My interest in astronomy was rekindled in 1997 (after a 25 year dormancy) with the appearance of Hale-Bopp. I dragged out my Nikon FG (early 80's vintage) and had it repaired (stuck shutter), bought a shutter cable, and took my tripod out for several nights. Four rolls of film later I had several decent photos to remember this great comet with, and I had ignited a passion for astrophotography.
I started going to Raleigh Astronomy
Club meetings and researching mounts, telescopes
and cameras in May 1997. I didn't want to spend alot of time building things
from scratch -- I wanted to start taking pictures. By December 1997, I
had the main pieces needed to get started taking photographs of deep sky
objects:
After building an opto-isolator box to isolate the camera from the mount drive electronics, and a couple of nights learning how the get the telescope to track on a guide star, I was ready to try some longer exposures. The first thing I realized is that with the f7 focal reducer in place, vignetting was a much bigger problem than at f11. This meant that I had to catch the sky near dusk to take some flat field exposures at the zenith so I could divide out the vignetting and dust donuts (circular rings created by the shadows of dust particles on the camera optics). This also meant that I needed to either leave the equipment set up exactly the same way all night, or I had to make marks on my parts so I could reproduce assemblies exactly.
In 1999 I purchased some additional equipment from Astro-Physics (picture):
Useful Tools for CCD Imaging
These are some of the tools I have found very useful in making my pictures of the sky. I'm not being paid to say this. I am sure there are many other very good (possibly better) tools out there that I simply have not used yet. In the cases of Losmandy, Megastar, Van Slyke, and Picture Window, I have found support to be very fast and on the mark (Van Slyke support has been exceptionally fast on both occasions I've needed them.) . I have not yet needed support services from the others.
Losmandy Digital Setting Circles: This device connects to digital encoders installed on your mount's Right Ascension and Declination axes, and will tell you where your telescope is pointed in the sky. It can send this location information to a computer via a serial port so star atlas software on the computer can visually display where you are pointed.
Megastar Star Atlas: This is a star atlas program that interfaces the serial port of the computer and works with the setting circles to display the area of the sky where the telescope is pointed. It can be configured to show exactly the field of view of any eyepiece or CCD imaging camera.
Van-Slyke Versaport II: This is a device called a flip mirror. It allows you to use an eyepiece to find and focus an object, then you flip the mirror out of the optical pathway so light falls on the imaging camera. This particular one also has a second small mirror in the optical pathway which allows addition of a guiding eyepiece for off-axis guiding.
Celestron Focal Reducer: This is a lens you place in the optical path before the imaging camera. It reduces the focal length of the imaging system by a factor of .63. For example, an f11 Celestron 14" telescope becomes an f6.93 optical system. This has the advantage of increasing the field of view and reducing the exposure time. Vignetting is quite a problem though.
JMI NGF-S Electronic Focuser with Digital Readout: This device aids the difficult task of focusing the image on the imaging surface by mostly eliminating the image shift inherent in commercial Schmidt-Cassegrain designs. You do rough focusing with the knob on the telescope, then you use the electronic control to fine tune focus without image shift.
Picture Window Digital Image Processing Software: This software application allows overlaying several images into one image. This process is useful for increasing image detail and creating color images. It also has many functions useful in improving digital images.
MaxIm DL Image Processing and Camera Control Software: This program is very strong in image processing and camera control features. It has saved me a lot of time during the imaging process. The only down sides are that updates are only free for a year, then the subscription service is expensive, and major revisions are slow in coming, and I'd like it to give more help with focusing. But I think it is the best program all around for what it does.
Articles
Occasionally a piece of equipment comes to me in less than a FULLY USEFUL state until I add some cable or circuit. Usually the manufacturer offers a cable, power supply, black box, etc., for some outrageous price (well, it's only outrageous if you don't count the labor you yourself will put into finding the pieces and building it), but I enjoy searching for parts and soldering. So, I sometimes bite off more than I can chew, and then I have what I lovingly call a "LEARNING EXPERIENCE". Once I learn something, I hate to think I'd have to learn it again, and maybe someone else can be spared the fun I had, so I use this area to document my experiences.
Losmandy Digital Setting Circle Cable
Opto-Isolator Box for Losmandy
Mounts with SBIG Cameras
Astrophotography
Click images for larger view.
I had a hard time finding dark skys for my Hale Bopp photography attempts. I had never attempted astrophotography, and had never realized how difficult it is to find a dark location. By the time I found a spot with a decent view of the comet, it was low on the horizon, and I had to shoot the telephone pole and all. 30 Seconds on Kodak 1000 Gold.
While I was out with the camera trying to take pictures of Hale-Bopp, I could not resist trying to capture some of the nebulae in the Orion Constellation. The only thing that came through for certain is M42, The Great Orion Nebula. In the original photo I can pick out slight red tints around Zeta Orionis (the left star of the three lined up across the center of the photo). 20 Seconds on Kodak 1000 Gold.
This is my first decent image of M31 (the Andromeda galaxy) with the SBIG ST-8 CCD camera. 240 seconds with the camera cooled to -10C. Taken in my back yard with a nearly full moon on 11/16/97 at approximately 10:30PM. No processing was done on this image beyond cropping and rescaling to 640x480. The lens is a Tokina 35-210mm zoom-tele for a Nikon camera. It was set at the 210mm setting and f5.6. The exposure was 240 seconds, unguided on a Losmandy HGM-200 mount (gross overkill!).
This is another view from the same raw .st8 image. No processing was done beyond cropping the original image. Note that M110 is also visible as a small fuzzy blob to the right and above M31.
Sagittarius Milky Way Region - This image spans the area from Declination -10° to -45° (running left to right) and Right Ascension 17h 25m to 19h 15m (bottom to top). Taken with a 50mm lens on a Nikon 35mm camera using Kodak 1000 speed film. This is a 15 minute exposure on the Losmandy mount using the C-14 as a guide scope! North is Right. If you sit down with a star chart, you can make out a fair number of open clusters, globular clusters, and dark and bright nebulae from the Messier, NGC and IC catalogs. This image was taken during a new moon, July 1998, at Greyson Highlands, Va.
I couldn't resist making a few notations on the above image to indicate
where a few of the visible objects are. It was fun.
More Pictures...
The following links will take you to pages of photos I have taken since putting all my equipment to full use. I am very pleased with some of these photos (others are actually rather disappointing), but I expect to make improvements over time as I learn. Note that some of the object names are links to the SEDS website for an explanation of the object (as with M31, M42, and M110 above). These explanations have interesting information like how large and how far away the object is currently estimated to be, as well as more pictures of the object, including some Hubble Space Telescope images.
Pictures from the Mid-Atlantic Star Party
General Astronomy Links
Astronomy Picture of the Day Archive: This NASA site has a wealth of information and photos. It leads you to many other interesting sites with Astronomical subject matter.
This page last updated on:
Jan 29, 2004, fixed some off-site links problems
August 22, 2001, updated with A-P equipment
August 26, 1999, added link to opto-isolator article
August 8, 1999, added Useful Tools and Articles sections, and
SEDS intro.
July 15, 1999, added Marked up Sagittarius image.
April 28, 1999, added Sagittarius photo.
April 27, 1999, added link to pictures from MASP.
