Hey, welcome!
If you have a problem, its great if you upload a sample photo with in-tact exif data.
But I think Steve is on the right path. You see, a long tele lens (high mm number) will show handshake blur much more than a wider lens. For a 270mm lens, you need very steady hands and a fast shutter speed (rule of thumb used to be at least 1/ (1.5*focal length), but with modern high-resolution cameras, this is increasing). Better yet, use a sturdy tripod and 2 sec timer.
Another thing is aperture - a wide open (small f-number) photo will have a shallow Depth of field, and that means it might look "soft" in some places. So you want to stop down to a slightly higher f-number (but don't go above f12, as that will soften the photo due to diffraction).
Oh, and if a lens has built-in image stabilization, you must disable it. With image stabilization, it should be enabled only on the lens, or on the camera (SR), never both.
And just one more thing, lens with a big zoom range is more likely to be soft. If you want great sharpness, get one of the Limited lenses, or even the DA 35mm f2.4, DA 40mm XS, DA 50mm f1.8. This will automatically give you better IQ at the expense of zoom flexibility.
Last edited by Na Horuk; 02-02-2014 at 08:36 AM.