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« on: July 15, 2017, 04:55:06 PM »
C and CS mount lenses are an easy way to go but I have found that unless you pay "real" lens prices you are going to get quality somewhere between security camera and VHS, you get what you pay for.
I have been using a pair of C-mounts, an 8mm f1.3 and a 16mm f1.4 which are both good for a normal field of view, catching what you might expect to see when looking an an object within a few meters of the camera, the 8mm allowing you to fit an ~1m object in view at a distance of 1m.
For close cropped shots I have been using manual focus SLR lenses with a C-mount adapter, lenses like a 50mm f1.4 are great for catching outdoor subjects (birds or squirrels in a park). With the 50mm an object ~1m wide will fill the screen at a distance of 6m.
If the 50mm lens lets you focus at distances of 1m or less you can use it for macro shots of large insects, with an 80mm+ lens you can capture fairly small insects. If your lens wont let you focus at very short distances you have a couple of options, first is to buy a macro filter, these fit on most SLR lenses and make it so you can focus very close (almost touching the lens). If you don't want to use a macro filter you can use macro-rings/extension rings, these move the lens slightly farther away from the camera which makes the lens focus closer, they are made specifically for each lens mount BUT if you want to just hack it you might be able to get away with stacking 1 or 2 CS to C mount adapters. This will have the same effect as macro rings but may cut off the corners of your image.
For insanely high magnification I have used a 400mm f8 lens on the Chronos, it let me see a golfer teeing off from nearly 1km away and still have the ball visible. An ~1m object would have to be 50m away in order to fit on the screen at that point.
Finally, all of the "will fit on your screen" numbers only apply when you shoot at 1280px image width, when you increase the frame rate and shrink the resolution you will need to use lenses with shorter focal lengths to get a wider field of view. For example if I can see my whole shot with the 16mm lens at 1280x720 I will have to switch to the 8mm lens if I want to film at 640x360.
Hope this was helpful.
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