On 11/07/2013 03:15 AM, Russell Brown wrote: ... snip > Has anyone found a USB camera with both a high magnification and a > decent depth of field? (I've a feeling that these are mutually > exclusive) or even one that can focus at a high resolution from a > workable (~200mm?) distance? > > TIA >
In my opinion, you really don't want a long depth of field. The camera edge finder should be used like a normal finder or probe in that the sensitive area is basically a point. Once dialed in, that one point will be a constant. If anything changes, such as lens position to change focal length or zoom, the known fixed point will go away. Either that or a system will be needed to accommodate multiple points, which could get complicated in a hurry. Changing aperture should not be a problem if it doesn't change the lens position. My plan would be to use a standard USB camera with a fixed large aperture lens, mounted in a tool holder. The Z axis would be used to focus on the edge which, if the depth of field is narrow, will put the known point on the edge. The fixed lens could have any focal length, so the sensitive point could be at 50mm, 500mm or wherever you want. Finding or modifying a camera with a C-mount might be best. Camera resolution would not be important. There are many websites covering the modifying of webcams for use in astronomy. Such as: http://ghonis2.ho8.com/lifecam/lifecam1.html Tormach has a paper here: http://www.tormach.com/engineering_scanner.html and camera: http://www.tormach.com/product_cnc_scanner.html -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ November Webinars for C, C++, Fortran Developers Accelerate application performance with scalable programming models. Explore techniques for threading, error checking, porting, and tuning. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
