MACRO PHOTOGRAPHY

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Hnh chup vi Canon Macro lenses - Lay t internet khong nh ten tac gia

 

            Trong mot vai Email trc, anh Huynh Chieu ang co gii thieu mot tam anh chup hoa rau que. Tam anh o cung nh hai tam hnh tren ay c chup that can - CLOSE UP- con  goi la macro photography. Toi chac la cac anh ch cung a co oi lan muon chup nhng tam hnh nh vay, co ngi thanh cong, co ngi con gap tr ngai ky thuat nen hom nay toi xin trnh bay mot t chi tiet.

            Khi chup anh, e cho hnh c ro net ta luon luon phai ieu chnh ong knh ti lui -focus- tuy theo vat xa hay gan may anh. Nh lai bai hoc ve quang hoc t thi trung hoc, khi vat vo cc th anh nam cach quang tam 1 khoang  bang vi tieu c, neu vat cang en gan th anh ro se tap hop xa quang tam hn. Tieu c cua cac ong knh may anh pho thong tng oi ngan -50mm cho phim 35 ly, 75mm cho phim 4x6 hay 6x6- khi vat di chuyen t vo cc en trc may anh 1-2 feet th ong knh ch can di chuyen khoang 1/5 tieu c la ap ng c nhu cau cho anh ro, do o gan nh tat ca may anh thong dung eu c che tao e focus trong khoang nay,v vay ch co the chup c chan dung la toi a con neu muon chup can hn th khong the c.

Muon co anh bang vi vat th khoang cach t vat en quang tam = khoang cach t quang tam en anh = 2 lan tieu c, nh vay khoang di chuyen phai tang nhieu hn, viec che tao kho khan hn va ton kem hn.

            Chac cac anh ch con nh may anh cac tiem chup hnh ngay xa,  gia ong knh va phim la mot man xep nh an accordeon, may ong th chup hnh ch viec keo man nay dai ra la chup macro c ngay. Mot so ong knh Zoom cho may SLR co ghi la macro, nhng that ra ch co gia tr tng oi - focus gan hn mot chut neu so sanh vi cac ong knh khac ch khong that s la macro.

            Vay muon chup macro vi cac camera pho thong th sao?

 

 

1. Chup close-up vi may anh SLR (single lens reflex) film hay digital.

            ac iem cua may SLR la khi ngam qua may hnh anh thay sao la c ghi len phim ung y nh vay nen co nhieu cach e chup macro.

 

 

 

MACRO LENSES-

            Moi hang may anh hay hang che tao ong knh oc lap thng co san xuat 1 vai ong knh ac biet co kha nang focus lien tuc t vo cc en that gan e co anh bang vi hoac bang 1/2 vat. - 1:1  hay 1:2 - goi la MACRO LENSES (rieng hang Nikon th goi la Micro).

            Xin chu y ay la kch thc cua anh hien tren phim so vi kch thc cua vat - khong phai la kch thc cua anh sau khi phong ai - Cac ong knh nay v khong c thong dung nen gia kha mac- khoang 400-1000 dollars -

                        

 

            Vai iem ky thuat can chu y khi chup macro.

Moi rung ong nho cung anh hng nhieu en anh nen anh de b nhoe - nen gan may tren tripod. o sau cua anh ro (depht of field) rat ngan khi chup macro nen phai ong diaphragm lai that nho va thng phai dung them flash. V o phong ai kha ln macro nen o sang giam i rat nhieu - thng la giam i 2 nac - th du nh ong knh set vao khau o 4 th khau o that s ch con 8 ma thoi- neu set manual th phai lam bai toan gia giam nay, con neu dung cac may co bo phan o sang sau ong knh  TTL -through the lens- va set Auto th may co the t ieu chnh compensate dum phai lam toan.

 

CLOSE-UP SET-

            Neu khong muon bo ra mot so tien kha ln cho macro lenses th close up set la mot alternate e chup macro. Close up set la mot bo knh lup co o diopter +1  +2 va +4 c gan trc ong knh giong nh filter-  ghi theo ng knh - th du 49mm hay 52mm, gia ca tng oi nhe nhang khoang 20 dollars / set. Mac du khoang di chuyen cua ong knh khong thay oi nhng tieu c cua tap hp  "lens + close up" a ngan lai hn, tnh tng oi ong knh di chuyen khoang cach dai hn  nen co the chup anh gan hn, so diopter cang ln th chup c cang gan - co the gan chong nhieu close up chong len nhau e tang o diopter - co mot vai li khuyen la khi gan nhieu close-up lens th nen gan cai co so ln sat ong knh roi cai co so nho hn ben ngoai. Neu khong co close-up lenses th knh lup hay knh lao cung thay the c, ch co bat tien la khong gan chat c phai cam tay.

