The setting: a free evening during the dark of the moon with weather unfit for sky viewing. Settle comfortably in a darkened room and pull out an album page of color slides taken over the past few months of some interesting areas of the night sky. Put them on a light table and select several for projection on a wall screen.
Being widefield 35-mm photos taken with a 50-mm camera lens, the slides show the sky without magnification in bright color and in very sharp detail. Nebulae, double star systems, star clusters, and constellation groups show up clearly. Now place the most interesting slide on the stage of a microscope, set the power on 50X, and systematically scan the slide strip by strip. Quickly seen are sky objects magnified at more than the prime focus of a 2000-mm f10 telescope. A search for nonstellar fuzzy objects and faint light specks reveals a blue-green irregular speck that looks interesting. Increase the power to 200x and look again. When 500x is used, a bar-shaped object comes sharply into view. Connect the camera to the microscope adapter, focus the picture, and push the shutter release. After about 30 seconds, the camera meter signals enough exposure, the shutter closes, and the photo is taken.
Welcome to the world of observing and taking pictures through a microscope! It is a world full of startling revelations and a world free of weather problems, insects, light interference, air pollution, and the other frustrations of nighttime viewing. Indeed, this method of recording the sky first photographically and then magnifying certain areas for observation and photography differs dramatically from conventional methods of magnifying first and then observing.
Chance played an important part in my interest in this method. As an artist who was finding conventional painting subject matter tiresome, I became interested in astronomy--a hobby--as a source of new painting material. One thing then led to another, as I turned further to the microscopic field in my search for unique material. The chance viewing of a color astroslide under a microscope led to subsequent experimentation and the techniques outlined below. What follows, however, is a simple introduction to the subject. What clearly lies ahead is the challenge of learning and redefining the use of the microscope for astronomical observation.
Creating the Original Color Slides
The first part of this process consists of photographing a number of areas of the night sky over the four seasons, especially constellation areas. Required are a 35-mm single lens reflex camera, ASA 400 Ektachrome film (push processed to ASA 800 when developed), filters, and a tracking telescope with accurate setting circles.
After the film is loaded, set the camera on bulb exposure and the aperture on f2, focus on infinity, attach a locking cable release, mount a wide-band light pollution reduction filter of 52mm (Orion Sky-Glow) and a minus-violet filter of 52mm or larger (Lumicon), and a lens shade. Piggy-back mount the camera on a tracking telescope, which has been polar-aligned, and then, using a bright star, set the setting circles and align the camera with the scope. Sight the sky area to be photographed through the camera viewfinder and fine-tune the tracking for accuracy. Then take an 8-minute time exposure, or a 10-minute one if considerable nebulosity is anticipated. Guiding is not necessary.
For photo sessions, an exposure journal should be kept. Record the information for each exposure by number, including the right ascension and declination co-ordinates. Take a number of areas of the sky at each photo session. Some cautions and hints for better pictures are: (1) take areas high in the sky to avoid horizon sky-glow; (2) stick to clear nights with good visibility; (3) achieve a vibration-free exposure; and (4) avoid dew on the lens.
When the film has been processed, examine the slides with an 8x loupe on a light table and enter the data from the log on each slide, especially the area and co-ordinates. If the task has been carried out carefully, the reward will be slides of pinpoint stars in their natural colors, glowing nebulae, a host of double stars, and identifiable Messier and NGC objects. The second part of the process now begins--observation and photography of the widefield color slides.
The slides should be projected on a screen of at least two by three feet. A white matte cardboard screen could be affixed to a wall; the back of art matboard is also a good surface. Do not use a glass bead projection screen because of its grain. Examine the image close-up with a sky atlas at hand, using the right ascension and declination co-ordinates for orientation. Determine the areas worthy of microscopic examination. Then try to learn about the sky area represented by the image and look for objects readily identifiable and those that are not. The next step is astromicroscopy, a name chosen to describe the process of examining astro color slides visually through a microscope.
Visual Use of the Microscope
I use a microscope (Edmund Scientific) with 5x, 20x, and 50x objectives and 10x and 20x eyepieces capable of magnifications of 50, 100, 200, 400, 500, and 1,000x. It is equipped with a rotary aperture, a coarse and fine focuser and lock, an illuminator, and a camera adapter for photomicrography. The spring clips should be removed and a color slide placed on the viewing stage. Adjust the light volume with the aperture to eliminate any excess light halos, set for 50x, and focus. Propelling the slide gently with the fingers, start in one corner and view a strip to the opposite corner, then reverse, repeating this process until the entire slide is viewed. Notes of interesting objects and their approximate locations on the slide may be made. Or a photo can be taken as each object is found while it is in the eyepiece. To stabilize the slide, use the spring clips but do not allow them to scratch the film surface. This viewing is very important, so look sharply and investigate each little mass, blur, or speck. Use up to 500x to see objects in greater detail. The Messier list, or other guides to unusual sky objects, can be used to identify unusual objects on the slide. Since the slide is centered on the right ascension and declination co-ordinates identifying the slide, this will help in celestial orientation. Above all, enjoy the fun of searching for and viewing objects at magnifications higher than usual telescopic ones. Embedded in the film emulsion is a wealth of faint astronomical information.
Astrophotomicrography: Photos of Astroslides Through a Microscope
I use a Nikon FE2 35-mm loaded with ASA 400 Ektachrome. The camera lens is removed and replaced by a T-ring, which then threads into the microscope camera adapter. The adapter in turn is mounted on the microscope barrel and tightened with set screws. The exposure dial should be set to automatic and a cable release attached. The next step is unusual and important. Set the film-speed indicator at ASA 50 and the exposure compensation at plus two stops, giving in total by this process the five stops of overexposure needed to obtain a correct exposure through the microscope. This overexposure is needed because the unusual backgrounds together with the light through the microscope fool the camera meter.
