±´¿Çµç×ÓÊé > Ó¢ÎÄÔ­Öøµç×ÓÊé > the history and practice of the art of photography >

µÚ17ÕÂ

the history and practice of the art of photography-µÚ17ÕÂ

С˵£º the history and practice of the art of photography ×ÖÊý£º ÿҳ4000×Ö

°´¼üÅÌÉÏ·½Ïò¼ü ¡û »ò ¡ú ¿É¿ìËÙÉÏÏ·­Ò³£¬°´¼üÅÌÉ쵀 Enter ¼ü¿É»Øµ½±¾ÊéĿ¼ҳ£¬°´¼üÅÌÉÏ·½Ïò¼ü ¡ü ¿É»Øµ½±¾Ò³¶¥²¿£¡
¡ª¡ª¡ª¡ªÎ´ÔĶÁÍꣿ¼ÓÈëÊéÇ©ÒѱãÏ´μÌÐøÔĶÁ£¡



e¡¡cheaper¡¡sorts¡¡of¡¡demy£»¡¡and¡¡therefore¡¡can¡¡be¡¡easily¡¡avoided¡£¡¡In¡¡all¡¡cases¡¡such¡¡paper¡¡should¡¡be¡¡rejected£»¡¡as¡¡no¡¡really¡¡sensitive¡¡material¡¡can¡¡be¡¡obtained¡¡with¡¡it¡£¡¡¡¡Paper¡­makers£»¡¡as¡¡is¡¡well¡¡known£»¡¡often¡¡affix¡¡their¡¡name¡¡to¡¡one¡¡half¡¡the¡¡sheet£»¡¡this¡¡moiety¡¡should¡¡also¡¡be¡¡placed¡¡aside£»¡¡as¡¡the¡¡letters¡¡must¡¡frequently¡¡come¡¡out¡¡with¡¡annoying¡¡distinctness¡£¡¡Well¡¡sized¡¡paper¡¡is¡¡by¡¡no¡¡means¡¡objectionable£»¡¡indeed£»¡¡is¡¡rather¡¡to¡¡be¡¡preferred£»¡¡since¡¡the¡¡size¡¡tends¡¡to¡¡exalt¡¡the¡¡sensitive¡¡powers¡¡of¡¡the¡¡silver¡£¡¡¡¡The¡¡principal¡¡thing¡¡to¡¡be¡¡avoided£»¡¡is¡¡the¡¡absorption¡¡of¡¡the¡¡sensitive¡¡solution¡¡into¡¡the¡¡pores£»¡¡and¡¡it¡¡must¡¡be¡¡evident¡¡that¡¡this¡¡desideratum¡¡cannot¡¡be¡¡obtained¡¡by¡¡unsized¡¡paper¡£¡¡¡¡Taking¡¡all¡¡things¡¡into¡¡consideration£»¡¡the¡¡paper¡¡known¡¡as¡¡satin¡¡post¡¡would¡¡appear¡¡to¡¡be¡¡preferable£»¡¡although¡¡the¡¡precautions¡¡already¡¡recommended¡¡should¡¡be¡¡taken¡¡in¡¡its¡¡selection¡£

Brushes¡£The¡¡necessary¡¡solutions¡¡are¡¡to¡¡be¡¡laid¡¡upon¡¡the¡¡paper¡¡by¡¡brushes¡£¡¡Some¡¡persons¡¡pass¡¡the¡¡paper¡¡over¡¡the¡¡surface¡¡of¡¡the¡¡solutions£»¡¡thus¡¡licking¡¡up£»¡¡as¡¡it¡¡were£»¡¡a¡¡portion¡¡of¡¡the¡¡fluid£»¡¡but¡¡this¡¡method¡¡is¡¡apt¡¡to¡¡give¡¡an¡¡uneven¡¡surface£»¡¡it¡¡also¡¡rapidly¡¡spoils¡¡the¡¡solutions¡£¡¡At¡¡all¡¡events£»¡¡the¡¡brush¡¡is¡¡the¡¡most¡¡ready¡¡and¡¡the¡¡most¡¡effectual¡¡means¡£

Distilled¡¡Water¡£All¡¡the¡¡water¡¡used£»¡¡both¡¡for¡¡mixing¡¡the¡¡solutions£»¡¡washing¡¡the¡¡paper£»¡¡or¡¡cleaning¡¡the¡¡brushes£»¡¡must¡¡be¡¡distilled£»¡¡to¡¡obtain¡¡good¡¡results£»¡¡for¡¡reasons¡¡before¡¡specified¡£

