Ealing equipment setups and reference schematics posted to the gallery. Enjoy - Kurt ============================= I. Filter wheel load chart Handy for loading filters into a circular filter wheel. Filter wheel load chart http://gallery.utahastronomy.com/main.php?g2_itemId=11571 II. 2 inch version of double targeting and observing setup for Ealing and star parties Last week I posted a preliminary setup for a 2 inch double eyepiece setup for targeting the Ealing. Last night I tested the setup and made some revisions to make both the 2 inch eps parafocal. Ealing - visual - double targeting setup - 2 inch version http://gallery.utahastronomy.com/main.php?g2_itemId=11558 Ealing - visual - double targeting setup - 2 inch version - index error wheel http://gallery.utahastronomy.com/main.php?g2_itemId=11560 Ealing - visual - double targeting setup - 2 inch version - index error wheel view 2 http://gallery.utahastronomy.com/main.php?g2_itemId=11562 Ealing - visual - double targeting setup - 2 inch version - schematic http://gallery.utahastronomy.com/main.php?g2_itemId=11564 Ealing - visual - Mak use of index error wheel http://gallery.utahastronomy.com/main.php?g2_itemId=11566 Please disregard and discard the prior preliminary rough setup. More on "index error wheel" use in a follow-up post. A quick test on targeting M13 under a sky washed out by a near Full Moon indicated the setup works very well and quickly brings targets into the small eyepiece TFOVs (less than 20') typical of the Ealing and despite targeting and tracking errors in inherent in the Ealing. III. Schematic for visual spectroscopy observing on the Ealing A couple of weeks ago, I posted a photo of a setup for visual spectroscopy observing of bright stars using the Rainbow Optics grating on the Ealing. Here's a supplemental schematic showing the components of the setup. Ealing visual spectroscopy setup http://gallery.utahastronomy.com/main.php?g2_itemId=11449 Ealing visual spectroscopy schematic http://gallery.utahastronomy.com/main.php?g2_itemId=11579 Note for visual observing, the Rainbow Optics grating manual statest that the spectrum must be defocused slightly infocus to bring out the spectral bands. A separate eyepiece magnifier, that is a cylindrical magnifier lens sits on top of the grating stack. This is also intended to smear out the spectrum in one axis to better see the element absorption lines. (My impression was that either practice did not help much.) IV. Slitless spectrograph imaging setup for the Ealing Yesterday, I posted drift spectrographs taken with the Ealing on June 8. A couple of weeks ago, I posted a spectroscopy imaging setup. When retesting on June 8, I discovered there were some instances with Johnson filters in place that the camera did not have sufficient infocus travel to reach focus. Here is revised spectrograph setup for slitless grating spectroscopy of bright stars. This was the setup used to take the June 8 drift spectrographs: Ealing spectroscopy imaging - revised setup 20080608 http://gallery.utahastronomy.com/main.php?g2_itemId=11573 Ealing spectroscopy imaging - independently rotatable grating and camera http://gallery.utahastronomy.com/main.php?g2_itemId=11575 Ealing spectroscopy imaging - revised schematic 20080608 http://gallery.utahastronomy.com/main.php?g2_itemId=11577 Please disregard the prior setup version. A key feature of this setup is the ability to independently rotate the grating and camera. The grating is stored on the end of a shorty barlow with the lens removed. First, an eyepiece is substituted for the camera. The grating is rotating while viewing a bright star, such that the spectra falls aligned to the north-south declination line. Then the grating is fixed in place. Second, the camera is inserted behind the grating and then is rotated so the north-south aligned spectra falls on the long side of the camera's image frame. Then the camera is fixed in place and neither component is moved for the rest of the imaging session. This process simplifies finding and placing the spectra on the chip. Whenever the star's (first order) image can be found, you then just push the north declination slew button. You can be certain the spectra will shortly appear. Once the spectra is aligned on the chip, a long exposure (7-10 seconds) is taken with the right ascension drive turned off. That allows the spectra to drift across the camera image frame and making a smeared image. The smeared image better brings out the spectral lines as in - A drift strip spectrograph of Arcturus 20080608 http://gallery.utahastronomy.com/main.php?g2_itemId=11543 - Kurt