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Schneider Optics Announces Two New Dealers in Germany

Ira Tiffen joins Schneider Optics as VP of Motion Picture Filters

Schneider becomes exclusive U.S. distributor of Chrosziel

Schneider introduces new Vari-ND filters

FAQ

Industrial

For any questions not covered here, please email us at .

  1. What is the meaning of 1 inch Video Format?
  2. What is the meaning of 2/3 inch Video Format?
  3. What is the meaning of 1/2 inch Video Format?
  4. What is a C-Mount?
  5. What is the difference between “C-Mount” & “CS-Mount”?
  6. What is an F-Mount?
  7. What is a T2 thread?
  8. What is a Pentax thread?
  9. What is a Leica Thread?
  10. What is the difference between “Back Focal Distance” and “Flange Focal Distance” of a Lens?
  11. What is considered the region of Visible Light?
  12. What is the wavelength region that a typical CCD can image?
  13. What does CCTV stand for?
  14. What's a Spot Filter?

1. What is the meaning of 1 inch Video Format?

The actual image size (active area) = 12.8mm x 9.6mm with the image diagonal = 16mm. The 1 inch (1” = 25.40mm) value that is used to describe the common format name stems from the days of Videcon Tubes and was used to describe the tube diameter and not the actual image size.

 

2. What is the meaning of 2/3 inch Video Format?

The actual image size (active area) = 8.8mm x 6.6mm with the image diagonal = 11mm. The 2/3 inch (2/3” = 16.93mm) value that is used to describe the common format name stems from the days of Videcon Tubes and was used to describe the tube diameter and not the actual image size.

 

3. What is the meaning of 1/2 inch Video Format?

The actual image size (active area) = 6.4mm x 4.8mm with the image diagonal = 8mm. The 1/2 inch (1/2” = 12.70mm) value that is used to describe the common format name stems from the days of Videcon Tubes and was used to describe the tube diameter and not the actual image size.

 

4. What is a C-Mount?

C-Mount is a camera / lens standard that is commonly found on CCD/CMOS Digital Cameras as well as 16mm film cameras. The C-mount specification has several dimensions associated with it:

Mounting Thread = 1 inch x 32 tpi UN 2A
Length of Lens Thread = 3.8mm
Lens Flange Focal Distance = 17.52mm
Camera Depth (C-Mount Face to Image) = 17.52mm

The above dimensions are employed by all C-Mount lens manufacturers as well as all C-Mount camera manufacturers in order for any lens and camera combination to image properly.

 

5. What is the difference between “C-Mount” & “CS-Mount”?

The only difference between the two mounts = the Camera Depth (5mm delta):

C-Mount Camera Depth (Mount Face to Image plane) = 17.52mm
CS-Mount Camera Depth (Mount Face to Image plane) = 12.52mm

FYI – You can use any standard C-Mount lens on a CS-Mount Camera by simply employing a 5mm extension tube. However, you can not use a standard CS-Mount lens on a C-Mount Camera. All other aspect aspects of the CS-Mount are the same as the C-Mount specification.

 

6. What is an F-Mount?

F-Mount was developed by Nikon and has become an industry standard for numerous Industrial Camera companies as well as for Lens manufacturers:

Mounting Interface = Nikon F-Mount Bayonet
Camera Depth (F-Mount Bayonet to Image) = 46.5mm
Lens Flange Focal Distance = 46.5mm

 

7. What is a T2 thread?

The T2 thread (Metric Thread) = M42 x 0.75 pitch thread that is commonly used to join a lens with a camera.

 

8. What is a Pentax thread?

The Pentax thread (Metric thread) = M42 x 1.0 pitch thread that is commonly used to join a lens with a camera.

 

9. What is a Leica Thread?

The Leica thread is a hybrid thread that employs a Metric dimension for the thread diameter as well as an English (inch) dimension for the thread pitch:

M39 x 26Gg

Note – that the 26Gg pitch is very close to a pitch = 1mm. A true Leica thread (pitch = 26Gg) will not properly secure to a Pitch = 1mm (parts will seize).

 

10. What is the difference between “Back Focal Distance” and “Flange Focal Distance” of a Lens?

Back Focal length of a lens = the distance between the last glass element (outward facing vertex) to the image plane.
Flange Focal Distance = the distance between the lens mounting plane (thread reference surface) to the image pane.

 

11. What is considered the region of Visible Light?

The wavelength region commonly associated with “Visible Light” = 400nm to 700nm (blue to red) that the human eye can see/image.

FYI – 1 nanometer (nm) = 1 x 10-9meters

 

12. What is the wavelength region that a typical CCD can image?

A typical CCD or CMOS sensor that does not have any special wavelength limiting filters can image light from the visible region into the near infrared region:

400nm to 1200nm

FYI – 1 nanometer (nm) = 1 x 10-9meters

 

13. What does CCTV stand for?

CCTV stands for Closed Circuit Television.

 

13. What's a Spot Filter?

Motorized iris versions of Schneider lenses are supplied with a Spot Filter.

If you look through a lens with a Spot Filter, the Spot Filter appears as a small, dark "spot" at the center of the lens.

The Spot Filter is a reflective type (wavelength independent), Neutral Density, radial, gradient filter. It is deposited on a glass surface that is located coplanar to the optical stop surface (at the iris blade location). The Spot Filter allows rapid light-sensitivity adjustment. Light passes thru the spot filter from the center which is fairly dark to the edges where is phases out to 100% clear. So, if the iris blades move just a little bit, you greatly impact the overall light level that passes thru the lens.

Motorized lenses can be purchased without the spot filter, but there is no price difference. Almost all of our customers want the spot filter once they understand what it does. The only times we have seen customers not want the spot filter on a motorized-iris lens is when the application is light-starved to begin with.