Learning Center
Astrophotography

Jeff Peronto of Madison, Wisconsin, is a music professor with over 35 years experience teaching at the University of Wisconsin, and his local community college, Madison Area Technical College. He still works with two area jazz ensembles and one band. But in his spare time, Peronto’s passion is directed skyward to the music of the spheres, and capturing the awesome beauty of the celestial realm in photographs. “I’ve been seriously involved with astrophotography since I was a junior high school kid in Milwaukee,” recalls Peronto, “and when I was in high school, I won a Future Scientists of America Award for color filter photometry, that is estimating the magnitude of stars by shooting them through different colored filters. I’ve also been using Tamron lenses for over 40 years—back in the day I used a Tamron 200mm f/3.5 on my Contax RTS 35mm SLR because its performance was superior to any other 200mm lens available in Contax mount.

Before the dawn of the digital era, Peronto shot some outstanding comet pictures on film—Halley’s comet in 1985, and the Hale-Bopp comet in 1997 (see photo and caption). These days, he’s made the transition to digital, using a Canon EOS 20D, an EOS 5D and a variety of Tamron lenses to shoot everything from exquisitely detailed close-ups of the moon to striking images of Comet Holmes, the latest and brightest comet of 2007. “It just brightened in a matter of hours and looks like a fuzzy patch in the sky,” notes Peronto, “so I shot it in the wee hours of the morning with one of my favorite lenses, a manual focus Tamron 180mm f/2.5. The lens really came through, capturing very faint tail and the teal glow around the head of the comet.”

Shooting the moon, and more

“With digital I can shoot 100-300 images at virtually no extra cost instead of 5-10 as I did back in film days,” says Peronto, “and that really helps you get the perfect shot when you’re photographing something as transient as a comet. But I didn’t have to take that many frames when I shot the full moon with my Tamron SP AF200-500mm f/5-6.3 Di LD (IF) super telephoto zoom. I was able to zoom out to 500mm, auto focus on the subject with my tripod-mounted Canon EOS 5D, and fill the frame with an amazingly crisp lunar portrait at 1/500 sec at f/8 with the exposure compensation set to minus 1-1/2 stops. I also use my Tamron SP AF 28-75mm f/2.8 XR Di LD Aspherical (IF) and AF17-50mm f/2.8 XR Di II LD Aspherical (IF) to shoot wide-field pictures of the heavens.”

Comet and moon photography made simple

Here are 6 astrophotography shooting tips by Jeff Peronto that will let you get satisfying celestial pictures of your own with a minimum of equipment.

1. Use a good late-model DSLR that will deliver excellent image quality at ISO 400 and ISO 800 and reasonably good image quality at ISO 1600. The current 10-megapixel models from top makers all qualify.
2. Use a good sturdy tripod—a full-size heavy-duty model is best but a medium-sized model or a robust tabletop model will do. Make sure to place the tripod on a flat, stable surface that is not subject to vibration—the ground or a rock is a lot better than a wooden porch or deck, and extend the center column as little as possible for maximum stability.
3. Set your camera’s self-timer for 10 sec (to minimize residual vibration from pressing the shutter release) and set the shutter for as long an exposure as you need—25-30 sec if necessary. Really long exposures in minutes require a fairly expensive tracking mount to eliminate star trails due to the earth’s rotation, but these can actually enhance the picture if your objective is artistic rather than scientific.
4. Get out in the boonies where it’s really dark, especially when shooting comets and faint stars. All urban and most suburban locations have far too much light pollution that will be recorded by your camera and degrade the image. If you can see all the stars in the Big Dipper and Little Dipper clearly, you’re probably in a dark enough location.
5. Make sure your lens is focused at infinity—many lenses will focus past infinity. Manual focus works best with faint objects and with comets, but auto-focus Tamron lenses will focus on the moon and other very bright objects.
6. Make sure there is no moon in the sky if possible when shooting other things. The darker the sky the better and you’ll generally get the best results with fast, single-focal length lenses (like Tamron’s SP AF180mm F/3.5). An exception is the Tamron SP AF200-500mm f/5-6.3 Di LD (IF), which works well on both full-frame (24x36mm format) and APS-C-format DSLRs for all but the faintest objects.

“Shooting pictures of comets, stars, the moon and other celestial objects is not only easy and satisfying, but it also gives you a real sense of awe at the majesty of the universe,” notes Peronto. “And while sensing our place in this vast cosmos measured in light years may make you feel small, it’s also a great way of enjoying life, seeing what’s out there, making it more visible, and sharing it with other people.” We couldn’t agree more.

Comet Holmes, November 10, 2007: Straight 25 sec exposure with tripod-mounted Canon EOS 20D and Tamron 180mm f/2.5 lens, at ISO 1600. “You can see that the stars trailed during the time of the exposure, but the head of the comet is very visible along with a fog-like coma surrounding it. This picture shows what you can do with limited equipment.”

Comet Holmes shot with same camera and Tamron lens as above, but with a tracking telescope mount. Nine 3-minute exposures were digitally combined to yield an image with more detail and color information and no visible star trails. More advanced stargazers with the right equipment can do the same quite easily.

Full moon: To shoot a picture like this just mount a long telephoto lens such as the Tamron SP AF200-500mm f/5-6.3 Di LD (IF) on your tripod-mounted DSLR and take the shot. This one was shot in auto-focus mode at 500mm at an exposure of 1/500 sec at f/8 with a Canon EOS 5D.

Hale-Bopp Comet of 1997: Canon F-1 with Tamron SP 300mm f/2.8 LD (IF) lens, 9 minutes at f/2.8 on Fujicolor 400 film

Comet McNaught: Here are two views of it taken in January 2006 with a tripod-mounted Canon DSLR and Tamron SP 300mm f/2.8 LD (IF) lens at 1/8 sec. The ISO was set to 800.