Inon UCL-330 or UCL-165M67 Marco Len

Just like to find out from PT-015 users who has used Inon Marco Len, which type do you get. The Inon UCL-330 or UCL-165M67 ?

What is the difference between the two ?

Thanks

The UCL-165M67 has a shorter focal length than the UCL-330.

Focal Length:

UCL-330 330mm

UCL-165M67 165mm

Documentation on the lenses is at:

Inon product documentation pages

-Mark Rupert

Inon America, Inc.

Focal Length:

UCL-330 330mm

UCL-165M67 165mm

 

-Mark Rupert

Inon America, Inc.

I am a little confused by these references to focal lengths -- especially the higher magnification lens having the shorter focal length. Does the 165mm refer to the maximum distance to object (i.e., the distance of focus when the prime lens is focused at infinity with the adapter attached -- corresponds to ~+6 diopter for a max focusing distance of 165mm)?

The shorter the focal length the higher the magnification. If an object is twice as close it will subtend an angle twice as large. Meaning if the object is twice as close (half the focal length) it will be twice as large.