http://www.nikonchat.com/lenses-nikon-d300/

I am having problems with my Nikon D300 sharpness and my glasses. Can I get technical assistance? Lenses follows:?
Nikon Sigma 18-55 10-20 Tamron 18-70 Nikon 28-300 nikon 50mm 1.8 does not know what I'm doing wrong, but the images are not clear at all. Any help would be greatly appreciated.
If everything else is fine (the autofocus, viewing 100%, lenses are clean, etc.). – Avoid direct passage of bright light sources in the frame and the diffused light of falling in Use a lens hood when you can. Reduce the number of filters in front of your lens. In the camera settings, sharpness set to 'auto' and post-processing if manually to whatever value suits. Increase the contrast of their images, but be sure not to turn the time, highlights black or dark area. I prefer to do this through the use of curves.
Nikon D300 & Nikkor 105mm VR Lens: Unboxing