This lens looks good at first, but has some serious issues. Definitely not what one would expect from Vivitar. Image quality is rather poor: soft at f5,6 and slightly better at f8, acceptable sharpness at f11. Chromatic Aberrations (CA) are terrible: awful red fringing on almost all pictures (see samples), it is even visible in the "bokeh". The lens seems to have some kind of coating, but it is not very effective on the CA issues. I did not notice any haze or lack of contrast, so in that aspect the lens is fine. Handling is easier than one would think. The lens is not that long and can be hand held, although there is an adjustable tripod collar. Focusing is smooth and can be done pretty fast, after some practice. I would not recommend this lens unless you really need a telephoto and if you don't mind clearing the CA in post-processing. I'd say it would be worth maximum 25 euros, any higher than that and you can probably find something better, but for under 25 euros, it's acceptable. (I paid 10 euros)

 

(by Tom De Nies)