Blotting¡¡Paper¡£In¡¡many¡¡instances£»¡¡the¡¡prepared¡¡paper¡¡requires¡¡to¡¡be¡¡lightly¡¡dried¡¡with¡¡bibulous¡¡paper¡£¡¡¡¡The¡¡best¡¡description¡¡is¡¡the¡¡white¡¡sort¡£¡¡In¡¡each¡¡stage¡¡of¡¡the¡¡preparation¡¡distinct¡¡portions¡¡of¡¡bibulous¡¡paper¡¡must¡¡be¡¡used¡£¡¡¡¡If¡¡these¡¡be¡¡kept¡¡seperate¡¡and¡¡marked£»¡¡they¡¡can¡¡be¡¡again¡¡employed¡¡for¡¡the¡¡same¡¡stage£»¡¡but¡¡it¡¡would¡¡not¡¡do£»¡¡for¡¡example£»¡¡to¡¡dry¡¡the¡¡finished¡¡picture¡¡in¡¡the¡¡same¡¡folds¡¡in¡¡which¡¡the¡¡sensitive¡¡paper¡¡had¡¡been¡¡pressed¡£¡¡A¡¡very¡¡convenient¡¡method¡¡is¡¡to¡¡have¡¡two¡¡or¡¡three¡¡quarto¡¡size¡¡books¡¡of¡¡bibulous¡¡paper£»¡¡one¡¡for¡¡each¡¡seperate¡¡process¡£

Nitrate¡¡of¡¡Silver¡£In¡¡the¡¡practice¡¡of¡¡the¡¡photographic¡¡art£»¡¡much¡¡depends¡¡on¡¡the¡¡nitrate¡¡of¡¡silver¡£¡¡¡¡Care¡¡should¡¡be¡¡taken¡¡to¡¡procure¡¡the¡¡best£»¡¡the¡¡crystalized¡¡salt¡¡is¡¡most¡¡suitable¡¡for¡¡the¡¡purpose¡£¡¡¡¡While¡¡in¡¡the¡¡form¡¡of¡¡crystal¡¡it¡¡is¡¡not¡¡injured¡¡by¡¡exposure¡¡to¡¡light£»¡¡but¡¡the¡¡bottles¡¡containing¡¡the¡¡solutions¡¡of¡¡this¡¡salt¡¡should¡¡at¡¡all¡¡times¡¡be¡¡kept¡¡wrapped¡¡in¡¡dark¡¡paper£»¡¡and¡¡excluded¡¡from¡¡daylight¡£

