Thin Negatives: Wash that will revive contrast?greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
Hello all -- new to the B&W thing. My negatives during my last processing have become quite thin. All my prints are looking flat. My teacher has suggested a rewash in a Sylliquim (sp?) which should revive the contrast. Anybody heard about this?
Thanks in advance
-- Mike Martoccia (email@example.com), October 11, 2001
I think you mean Selenium. This will work but it is permanent. You might try using a higher contrast filter or split printing with two different filters; each with a different exposure.
-- Justin Fullmer (Provo.firstname.lastname@example.org), October 11, 2001.
All the processes I know to intensify a negative (which is what you are trying to do) are permanent, and irreversible. If this is important work, make a dupliacate negative for safety.
Intensification is generally regarded as a "salvage" technique--that is, you have an important negative that cannot be re-done, and you must make the best possible print. There is always some risk of damage to the negative when doing these sorts of processes.
More importantly, if this work isn't critical, is to know why your negatives are thin.
Did you not give enough exposure? Did you not develop long enough? Was your developer exhausted?
-- Charlie Strack (email@example.com), October 11, 2001.
As stated, Selenium Toner is a great way to intensify. You can do it in daylight, but rewet your film first. It works alot nicer than the Kodak Intensifier which adds ALOT of grain. You won't get a whole lot of intensification but it will definitely boost everything so the negs are more printable. I would FIRST try printing at a higher grade contrast first to see if you need to do this. If everything is still muddy, do the intensifying. Just remember, if you don't have shadow detail to start off with, you won't have shadow detail but a higher lever of density in the shadow regions!
-- Scott Walton (firstname.lastname@example.org), October 12, 2001.
Selenium intensification is fairly safe for your negs. Don't worry too much about doing copies first etc, except if we are talking about some extra important work that should be copied anyway (and stored separately, in fire proof containers and so on...). Other intensification techniques (involving bleaching and redeveloping) are dangerous, but you shouldn't (as a beginner) try them yet.
-- George Papantoniou (email@example.com), October 12, 2001.
First, trust your teacher enough to ask him/her further questions as to how to handle something such as this... Especially if you did not understand what was said the first time.
You can't 'revive' contrast if you didn't get it in the negative originally when you developed it. You can put some in by intensifying it per your teachers suggestion or by other formulas. Use this as a good learning experience and ask the instructor for a demonstration, personal help or more explanation.
-- Dan Smith (firstname.lastname@example.org), October 12, 2001.
There are reversible ways for intensification. The "classic" method is to rehalogenize the silver into a form that can be redeveloped. There are various formulas that will achieve this. It is recommended to do this under subdued light, but I never had difficulties with this. The bleach bath used for sepia toning for example will achieve this. To intensify redevelop in high contrast developer, such as pape or lith developer or other highly active formulas. The process can be repeated to achieve higher densities, but -- off course -- it is all based on the remaining silver in the image. The results are already superior to selenium intensification. An additional benefit is that the image densitiy can also be "decreased" if something goes wrong using the same method but employong a normal working developer. The method is very safe and I do not see any way in which the negative could be spoilt (as long as it is not put into fix between bleaching and redeveloping). Not only selenium will intensify, but also other metal based toners, such as copper toner (Calbe sells copper intensifier). Far more effective are mercury intensifiers. They can achieve intensification of up to 3 paper grades. They will also increase the appearant graininess, but the results are fabulous. Although extremely useful I would not recommend their use due to the high health risk. Even better results can be achieved by repdrodcution of the negative before a dark background, a classic method not widely known even among pros. According to my experience this will achieve the highest possible intensification (without having to use mercury based intensifiers). Place the negative with some distance in front of a black board. Use one photolamp or flash at a very narrow angle from one side to illuminate the slide. Do not place the lamp /flash behind the slide, otherwise you will lose the effect. Copy the negative using your camera. You wil be suprised about the contrast gain. This method is -- as mentioned -- for very underexposed /underdeveloped negatives which otherwise could not be printed.
-- Volker Schier (Volker.Schier@fen-net.de), October 13, 2001.
The best way is usually to start simple. One function of a good teacher is to help students learn from their mitakes. With low contrast, thin negs, and a beginning photographer, it is usually either improper exposure and/or improper development. Ask your teacher to let you look at either properly exposed/developed negatives, or find some pictures in a basic photo text. Next, see which of the "horrible examples" YOUR negs look most like, and see what the book says caused it. Then investigate the developer. How many hundred rolls have been processed before yours? Has some bright spark been filling it with water? It's truly amazing what improvement fresh developer used properly will make in negative quality. Usually by this time, your negatives will be progressing towards pleasing, but if not, again, that is what teachers are for. It's also a reason to use only one film and developer till you can make it do what you want before changing something. Have fun! CC
-- Carl Crosby (email@example.com), October 17, 2001.