M.T.O. "JUPITER" 1084mm f10.5 MIRROR LENS

[Robert Hart]

This mirror telephoto lens was offered in the 70s with a variety of adaptor mounts for 35mm stills cameras. They all attach via a collar-over-shoulder arrangement secured with small grubscrews. Given that the EPIC/SCARLETT owner-operators I know in my vicinity don't have the Nikon mount, I examined the rear of the lens to see if a PL Mount was feasable. There is enough clearance behind the body of the lens to permit it.

It appears that the 3.5mm front overhang of a standard PL clamp ring will itself impinge on the base of the shoulder mounting to the rear lens body. The shoulder base could be skimmed to allow clearance. The available metal thickness of a PL adaptor collar would be limited to 3mm parallel to the optical centreline which would make it a bit thin. Given the mass of the lens and the wider span of the PL flange, this would allow a weakness.

What might be a better option would be to eliminate grubscrew fixing entirely and remake the entire shoulder with a PL bayonet disc machined into the rear rather than mutilate the original shoulder base. There is just enough clearance around the heads of the four attachment screws to get away with it. For fine collimation, shims between the shoulder base and lens rear body would suffice.

On a 2K camera this lens is distinctly soft but on larger sensors it is acceptable. The aperture is fixed at f10.5 as it is a mirror lens. Control of light is only available by shutter speed, gain setting or huge ND filter on front or a filter gel shoved in the back, which means disturbing the lens mount. Some control of light can also be had by making disk inserts for the front of the lens with holes cut in the disks in a circular pattern surrounding the centre internal reflector. This might create a pattern artifact with digital sensors.

Images of far distant wildlife on water are pleasing. The image circle covers the 35mm stills frame so should cover the Dragon sensor when it arrives.

If anyone is contemplating making a PL Mount adaptor for this lens, here are a few measurements from the specimen I have which is Ser No. 812652.

Adaptor shoulder diameter = 49mm.
Adaptor shoulder depth - rear shoulder face to face of shoulder base = 4.5mm
Shoulder base outer diameter = 64.4mm.
Nikon Flange to shoulder face = 9mm.
Nikon Flange to focal plane = 46.5mm.

PL Flange to focal plane = 52mm.
PL Bayonet pattern disk is 2mm thick.
PL Inner diameter of bayonet pattern lugs = 64mm.
PL Flange to lens rear shoulder face should therefore be 3.5mm.
Shoulder face to rear machined face of lens body = 6mm.
The replacement shoulder/PL piece would therefore be 9.5mm front to rear ( flange face ) plus the PL centering shoulder extends furthur rearwards.

The RED PL-Mount Clamp ring outer diameter, grip pattern and front overhang appears to be larger on all counts ( otherwise it might infringe a registered design ) If the inner diameter of the bayonet pattern lugs is slightly wider than the standard PL clamp ring, then it might just slip over the existing shoulder base on the M.T.O. lens without need for skimming a clearance on the base or making a new custom shoulder base/PL lens rear.

Because of the 138mm rear diameter of the lens barrel, there would be restricted workspace between an EPIC/SCARLETT camera body and rear of lens to operate the PL-Mount rotating collar. The lens is also a weighty item. The focus barrel is large and draggy. The lens would need support to avoid stressing the structure of the camera.

Here is a link to an image of the lens.

http://www.flickr.com/photos/dimatsvetkov/5518377753/

Here is a link to some vision shot on one - not my vision.

http://vimeo.com/11178113


If anyone in Perth is chasing one, CESCO aka Camera Electronic had a used one in stock about two years back and could probably make the PL-Mount adaptor.

There you go. Some useless information for you.

 

[john jeffreys]

Wow that moon video tripped me out! So cool.

 

[Nick Morrison]

This mirror telephoto lens was offered in the 70s with a variety of adaptor mounts for 35mm stills cameras. They all attach via a collar-over-shoulder arrangement secured with small grubscrews. Given that the EPIC/SCARLETT owner-operators I know in my vicinity don't have the Nikon mount, I examined the rear of the lens to see if a PL Mount was feasable. There is enough clearance behind the body of the lens to permit it.

