Top positive review
51 people found this helpful
What an incredible piece of glass !!!
on December 9, 2010
Being an optical systems designer by training, with some of the finest glass on the market in my inventory (including the past purchase of a $70K aerial lens), I was amazed by the quality and capabilities of this reflection based 500mm T-mount lens. When shipped through an Amazon reseller, the package included a 2x teleconverter and a T-K mount Pentax adapter.
An important consideration behind this lens is that it is a fixed aperature (f/8 with supplied 2d (f/16) and 4d (f/32) neutral density filters). I found this lens to be worth ever dollar of the original $400.oo list price, instead of the very attractive package that Amazon put together.
Having worked with other reflector based tele lenses and telescopes, including Celestron optics which I am very familiar with, I found this lens to be at the top of it's class. Along with it's solid metal construction and light weight, this lens also surprised me by it's macro capabilities, focusing down to about 5', amazing for a 500mm lens. Keep in mind, that on a Pentax K camera, with an approx 80% sensor size of a 35mm format, this lens is comparable to a 600+ mm lens on a 35mm camera, with the 2x adapter doubling that.
I have tried this lens out in a number of situations with my Pentax K100 and K200D cameras, letting the shutter priority (default in Auto mode) take care of the proper exposure. With the body based stabilizer capability of the Pentax K200D camera, at 500mm, this lens provided motion free images in a pee-wee league football game which I tested it at. That would have been a 4 figure investment for a Canon or Nikon order, for a comparable auto stabilization function.
In shooting some images cross a very neutral field, I noticed some brightness falloff from the center to the edges, but for most subject situations, this is not a factor, and can actually make for a nice effect on landscape and some of the yacht race pics that I expect to put this lens to use for.
So, if you have a Pentax DSLR, with the auto stabiliztion feature, and want a great high power tele lens, for a surprising low price, this is the one to get. Keep in mind that with the power of this lens with the 2x converter, a sturdy tripod becomes a must.
My other addition to this lens will be a 72mm Skylight and Polarizer filters, to both protect and expand on the capabilities of this fine piece of optical glass.