With the camera mounted on the microscope, focus through the camera carefully, lock the microscope focus, and then release the shutter. The camera does the rest, sometimes taking up to 40 seconds for the exposure. Bracketing of exposure may be done by one stop more or less by adjusting the film speed to either ASA 25 for more exposure or ASA 100 for less. This process works well for my microscope and camera combination. It may differ for other equipment, but the principles remain the same.
An exposure log should be kept with identifying information on each frame so that slides can be identified after processing. Viewing the slides would be done in the same manner as projecting the original widefield ones.
A slide duplicator may be used, not only for duplicates but also for magnifying areas of the original slides. To do this, use one (or even two) 2x teleconverters mounted between the camera and duplicator. Set the camera on automatic but give seven stops of overexposure by setting the ASA on 25 and the exposure compensation on plus two stops. Rotate the slide in the holder to expose various areas. Ektachrome 400 (push processed to 800) is needed for this process to allow for the extreme overexposure.
Because of the variance in lightness of the backgrounds, I prefer to let the camera meter function rather than guess at time exposures. This requires a film fast enough to provide for the overexposure adjustments but with a fine enough grain for satisfactory results. Other considerations, such as overall color balance and the availability of E-6 film processing, have led me to use Ektachrome ASA 400 as is or push processed to ASA 800, depending on what procedure is being followed. If the grain in the slides becomes too pronounced, it may be eliminated by one or two stops of underexposure. The usual color enhancement procedures using color compensation filters, over- and underexposure, and centering can be used with microscope slides.
Variations of the Process
A number of variations appear possible. Portions of the sky can be photographed with 200- to 800-mm lenses and then viewed under the microscope. Color print films with very fast speeds can be used to create material for astromicroscopy. Variations in film brands, speeds, and types are possible. Filtering methods on the original wide-field slides also can be changed. Indeed, this entire process can be modified by any astronomer or astrophotographer interested in further innovation or wishing to conform the process to his or her circumstances.
This method is just one more process through which amateur astronomers can expand their knowledge of what lies in the night sky. As a different type of visual and photographic observation, it may produce unique results, as well as the fun of discovery and interpretation, supplemented by photography for record-keeping. And unquestionably for amateur astronomers, astronomical observation under pleasant indoor conditions can be a welcome change from the many frustrations that often accompany nighttime outdoor star gazing.
AFFILIATES OF THE ASTRONOMICAL LEAGUE
The purpose of this letter is to inform the membership of the Astronomical League about an interesting project that has come to our attention with the hope that it will make a contribution to the practice of amateur astronomy in the USA.
After a three year period of research, a member of our club, Samuel D. Bissette, has originated an unconventional method of astronomical observing which has been named "Astromicroscopy" and "Astrophotomicrography". Simply stated, this method involves photographing the night sky without magnification with an ultraviolet and light pollution reduction filter pack. The resulting 35mm color slides are then viewed under a microscope at magnifications of 50x to 500x with additional color photography through the microscope. This process is the reverse of normal telescope observing. Bissette now has several hundred color slides recording his observations.
The method can be used indoors at any time dispensing with the weather problems of direct outdoor observation and offers several other distinct advantages. Its strongest point is the viewing of double star systems in sharp detail, as well as identification of all types of nebulae, star clusters, and galaxies to the fifteenth magnitude. Viewing characteristics include color, shape, RA and Dec locations, brightness, cinfiguration, and individual peculiarities.
Bissette's first report on this was made in May, 1992 in a presentation to the Southern Star Convention in North Carolina. He has just completed his final report and a copy of both reports is enclosed with this letter. A copy of our news release just issued is on the reverse and it is suggested that it might be included in your next newsletter. The Cape Fear Astronomical Society would like to share this report with others in the hope that it might add another method for the amateur to enjoy astronomy. Please feel free to duplicate any of the enclosures for the use of your members.
Best wishes to our fellow astronomers.
Ronnie Hawes President
CAPE FEAR ASTRONOMICAL SOCIETY
News Release, Cape Fear Astronomical Society, Dated March 1, 1994
1939 S. Liveoak Parkway
Wilmington, N.C. 28403
NEWS RELEASE - IMMEDIATE - MARCH 1, 1994
The Cape Fear Astronomical Society of Wilmington, N.C. has announced the origination of a new and unconventional method of astronomical observing called "Astromicroscopy" and "Astrophotomicrography", as the result of a three-year project by one of its members. The process consists of photographing the night sky without magnification using filters to remove ultraviolet light and commercial light pollution. The resulting color slides are then viewed both by projection and under a microscope offering magnification up to 500 times. This permits astronomical study of stars, nebulae, galaxies and other celestial objects with the option of photographing these in color through the microscope. This method is the reverse of using a telescope for magnification first, followed by observation and photos which is the conventional method of sky
This new method is an additional tool for amateur astronomers, and offers the advantages of observing indoors at any time and seeing objects that do not show up as well with other observing methods. The local Society is in the process of distributing information to other astronomy clubs and societies throughout
the United States who are members of the Astronomical League.
Astromicroscopy was originated by Samuel D. Bissette, a Life Member of CFAS, as a result of the accidental viewing of an astro color slide under a microscope. He then refined the process of creating the photos, observing and photography with the microscope. Bissette is a retired banker, artist, and amateur astronomer. In 1993, he donated to the University of North Carolina at Wilmington a sixty painting educational exhibition on space titled "The Universe According To Earth".
Article in The Reflector, Quarterly Newsletter of the Astronomical League, May 1994
The first two links below are scans of the original article and are very large.
Scanned copy of page 1 of article (237K)
Scanned copy of page 2 of article (273K)