These few months I have been taking photos and I found out that my picture aren't that sharp and the color is not dynamic as it was before. Is it due to my lens, body or my skill of taking photos? Initially, I used the Canon EF-S 18-55mm f3.5-5.6 and the color is striking and much more dynamic. Then I changed to Sigma 18-200mm F/3.5-6.3 DC OS, and the picture I have been taking is acceptable for me. Not quite sure what happen. And my view finder also a bit blur. But the picture taken isn't like the view finder.