[初心者]

請問其運作方法、原理、特色、缺點與SLR的分別?
請各位老行尊指教一下~~ (請用中文=.=") 謝謝

[初心者]

push~

[Mike Chan]

連動測距簡單的講就之係指個的直接從觀景器取景而唔經取景的相機。優點係機身較細，震盪較少(反光鏡開闢引起的震盪)。但亦都因為直接從觀景器取景的關係，觀景角度受限制，用21mm或以上的廣角鏡就要加附助觀景器才可取得實際的拍攝角?度，亦都冇長焦距鏡頭。大部份連動測距機都係手動對焦(?影對焦)，只有contax G2有自動對焦。現時較為出名的品牌有Leica, Voightlander, Contax，而Nikon 及Konica也有一兩部復刻版出售。在SLR流行之前係主流相機，早年National Geographic, Times等各大報章雜誌的記者大多採用。
以上只能說出一的皮毛，希望能拋磚引玉，對連動測距機有深刻認識的同道發表一下。

[kzescher]

真巧..這個topic今期數碼流動有講..可以買本睇下

[ninekit]

rangefinding is a technique to measure distance.

assuming there is an object right in front of you, i.e. its at your 0 degree direction.

if you step sideway to the right by say 1 metre, the object will now shifted to your left, and you have to twist your body anti-clockwise to an X degree in order to face the object directly again.

a simple example if, if the object is 1 metre away from you originally at 0 degree, then when you step 1 metre to the right, you will have to twist yourself 45 to the left in order to lineup your eyesight.

So its just some simple math, given we know the horizontal distance between the two observation positions, and the angle you need to twist your eye to point to the object. The distance can be calculated.

A rangefinder camera has two windows, window 1, the direct viewfinder (0 degree observation point), and window 2, with a fixed distance to the right of the window 1. There is a rotatable mirror attached at the window 2 (resembling the twisting action when we stand at position 2), hinged to the lens' focusing ring / lever, and the image see throught from the window 2 are channelled back to the window 1 via a mirror or prisom block built inside the camera.

When focusing, we view through the window 1 (0 degree position), and adjust the focusing ring to rotate the mirror such that the window 2's view superimpose with the window 1's view. Then we know the object distance is determined.

The chinese name 連動測距 come from the fact that the focus ring/lever of the lens is hinged or coupled to the rotation mirror in the window 2 of the rangefinder.
hope it help explain how it works.