Helpful Posts: 0
29th August 2012, 12:28 AM
Good Night. I am Brazilian and my English is not good, sorry.
I wonder about latitude, can someone help me?
The curve of the foot to the shoulder of the negative curve is equivalent to negative zone III to VIII (system zones ancel Adans), we would have in this case 7f. stop latitude.
Is that correct?
Boa Noite Senhores. Sou brasileiro, e meu inglês não é bom, desculpe-me.
Gostaria de saber sobre latitude, alguém pode me ajudar?
Da curva do pé do negativo ao ombro da curva do negativo está o equivalente a zona III a VIII ( sistema de zonas de ancel Adans). teríamos neste caso 7 f. stop de latitude.
29th August 2012, 05:16 PM
Re: Film´s Latitude
Hello and welcome to CiC.
The translation of your native language is difficult for me to understand. I apologise if I am not understanding your question correctly.
I think you are asking about the dynamic range of photographic film.
You write that you think film has the equivalent of 7 f-stops. I am not a technical expert, but I have read that the dynamic range of negative film can be greater than 7 stops.
I do not think it is useful to compare this to the zone system as developed by Ansel Adams. That is about the range of tones that result from your composition, arrangement of objects in the scene being photographed and your exposure settings.
I hope some of my more knowledgeable colleagues will also provide some opinions for you.
Olá e bem vindo ao CiC.
A tradução de sua língua nativa é difícil para mim entender. Peço desculpas se eu não estou entendendo sua pergunta corretamente.
Acho que você está perguntando sobre o intervalo dinâmico de filme fotográfico.
Você escreve o que você acha que o filme tem o equivalente a 7 f-stops. Eu não sou um especialista técnico, mas tenho lido que a faixa dinâmica do filme negativo pode ser maior que 7 paragens.
Eu não acho que é útil comparar isso com o sistema de zonas, desenvolvidos por Ansel Adams. Que é sobre a gama de tons que resultam da sua composição, a disposição dos objetos na cena sendo fotografada e as configurações de exposição.
Espero que alguns dos meus colegas mais experientes também irão fornecer algumas opiniões para você.
29th August 2012, 10:12 PM
Re: Film´s Latitude
Thanks for responding.
I understood your answer, I understand this in the same way.
We have difficulty finding literature that addresses technical issues about photography in Brazil.
If you have any texts or books that talk about the subject that you could indicate for me, i can translate it.
What I want to know about the dynamic area, or film latitude is: How many f. stop the film is able to register.
The dynamics area of a film is the ability to record different area of light in a scene. In a scene that has from the sunlight for the shade 15 f stop, a film or digital sensor could print scene recording all the different lights?
I don't understand why the zone system is not related to the dynamics area of a negative?
Obrigado por responder.
Compreendi sua resposta, também compreendo assim.
Nós temos dificuldade de encontrar literaturas que aborde forma mais técnica o assunto fotografia no Brasil.
Se tiverem textos ou livros que falem sobre o assunto eu posso pesquisar, em bora meu inglês seja básico eu consigo traduzir.
o que quero saber com relação a área dinâmica, ou latitude do filme é: Quantos f. stop o filme tem condições de registrar.
A área dinâmica de um filme é a capacidade do mesmo de registrar diferentes área de luz numa cena. Em uma cena que tenha da sombra ao sol 15 fstop, um filme ou sensor digital coseguiriam imprimir a cena registrando toda sua variação tonal ?
Não entendi porque o sistema de zonas não está relacionado com área dinamica de um filme??
Muito obrigado por responder.
Originally Posted by Donald
29th August 2012, 11:27 PM
Re: Film´s Latitude
If memory serves me correctly, the best one can expect to see with film is about 11 EV units (or f/ stops); and that is only for black and white film.
Color film has a considerably reduced dynamic range relative to black and white; with slide film being even less.
Digital sensors were at first hard pressed to even match slide film in dynamic range. From what I have seen and heard, this is no longer the case. The average digital sensors might still be hard pressed to match black and white film in dynamic range, but with High Dynamic Range (HDR) photography this is no longer an issue in many critical cases.
The software for HDR photography is actually a pretty good option for getting the most out of scans made from black and white film; because at the end of the day the real limiting factor is what can be printed for people to hold in their hands and actually see.
