Lens Use a c-mount lens on a f-mount camera

[Johimi]

Hi everyone,

I am fairly new to this forum and the topic in general so please excuse any dumb mistakes, I will do my best to avoid them. I also don't know if I am at the right place.

My problem is that I have a c-mount lens (1" male thread) that I want to use on a camera with a f-mount. Most adapters I can find posess a male 1" themselfe, hence they dont fit my prupose.
From my understanding I need a femal 1" thread going to a f-mount lens, but I can't find anything like that, so i reach out to you for help.

Is it even possible to use a lens designed for a c-mount camera onto a f-mount camera?

Thanks in advance.

 

[mike3996]

What F-mount are we talking about? Nikon F?
If so, I don't think you can get any usable results out of it.

 

[Mr_Flibble]

I know C-mount lenses will fit on the Robot-to-LTM adapters, but C-mount lens-to-film registration distance is much shorter than that of Robot glass.

 

[Johimi]

What F-mount are we talking about? Nikon F?
If so, I don't think you can get any usable results out of it.

Yes, I mean Nikon F. Can you explain why you think there are no usable results?

 

[mike3996]

Yes, I mean Nikon F. Can you explain why you think there are no usable results?

Unless I'm mistaken, the C-mount lenses are designed for 16mm film. The designed flange distance of C-mount is 17.5 mm while Nikon F has one of the longest flange distances (for 35mm) at 46.5mm. There may not be any way to get a C lens to focus at any distance adapted on a Nikon F.

 

[Johimi]

Unless I'm mistaken, the C-mount lenses are designed for 16mm film. The designed flange distance of C-mount is 17.5 mm while Nikon F has one of the longest flange distances (for 35mm) at 46.5mm. There may not be any way to get a C lens to focus at any distance adapted on a Nikon F.

Ah I think I geht the problem now. Thanks for the explanaition and your time.

 

[Mr_Flibble]

The size of the image circle of a c-mount lens is presumably not big enough to cover a full 35mm frame either.

 

[Petrochemist]

Yes, I mean Nikon F. Can you explain why you think there are no usable results?

Firstly the lens will need to sit MUCH closer to the sensor than F mount allows. To get infinity focus c-mount lens flanges have to be 17.526 mm from the sensor, while F mount has it's flange 46.5mm from the sensor. This is the equivalent of using something like a 30mm extension tube.
If you have a long focus c-mount lens of 100mm focal length, this extension will prevent you focusing beyond 560mm, a more typical 25mm lens will be limited to ~100mm maximum focus & a 10mm lens is limited to ~53mm.

Coverage is the second main issue, with c-mount lenses being designed to cover at best around 12mm x 8mm (super 16mm cine), but often only 5mm x 3.5mm (8mm cine).

C-mount lenses can be usable on mirrorless bodies, where the registration issue no longer exists, but coverage is certainly often an issue even for micro four thirds bodies - lenses wider than 25mm hardly ever cover the MFT sensor.

Macro images are theoretically possible were both coverage & rear distance are bigger) but the relatively low resolution of most c-mount lenses means results here will likely be unimpressive. The better C-mount lenses seem to be sold rated for 6MP digital usage.

Jury rigging a c-mount microscope objective (to MFT) does give some impressive macro results filling the sensor with a 6mm subject at a fantastic 90mm working distance

ultra macro lens set up by Mike Kanssen, on Flickr

Sadly the images aren't wonderfully sharp

P1340885 small by Mike Kanssen, on Flickr

 

[Johimi]

Firstly the lens will need to sit MUCH closer to the sensor than F mount allows. To get infinity focus c-mount lens flanges have to be 17.526 mm from the sensor, while F mount has it's flange 46.5mm from the sensor. This is the equivalent of using something like a 30mm extension tube.

Coverage is the second main issue, with c-mount lenses being designed to cover at best around 12mm x 8mm (super 16mm cine), but often only 5mm x 3.5mm (8mm cine).

Macro images are theoretically possible were both coverage & rear distance are bigger) but the relatively low resolution of most c-mount lenses means results here will likely be unimpressive. The better C-mount lenses seem to be sold rated for 6MP digital usage.

C-mount lenses can be usable on mirrorless bodies, where the registration issue no longer exists, but coverage is certainly often an issue even for micro four thirds bodies - lenses wider than 25mm hardly ever cover the MFT sensor.

Jury rigging a c-mount microscope objective (to MFT) does give some impressive macro results filling the sensor with a 6mm subject at a fantastic 90mm working distance
View attachment 475258ultra macro lens set up by Mike Kanssen, on Flickr

Sadly the images aren't wonderfully sharp
View attachment 475259P1340885 small by Mike Kanssen, on Flickr

Wow, thanks for the explanaition.

 

[Mr_Flibble]

On a side-note; With a bit of internet-trawling I've discovered that a C-to-LTM adapter actually exists! It sinks the lens deeper into the LTM camera body.