It appears that the 3.5mm front overhang of a standard PL clamp ring will itself impinge on the base of the shoulder mounting to the rear lens body. The shoulder base could be skimmed to allow clearance. The available metal thickness of a PL adaptor collar would be limited to 3mm parallel to the optical centreline which would make it a bit thin. Given the mass of the lens and the wider span of the PL flange, this would allow a weakness.

What might be a better option would be to eliminate grubscrew fixing entirely and remake the entire shoulder with a PL bayonet disc machined into the rear rather than mutilate the original shoulder base. There is just enough clearance around the heads of the four attachment screws to get away with it. For fine collimation, shims between the shoulder base and lens rear body would suffice.

On a 2K camera this lens is distinctly soft but on larger sensors it is acceptable. The aperture is fixed at f10.5 as it is a mirror lens. Control of light is only available by shutter speed, gain setting or huge ND filter on front or a filter gel shoved in the back, which means disturbing the lens mount. Some control of light can also be had by making disk inserts for the front of the lens with holes cut in the disks in a circular pattern surrounding the centre internal reflector. This might create a pattern artifact with digital sensors.

Images of far distant wildlife on water are pleasing. The image circle covers the 35mm stills frame so should cover the Dragon sensor when it arrives.

If anyone is contemplating making a PL Mount adaptor for this lens, here are a few measurements from the specimen I have which is Ser No. 812652.

Adaptor shoulder diameter = 49mm.
Adaptor shoulder depth - rear shoulder face to face of shoulder base = 4.5mm
Shoulder base outer diameter = 64.4mm.
Nikon Flange to shoulder face = 9mm.
Nikon Flange to focal plane = 46.5mm.

PL Flange to focal plane = 52mm.
PL Bayonet pattern disk is 2mm thick.
PL Inner diameter of bayonet pattern lugs = 64mm.
PL Flange to lens rear shoulder face should therefore be 3.5mm.
Shoulder face to rear machined face of lens body = 6mm.
The replacement shoulder/PL piece would therefore be 9.5mm front to rear ( flange face ) plus the PL centering shoulder extends furthur rearwards.

The RED PL-Mount Clamp ring outer diameter, grip pattern and front overhang appears to be larger on all counts ( otherwise it might infringe a registered design ) If the inner diameter of the bayonet pattern lugs is slightly wider than the standard PL clamp ring, then it might just slip over the existing shoulder base on the M.T.O. lens without need for skimming a clearance on the base or making a new custom shoulder base/PL lens rear.

Because of the 138mm rear diameter of the lens barrel, there would be restricted workspace between an EPIC/SCARLETT camera body and rear of lens to operate the PL-Mount rotating collar. The lens is also a weighty item. The focus barrel is large and draggy. The lens would need support to avoid stressing the structure of the camera.

Here is a link to an image of the lens.

http://www.flickr.com/photos/dimatsvetkov/5518377753/

Here is a link to some vision shot on one - not my vision.

http://vimeo.com/11178113


If anyone in Perth is chasing one, CESCO aka Camera Electronic had a used one in stock about two years back and could probably make the PL-Mount adaptor.

There you go. Some useless information for you.

Super famous mirror lens. I went through a faze scoping out a number of well regarded mirror lenses, and this one kept coming up. Several photographers held it in extreme regard. Another rare, great gem to consider is the Yashica 500mm f8, that some nature lovers preferred even over the Zeiss 500mm f8.

Anyway. I'm threatening to add MORE useless information here (haha), but again...very cool lens. I'm pretty sure you can find this in M42 mount, and from there it's pretty easy to screw on an EOS adapter to get it on an Epic/Scarlet. However, considering how heavy the lens is, that may only be a short-term solultion.

A longer term solution would be to get this in M42, and then attach an ALL-STAR M42 adapter on the back (will feel as durable and sturdy as PL)...and use it with the A-Mount.

Thanks for sharing!

 

[Robert Hart]

As originally supplied, it came with M42, Nikon, C-mount and Pentax. I bought in a Canon mount adaptor when I had a loan of a Canon stills camera. That mount was not like FP or EOS. It was a reverse mount like Ikegami. I muchly liked that camera and was sad to hand it back. It gave me a beautiful evening red moon shot. I did not buy one. I was sending myself broke buying 16mm neg film, getting it processed and workprinted. Whether the M42 mounts managed to stay with the few lenses for sale is another matter but your suggestion would be a readymade means to achieve the same end.