There are getting to be more posts about needing information about the lens on a camera. The following applies to any good photographic camera: basic information that is engraved on the front of the lens:

focal length (how wide an angle or powerful a telephoto or strong a zoom): shown by an f= followed by the number(s). For a zoom, divide the larger number by the smaller to determine zoom ratio (e.g.: 43.2mm divided by 2.7=16X).

widest aperture: shown by an F followed by a number

filter size (if there is a thread for filters: not all lenses have threads): shown by a 0 with a slash through it followed by a number

the manufacturer of the lens (or who did the licensing if not designed by the camera body manufacturer)

optionally:
the power of the zoom followed by an X;

if the lens uses AutoFocus (AF is shown);

etc., etc.

MORE facts about zoom ratios:

One thing we all neglect about the "X" power of a zoom: The number before the X is how many times from the Wide angle setting. So the wider the wide angle is, the less strong the tele end is.
Let me convert this to 35mm terms, as every camcorder has too many variables (CCD size, effective pixels, max wide angle).
if you have a 28-168mm zoom, that is 6X.
if you have a 50-300mm zoom, that is 6X
(168mm is 3.3 power and 300mm is 6 power compared to numbers used for binoculars: 50mm= 1X.)
The second one would be considered by many "newbies" to be a more powerful zoom, but it isn't: it's still 6X. It's just the range that changed from more wide angle oriented to mor tele oriented.

For instance, my JVC GR-D32 is 16X or 52-829mm in 35mm (tele oriented). These numbers are related to the fact it has a 1/6 inch CCD. If it had a different sized CCD, the 35mm conversion would change.

This link should take you there:
http://www.camcorderinfo.com/bbs/sh...5852#post125852

Thank you for that information. Knowing this, could you please help me to figure out what type of fisheye lens to get?

I have a Panasonic HDCSD5K HD camcorder. The filter diameter is 37mm, and the image sensor is 1/6" CCD x 3 (560K x 3 pixels total)

I want a fisheye that is .043X. No one seems to know the answer, even Panasonic hasn't got any listed yet on their website.

Any help will be great!