Moin!
Gleich vorweg: Nein, ich kenne das Objektiv auch nicht. Aber da ich gerade am googeln war, hab' ich 2 Kommentare ergoogelt. Bist Du ausreichend des Englischen mächtig?
"Wondering if anyone has any experience with the Vivitar 400/5.6. I've
got one that i've had for a few months now, and i have difficulty
getting sharp pictures with it - even 4x6's aren't very sharp - i can
tell that it would look really awful going larger."
Und:
"I owned a Vivitar 400mm F5,6 lens some years ago. Actually it was purchased in 1980. At that time it was supposed to be sharp (comparing it to independent lens rivals). I've used it on my Canon to shoot wildlife pictures in Namibia's Etosha National Park. Even at that time I was not quite satisfied with the resolution. It lacked that biting sharpness I was looking for and the minimum focus (20ft) was awfull. After about 10-12 years shooting with the Vivitar I decided to buy a
Sigma AF 400mm F5,6 APO. What a difference ! Up to this day I am still shooting with the Sigma and most of my work get published, as I am a calendar publisher here in Namibia. Hope the information is of any value."
Dafür kann's doch eigentlich gar nicht billig genug sein, oder?
Gruß, Matthias