Kirkirar hoto a karni na 19 yana da sifa iri daban-daban da nau'ikan hanyoyin da ake amfani dasu don kamawa da gyara hotuna: daguerreotypes, ambrotypes, tintypes, kwafin carbon da robar bromromated wasu daga cikinsu.
Za'a iya raba wannan matakan da yawa zuwa kungiyoyi biyu: wadanda suka samar da hoto guda - wanda kuma ake kira hoton kyamara kuma hakan yana da asalin asalinsu a cikin daguerreotype- da kuma wadanda suka bada damar haihuwa mai yawa - daga matrix mara kyau da aka samu a cikin ɗakunan duhu-, wanda asalinsa yake zuwa ga calotype.
Na rukuni na biyu - waɗanda suka samar da ɗimbin yawa - dabarun buga abubuwa biyu sun yi fice: bugawa da gishiri ko takarda mai gishiri da takarda mai fa'ida. Wanda ya kirkiro na farko shine Henry Fox-Talbot, wanda ya samo hotunansa ta hanyar takarda mai laushi. Bugun Albumen, a daya bangaren, wata dabara ce wacce da kashi 85% na hotunan da aka samar a karni na 19 aka yi su, wanda ke nufin cewa yawancin kayan tarihin kasarmu - wadanda suka dace da wancan karnin - shine samu a cikin wannan tsari.
Takardun Albumen na ɗaya daga cikin kayan farko da aka yi amfani da su don buga tabbatattun abubuwa, kuma a cikin 1839 Louis Blanquart-Evrard ya yi ƙoƙarin yin hakan ta hanyar ɗaukar matakan yin gilashin gilashi daga Niépce de St. Victor, wanda aka inganta albumin da gishirin azurfa. . Ta wannan hanyar, Louis ya gudanar da gwaje-gwaje tare da wannan nau'in haɗin gwiwa kuma ya yi amfani da shi a kan takardu, yana inganta sakamakon calotypes na Henry Fox Talbot, don yin kwafin hoto daga baya kuma ya gabatar da sakamakonsa ga Kwalejin Kimiyya ta Faransa (Mayu) 27 na 1850). Koyaya, amfani da shi yana raguwa saboda gaskiyar masu ɗaukar hoto - waɗanda kawai suka yi amfani da shi - sun sami kyakkyawan sakamako tare da takaddun emulsified don bugawa kai tsaye (collodion ko gelatin).
Daya daga cikin mawuyacin matsala wajen kera takardar albumin ita ce lokacin da aka wayar da takardar da sinadarin nitrate na azurfa, wani lokacin takan hadu da takardar ta hanyar albumin din, kuma idan ba a yi takardar ba mai kyau mai kyau, nitrate yayi tasiri ta hanyar haifar da tabo baƙi ko tabo a saman hoton. Wani mawuyacin matsalar shine matakin rashin tsabtar takarda da abubuwan sizing, tunda a cikin toning ko toning na hotunan da aka samo akan takardar kundin album ɗin zasu iya samar da canje-canje na chromatic. Don haka, kodayake ƙirƙirar kundin kundin abu ne mai sauƙi, amma ya gabatar da manyan matsaloli. Koyaya, akwai masana'antun da ke siyar da kyallen albam mai inganci, sanannun masana'antun sune waɗanda suke a Jamus - musamman waɗanda ke Dresden-, inda miliyoyin ƙwai ke cinsu kowace shekara don wannan masana'antar.
Rodolfo Namias ne ya bayyana "girke-girke" na yin takarda, da kuma wayar da kai da gishirin azurfa, a shekarar 1898:
Qwai suna fashewa a hankali kuma an raba albumin daga gwaiduwa; ana sayar da na ƙarshen zuwa shagunan safar hannu da shagunan kek. Bayannan albumin mai ruwa sai a buge shi zuwa flakes, ko dai da hannu ko da injuna na musamman, sannan a barshi ya zauna: bayan aan awanni kaɗan ya sake zama ruwa, kuma ƙwayoyin membranous ɗin sun rabu sosai. Bai kamata a yi amfani da albumin ruwan da aka samo nan da nan ba, amma dole ne a bar shi ya dan yi kaɗan, saboda wannan yana ba da sauƙi mai sauƙi na hoto […] galibi ana barin shi [fermenting], kamar yadda yake na kwana takwas ko goma. , kuma a lokacin sanyi har zuwa kwana goma sha biyar; ta hanyar tashin kamshi wanda yake bayarwa, lokacin da ya kai iyakar iyawarsa za'a iya lissafa shi. Bayan haka sai a dakatar da ferment din tare da karin karamin adadin acetic acid sannan a tace. Kafin amfani da wannan albumin, dole ne a ƙara adadin alkali chloride. Manufar wannan chloride ita ce ta haifar, a cikin wayar da hankali, zuwa samuwar chloride na azurfa tare da albumin layer, kuma wannan chloride na azurfa ya zama daidai, tare da albumin azurfa, abin damuwa.
