一、相機紅外濾鏡干嘛的
紅(hong)(hong)外(wai)濾鏡(jing)的外(wai)表(biao)顯示(shi)是(shi)完全(quan)不(bu)透光(guang)(guang)呈黑色的玻璃體。由于我(wo)們(men)用(yong)肉眼能看(kan)見(jian)(jian)的只是(shi)全(quan)部(bu)(bu)電磁(ci)光(guang)(guang)譜(pu)中(zhong)極(ji)少(shao)的一(yi)部(bu)(bu)分(fen),也(ye)就是(shi)可(ke)(ke)(ke)見(jian)(jian)光(guang)(guang)區(qu)域,其實還有(you)我(wo)們(men)的視網膜(mo)不(bu)能感知(zhi)的光(guang)(guang)線(xian),例(li)如(ru):紫(zi)(zi)外(wai)線(xian)和紅(hong)(hong)外(wai)線(xian)。在光(guang)(guang)譜(pu)中(zhong)人眼可(ke)(ke)(ke)見(jian)(jian)的區(qu)域落在430nm~690nm波(bo)長(chang)之間,紅(hong)(hong)外(wai)光(guang)(guang)比可(ke)(ke)(ke)見(jian)(jian)光(guang)(guang)具有(you)更長(chang)的波(bo)長(chang)。與紫(zi)(zi)外(wai)線(xian)和可(ke)(ke)(ke)見(jian)(jian)光(guang)(guang)不(bu)同,紅(hong)(hong)外(wai)線(xian)的大(da)波(bo)長(chang)很(hen)容易地(di)穿透任何的物體,也(ye)就是(shi)紅(hong)(hong)外(wai)線(xian)在經過物體時不(bu)會發生折射。那么相機紅(hong)(hong)外(wai)濾鏡(jing)是(shi)干嘛的呢?
紅外(wai)(wai)線(xian)(xian)濾鏡(jing)利用紅外(wai)(wai)線(xian)(xian)的(de)這個(ge)特性,只讓(rang)長(chang)(chang)波長(chang)(chang)的(de)紅外(wai)(wai)線(xian)(xian)通過,濾除短波長(chang)(chang)的(de)紫外(wai)(wai)線(xian)(xian)和(he)可見光。阻擋(dang)可見光而讓(rang)紅外(wai)(wai)光通過。有夜攝功能的(de)相機就是(shi)通過機械(xie)裝(zhuang)置將這片ICF移開使CCD能充分接收紅外(wai)(wai)線(xian)(xian)。
二、相機紅外濾鏡怎么用
1、在(zai)進行(xing)紅外攝影(ying)之前,要(yao)準備一下器材:數碼相機、三腳架、快門(men)線以及我們(men)的紅外濾鏡(jing)。
2、調整相機(ji)的(de)(de)(de)自定(ding)義白平衡。選擇相機(ji)的(de)(de)(de)手(shou)動曝光(guang)模式,對(dui)準(zhun)戶外(wai)(wai)的(de)(de)(de)綠(lv)色植物進行對(dui)焦,裝上紅外(wai)(wai)濾鏡,拍(pai)攝(she)一張作為自定(ding)義白平衡的(de)(de)(de)標準(zhun)樣張。若你使用的(de)(de)(de)是720nm波段的(de)(de)(de)話,照片中(zhong)的(de)(de)(de)清空會是 琥珀 色的(de)(de)(de),而綠(lv)色植物則變成白色或(huo)帶淺藍色。
3、在(zai)拍(pai)攝過程(cheng)中,盡量使(shi)用(yong)三(san)腳架,因為紅外濾鏡會使(shi)曝光時間相對延長(chang),為了獲得清晰的影響(xiang),可(ke)以三(san)腳架結(jie)合快門(men)線使(shi)用(yong)。
4、由于(yu)紅(hong)(hong)(hong)外(wai)(wai)光(guang)會使原先可見光(guang)的對焦(jiao)點發生(sheng)偏移,所以具體步驟應該是:設置相(xiang)機白(bai)平衡、取下紅(hong)(hong)(hong)外(wai)(wai)濾鏡(jing)、取景構圖、擰(ning)上紅(hong)(hong)(hong)外(wai)(wai)濾鏡(jing)、人(ren)工前后移動(dong)調焦(jiao)。最后拍攝所需要的曝光(guang)時間則需要根據不(bu)同(tong)(tong)相(xiang)機和不(bu)同(tong)(tong)紅(hong)(hong)(hong)外(wai)(wai)濾鏡(jing)進行(xing)多次反復(fu)操作(zuo)得出基(ji)本(ben)規律。