This is where the zone system comes into play: it is a way for making the most of the dynamic range that can be physically presented to viewers through an actual print. Think of it as an early foreshadowing of the HDR technology yet to be invented!
So, the reason that the zone system does not apply directly to film is simply that the zone system presupposes that one has a negative to work with, and that one wants to make the best use of the dynamic range which can be printed. You have to have a negative as a starting point before you can put the zone system into play.
It might help us here to help you if we knew what you were trying to do; that is, what you are working with and what you are trying to achieve with it. There are people here who first worked with film before becoming dedicated digital photographers so if you could tell us what you have in hand and where you would like to go with it, we might better be able to point you in a good direction for you to explore.
1st September 2012, 10:55 PM
Re: Film´s Latitude
Hi John, thanks for the clarification, I'm starting my career as a teacher of photography, and am trained in arts photographer for some time.
And in practice I never had the need to increase the dynamic range of film.
When photographed using studio flash, and when photographing weddings and more sensitive films used flash as fill light.
But as a teacher I have sought out the comfort zone and have done experiments and research, to offer my students a more comprehensive content.
I have noticed that there's books and blog in English with a more technical content, and complete, an American photographer who maintain contact indicated the CIC as a reliable source where I could ask questions.
The material I need is more theoretical, if they have any books to indicate I am grateful.
Thank you for your attention
Oi John, obrigado pelos esclarecimentos, estou começando minha carreira como professor de fotografia, sou formado em artes e fotografo a algum tempo.
E na prática nunca tive necessidade de aumentar a faixa dinâmica de um filme.
Sempre fotografei utilizando flash de estúdio, e quando fotografava casamentos utilizava filmes mais sensíveis e flash como luz enchimento.
Porém como professor tenho procurado sair da zona de conforto e tenho feito experimentos e pesquisas, para oferecer aos meu alunos um conteúdo mais abrangente.
Tenho percebido que existem livros e blog´s em inglês com um conteúdo mais técnico, e completo, uma fotógrafa americana que mantenho contato indicou o CIC como uma fonte confiável onde eu poderia tirar dúvidas.
O material que preciso é mais teórico, se tiverem algum livro para indicar fico grato.
Agradeço pela atenção
Originally Posted by John Morton
2nd September 2012, 01:08 AM
Re: Film´s Latitude
I'm not sure if this helps, Pedro, but:
Back in the days of film, when photography stores stocked high quality film in on-site refrigerators, the better stores also had manufacturers specification sheets for each film. You had to ask for them, and they often had to go look in the back room somewhere, but these sheets had all the technical information about each film's sensitivity to light and other notable characteristics.
I know that for black and white films, such information was often available in a booklet form that brought together the specifications for all the films a manufacturer had available.
Using the response curves published in these spec sheets, and with a densitometer under the enlarger, it was possible to fine tune the optimum development and printing conditions for any specific (black and white) film. Since the final characteristics for any developed film are determined by many factors (actual ASA the film is exposed for; the type of the developer used; the developer's concentration/dilution; temperature of the developer; duration of the development process; any intermittent water washes and replenishment of the developer during the development process, and so on), photographers tended to fine tune their film development according to the demands they were putting on the film.
I can't speak to color film as I never developed that but my understanding is that it is very sensitive to any deviations from an established development protocol. Black and white film is much more resilient and forgiving of such deviations.
Color film is (was) also much more demanding in the exposure latitudes it was capable of supporting. Some films, for instance, had very poor low light performance in that they exhibited a high degree of reciprocity failure, where different wavelengths of light required longer than expected exposure times. For instance, Fuji NPS low contrast film had a very hard time accurately capturing red light in particular, at exposures exceeding one second.
So although general answers might be forthcoming for your question, in fact each film had its own particular characteristics which were outlined by the manufacturer in the spec sheets they provided to photographers.
2nd September 2012, 03:25 AM
Re: Film´s Latitude
Are you maybe relative of misterious Don Pedro - a spy from Rainmen Land ?
But seriously - you are not from Brasil. Are you maybe formrr member of Polish communictic security service repainted to new bandits and thieves from CIA ? Do you belong to PO party or any quasipolitical ecological so-called non-governmental ecological organisation controlled by that party ?
Last edited by darekk; 2nd September 2012 at 09:52 PM.