II¡£¡¡DIFFERENT¡¡METHODS¡¡OF¡¡PREPARING¡¡THE¡¡PAPER¡£Preparation¡¡of¡¡the¡¡Paper¡£¡¡Dip¡¡the¡¡paper¡¡to¡¡be¡¡prepared¡¡into¡¡a¡¡weak¡¡solution¡¡of¡¡common¡¡salt¡£¡¡The¡¡solution¡¡should¡¡not¡¡be¡¡saturated£»¡¡but¡¡six¡¡or¡¡eight¡¡times¡¡diluted¡¡with¡¡water¡£¡¡¡¡When¡¡perfectly¡¡moistened£»¡¡wipe¡¡it¡¡dry¡¡with¡¡a¡¡towel£»¡¡or¡¡press¡¡it¡¡between¡¡bibulous¡¡paper£»¡¡by¡¡which¡¡operation¡¡the¡¡salt¡¡is¡¡uniformly¡¡dispersed¡¡through¡¡its¡¡substance¡£¡¡¡¡Then¡¡brush¡¡over¡¡it£»¡¡on¡¡one¡¡side¡¡only£»¡¡a¡¡solution¡¡of¡¡nitrate¡¡of¡¡silver¡£¡¡¡¡The¡¡strength¡¡of¡¡this¡¡solution¡¡must¡¡vary¡¡according¡¡to¡¡the¡¡color¡¡and¡¡sensitiveness¡¡required¡£¡¡Mr¡£¡¡Talbot¡¡recommends¡¡about¡¡fifty¡¡grains¡¡of¡¡the¡¡salt¡¡to¡¡an¡¡ounce¡¡of¡¡distilled¡¡water¡£¡¡¡¡Some¡¡advise¡¡twenty¡¡grains¡¡only£»¡¡while¡¡others¡¡say¡¡eighty¡¡grains¡¡to¡¡the¡¡ounce¡£¡¡¡¡When¡¡dried¡¡in¡¡a¡¡dark¡¡room£»¡¡the¡¡paper¡¡is¡¡fit¡¡for¡¡use¡£¡¡¡¡To¡¡render¡¡this¡¡paper¡¡still¡¡more¡¡sensitive£»¡¡it¡¡must¡¡again¡¡be¡¡washed¡¡with¡¡salt¡¡and¡¡water£»¡¡and¡¡afterwards¡¡with¡¡the¡¡same¡¡solution¡¡of¡¡nitrate¡¡of¡¡silver£»¡¡drying¡¡it¡¡between¡¡times¡£¡¡¡¡This¡¡paper£»¡¡if¡¡carefully¡¡made£»¡¡is¡¡very¡¡useful¡¡for¡¡all¡¡ordinary¡¡photographic¡¡purposes¡£¡¡For¡¡example£»¡¡nothing¡¡can¡¡be¡¡more¡¡perfect¡¡than¡¡the¡¡images¡¡it¡¡gives¡¡of¡¡leaves¡¡and¡¡flowers£»¡¡especially¡¡with¡¡a¡¡summer's¡¡sun£»¡¡the¡¡light£»¡¡passing¡¡through¡¡the¡¡leaves£»¡¡delineates¡¡every¡¡ramification¡¡of¡¡their¡¡fibres¡£¡¡In¡¡conducting¡¡this¡¡operation£»¡¡however£»¡¡it¡¡will¡¡be¡¡found¡¡that¡¡the¡¡results¡¡are¡¡sometimes¡¡more¡¡and¡¡sometimes¡¡less¡¡satisfactory£»¡¡in¡¡consequence¡¡of¡¡small¡¡and¡¡accidental¡¡variations¡¡in¡¡the¡¡proportions¡¡employed¡£¡¡It¡¡happens¡¡sometimes¡¡that¡¡the¡¡chloride¡¡of¡¡silver¡¡formed¡¡on¡¡the¡¡surface¡¡of¡¡the¡¡paper¡¡is¡¡disposed¡¡to¡¡blacken¡¡of¡¡itself£»¡¡without¡¡any¡¡exposure¡¡to¡¡light¡£¡¡This¡¡shows¡¡that¡¡the¡¡attempt¡¡to¡¡give¡¡it¡¡sensibility¡¡has¡¡been¡¡carried¡¡too¡¡far¡£¡¡The¡¡object¡¡is£»¡¡to¡¡approach¡¡as¡¡nearly¡¡to¡¡this¡¡condition¡¡as¡¡possible¡¡without¡¡reaching¡¡it£»¡¡so¡¡that¡¡the¡¡preparation¡¡may¡¡be¡¡in¡¡a¡¡state¡¡ready¡¡to¡¡yield¡¡to¡¡the¡¡slightest¡¡extraneous¡¡force£»¡¡such¡¡as¡¡the¡¡feeblest¡¡effect¡¡of¡¡light¡£

Cooper's¡¡Method¡£Soak¡¡the¡¡paper¡¡in¡¡a¡¡boiling¡¡hot¡¡solution¡¡of¡¡chlorate¡¡of¡¡potash¡¡£¨the¡¡strength¡¡matters¡¡not£©¡¡for¡¡a¡¡few¡¡minutes£»¡¡then¡¡take¡¡it¡¡out£»¡¡dry¡¡it£»¡¡and¡¡wet¡¡it¡¡with¡¡a¡¡brush£»¡¡on¡¡one¡¡side¡¡only£»¡¡dipped¡¡in¡¡a¡¡solution¡¡of¡¡nitrate¡¡of¡¡silver£»¡¡sixty¡¡grains¡¡to¡¡an¡¡ounce¡¡of¡¡distilled¡¡water£»¡¡or£»¡¡if¡¡not¡¡required¡¡to¡¡be¡¡so¡¡sensitive£»¡¡thirty¡¡grains¡¡to¡¡the¡¡ounce¡¡will¡¡do¡£¡¡¡¡This¡¡paper¡¡possesses¡¡a¡¡great¡¡advantage¡¡over¡¡any¡¡other£»¡¡for¡¡the¡¡image¡¡can¡¡be¡¡fixed¡¡by¡¡mere¡¡washing¡£¡¡It¡¡is£»¡¡however£»¡¡very¡¡apt¡¡to¡¡become¡¡discolored¡¡even¡¡in¡¡the¡¡washing£»¡¡or¡¡shortly¡¡afterwards£»¡¡and¡¡is£»¡¡besides£»¡¡not¡¡so¡¡sensitive£»¡¡nor¡¡does¡¡it¡¡become¡¡so¡¡dark¡¡as¡¡that¡¡made¡¡according¡¡to¡¡Mr¡£¡¡Talbot's¡¡method¡£

