Free Tools, Utilities, and Helpful Information
Please feel free to use the following tools and information to help you in your machine vision needs.
Tools & Utilities
Convert
This free utility performs conversions between different units in over 20 categories. Very useful for converting from English units to metric and vice versa.
Lens & Sensor
Back Flange Distance – The distance from the mount face plane to the image detector plane. Each mount has its own specification. This data is useful for optical designs.
|
Lens Type
|
Back Focal Distance
|
Notes
|
| C mount | 17.526 mm = 0.690 inches | Standard for CCD cameras |
| CS Mount | 12.5 mm = 0.492 inches | Alternate standard for CCD cameras, especially those with small sensor arrays. |
| F-Mount | 1.831 inches | Nikon 35mm SLR |
| 2/3 inch Bayonet mount | 48 mm | This is normally called “B4 mount” or “Bayonet |
| 1/2 inch Bayonet mount – general | 35.74 mm | Various manufacturers, except Sony, use this mount (usually called general mount). |
| 1/2 inch Bayonet mount – SONY | 38 mm | Sony uses this mount (usually called “Sony mount” or “38-mount”). |
*When you want to use a C-mount lens on a CS-mount camera, you should use a 5mm thick CS-C mount adapter.
Similar adapters are available from C-mount to F-mount (Nikon) lenses.
Image Diagonals – Active image area on various sized CCD arrays.
|
Sensor Size
|
Array Size
|
Diagonal
|
| 1/4″ chip | 2.7 x 3.7 mm | 4.6 mm |
| 1/3″ chip | 4.8 x 3.6 mm | 6.0 mm |
| 1/2″ chip | 6.4 x 4.8 mm | 8.0 mm |
| 2/3″ chip | 8.8 x 6.6 mm | 11.0 mm |
| 1″ chip | 12.7 x 9.525 mm | 15.9 mm |
Lenses for these chip sizes are actually designed to fill only this size array. Note that a 1″ chip only fills a 15.9 mm array size, which is about 5/8″. You can use a lens designed for a larger chip on a smaller chip. For example, you could use a lens designed for a 2/3″ chip (often called a 2/3″ lens” on a camera with a 1/2 ” array. F-mount lenses are designed to fill a 35 mm diagonal array.
