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

Re: What would you buy with $10-12,000?

Expand Messages
  • theweaveastro
    Here s my stab: You can easily spend most of your time polar aligning and focusing, so you want to buy equipment to minimize that. Some deep sky objects can be
    Message 1 of 45 , Jan 1, 2004
    • 0 Attachment
      Here's my stab:

      You can easily spend most of your time polar aligning and focusing,
      so you want to buy equipment to minimize that.

      Some deep sky objects can be difficult to find, a goto scope will
      save you time.

      Having licked those problems, you can get on with imaging.

      What works for me:

      Takahashi EM-200 Temma PC Jr. mount (save money by getting the Jr, if
      you don't care about 700x slewing). $4,100 new (you may need
      dovetail plate hardware for the OTA)
      EM-200 Tripod $600.00 new
      SBIG ST-2000XM with CFW-8a. $4,500 new

      If you can buy the above used, you can save some for the OTA &
      accessories.

      Depending on the OTA, you will want a motorized focuser to use with
      FocusMax (freeware). For refractors you can probably just get a
      RoboFocus. For SCTs you may want a Crayford add-on.

      The OTA comes down to preference, get the largest aperture you can
      afford with the remaining money, but leave some money for
      accesories. But if you get a refractor, make sure it is an APO.
      Celestron has a deal: 5 eyepieces & filters for $99 with the purchase
      of one of their scopes (OTA's count).

      Make sure the OTA isn't too much for the EM-200 to handle (ask the
      group). I think most OTAs in your remaining budget should be OK. I
      like the EM-200 because it is easy to polar align, itsets up quickly
      and is portable (the counter-weight shaft retracts into the mount
      body).

      The FS-102 sale is continued until June, but that scope will probably
      push you over budget with all the accessories.

      Required accessories:
      Eyepieces
      Mounting Hardware

      Useful accessories::

      Kendrick Heaters and / or dew shields
      Optional finder scopes.
      Focal Reducers
      Powermates (instead of barlows)

      If you have existing 35mm lenses, you could consider buying one of
      the lens adapters for the ST-2000XM (one of the 3rd party ones that
      supports the CFW-8a). That can give you the wide-field views, then
      you can use a longer focal length for your OTA.

      Hopefully you find some or all of this useful,
      -Dave
    • Bill Bradford
      Hi Richard, Thanks a lot for the comparisons. I liked the way you used the filters on the Crab. It seems that I would be better of starting with a 9nm or 10nm
      Message 45 of 45 , Jan 2, 2004
      • 0 Attachment
        Hi Richard,
        Thanks a lot for the comparisons. I liked the way you used the filters on the Crab. It seems that I would be better of starting with a 9nm or 10nm filter.
        Regards and Happy New Year!
        Bill
        ----- Original Message -----
        From: rdcrisp
        To: ccd-newastro@yahoogroups.com
        Sent: Thursday, January 01, 2004 11:41 PM
        Subject: [ccd-newastro] A DIFFERENT CONCLUSION ABOUT 4" refractorRe: What would you buy with $10-12,000?


        --- In ccd-newastro@yahoogroups.com, "Bill Bradford"
        <bcbradford@a...> wrote:
        > Richard,
        > Great example of images. What is your opinion as to the Ha filter
        that would enable you to image the greater number of targets. I saw
        that you used the 3nm a lot in your photos.


        I have two different Ha filters: a 3nm Custom Scientific and a 9nm
        Schuler. The Schuler really is an Ha + [NII] filter though: the two
        [NII] lines are just either side of the Ha line and are only about
        2nm separated. So the Schuler picks them all up. The Cust Sci doesn't

        The Cust Sci also doesn't let as much light through so it will not
        expose the detector as fast as the Schuler.

        I ended up putting my Schuler in my LRGB filter wheel as my 5th
        filter. My Cust Sci is in my Emission Line Filter wheel along with my
        other Cust Sci filters: [SII], [NII], [OIII] and Hbeta.

        I have obtained good results with both filters. For the ST10XME, it
        is nice to have a bit of a speedup so the Schuler is a good choice
        and particularly so if you want to self-guide because the Ha really
        socks the stars.

        I mostly use the Cust Sci with my FLI Dream Machine. With the higher
        quantum efficiency in the TK1024 back-illuminated detector and the
        huge 24 x 24 micron pixels, the camera is very very fast compared to
        my ST10XME. Just the geometry alone accounts for about a 9:1 speedup.
        So the greater attenuation going through the Cust Sci doesn't seem
        too bad with the DM. Some folks have been using the newer 4.5nm Cust
        Sci filters with good success, but I cannot speak to any first hand
        experiences with them.

        I did a comparsion shot of the Schuler versus Cust Sci filters back
        in mid 2002. I shot the Pelican: 6 x 10 minutes with each filter.
        Here's the comparision result:

        http://www.rdcrisp.darkhorizons.org/comparsion_of_ha_filters_page.htm

        Because I was concerned about whether or not the 3nm Cust Sci filters
        really would separate [NII] from Ha, I shot a "tricolor" image of the
        Crab using Ha for Red and [NII] for both Green and Blue. If the data
        were the same in both filters, the color image would be greyscale
        basically. But it is not:

        http://www.rdcrisp.darkhorizons.org/m1_crab_nebula_ha_n2_page.htm

        Happy New Year!
        Richard



        Yahoo! Groups Sponsor
        ADVERTISEMENT





        ------------------------------------------------------------------------------
        Yahoo! Groups Links

        a.. To visit your group on the web, go to:
        http://groups.yahoo.com/group/ccd-newastro/

        b.. To unsubscribe from this group, send an email to:
        ccd-newastro-unsubscribe@yahoogroups.com

        c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.



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