Daguerre's¡¡Method¡£Immerse¡¡the¡¡paper¡¡in¡¡hydrochloric¡¡£¨or¡¡as¡¡it¡¡is¡¡more¡¡commonly¡¡called£»¡¡muriatic£©¡¡ether£»¡¡which¡¡has¡¡been¡¡kept¡¡sufficiently¡¡long¡¡to¡¡become¡¡acid£»¡¡the¡¡paper¡¡is¡¡then¡¡carefully¡¡and¡¡completely¡¡dried£»¡¡as¡¡this¡¡is¡¡essential¡¡to¡¡its¡¡proper¡¡preparation¡£¡¡It¡¡is¡¡then¡¡dipped¡¡into¡¡a¡¡solution¡¡of¡¡nitrate¡¡of¡¡silver£»¡¡and¡¡dried¡¡without¡¡artificial¡¡heat¡¡in¡¡a¡¡room¡¡from¡¡which¡¡every¡¡ray¡¡of¡¡light¡¡is¡¡carefully¡¡excluded¡£¡¡¡¡By¡¡this¡¡process¡¡it¡¡acquires¡¡a¡¡very¡¡remarkable¡¡facility¡¡in¡¡being¡¡blackened¡¡on¡¡a¡¡very¡¡slight¡¡exposure¡¡to¡¡light£»¡¡even¡¡when¡¡the¡¡latter¡¡is¡¡by¡¡no¡¡means¡¡intense¡£¡¡The¡¡paper£»¡¡however£»¡¡rapidly¡¡loses¡¡its¡¡extreme¡¡sensitiveness¡¡to¡¡light£»¡¡and¡¡finally¡¡becomes¡¡no¡¡more¡¡impressionable¡¡by¡¡the¡¡solar¡¡beams¡¡than¡¡common¡¡nitrate¡¡paper¡£

Bromide¡¡Paper¡£Of¡¡all¡¡common¡¡photographic¡¡paper£»¡¡the¡¡best£»¡¡because¡¡the¡¡least¡¡troublesome¡¡in¡¡making£»¡¡and¡¡the¡¡most¡¡satisfactory¡¡in¡¡result£»¡¡is¡¡that¡¡which¡¡is¡¡termed¡¡bromine¡¡paper£»¡¡and¡¡which¡¡is¡¡thus¡¡prepared£ºDissolve¡¡one¡¡hundred¡¡grains¡¡of¡¡bromide¡¡of¡¡potassium¡¡in¡¡one¡¡ounce¡¡of¡¡distilled¡¡water£»¡¡and¡¡soak¡¡the¡¡paper¡¡in¡¡this¡¡solution¡£¡¡Take¡¡off¡¡the¡¡superfluous¡¡moisture£»¡¡by¡¡means¡¡of¡¡your¡¡bibulous¡¡paper£»¡¡and¡¡when¡¡nearly¡¡dry£»¡¡brush¡¡it¡¡over¡¡on¡¡one¡¡side¡¡only£»¡¡with¡¡a¡¡solution¡¡of¡¡one¡¡hundred¡¡grains¡¡of¡¡nitrate¡¡of¡¡silver¡¡to¡¡an¡¡ounce¡¡of¡¡distilled¡¡water¡£¡¡The¡¡paper¡¡should¡¡then¡¡be¡¡dried¡¡in¡¡a¡¡dark¡¡room£»¡¡and£»¡¡if¡¡required¡¡to¡¡be¡¡very¡¡sensitive£»¡¡should¡¡a¡¡second¡¡time¡¡be¡¡brushed¡¡over¡¡with¡¡the¡¡nitrate¡¡of¡¡silver¡¡solution¡£