 

EXTENSION TUBES / EXTENSION BELLOW

            Dung cu nay la cac ong hay man xep accordeon gan gia may anh va ong knh, dung cu nay ch thch hp cho cac may anh xa hoan toan manual,  nhng vi cac may anh hien nay auto focus, auto everthing ong knh co nhieu contact noi vi than may th that chang tien li va gia ca khong re chut nao.                         

 

 

 

REVERSED LENS

            Co mot adapter giup cho gan quay ngc ong knh len than may cung giup chup c macro. Co the giai thch nh sau- trong cac ong knh may anh, quang tam thng nam ve pha sau nhieu hn nen khi quay ngc ong knh, khoang cach t quang tam en phim dai hn nen co the chup anh gan hn.

 

2. Macro vi may Point & shot FILM hay Twin Lens Reflex cameras.

            V he thong ieu chnh khoang cach va lay khung   may auto focus PS, rangefinder cung nh may TLR khac vi he thong ghi anh, nen b parallax. Khi gan them phu tung v khong co preview nen khong the xac nh c luc nao anh ro... V vay cac may nay gan nh khong the chup macro  c.

 

3. Macro vi point & shot DIGITAL cameras

 

            May anh digital point & shot ang chiem mot th trng kha ln nh gia ca giam en mc va tui tien cua moi ngi. ieu ly thu bat ng la kha nang chup macro cua cac may anh nay. Phan ln cac may co option e chup macro, khi bam nut MACRO - logo hnh canh hoa- th ong knh c ay ra xa hn mot chut giup cho focus lai gan hn. Tieu c cua ong knh thng rat ngan nen cho depht of field kha ln, hnh nhan c rat ro. May lai co preview nen khi quan sat hnh hien tren monitor ta kiem soat c o ln, o ro net cung nh bo cuc cua anh (ac tnh nay au khac g may SLR). Neu can co the ghep them close up lenses pha trc ong knh. Khi preview rat tien li v co the cam may xa, a len cao hay xuong thap, vao cac cho chat hep cung c khong nh may SLR phai ap mat vao sat viewfinder (v monitor khong co preview c - ch co postview ma thoi).

 

                              

Nut chup Macro - hnh canh hoa - may digital PS

 

            Chuyen kho tin nhng vi may digital point & shot, du khong phai chuyen mon, ai cung co the chup c anh macro ep, chac chan an bt so vi may SLR mac tien (neu khong ke en may SLR vi macro lenses vi gian o nghe rac roi). Cai hay cua may digital la tha ho chup khong s ton tien phim ong ngha vi ton tien, hnh co the check ngay e ieu chnh sa cha lai cho ung,  ngoai ra con co the crop theo y muon tai gia ma khong phai le thuoc vao photo lab.

            Mi ay oc trong bao co ngi a thanh cong trong viec chup SUPER MACRO vi may digital PS bang cach ap sat mot ong knh normal 50mm quay ngc pha trc ong knh cua may digital va zoom may en het mc tele.

                      

Anh chup vi may Canon A50 rat xa- ch co 1.2 Megapixel - gia tr hien nay chng 5 dollars -

 set CloseUp va khong co phu tung nao ca.

 

4. Macro photography khong dung may anh

            Scanner cung giup cho ta co c anh macro ep ma khong can en cac may moc ac tien. thch hp nhat la cho tem th, ong tien, vo oc... v.v..                                                                                                                                               

                                ong Yen - ai Nhat Ban  Minh Tr Tam Nien - va ong bac " Con Co "  scan vi Epson scanner

 

Li ket.

            Bo ra mot so tien ln e mua ong knh macro chac khong phai la y kien hay cho nhng nhiep anh gia tai t lau lau mi chup close-up mot lan. Neu cac anh ch ang co PS digital camera th tha ho ma th au can sam them phu tung, con ang dung SLR th tau 1 bo close up lens dung vi ong knh normal chac chan cung co hnh va y.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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