hydroquinone
a white crystalline compound (C6H4(OH)2 chemical used in some developer formulas.
hydroxyl
chemical group consisting of one hydrogen atom plus one oxygen atom.
Hydroquinone
A developing agent, also know as Quinol.
Hyperfocal Distance
Distance of the nearest object in a scene that is acceptably sharp when the lens is focused on infinity.
-Chlorhydroquinone - developing agent contained in warm tone developers.
-Chloride paper - printing paper with a silver chloride emulsion. Much less sensitive than bromide paper. Mainly used for contact printing.
Hydroquinone - reducing agent. It is used in developers to provide high contrast results in the presence of a strong alkali.
Hyperfocal distance - distance between the camera and the hyperfocal point.
Why do Metol- Hydroquinone Developers Solarize Relatively Poorly? -
It is well known that developers containing both metol and hydroquinone are much faster- acting than developers containing either developing agent alone.
Hydroquinone, Metol, paraphenylenediamine, and phenidone are some of the more commonly used developing agents. PRESERVATIVE All developing agents in an alkaline state are affected by oxygen.
In color reversal processing the film is developed in an MQ (metol/hydroquinone) developer similar to a black-and-white developer, followed by a rinse or a stop bath. The film is fogged in the reversal step, and is then developed in a color developer.
Common reducers are hydroquinone, metol, and phenidone. AcceleratorThe accelerator is added to the reducing agent to speed development. It also increases contrast.
NOTE: If you use D-76 developer be sure to use FRESH D-76 (not some that has been sitting around in a half-full bottle for a month!) As D-76 ages a chemical compound, hydroquinone monosulfonate, is formed.
MQ/PQ developers
Are developing solutions containing the reducing agents metol and hydroquinone or phenidone and hydroquinone.
Search SWPP and BPPA
Information provided by: SWPP BPPA
More Photographic Terms ...
Developing agents. Chemicals (typically phenidone, metol and hydroquinone) able to change light-struck silver halides into black metallic silver.
A black & white film or paper developer that includes the developing agents phenidone and hydroquinone.
Related Terms
Bookmark This ...
order, a little of the Sodium Sulphite, to stop the Metol oxidising when you mix it, then gradually add the Metol , stirring until it is all dissolved. Add the Sodium Sulphite, again stirring until dissolved then do the same with the Hydroquinone and ...
 See also: Hydroquinon, Image, Developer, Photograph, Film
  
|
RSS
