Vivitar 650-1300mm f/8

This lens is marketed under may rebrand names. I own it and the lessor 450-800 MM, both I feel are good lens for the price presuming one realizes the short fall of lense of this type. It is not a grab and shoot lens, one needs time to setup and focus and due to its size it really requirers a tripod.
That said, is it as sharp and crisp as the big Canon lens? NO! But, $250 verses thousands one would expect less. I find after the learning curve it works very well for the planned shot when one has setup time! This lens is for planed or staged shots and for that it is a really nice lens, once one gets experienced with it! I use mine often and get results I like. Birds at a feeder, set up and focus on the feeder then use an intervolmeter and let the camera just do timed shots, you will get some very good shots of birds after sorting through many, many dud shots, good shots always come with a cost!
The smaller lens, 450-800 MM. Much smaller and more portable with the same short falls as the big one. I have used my Canon 600 MM for shots to compare ( same time, place, object , and distance ) with the smaller 450-800 MM lens set for 600 MM to find no one yet has realized it was done with two different lenses so picture quality isn’t that big an issue. I have no lens to compare the big one with.
Both lenses can be purchased with a X2 converter, I have one for mine. The converter works well buy cuts a lot of light requiring some setting changes, no big deal in day light. The converter also doubles the setup making it tougher as the lens with it became larger. Bother lenses came with covers and nice cases or bags to protect them in storage.
All said and done, I see an abundance of people unhappy with these lense in coments. I fell it is people not grasping what they bought before they bought it. First it is an inexpensive lens. Second, manual everything and people seem to want everything auto focus. Third, any, and stress ANY! long lens is subject to shake and thus is hard to aim and focus until one gets to know the lens and even then it takes time to set up. If one can get past the learning curve I get some truly nice pictures with these lense and have no regrets for buying mine. Each lense has it’s place and has worked well. The big lens for real distance shots, the smaller lens is handier for setup and is quicker to use. The big lens is for planed shots, the smaller is more sized to carry incase one desides he needs it unexpectedly. The big lens is big and heavy, smaller is far lighter and smaller to carry.
I own both, use both and am satisfied with both realizing I have only about $350 in both and get what I find exceptable pictures! I would suggest not doing what I did, buying the big one first! If one buys the smaller it’s cost is about half and it does a fine job for distance shots. It also is easier to setup and lean in my opinion, I feel most people would be very happy with just it. I have both, use both and find each definitly has it’s own place.