Unconventional telephoto lenses

The majority of DSLR telephoto lenses, whether sold by Canon, Nikon or third-party companies like Sigma or Tamron, cost at least several thousand dollars. Only professional or passionate amateur photographers afford such lenses, generally used for sports and wildlife imaging. Other enthusiastic amateur photographers may purchase a zoom telephoto lens for 1,200-1,700$. While they crave for a bigger and better lens, it will remain a fantasy.

Frustrating situation, indeed. However, telephoto lenses are very delicate optical devices made of 10-20 separate lenses. Some are coated with expensive high-transmission or extra-low dispersion layers, and others are to be moved by the focusing mechanism. Moreover, lens glasses are made of high quality pricey materials. Increase a lens aperture and thickness by 2, its price will thus increase 4-fold, if not more.

Consequently, crafty (and reasonable) photographers have experimented alternate solutions to invaluable telephoto lenses. The Russian Maksutov optical design, common in astronomy, is among such solutions (www.novacon.com.br/lenses05.ht…).

Alike astrophotographers, others have attempted to combine their camera to a small telescope or spotting scope, a method known as digiscopy. These telescopes often share similar characteristics to telephoto lenses like aperture (80-100mm) and focal length (400-600mm), but are much less expensive! With the proper camera adaptor, they yield stunning images. It however requires a sturdy mount or tripod due to the telescope weight and lack of image stabilizing system.

Below are two examples of digiscopy images.



If any of you have questions about digiscopy, please send a note to Myriam (sicmentale.deviantart.com).