視覺獵人 wrote:
回正題，因為看到很多範例圖、網友的作品、還有PhotoZone的國外測試(如下圖)
都覺得副廠鏡Sigma 10-20mm在變形控制方面一直很出色
...(恕刪)
因為視覺獵人提供的資料與小弟親身經驗有點出入，所以仔細看了一下友站的測試報告。
發現雖然Sigma 10-20平均的變形（失真）控制的不錯，可是文中也提到10mm端邊緣失真是很嚴重的（-2-3％）。我想這就是這支鏡頭雖然測試值不錯，可卻又令人感覺變形比較大的原因吧。
以下節錄自Photozone:
The Sigma AF 10-20mm DC showed a rather unusual distortion characteristic. At 10mm most of the image field is almost free of distortions so the measured distortions figures look fairly fine here (taken a little inward from the borders). However, this is only part of the truth. If you check the 10mm distortion chart below you will notice that the outer image portion is actually heavily (barrel-)distorted - probably in the 2-3% range.
At 14mm the lens shows a rather strong degree of pincushion distortions, less so at 20mm.
提供大家參考。
