I am using Sigma APO 70-300mm f4.5-5.6 DG Macro. APO Revision is much better. it provides a better sharpness, brightness and saturation than that of non-APO len. Marco (1:2) is enought and usefull for the most users. It is very cost effective for general purposes.
缺點:
Marco functions only in range 200-300mm. In the marco mode, the front len will extend, the Auto-Focus speed will be reduced specical in S, N & C DSLR. For Pentax, the AF speed can be maintained. As the AF is powered by the motor of DSLR body, the noise level is quite large as traditional SLR.
評價:
Narrow image depth is very easy to be achieved. APO Revision provide a better ratio of performance to costs. It is very suitable for starter.