{"id":27,"date":"2014-07-06T14:34:53","date_gmt":"2014-07-06T13:34:53","guid":{"rendered":"http:\/\/www.enface.cz\/7x10\/?p=27"},"modified":"2014-07-06T14:34:54","modified_gmt":"2014-07-06T13:34:54","slug":"autofokus-kontra-manual-kdy-a-jak-ostrit","status":"publish","type":"post","link":"https:\/\/www.enface.cz\/7x10\/27\/autofokus-kontra-manual-kdy-a-jak-ostrit\/","title":{"rendered":"Autofokus kontra manu\u00e1l: kdy a jak ost\u0159it"},"content":{"rendered":"

Manu\u00e1ln\u00ed ost\u0159en\u00ed je prost\u011b pro manu\u00e1ln\u00ed objektivy. Nen\u00ed to nic starom\u00f3dn\u00edho \u2013 i ta na trhu velmi drah\u00e1 nejmodern\u011bj\u0161\u00ed Leica<\/a> autofokus ignoruje. Vnit\u0159n\u00ed zaost\u0159ov\u00e1n\u00ed posunem \u010dlen\u016f, kter\u00e9 v\u011bt\u0161ina autofokusov\u00fdch objektiv\u016f pou\u017e\u00edv\u00e1, toti\u017e p\u0159ece jen \u0161pi\u010dkov\u00e9 parametry objektivu (barevn\u00e1 vada, aberace) m\u016f\u017ee pon\u011bkud degradovat. \u0158ada portr\u00e9tn\u00edch, ateli\u00e9rov\u00fdch a\u00a0reproduk\u010dn\u00edch kompozic vy\u017eaduje konstantn\u00ed zaost\u0159en\u00ed, kter\u00e9 se nehne. Na displeji mirrorlessu je p\u0159itom u manu\u00e1ln\u00edch objektiv\u016f automaticky v\u00a0n\u00e1hledu d\u00e1na i hloubka ostrosti a umo\u017e\u0148uje-li p\u0159\u00edstroj i zv\u011bt\u0161en\u00ed obrazu p\u0159i manu\u00e1ln\u00edm ost\u0159en\u00ed, p\u0159\u00edpadn\u011b zd\u016frazn\u011bn\u00ed zaost\u0159en\u00fdch kontur (focus peaking<\/a>), lze doc\u00edlit dokonal\u00e9ho v\u00fdsledku. Nakonec i v\u00fdtvarn\u00fd efekt panningu \u2013 tedy rozmaz\u00e1n\u00ed pozad\u00ed p\u0159i sledov\u00e1n\u00ed rychle se pohybuj\u00edc\u00edho objektu kamerou s expozic\u00ed nep\u0159\u00edli\u0161 rychl\u00fdm \u010dasem \u2013 se s\u00a0v\u011bt\u0161inou kamer ani jinak, ne\u017e zaost\u0159en\u00edm na p\u0159edem nastavenou vzd\u00e1lenost, doc\u00edlit ned\u00e1.<\/p>\n

<\/p>\n

Nebroj\u00edm proti standardn\u00edm zoom\u016fm pro standardn\u00ed pou\u017eit\u00ed u\u017e proto, \u017ee p\u0159i koupi v setu jsou obvykle cenov\u011b v\u00fdhodn\u00e9 a najdou sv\u00e9 uplatn\u011bn\u00ed. Le\u010d dal\u0161\u00ed kvalitn\u00ed p\u0159\u00edslu\u0161enstv\u00ed \u2013 tedy zejm\u00e9na portr\u00e9tn\u00ed a tele objektivy obvykle cenu p\u016fvodn\u00edho setu hrav\u011b p\u0159ekon\u00e1vaj\u00ed a za\u010d\u00ednaj\u00ed na hranici 1000 US dolar\u016f. Vzd\u00e1te-li se autofokusu, po\u0159\u00edd\u00edte star\u0161\u00ed objektiv srovnateln\u00e9 kvality i za 10\u201320 % t\u00e9to ceny. I s t\u00edm, \u017ee jeho kovov\u00e9 proveden\u00ed je do\u017eivotn\u011b bezporuchov\u00e9. V\u00fdrobci v\u00a0Hong Kongu a \u010c\u00edn\u011b u\u017e tento slibn\u00fd trh objevili a v internetov\u00e9 nab\u00eddce na eBay nab\u00edz\u00ed redukce snad na v\u0161e, co se od sedmdes\u00e1t\u00fdch let vyr\u00e1b\u011blo.<\/p>\n

\"Portr\u00e9tn\u00ed<\/a>

Portr\u00e9tn\u00ed objektivy s ohniskovou vzd\u00e1lenost\u00ed kolem 100 mm a sv\u011btelnost\u00ed 2,8 (na sn\u00edmku Miranda 105\/2,8) umo\u017e\u0148uj\u00ed bez clon\u011bn\u00ed z\u00edsk\u00e1n\u00ed pot\u0159ebn\u00e9 ostrosti i kr\u00e1sn\u00fd bokeh zejm\u00e9n\u011b \u010dlenit\u00fdch a v protisv\u011btle sn\u00edman\u00fdch pozad\u00ed<\/p><\/div>\n

