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

Starshoot /Focal Reducer

Expand Messages
  • Bob
    Hi all I am new to this group and am getting into astro imagery. I have had a Meade ETX105 Maksutov - Cassegrain telescope, for about ten years. I have
    Message 1 of 4 , Jul 30, 2012
    • 0 Attachment
      Hi all I am new to this group and am getting into astro imagery. I have had a Meade ETX105 Maksutov - Cassegrain telescope, for about ten years. I have recently bought a Orion Starshoot colour imaging camera. I have taken some pictures of the Moon and Saturn so far. The field of view is rather small to take a picture of the whole Moon. So I need a focal reducer,I have bought one which is x.5 but still can only see part of the moon. The question is what size would you recommend so I can see the whole of the Moon. The scope diameter 105mm focal length 1470mm (F14). The imager sensor size 1/3", number of pixels 1280 x 960 and pixel size 3.6um x 3.6um.

      Regards Bob
    • Bob Franke
      Hello Bob, The Moon is about 1920 in diameter. This means you need an image scale of 2.0 arcSec/pixel to exactly fit the Moon on the chip. So I would go
      Message 2 of 4 , Aug 1, 2012
      • 0 Attachment
        Hello Bob,

        The Moon is about 1920" in diameter. This means you need an image scale of 2.0 arcSec/pixel to exactly fit the Moon on the chip. So I would go for about 2.25. To get this image scale you need to get your focal length down to about 325mm.

        This large reduction is not at all practical or for than matter even possible. I suggest you concentrate on close-up views of interesting craters. For a wider FOV start experimenting with mosaics.

        Hope this helps,
        Bob
        http://bf-astro.com


        --- In ccd-newastro@yahoogroups.com, "Bob" <bobden72@...> wrote:
        >
        > Hi all I am new to this group and am getting into astro imagery. I have had a Meade ETX105 Maksutov - Cassegrain telescope, for about ten years. I have recently bought a Orion Starshoot colour imaging camera. I have taken some pictures of the Moon and Saturn so far. The field of view is rather small to take a picture of the whole Moon. So I need a focal reducer,I have bought one which is x.5 but still can only see part of the moon. The question is what size would you recommend so I can see the whole of the Moon. The scope diameter 105mm focal length 1470mm (F14). The imager sensor size 1/3", number of pixels 1280 x 960 and pixel size 3.6um x 3.6um.
        >
        > Regards Bob
        >
      • Bob
        Bob, Thanks for the info and I am looking into the various programs available for my Mac. Will post some pictures when I have something to show. When the rain
        Message 3 of 4 , Aug 1, 2012
        • 0 Attachment
          Bob,
          Thanks for the info and I am looking into the various programs available for my Mac. Will post some pictures when I have something to show. When the rain clears.

          Regards Bob
          Devon

          --- In ccd-newastro@yahoogroups.com, "Bob Franke" <bfranke@...> wrote:
          >
          > Hello Bob,
          >
          > The Moon is about 1920" in diameter. This means you need an image scale of 2.0 arcSec/pixel to exactly fit the Moon on the chip. So I would go for about 2.25. To get this image scale you need to get your focal length down to about 325mm.
          >
          > This large reduction is not at all practical or for than matter even possible. I suggest you concentrate on close-up views of interesting craters. For a wider FOV start experimenting with mosaics.
          >
          > Hope this helps,
          > Bob
          > http://bf-astro.com
          >
          >
          > --- In ccd-newastro@yahoogroups.com, "Bob" <bobden72@> wrote:
          > >
          > > Hi all I am new to this group and am getting into astro imagery. I have had a Meade ETX105 Maksutov - Cassegrain telescope, for about ten years. I have recently bought a Orion Starshoot colour imaging camera. I have taken some pictures of the Moon and Saturn so far. The field of view is rather small to take a picture of the whole Moon. So I need a focal reducer,I have bought one which is x.5 but still can only see part of the moon. The question is what size would you recommend so I can see the whole of the Moon. The scope diameter 105mm focal length 1470mm (F14). The imager sensor size 1/3", number of pixels 1280 x 960 and pixel size 3.6um x 3.6um.
          > >
          > > Regards Bob
          > >
          >
        • Ron Brant
          Mosaic is a good way to go. One of the best pictures I ve made is a 13 panel mosaic of the moon when it was about 55% illuminated. Excellent relief and detail.
          Message 4 of 4 , Aug 1, 2012
          • 0 Attachment
            Mosaic is a good way to go. One of the best pictures I've made is a 13 panel mosaic of the moon when it was about 55% illuminated. Excellent relief and detail. Of course it is about 2 feet in diameter when finished!! Excellent wall hanging photo!
            Ron
            ----- Original Message -----
            From: Bob Franke
            To: ccd-newastro@yahoogroups.com
            Sent: Wednesday, August 01, 2012 12:41 AM
            Subject: [ccd-newastro] Re: Starshoot /Focal Reducer



            Hello Bob,

            The Moon is about 1920" in diameter. This means you need an image scale of 2.0 arcSec/pixel to exactly fit the Moon on the chip. So I would go for about 2.25. To get this image scale you need to get your focal length down to about 325mm.

            This large reduction is not at all practical or for than matter even possible. I suggest you concentrate on close-up views of interesting craters. For a wider FOV start experimenting with mosaics.

            Hope this helps,
            Bob
            http://bf-astro.com

            --- In ccd-newastro@yahoogroups.com, "Bob" <bobden72@...> wrote:
            >
            > Hi all I am new to this group and am getting into astro imagery. I have had a Meade ETX105 Maksutov - Cassegrain telescope, for about ten years. I have recently bought a Orion Starshoot colour imaging camera. I have taken some pictures of the Moon and Saturn so far. The field of view is rather small to take a picture of the whole Moon. So I need a focal reducer,I have bought one which is x.5 but still can only see part of the moon. The question is what size would you recommend so I can see the whole of the Moon. The scope diameter 105mm focal length 1470mm (F14). The imager sensor size 1/3", number of pixels 1280 x 960 and pixel size 3.6um x 3.6um.
            >
            > Regards Bob
            >





            [Non-text portions of this message have been removed]
          Your message has been successfully submitted and would be delivered to recipients shortly.