Miscellaneous

FAQ's

What is the "B" stand for on my 35mm camera?

The "B" setting is an almost century-old designation for "bulb". This setting gives the photographer control over the duration of the exposure. Anotherwords, it overrides the camera. This setting is crucial for long exposures used especially in astrophotography.

Why is a fully-manual 35mm camera recommended for astrophotography as opposed to a automatic type?

Fully manual 35mm cameras have the distinct advantage over automatics because the internal mechanisms are mechanical and not electronic. In astrophotography, long exposures are frequently taken and electronic cameras requiring battery power will quickly deplete especially photography in cold temperatures. Electronic automatic cameras would do for short time exposures for instance during twilight or dawn but for very long exposures, the fully manual camera is the astrophotographer's workhorse. Most of today's automatic cameras are geared for the professional photographer or individual who takes the everyday shot. Astrophotographers deal with a unique type of photography which centers on subjects in low-light situations and celestial targets that are points of light millions of miles or light years away.

What 35mm fully-manual cameras are recommended for astrophotography?

These types of cameras are hard to find today and are no longer made. They can be found on the secondary market and possibly on your camera shop's used camera section. The all-time favorite, and one of the most popular cameras a generation ago, is the Olympus OM-1. These can be had for about $200 with the standard 50mm f1.8 lens. Other excellent possibilites are the OM-2, OM-3, Canon F-1, Nikon F, Nikon F2 and Pentax LX and the Pentax K-1000. Personally, I use a Chinon CM-5 and a Nikon F, both fully manual.

Why is it beneficial to use a bright focusing screen in a 35mm camera for celestial objects?

The standard ground-glass focusing screens in the viewfinders of many 35mm cameras are perfectly adequate for snapshot photography. Unfortunately, they produce images that are too dim to allow focusing on stars or seeing faint deep-sky objects such as nebulae and galaxies. Several camera models, including the Olympus OM, Nikon F, and Pentax LX series, have interchangeable focusing screens. There are also several types of focusing screens depending on the type of photography. For planetary photography, one with a clear central spot and cross hair reticle is highly recommended. A type that has a clear ground glass is ideal for wide angle astrophotography.

Where should I go to have my astrophotos developed?

Most photo labs do an adequate job developing astronomical slides and negatives. But it's safer to start each roll of film with a conventional snapshot also called a 'guide shot'. This standard exposure helps the lab distinguish dark sky from the unexposed border between frames, which reduces the chance of your precious negatives or slides being cut in half. Though they do a reasonable job developing the negatives, most photo labs come up short in making prints and enlargements. Your best defense is to educate the personnel at your favorite photo lab. Ask them to print for a "neutral dark-gray sky background;" this should reduce the chance of receiving prints with green skies and purple stars. A better alternative is to find a professional custom photo lab who have personnel experienced in astrophotography.

Astrophotography & Astronomy Definitions

Cable release: A length of cable that screws into the shutter button with a lever on the other end that pushes air down into the cable to engage the shutter and a thumb screw that locks it in place.

SLR: A single-lens-reflex camera. The lens that directs light onto the film also is used to view and focus the composition in the viewfinder. This type of unit also allows the photographer to use interchangeable lens on the same camera body.

Focal ratio: The speed of a lens. The lower the f/stop (e.g., f2.8 as opposed to f4) the faster the lens and the more light it takes in which means faster exposures. In astrophotography, fast lenses are preferred since the photographer is working with dim scenes and subjects far away.

Star trails: The movement of the stars and planets from east to west due to the earth's rotation and known as diurnal motion causes streaks on the photographic exposure during long exposures. If the camera is centered directly on Polaris (the north star) the streaks will appear circular with Polaris in the center and known as circumpolar star trails. This is the easiest form of astrophotography.

Burning film: Taking many exposures and using lots of film to capture the proper exposure and a rewarding and pleasing image. Burning film is a approach used in conjuction with bracketing exposures.

Bracketing: A photographer's method of shooting exposures on either side of the recommended exposure value in order to capture the widest range of exposures in order to increase the chances of a rewarding photo. This is especially important during twilight and early morning photography when lighting conditions change fast.

Sky-fog limit: This term refers to the exposure time limit of a particular emulsion when the film starts to overexpose and pick up light pollution. The exposure will have a washed-out look. In general skyglow is determined by several sources including light pollution from distant cities, the natural airglow from atmospheric particles as well as surrounding and stray light sources from the immediate site.

Some Quick Astrophotography Tips for Good Images

For wide field shots such as constellations, conjuctions, twilight, etc. keep exposure under 30 seconds to avoid star trailing.

Use slower print or slide films in 100-200 range for more rich colors and finer grained images. This is important if you are going to enlarge your photo for display. Use higher speed films from 400 to 1600 ranges for instances where short exposure times are needed and/or when unguiding your shots. The trade off will be that your images will reach the sky fog limit more quickly and, of course, be more grainy. Personally, I stick with the slower film range for twilight and morning shots and use the medium to fast range of films for times when fast exposure times are needed for example in meteor photography and planetary photography. Sometimes I like to use the 200 speed film because it is especially an advantage during changing light conditions like twilight scenes when you need a little more sensitive film. Slower films are also useful during piggyback or barn-door tracker imaging so that you can keep your exposure times down to avoid sky fogging and still maintain the sharpness and detail of the slower range of the film speed. The trick is to process the film in a procedure called "push processing" so that more of what the film caught or gathered can be exposed. This method works well with low-light, workhorse films like Elitechrome 200. Remember, the longer your exposure, the greater the chance something can go wrong.

