To Fruitpassion (others welcome): focus length magnification

"我预备拿它做备用相机放车里，另外，我的新相机是全幅的，长镜头只有７０－２００，

用惯了以前的１８－２００，真的觉得“手不够长”，所以我带D50在身边“远射”"

You are thinking that your 200mm on the Nikon D50 is equivalent to 300mm (1.5x crop) on a full frame camera.

This is actually a VERY common misunderstanding. EVEN professional photographers make this mistake. Here is why:

Your Canon 5D has 13.3 MP resolution. If you take a picture using your 200mm lens, then crop it by a factor of 1.5x, you end up with 5.9MP with the same field of view as your Nikon D50. Your Nikon D50 has a resolution of 6.1 MP, which is more or less the same as 5.9MP. In other words, your 5D gives essentially the same resolution as your D50 in that cropped field of view.

Now, which camera produces better images? I am quite sure 5D has lower noise level than D50. I would think other parameters would also favor 5D.

Now which lens produces better images? Canon 70-200mm f/2.8 or Nikon 18-200mm f/3.5-5.6? There is no doubt 70-200mm f/2.8 is the winner.

To conclude, if you want to shoot birds, you should still use 5D. D50 does not give more "reach".

所有跟帖： 

• Agree with you. This is indeed a common misconception -psms- ♂ (0 bytes) () 12/01/2006 postreply 20:50:59

• 回复：To Fruitpassion (others welcome): focus length magnificati -waterbottle- ♂ (0 bytes) () 12/01/2006 postreply 22:44:34

• Oops, ignore last one -waterbottle- ♂ (112 bytes) () 12/01/2006 postreply 22:47:04

• Yes, but again, after cropping on a full frame photo, -pieq314- ♀ (49 bytes) () 12/02/2006 postreply 07:19:22