The Bower 85mm f/1.4 Manual Focus Lens is a special effort in the independent lens manufacturer world, being a popular focal length for serious portraiture combined with an extra large f/1.4 maximum aperture. Most independent manufacturer lenses are either zooms or very short or long focal length fixed lenses. This lens is precision manufactured in South Korea.
This lens mounts to any Sony (or Minolta Maxxum) camera and works on both "full frame" cameras like the DSLR-A900 as well as the "APS-C" style digital SLR cameras, but the aperture is neither communicated to nor controlled by the camera body. As such, you can use the lens in "M" manual exposure mode or "A" aperture-priority mode only, and in both cases you will physically move the aperture ring to the aperture of your choice and it will stay at that aperture even before the exposure.
With a 35mm equivalent focal length of ~127mm and that f/1.4 aperture, this Bower 85mm lens opens up photographic opportunities you'll never get with your zoom. Capture close portraits of singers on dark stages with only spotlights on their faces, and those background lights will be soft cascades of low-contrast coloring. With the big f/1.4 opening, you'll have enough light to stop subject motion. Or try it in brighter conditions at fast shutter speeds and low ISOs to make great shots of people in front of blooming trees, with background flowers almost looking like paintings. It isn't easy nailing manual focus at f/1.4-2.0 (nor for that matter is it easy for an AF system), but you'll get better with practice, and soon be making many snaps that stand out in a crowd.
This lens was truly created with large-aperture shooting in mind. Though a fine performer with plenty of contrast and resolution at f/5.6-f/11 apertures, it is at its best shooting between f/1.4-2.8, where it presents a high-peak-resolution focus point surrounded by lower resolution/contrast out-of-focus areas. Rather than just sharpness all around, for many pictures it is this stark drop off in resolution and contrast that effectively draws a viewer's eye towards a subject.