Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Is this a full frame lens? I have a Sony A99.
Document: It makes for more artistic photos if you  allow that to happen.I highly recommend this lens.additional: A few weeks later, this is still my favorite lens. It is a special purpose lens and that is how I use it. The one thing I have noticed on the Sony A-580 is that you cannot judge exposure by what you see in the viewer. Your photo will be several stops (depending on the light) brighter that what you see.
A real sharp lens with a wide aperture and I don't have to wait for the focus to hunt around,
Vivitar/ Rokinon/Samyang  85mm f/1.4 manual focus lens.I just purchased and received this lens today and I am extremely pleased with it. The focus ring glides like a pro lens, the defocused areas are smooth and buttery, the colors are very nice and it is deadly sharp. I think it is already my favorite lens. Using manual focus takes a little practice but you can develop an eye for it pretty quickly if you try.
The real negative in my opinion is that the sharpness of this lens makes me feel my other lenses are not sharp ... not a bad problem to have.
It takes some time to get used to manual focus but results are good. Recommended if you have the time to compose your picture. Not for action pictures.
Great for the price, sharp.MF takes some getting used to but its fairly easy.Love it, if you are looking for an 85mm this one is a great choice.
Answer: Yes it is, I'm using it with the Sony A7 (via an adapter) and it works fine.