Could anyone help me on telecentric and f-theta lenses? What actually I want is to measure the distance between two objects using a camera. I googled and I could not get a clear picture of these types of lenses. Can you provide me some link where I can get the information about these lenses? Are telecentric and f-theta is one and the same???
Lens
- Thread starter hariharan
- Start date
I dunno a lot about these things, but I don't think a telecentric and f-theta lens are the same thing. Telecentric lenses are used for machine vision systems and form an image of the same size on the sensor regardless of the size of the object being viewed. F-theta lenses are used for scanning and printing documents, and are so-called because the detected height of something being scanned is proportional to the angle of view (which is what theta is) instead of the tangent of the angle, which is what most lenses do. I don't understand exactly what you're trying to do either, but it seems to me that a camera isn't the best tool to use for measuring the distance between two objects. If they're on the same optical axis you can just compare focal lengths for a foreground and background object, and if they're separated on a line that crosses the optical axis you can compare respective focal lengths and the angle between the lines of sight and calculate their separation with a little trigonometry. But camera lenses don't generally give you very accurate indications of focal length. I think you need surveyor's equipment.
No Dexter I cannot use anything other than CCD camera. Because I can interface the CCD camera easily with the computer and also my customer insists on using CCD camera. My application is more like scanning the document but for larger area. The CCD camera will be mounted on a moving arm which can move in x and y-axis (Z is constant).