Mailinglist Archives:
Infrared
Panorama
Photo-3D
Tech-3D
Sell-3D
MF3D

Notice
This mailinglist archive is frozen since May 2001, i.e. it will stay online but will not be updated.
<-- Date Index --> <-- Thread Index --> [Author Index]

P3D Re: focal length

  • From: Greg Erker <erker@xxxxxxxxxxxxxx>
  • Subject: P3D Re: focal length
  • Date: Thu, 11 Feb 1999 08:35:59 -0600
>Could someone one the list tell me if there is a formula for converting
>close up lenses to focal length. For example, what is the focal legth of
>a +1,+2 etc. close-up lens. I guess these are diopters. Should I be
>asking how to convert diopters into focal length. I want to order some
>lenses from Edmund Scientific. Sorry if this should have gone to T3D.
>Rod Sage

  The formula is 1/Diopters = focal length in metres,
or 1000/Diopters = FL in mm.

Greg E.

List of all currently available 2-element
(achromatic) closeup lenses on my web page:
http://www.angelfire.com/ca/erker


------------------------------