- The lens is without a tripod hardly einzusetzten, free hand goes there (almost) anything!
Consider that at the 500mm the crop factor is not even included. When c = 1.6, this results in a focal length of (500 * 1.6) mm = 800mm without electronic image stabilizer. According to the common rule of thumb this results in a maximum Freehand exposure time from [1 / (800/2)] s = 1/400 s, which is also a pretty bright 500mm telephoto rarely allowed.
But all this is not the fault of the lens but is the thing!
- For focusing one needs patience, but worth it!
Unfortunately, the adjustment path is just at a great distance, where you most frequently uses a telephoto, very short. Since one naturally desires an autofocus costing halt. It should be noted, incidentally, that one can focus up under 2,0m distance! The sluggishness I personally feel very pleasant, the focus is once found you lose him lightly (eg astrophotography there are for telephoto lenses for focusing the way Mikroverstellschrauben usual).
For religious war whether a mirror objective is at all a viable option for professionals I just say: First, a 170.- Tele course nothing for true professionals. Secondly, I am of the astrophotography there is an obstruction, the most normal thing in the world (artifacts are usually mathematically removed).
In short:
In my opinion, one obtains for 170.- a lens that makes excellent, bright and sharp images, if you take the time for it.
Dr. R. Hofmann