In¡¡preparing¡¡the¡¡papers¡¡mentioned¡¡above£»¡¡there¡¡are¡¡two¡¡circumstances¡¡which¡¡require¡¡particular¡¡attention¡£¡¡¡¡In¡¡the¡¡first¡¡place£»¡¡it¡¡is¡¡necessary¡¡to¡¡mark¡¡the¡¡paper¡¡on¡¡the¡¡side¡¡spread¡¡with¡¡the¡¡solutions¡¡of¡¡nitrate¡¡of¡¡silver£»¡¡near¡¡one¡¡of¡¡the¡¡extreme¡¡corners¡£¡¡This¡¡answers¡¡two¡¡purposes£º¡¡¡¡in¡¡the¡¡first¡¡place¡¡it¡¡serves¡¡to¡¡inform¡¡the¡¡experimemtalist¡¡of¡¡the¡¡sensitive¡¡surface£»¡¡and¡¡secondly£»¡¡it¡¡will¡¡be¡¡a¡¡guide¡¡as¡¡to¡¡which¡¡portion¡¡of¡¡the¡¡papers¡¡has¡¡been¡¡handled¡¡during¡¡the¡¡application¡¡of¡¡the¡¡solution£»¡¡as¡¡the¡¡impress¡¡of¡¡the¡¡fingers¡¡will¡¡probably¡¡come¡¡out¡¡upon¡¡the¡¡photograph¡£¡¡The¡¡second¡¡caution¡¡is£»¡¡that¡¡the¡¡application¡¡of¡¡the¡¡sensitive¡¡solution¡¡£¨nitrate¡¡of¡¡silver£»£©¡¡and¡¡the¡¡subsequent¡¡drying¡¡of¡¡the¡¡paper£»¡¡must¡¡be¡¡always¡¡conducted¡¡in¡¡a¡¡perfectly¡¡dark¡¡room£»¡¡the¡¡light¡¡of¡¡a¡¡candle¡¡alone¡¡being¡¡used¡£

III¡£¡¡PHOTOGENIC¡¡PROCESS¡¡ON¡¡PAPER¡£Method¡£The¡¡simplest¡¡mode¡¡is¡¡to¡¡procure¡¡a¡¡flat¡¡board¡¡and¡¡a¡¡square¡¡of¡¡glass£»¡¡larger¡¡in¡¡size¡¡than¡¡the¡¡object¡¡intended¡¡to¡¡be¡¡copied¡£¡¡On¡¡the¡¡board¡¡place¡¡the¡¡photographic¡¡paper¡¡¡¡£§hipho_29¡£gif£§¡¡with¡¡the¡¡prepared¡¡side¡¡upwards£»¡¡and¡¡upon¡¡it¡¡the¡¡object¡¡to¡¡be¡¡copied£»¡¡over¡¡both¡¡lay¡¡the¡¡glass¡¡and¡¡secure¡¡them¡¡so¡¡that¡¡they¡¡are¡¡in¡¡close¡¡connection¡¡by¡¡means¡¡of¡¡binding¡¡screws¡¡or¡¡clamps£»¡¡similar¡¡to¡¡g¡£¡¡g¡£¡¡fig¡£¡¡29¡£¡¡¡¡Should¡¡the¡¡object¡¡to¡¡be¡¡copied¡¡be¡¡of¡¡unequal¡¡thickness£»¡¡such¡¡as¡¡a¡¡leaf£»¡¡grass£»¡¡&c¡££»¡¡it¡¡will¡¡be¡¡necessary¡¡to¡¡place¡¡on¡¡the¡¡board£»¡¡first£»¡¡a¡¡soft¡¡cushion£»¡¡which¡¡may¡¡be¡¡made¡¡of¡¡a¡¡piece¡¡of¡¡fine¡¡flannel¡¡and¡¡cotton¡¡wool¡£¡¡By¡¡this¡¡means¡¡the¡¡object¡¡is¡¡brought¡¡into¡¡closer¡¡contact¡¡with¡¡the¡¡paper£»¡¡which¡¡is¡¡of¡¡great¡¡consequence£»¡¡and¡¡adds¡¡materially¡¡to¡¡the¡¡clearness¡¡of¡¡the¡¡copy¡£¡¡The¡¡paper¡¡is¡¡now¡¡exposed¡¡to¡¡diffused¡¡daylight£»¡¡or£»¡¡still¡¡better£»¡¡to¡¡the¡¡direct¡¡rays¡¡of¡¡the¡¡sun£»¡¡when¡¡that¡¡part¡¡of¡¡the¡¡paper¡¡not¡¡covered¡¡by¡¡the¡¡object¡¡will¡¡become¡¡tinged¡¡with¡¡a¡¡violet¡¡color£»¡¡and¡¡if¡¡the¡¡paper¡¡be¡¡well¡¡prepared£»¡¡it¡¡will¡¡in¡¡a¡¡short¡¡time¡¡pass¡¡to¡¡a¡¡deep¡¡brown¡¡or¡¡bronze¡¡color¡£¡¡¡¡It¡¡must¡¡then¡¡be¡¡removed£»¡¡as¡¡no¡¡advantage¡¡will¡¡be¡¡obtained¡¡by¡¡keeping¡¡it¡¡longer¡¡exposed£»¡¡o

·µ»ØĿ¼ ÉÏÒ»Ò³ ÏÂÒ»Ò³ »Øµ½¶¥²¿ ÔÞ£¨0£© ²È£¨0£©

Äã¿ÉÄÜϲ»¶µÄ