A yau mun san cewa an sanya albumin a cikin kwantenan da aka yi da faranti na tutiya, kuma a ciki an shimfida mayafan takardu na takarda na musamman masu ƙima da ƙarancin nauyi da suke son shiryawa. An nitsar da zanen a cikin wannan wankan, yana riƙe da shi a kusurwa biyu akasin haka kuma a hankali ya saukad da shi, yana guje wa duk yadda zai yiwu samuwar kumfa; bayan minti daya ko biyu an cire shi kuma an rataye shi ya bushe. Gabaɗaya, ganyayyakin sunada furotin sau biyu don basu mafi kyawu mai haske da kama mai kama da shi.
Da zarar sun bushe, takarda dole ne ta zama satin don ƙara ƙwanƙolin farfajiya. Idan aka aiwatar da aikin yadda ya kamata, za a sami takarda mai kundi mai dauke da wari mara dadi (babban halayyar ingantacciyar takarda). An narkar da takaddar tsohuwar furotin a cikin fakiti waɗanda aka ajiye su a cikin busassun wuri don sanarwa daga baya. An gudanar da wannan kwana ɗaya ko biyu kafin amfani da shi, kodayake a tsakiyar 1850s (J.M. Reilly, 1960) yana yiwuwa a same shi tuni an fadakar da shi kuma an saka shi a wasu wuraren kasuwanci.
Don wayar da kai, anyi amfani da maganin azurfa na azurfa 10% tare da ruwa mai narkewa; Bayan haka, an zuba cakuda a cikin guga mai aron roba, kuma a karkashin fitowar wani rauni mai wucin gadi na wucin gadi (gas ko fitilar mai, ba mai yuwuwa ba), an yiwa ganyen albumen yawo kan ruwan azurfa na mintina biyu ko uku; a ƙarshe an sanya shi ya bushe kamar yadda yake lokacin da yake albumin, amma yanzu cikin cikakken duhu. Da zarar ya bushe, an jika takardar a cikin ruwan citric acid na 5% na minti ɗaya ko biyu sannan a kwashe ta bushe tsakanin takardar tacewa. Da zarar sun bushe, an cushe ganyen don amfani na gaba, ko kuma su birgima, tare da ɓangaren furotin da ke fuskantar, a cikin wani sikilan silinda da aka nannade da takarda. Hakanan, an adana takaddun da aka wayar a cikin busassun wuri (M. Carey Lea, 1886).
Don aiwatar da buga hoto a kan irin wannan takarda, an aiwatar da matakai masu zuwa:
a) An nuna wajan albumin da aka wayar da kai zuwa hasken rana don saduwa da mara kyau, wanda zai iya zama gilashi tare da kayan albumin, gilashi tare da collodion, ko tare da gelatin.
b) An goge ra'ayin a ƙarƙashin ruwan famfo.
c) An lalata shi, gabaɗaya tare da maganin zirin gwal.
d) An gyara tare da sodium thiosulfate.
f) A ƙarshe, an wankeshi kuma an ɗora shi a kan raƙuka don bushewa.
Rubutun faya-fayan albam na farko sun kasance matattu a farfajiya, kuma saman mai sheki ya bayyana a tsakiyar shekarun 1950. Tare da gabatar da hotunan stereoscopic da cartes de visite ("katunan ziyartar"), kundin albam yana da babbar nasara (1850-1890).
Don kasuwancinsu, waɗannan hotunan an ɗora su a kan tallafi na masu taimako, kuma an bi su da sitaci, gelatin, gum arabic, dextrin ko albumin (JM Reilly, op. Cit), duka don dalilai na fasaha da na ado, tunda nau'in takardar da aka yi amfani da ita a cikin Bugun hoto, kamar yadda aka riga aka tattauna, yayi siriri sosai. Hotunan da ba a haɗa su ba wani lokaci ana sanya su a cikin faya-faya, wani lokacin kuma a ajiye su cikin fakiti ko envelop, wanda a cikin su gabaɗaya sukan birgima ko murɗawa, wanda haka lamarin yake da kayan wannan abin binciken.