Nen\u00ed ov\u0161em objektiv jako objektiv: u n\u00e1s d\u0159\u00edve roz\u0161\u00ed\u0159en\u00e9 NDR objektivy b\u011b\u017en\u011b nedosahovaly dnes po\u017eadovan\u00e9ho vysok\u00e9ho rozli\u0161en\u00ed pro \u010dipy form\u00e1tu APS-C a zejm\u00e9na Meyerovy objektivy s m\u011bk\u010d\u00ed kresbou a kultivovan\u00fdm bokehem jsou vhodn\u00e9 p\u0159edev\u0161\u00edm pro portr\u00e9tn\u00ed z\u00e1b\u011bry. Rozli\u0161ovac\u00ed schopnost s ohniskovou vzd\u00e1lenost\u00ed rychle klesala a del\u0161\u00ed teleobjektivy jsou pro dne\u0161n\u00ed mal\u00e9 \u010dipy obvykle nevhodn\u00e9. Kvalitativn\u00ed zlom zapo\u010dal v 70. letech s\u00a0n\u00e1stupem japonsk\u00fdch zna\u010dek, zejm\u00e9na opticky vynikaj\u00edc\u00edch objektiv\u016f Olympus OM Zuiko<\/a>, nebo na americk\u00e9m trhu Miranda, kter\u00e9 se d\u00edky \u00fatlumu klasick\u00e9 fotografie daj\u00ed dnes po\u0159\u00eddit za v\u00fdhodn\u00e9 ceny. Objektivy pro Nikon, Canon a Minoltu se d\u00edky pou\u017eitelnosti na DSLR ji\u017e tak v\u00fdhodn\u011b po\u0159\u00eddit nedaj\u00ed.<\/p>\n

M\u00e1m zde na mysli p\u0159edev\u0161\u00edm pou\u017eit\u00ed t\u011bchto objektiv\u016f u \u010dip\u016f APS-C, tedy „p\u016flen\u00e9ho kinofilmu“ s crop faktorem „prodlu\u017euj\u00edc\u00edm“ ohniskovou vzd\u00e1lenost 1,5x. P\u016fvodn\u011b standardn\u00ed 50 mm objektiv se tak rekvalifikuje na portr\u00e9tn\u00ed sklo a se 100 mm objektivy lze krom\u011b portr\u00e9t\u016f zvl\u00e1dat i akt \u010di m\u00f3du, kde u\u017e se d\u00e1 tv\u016fr\u010d\u00edm zp\u016fsobem s bokehem pracovat. Je a\u017e p\u0159ekvapiv\u00e9, \u017ee se u kvalitn\u00edch objektiv\u016f t\u011bchto pevn\u00fdch ohnisek prakticky nevyskytuj\u00ed aberace \u2013 ony nep\u0159\u00edjemn\u00e9 barevn\u00e9 kontury na kontrastn\u00edch rozhran\u00edch, kter\u00e9 se i u dra\u017e\u0161\u00edch modern\u00edch objektiv\u016f \u010dasto odstra\u0148uj\u00ed a\u017e softwarov\u011b.<\/p>\n

Ukazuje se, \u017ee velkou brzdou konstrukce optim\u00e1ln\u00edho p\u0159\u00edstroje jsou nakonec sami v\u00fdrobci, p\u0159edh\u00e1n\u011bj\u00edc\u00ed se nab\u00eddkou \u010dasto zbyte\u010dn\u00fdch a ned\u016fle\u017eit\u00fdch parametr\u016f a sna\u017e\u00edc\u00ed se implementovat univerz\u00e1ln\u00ed prvky pou\u017eitelnosti i tam, kde jsou kontraproduktivn\u00ed. Vlastnosti, kter\u00e9 m\u00e1 p\u0159\u00edstroj m\u00edt, jakoby neur\u010dovali fotografov\u00e9, ale marketingov\u00ed l\u00edd\u0159i. Chcete p\u0159\u00edklad?<\/p>\n

