue. And at a FL of 12.5 mm, the hyperfocal distance is about 4.3 feet at F8, so sharpness at infinity might be OK for non-critical use.

Actually, for $25 there's not a lot of money at risk even if it doesn't work out.

regards
Santo
 

RichA

New member
Thanks Rich.

Can anyone tell me what the maximum distance this lens will focus to without machining? I would be using it mostly indoors so infinity focus isn't a big issue. And at a FL of 12.5 mm, the hyperfocal distance is about 4.3 feet at F8, so sharpness at infinity might be OK for non-critical use.

Actually, for $25 there's not a lot of money at risk even if it doesn't work out.

regards
Santo
Alas, about 2" is the max focus distance with the lens at infinity with no machining.
 

kai.e.g.

Member
Santo, I have a Cosmicar 12.5mm f/1.2, and the answer is: "not very far". Before I machined* it, I recall being able to focus on objects no further than about 7 ~ 8 inches away at best when wide open. I wasn't able to achieve decent focus even at f/16.

EDIT: RichA is probably closer to the truth with his 2 inch estimate. I only tried it once before setting to work on "machining" it. It certainly wasn't a useable distance for me!

Cheers,
Kai


* machining = I turned myself into a human lathe: by using the reaming tool of a Swiss Army Knife held down with my right hand on a cookbook about 1.5 inches high, and then spinning the lens manually with my left hand upon a soft cloth, scraping it against the cutter for a few hours (with lots of breaks in between!)
 
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