Wadannan kwafin albumin da ba a cire su ba sun kasance suna da murgudawa ko birgima saboda canje-canje na yanayin zafi da yanayin zafi da ke iya faruwa a wurin da aka ajiye su kafin isowarsu INAH Photo Library, wanda kuma ya haifar da saurin lalacewar wasu hotuna .
A hakikanin gaskiya, an bayar da rahoton matsalolin da aka samo daga mirgina kundin kundin a cikin littattafan farko don bayani game da irin wannan takarda ta daukar hoto, da ma maganinta, wanda ya kunshi gyara kwafiye a kan goyan bayan kwali na biyu, kodayake wannan maganin ya yi aiki ne kawai idan curl ya kasance mai haske (JM cit.).
Takaddun takarda yana haifar da bambancin yanayin zafi a cikin muhalli, tunda shayarwarta ba ta da yawa a cikin ƙaramin albumin fiye da na takardar tallafi, wanda ke haifar da zaren igiyar talla ya kumbura saboda banbancin tashin hankali.
Sinadaran da kwanciyar hankali na wannan aikin hoton yana da ƙasa ƙwarai, wanda ya sa hotunan da aka samar da wannan fasahar ke da saukin lalacewa, duka saboda abubuwan da suka shafi muhalli da kuma abubuwan da suka dace da halayen albumin da azurfar mai ɗaukar hoto na hoton kai tsaye bugu.
Kodayake akwai nazari kan abubuwan da ke canza rayuwar wannan nau'in kwafin, waɗanda ke ba da wasu hanyoyin don jinkirta lalacewa, babu hangen nesa na duniya game da matsalar da ke ba da damar adana ta hanyar haɗin hoto da hotunan hotunan da ayyukan da muka ambata suka samar.
INAH Photo Library yana da tarin kusan 10,000 a kan takarda mai faifai, dukansu suna da darajar gaske, galibi dangane da yanayin ƙasa da hoto. Hotuna da yawa na wannan tarin suna cikin ci gaba na lalacewa-duk da yanayin kwanciyar hankali-, wanda aka kafa aikin aikin maido da injiniya wanda zai ba da damar ceton waɗannan ɓangarorin da kuma yaɗa su. A cikin gyaran kanikanci, ana amfani da dabarun da aka dace wadanda aka yi amfani dasu wajen maido da takardu, wadanda suke aiki don dawo da "mutunci" da ci gaba na zahiri na tallafi, kodayake idan ana maganar tsoma baki a kan matattara ko hoton, ana fuskantar manyan matsaloli, tunda fasahohi da kayan aikin da aka yi amfani da su ba su dace da ƙa'idojin asali na sa hannun gyara ba. A gefe guda, hanyoyin sunadarai ba su da amfani a cikin irin wannan kwafin, tunda sun canza tsarin kwayar halitta ta azurfar da ke samar da hoto (daga azurfar mai daukar hoto zuwa azurfar filamentary), yana sauya sautin, aikin da ba za a iya sauyawa ba.
Wannan shine yadda aka yi haka:
a) Rikodi na hoto na asalin sassan juzu'i kafin magani.
b) Nazarin jiki da na sinadarai game da tsarin kwafin albumin.
c) Da zarar an gudanar da bincike na gutsutsuren, sai a bi da su wata hanyar ruwa mai sanyi, wacce idan aka kara yawan ruwa da nauyi a tsarin kowane yanki zai shagaltar da su.
d) Mun ci gaba da bushewa da sake kafa ainihin hoton hotunan ta hanyar latsa takarda.
e) A ƙarshe, kowannensu an ɗora shi a kan tsayayyen tsaka-tsakin ph, wanda ke taimakawa wajen adana tsarinta na asali, guje wa halayen sinadarai masu yuwuwa a kan tallafi na farko da kan hoton (shuɗewa, tabo, da sauransu).
Ya kamata a lura cewa ayyukan ceto da kiyayewa na tarin hotunan hoto suna da mahimmanci don fahimtar cewa ɗaukar hoto shine ainihin ƙwaƙwalwar ajiyar al'umma, ƙasa, kuma ba wai kawai sakamakon aiwatar da hoto ba ko haɗuwa da abubuwa masu yawa.
