Originally Posted by
paintingwithlight
I recently printed a 24 inch by 36 inch photo shot with a camera with a 24 MP sensor. You should be able to achieve similar effects with your 18 MP sensor. I don't think that you need to improve your camera. The problem with a lack of crispness lies elsewhere.
Some 20+ years ago zoom lenses were compromises - you can't bend red light and blue light the same way through a lens, but at a fixed focal length you can compensate for this quite well. If you have variable focal length (i.e., a zoom lens) then the red light and blue light don't perfectly register in the same way. You can achieve sharper images with a prime (i.e., fixed focal length) lens than with a zoom lens. That being said, try playing with your f-stop before buying a new lens. If you are shooting with the aperture wide-open then that is the most likely source of lack of sharpness.
Each lens has its own sharpest rendering at a given f-stop. For DSLR lenses this often lies between f/9 and f/16. Take a series of shots with your camera, zoom into the center of the image and note which f-stop was sharpest. A tripod might help.
If shooting with a cropped sensor (like your camera) try shooting no slower than 1/FL th of a second where FL is the focal length of your lens to reduce blurring caused by hand shaking.
Finally, maybe clean your lenses and sensor? If you take a shot of a uniform surface (e.g., a clear sky) with the lens stopped down to the highest f-stop (smallest opening) then you will be able to see dirt on the sensor when you zoom into the image.
Best of luck!
Michael