35mm to C mount adapter issue.

[Philip Kral]

Hi,

I have a feeling this topic has probably been discussed at one point but I cannot find the thread. If so please excuse me and perhaps link me to it? I've had a little accessory issue I was hoping someone here could help me with. Recently I've tried to adapt some of my 35mm Lenses to my 16mm cameras. (Yes I know there's a change in focal length/ crop issue when you do this.) The C mount adapter that I have recently stumbled upon does not fit entirely into my camera. The first thread or two does but then it doesn't go any farther, it doesn't fit any of my other C mount cameras either. I know that some of the video C mount cameras have slightly different threading so i'm assuming that's the core of the issue- It's probably a C mount video and not a C mount 16mm. Does anyone know how to resolve this issue? Is the difference with the thread pitch or is there some way I can modify it? How can I make sure which C mount adapter is which if I try to get another one?

[Freya Black]

Hi,

I have a feeling this topic has probably been discussed at one point but I cannot find the thread. If so please excuse me and perhaps link me to it? I've had a little accessory issue I was hoping someone here could help me with. Recently I've tried to adapt some of my 35mm Lenses to my 16mm cameras. (Yes I know there's a change in focal length/ crop issue when you do this.) The C mount adapter that I have recently stumbled upon does not fit entirely into my camera. The first thread or two does but then it doesn't go any farther, it doesn't fit any of my other C mount cameras either. I know that some of the video C mount cameras have slightly different threading so i'm assuming that's the core of the issue- It's probably a C mount video and not a C mount 16mm. Does anyone know how to resolve this issue? Is the difference with the thread pitch or is there some way I can modify it? How can I make sure which C mount adapter is which if I try to get another one?

 

There are two video mounts that are like c-mount. C-mount itself and cs-mount which looks similar but is slightly different. Could be you have the latter kind of adapter. You don't say what kind of lenses or what camera. Too little info.

 

As to the focal length changing... no it doesn't. A 50mm lens is still a 50mm lens in 16mm. The field of view changes.

[Jean-Louis Seguin]

The C-mount specs are nominally 1.000" - 32tpi (threads per inch).

 

In practice, most mounts measure out to around 0.985-0.990" so they won't bind.

 

Cheers,

Jean-Louis