Loading ...
Sorry, an error occurred while loading the content.

More on Barlow lens

Expand Messages
  • zapzap_it
    Hi, I have a SXV-M7 camera mounted on a manual filter wheel inserted by an extension tube on the Crayford of a 80 mm. APO refractor. I am now trying to
    Message 1 of 1 , Jul 1 12:49 AM
    • 0 Attachment
      Hi,

      I have a SXV-M7 camera mounted on a manual filter wheel inserted by an
      extension tube on the Crayford of a 80 mm. APO refractor.

      I am now trying to assemble my scope to get more magnification
      (resolution). I have a 2.8x Barlow lens, but I have not the right
      adaptors to mount it, so I am unable to try something. In the mean
      time I've searched documents to get information on the B.L.
      amplification factor and the adaptors commonly used.

      I feel a little confused by the various opinions one can find all over
      the Internet and I'ld like to know which is the most reliable. I think
      the following two are the most representative concepts with
      contrasting ideas to follow:

      1. Basically Ron says that to get a certain amplification factor (e.g.
      2x) you must put the Barlow just in front of your camera, to get 3x
      use 2"-3" spacers etc. Nothing of more simple;

      2. Thiery Legault presents a simple formula to get the Barlow factor
      knowing the Barlow lens focal lenght and its distance from the focal
      plane (CCD camera or film). The formula shows that when the distance
      increases, the amplification factor increases, and that a '2x' Barlow
      lens gives a true amplification factor of 2 only if its distance from
      the focal plane is equal to its focal length (100 mm in one example he
      does). If this distance is doubled, the amplification factor becomes
      3x etc.

      In conclusion the RW rule simplifies very much my problem, the TL
      rule, instead, complicates it since I'ld put the B.L. between the
      filter wheel and the scope.

      I hope someone has a similar equipment and he is so kind to help me.

      Emiliano
    Your message has been successfully submitted and would be delivered to recipients shortly.