Sony s modelem RX1 se Leice sna\u017e\u00ed p\u0159ibl\u00ed\u017eit tvarem a cenou. P\u0159ekvapuje, \u017ee si v\u00fdrobce mysl\u00ed, \u017ee nalezne v\u00edce exot\u016f, kte\u0159\u00ed se u FF form\u00e1tu spokoj\u00ed s pevn\u00fdm objektivem a sn\u00edm\u00e1n\u00edm s nata\u017een\u00fdma rukama na pevn\u00fd displej. Optick\u00fd hled\u00e1\u010dek, aby byl p\u0159\u00edstroj pou\u017eiteln\u00fd i za slune\u010dn\u00e9ho dne, se sice za n\u011bjak\u00fdch p\u00e1r stovek dolar\u016f dokoupit d\u00e1, ale to u\u017e je p\u0159\u00edstroj rozm\u011brov\u011b velk\u00fd jako zrcadlovka. A dra\u017e\u0161\u00ed. Sony p\u0159itom kvalitn\u00ed EVF hled\u00e1\u010dek vyrobit um\u00ed a modely NEX-7 a 6 jakoby \u0159adu v\u00fd\u0161e zm\u00edn\u011bn\u00fdch po\u017eadavk\u016f spl\u0148ovaly. Le\u010d pokud by byly o pouh\u00fd centimetr v\u011bt\u0161\u00ed, ve\u0161el by se do nich akumul\u00e1tor s v\u011bt\u0161\u00ed kapacitou a synchroniza\u010dn\u00ed konektory. A zaslou\u017eily by si ovl\u00e1d\u00e1n\u00ed z\u00e1kladn\u00edch parametr\u016f extra ovlada\u010di a ne p\u0159es nep\u0159ehledn\u00e9 menu. Nov\u00fd Sony objektiv 16\u201350\/3,5\u20135,6 m\u00e1 sice sympatick\u00fd rozsah, ale nevaln\u00e9 optick\u00e9 vlastnosti. Velk\u00e9 v\u016fle a elektrick\u00fd posun zoomu sv\u011bd\u010d\u00ed o tom, \u017ee se v\u00fdrobce nedovedl rozhodnout, co preferovat: zda fotografov\u00e1n\u00ed, nebo nat\u00e1\u010den\u00ed videa. P\u0159\u00edmo z\u00e1ludn\u00e9 a „protiz\u00e1konn\u00e9“ je pak blokov\u00e1n\u00ed u\u017eit\u00ed jak\u00fdchkoli ciz\u00edch blesk\u016f u standardn\u00edch s\u00e1n\u011bk hot-shoe modelu NEX-6, co\u017e ignoruje v\u0161emi ostatn\u00edmi v\u00fdrobci dodr\u017eovan\u00fd standard a zcela znemo\u017e\u0148uje pou\u017eit\u00ed ateli\u00e9rov\u00fdch blesk\u016f. Je to obdobn\u00e9, jako by dali na trh elektrick\u00fd spot\u0159ebi\u010d se z\u00e1str\u010dkou, vy\u017eaduj\u00edc\u00ed vlastn\u00ed elektrickou s\u00ed\u0165.<\/p>\n

P\u0159\u00edstroje vy\u0161\u0161\u00ed cenov\u00e9 t\u0159\u00eddy se nekupuj\u00ed na rok jako levn\u00e9 kompakty, kter\u00e9 se po uplynut\u00ed z\u00e1ruky vyhazuj\u00ed a nahrazuj\u00ed nov\u00fdm modelem. Je naprosto zbyte\u010dn\u00e9 p\u0159ich\u00e1zet s \u0159adou model\u016f, z nich\u017e ka\u017ed\u00fd m\u00e1 z\u00a0dostupn\u00fdch technologi\u00ed jen n\u011bco. Za vzor by m\u011bl slou\u017eit p\u0159\u00edstup Nikonu, kter\u00fd garantuje omezenou pou\u017eitelnost sv\u00fdch objektiv\u016f s bajonetem F od 70. let. St\u00e1le toti\u017e plat\u00ed, \u017ee kvalitn\u00ed objektiv by m\u011bl b\u00fdt dlouhodob\u011b pou\u017eiteln\u00fd na jakkoliv modernizovan\u00e9m t\u011ble. Koncept CSC mirrorless\u016f se tak st\u00e1v\u00e1 stejn\u011b univerz\u00e1ln\u00edm, jako d\u0159\u00edve syst\u00e9mov\u00e9 desk\u00e1\u010de typu Linhof Master Technika<\/a>; na p\u0159edn\u00ed standartu se dal aplikovat libovoln\u00fd objektiv a sn\u00edmat \u0161lo na libovoln\u00e9 z\u00e1znamov\u00e9 m\u00e9dium.<\/p>\n","protected":false},"excerpt":{"rendered":"

Manu\u00e1ln\u00ed ost\u0159en\u00ed je prost\u011b pro manu\u00e1ln\u00ed objektivy. Nen\u00ed to nic starom\u00f3dn\u00edho \u2013 i ta na trhu velmi drah\u00e1 nejmodern\u011bj\u0161\u00ed Leica autofokus ignoruje. Vnit\u0159n\u00ed zaost\u0159ov\u00e1n\u00ed posunem \u010dlen\u016f, kter\u00e9 v\u011bt\u0161ina autofokusov\u00fdch objektiv\u016f pou\u017e\u00edv\u00e1, toti\u017e p\u0159ece jen \u0161pi\u010dkov\u00e9 parametry objektivu (barevn\u00e1 vada, aberace)…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-27","post","type-post","status-publish","format-standard","hentry","category-nezarazene"],"_links":{"self":[{"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/posts\/27","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/comments?post=27"}],"version-history":[{"count":0,"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/posts\/27\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/media?parent=27"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/categories?post=27"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.enface.cz\/7x10\/wp-json\/wp\/v2\/tags?post=27"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}