To emphasize what has been said above...technique is important.
- How do you focus? DOF is very shallow at longer focal lengths.
- Is the camera steady?
Yep, missed focus and camera motion are the leading cause of soft photos. Now to the first point:
- If using AF, be sure of your focus point. If you allow the camera to choose the focus point where focus is critical, it will almost always choose wrong. I use the center point almost exclusively with AF.
- Be aware of the limitations of AF. Even in best case, the AF system may miss focus on a curved surface at portrait distance. This and the first point above are good reasons to explore manual focus.
- Calibration of your AF system to your lens may be in order
- If using manual focus (MF), it is important that the viewfinder diopter be adjusted for your eyesight. The scribed markings on the focus screen should be sharp when the diopter is properly adjusted.
- Manual focus with the stock focus screen may lack adequate precision when used with faster lenses. I found it very difficult to nail focus with my Jupiter-9 85/2 until I switched to the aftermarket KatzEye screen. Other users on this site report good results with the S-type (precision matte) screen from focusingscreen.com which is tuned for use with lenses faster than f/2.8.
In regards to the second point:
- There are limits to the in-camera SR feature
- Tripods are our friend, though it is important to turn off SR when shooting on tripod. The 2s time delay feature is the easiest way to accomplish this.
If you want to continue testing your lens, I would suggest a simple, non-moving subject with high contrast and fine detail in good indirect light. Have the camera on a tripod. I have used my daughter's china doll, a watch face, and a pewter box in the past. (Look
HERE for examples.)
Steve
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