Twilight and morning shots are especially tricky since the lighting is constantly changing. Your camera's light meter will weigh in a bit overexposed in these instances so bracketing your shots (especially in the underexposure range and when using slides) is highly recommended.

When using normal (50mm) to wide-angle lens (24mm to 28mm) lens for more wide field shots, try to 'eye' a nice composition in your scene. Use the surrounding landscaping to frame and compose your shot.

When setting your fstop, always stop down by one increment. Setting your aperature to the fullest open setting may introduce some bloated star images along the edges of the photo. The sweet spot for normal to wide angle lens is usually f2.8.

Remember to take (burn) lots of film and bracket your shots. Film is relatively cheap and getting that one prize shot you can hang on a wall or be published is worth the other 23 or 35 shots.

Remember to take good notes in the field. Taking notes while you do your exposing will help you not forget later and your log will act as a handy reference for when you want to improve on your techniques. I recommend using a small tape recorder so that you don't have to take your eye off the sky. This is also very useful in astronomical observations.

It is best to astroimage when the sky is settled and dark, later at night or during the early morning hours when light pollution is at its lowest and your neighbors have their porch lights off and there is less air traffic in the sky and fewer car headlights wizzing by.

Keep a watchful check on your lens (whether camera or telescope) for dewing, especially during the late and early morning hours when temperatures drop.

Always use a red light for seeing in the field and dark adaptation.

Have backup batteries for your light meter, red light and tape recorder.

Have a spare cable release in case one fails during your exposures.

One golden rule in the field is 'Murphy's Law'.

For meteor photography, use fast film. The faster the better. I find 1600 speed Fuji Provia or Ektachrome to be good. Meteors are swift and mostly faint. You need fast emulsion to capture the brighter meteors that may leave an impression on the film emulsion.

If your camera or telescope setup has some vibrations when activating the shutter, use the 'hat trick method'. Frame and compose your image in the field of view. Put a dark piece of material or hat in front of the lens and start the exposure. Once the vibrations settle down completely, remove the hat and start timing the exposure. When you are ready to stop the exposure, put the hat back in front of the lens and close the shutter. This method is also useful for me when I am exposing an image and a plane moves into the region of your target. Just use the hat trick without touching the shutter unless your want your image to record the plane trail.

And, of course, always watch out for creatures of the 4-legged variety like bears, deer, raccoons and foxes.

Recommendations

Books:

The Backyard Astronomer's Guide by Terence Dickinson and Alan Dyer.

Astrophotography for the Amateur by Michael Covington.

Astrophotography: An Introduction by H.J. P. Arnold (Sky Publishing).

Splendors of the Universe: A Practical Guide to Photographing the Night Sky by Terence Dickinson and Jack Newton.

Introduction to Observing and Photographying the Solar System by Dobbins, Parker and Capen

Nightwatch by Terence Dickinson

The Cambridge Star Atlas by Tirion

Wide Field Astrophotography by Robert Reeves

Chesapeake Invader by Poag

Astrophotography featuring the fx system of exposure determination by Barry Gordon

Meteors by Neil Bone

The Quest for Comets by David H. Levy

Full Moon by Michael Light

Peterson Field Guide to the Stars and Planets

Practical Astrophotography by Jeffrey R. Charles

Video Astronomy by Massey, Dobbins, and Douglass

The Planet Observer's Handbook by Price

Magazines:

Astronomy, Sky & Telescope, SkyNews, National Geographic, the Astrograph.

Astrophotographer's websites

Chuck Vaughn's site at www.aa6g.org/astro.html

Jerry Lodriguss's site at www.astropix.com

Brad Wallis's site at www.frazmtn.com/~bwallis

Doug Clapp's site at www.unicom.org/~dclapp/index.htm

Chris Schur's site at www.pulsar.la.asu.edu/~chris

Video astronomy at www.astroimaging.com/

Video astronomy at www.lafterhall.com/astro.html

Todd Gross's site at www.weatherman.com/todphots1.htm

Jason Ware's site at www.galaxyphoto.com/

Film Recommendations:

Personally, I recommend the Kodak Chrome series of films, especially EliteChrome 100, 200 and 400. These films, especially EC 200, are great great low-light, workhorse films and have provided me with some beautiful images (see my photo page for my astroimages). For more information on recommended films for astrophotography, see the weblinks below:

www.astropix.com/films.htm

www.connecti.com/~rreeves/filmtest.htm

www.covingtoninnovations.com/astro/films.html

www.geocities.com/CapeCanaveral/Lab/6529/primer.html

www.personal.umich.edu/~jstys/

www.darkskyimages.com/films.htm

www.galaxyphoto.com/thizy.html

www.willbell.com/new/widefieldast.htm

www.skypub.com/imaging/astrophotography/camera.html

www.astrophotographer.com/photographer_progress.htm

www.erols.com/astrogph/color_rt.htm

www.theskyguide.com/astrophotography/film.html