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Yes, it's really an astronomical telescope -- a 150mm Maksutov-Cassegrain telescope, to be precise. This particular model is sold by a company named Orion, which is a major optics provider, and a very reputable one at that. My unit was manufactured in China and is stamped with the ORION logo, though previously this model was manufactured in Russia. I have used this scope for long-distance observation of Bald Eagles nesting in North Carolina. Because it performed superbly for this terrestrial viewing task I decided to try using it for general bird photography.

The reason is simple: cost effectiveness. When attached to a normal SLR camera, this Maksutov telescope acts as an 1800mm f/12 lens. To achieve a comparable focal length (i.e., magnification) using a Canon EF lens I'd have to purchase a 600mm f/4 prime lens and then stack a 1.4x and 2.0x teleconverter (plus appropriate extension tubes) onto it to achieve 1680mm at f/12. The latter setup would be almost (but not quite) as powerful as the Maksutov telescope, while having the same aperture (f/12) and therefore roughly the same brightness. While the Canon system may very well be sharper and offer better color rendition (?), the above photographs show that the Maksutov can produce stunning results when used under ideal conditions.

And the cost of the Canon system?

Roughly $8000 new (!). By comparison, the Orion is $600 new -- less than 10% the cost of the "real" lens.

I only use this lens in bright sunlight. When the sun goes behind a cloud I find that I have to reduce the shutter speed to 1/80 or below, and then the quality is generally very poor due to movement of the subject (or the observer...). On dimmer days I sometimes use the Celestron C-5 instead, which has a slightly better f-ratio. The C-5 is another astronomical telescope -- a Schmidt Cassegrain, to be precise. I used the latter telescope to study a family of Bald Eagles in Washington, D.C. for 11 years, and found the optics to be exceptional. For photography it works very well also, though with a focal length of only 1250mm.

I've tried, but without much success. For birds in flight I prefer a hand-held solution, such as the Nikkor 80-400mm zoom lens, or my new Canon 300mm f/2.8 prime lens plus a 1.4x or 2.0x teleconverter, for an effective focal length of 420mm or 600mm. Both of these lenses feature image stabilization (IS), which is very useful for action shots, such as of birds in flight.

The 6-inch Maksutov is about 8 lbs., or 14 lbs. with the tripod. I've wrapped some rubber pipe insulation around the tripod, so it's not too uncomfortable to sling over my shoulder and walk around with it for moderate distances. For longer-distance hikes I sometimes take the C-5 instead, since it's only 6 lbs., which rivals my 300mm Canon EF lens.

It's all relative. If you don't have $8000 for a "real" Canon or Nikon lens, the Orion (or comparable alternative) can give excellent results at a far smaller expense. A "real" $8000 lens would probably be sharper, though at the current resolution of digital SLR cameras it's debatable how much of that added sharpness would translate into improved image quality. Also, note that this telescope is bulky (making it potentially difficult to take onto a commercial airliner) and it isn't airtight (dust can and will get into the interior of the lens when you remove the lenscap to attach the camera). Also, because this lens wasn't designed for use with cameras, there is no support for auto-focus nor auto-exposure, so everything must be set manually on the camera. I generally shoot one "test" photo of each subject, look at the resulting image on the camera's LCD screen, and adjust the shutter speed accordingly before commencing with the next series of shots.

On a more positive note, for the money you'd spend on a "real" lens you could buy no fewer than 13 Orion 150mm Maksutov telescopes...quite an arsenal!!

Happy shooting!

~Bill Majoros

Big Freakin Lens

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