Why does the fixer have to be at a certain temperature?

<p>When I develop my tri-x 400 film, why does the fixer temperature have to be at 68 degrees? What would happen if it were developed at 60 degrees lets say? Thanks a lot for your time. Any input you might have would be appreciated.</p>

<p>All of your liquids need to be at the same temperature, relatively, to avoid film reticulation, which is caused by rapid temperature change and is not generally a pretty sight. Also, different temperatures will cause your chemistry to work in different ways, generally slower for lower temps and faster with higher ones. Some chemistry, like Kodak Rapid Fix actually will "freeze" well above the temperature water freezes at--just a fun fact if you ever use it and leave it in the garage over night!</p>

<p>I pretty much develop at whatever room temperature is, so my developer and fixer are all the same temperature anyhow.</p>

<p>However, I think (dimly remembered from a day when film was king), that widely different temperatures of working solutions can cause emulsion problems like reticulation. (e.g., <a href="http://www.ephotozine.com/article/Create-reticulation-when-film-processing-4639">link</a>)</p>

<p>Fixer is not as critical as Developer , but like any chemical reaction the colder the chemicals the slower they work. Your fixer may not clear the film properly if its too cold. Reticulation is a possible problem , but with modern films it does not show up like the earlier ones. I have tried to get the reticulated look with Tri-x using very warm, or cold chemicals, and a water rinse and even then you can hardly see it. Best to develop your film correctly and do it the same way each time, so you have this as a constant, and not as a variable. </p>

<p>Reticulation is indeed the main problem. I've only had it happen once but it was a pretty extreme case. Keeping your chemicals at a relatively similar temperature will give you no problems. A few degrees is perfectly acceptable. Different films behave differently so you still need to be careful, especially with wash water coming straight from the tap but generally, if you keep everything (apart from the developer) at a comfortable temperature for you, you should be fine.</p>

<p>Hi Alicia,<br>

Fixers work from 65F until it is just too hot (100f or more). For a few films don't raise the temperature from the developer by more than 20 or so degrees (if you used acetic acid stop bath even that probably won't hurt). Usually we try to be reasonably close in all solutions. For thick or soft filmsand if you are using a rinse instead of short stop, then try to be within 10 degrees. Reticulation takes place with a few film and it is caused by very high temperatures following devekioment (I know you have heard something else but trust Professor Jones).</p>

<p>Lynn</p>

<p>I have some aluminum pop cans that I washed and cut the tops off of. I can easily pour 8oz of chemicals into them. I place them in my freezer to cool the chemicals if necessary. To heat the chemicals up, I place the cans in a container with warm water in it. I stir the chemistry with a thermometer to monitor the temperature.</p>

<p>It doesn't have to be at 68F, that's just a de facto standard that was developed by manufacturers as room temperature in an average home or business. You can vary it a few degrees up or down, and a lot of film data sheets will tell you how much to change your developing times to account for it. But as others have mentioned, whatever temperature you use, it's a good idea to keep all your chemistry around the same temperature so as not to stress the emulsion too much. Reticulation is what occurs when your emulsion is at a higher temperature, and you then dump in a much colder chemical. It's rare these days, but causes the emulsion to "crack," sort of like taking a wine glass right out of a dishwasher and plunging it into cold water.</p>

<p>I have processed using developer always at 68F / 20C and stop using water out of the spigot varying from 65F to 80F for many years. Fixer is always room temp 68F to 78F. Never saw any signs of reticulation. All film was modern day emulsions: Neopan400, Tri-X, HP5, Acros.<br>

I only use liquid one shot developers now (Rodinal & HC110) so it is easier to always cool to developer down to 68F by dropping in ice cubes than it is to convert the times to another temp. But after that, the stop, fix and wash temp is whatever comes from the tap or jug.<br>

My personal thought is that the reticulation warnings only apply to some wildly extreme temperature changes.</p>

<p>So my thinking is use the fixer at whatever your room temperature is if you have heat & AC in your house.</p>

<p>It is worth noting that whatever temperature you use, it is a good idea to make sure the film is close to the same temp too.</p>

<p>The activity of most chemical solutions increases with temperature so a lower temperature would lengthen your fixing time. In my own experience, the time difference is not significant.</p>

<p>Reticulation is a potential problem but I've never had a problem with it, even though, in winter, my developer and fixer temperatures can differ by 10 degrees F.<br>

There is a simple way for you to determine the correct fixing time for a temperature other than 68F. With 35mm film, cut the leader off the film roll before you load the rest of the film onto the processing reel (you can do this in the dark or leave the leader outside of the cassette when you rewind the film in the camera). This will leave you with a stub of film that is opaque gray/white in color.<br>

In daylight, put the leader into your fixer at the teperature of interest and watch it. After a few minutes, the leader will become transparent as the silver halide is dissolved by the fixer; record the time at which this occurs. Your fixing time for your negatives is three times the number of minutes it took for the leader to clear.<br>

This is also a good way to check the useability of fixer that has been stored for some time.</p>

<p>Another way to bring temperatures down is to obtain a pyrex test tube and fill it with crushed ice and water. Use it to stir the fixer (or any solution) until the temperature reaches the desired level. </p>

<p>Also, some films are more tolerant to temperature extremes than others. </p>

<p>To get reticulation, you'd have to have some pretty wild temp differences. 8 degrees difference isn't going to cause reticulation.<br>

I have heard that the reason why you want all your chemicals to be the same temp is to reduce grain size. Never tested it. It could be an old wives tale, as far as I know.<br>

See <a href="http://www.DarkroomGuide.com">DarkroomGuide.com</a></p>

<p>Only happened to me once (a long time ago). It was 1972 and I was developing a roll of VP 110 in a tray (since I had no 110 SS reels). Reticulated 110 negatives when enlarged have a very noticable texture.</p>

<p>Thanks a lot everyone!</p>