Developing Your Own Black and White Film

Preparation:
I use a changing bag to load the film into the canister. Getting a large bag makes life easier.

Preparing solution:

D76: I mix stock solution from the powder a day or so before I need to use it. You need to mix it at 120 F so it I prefer to let it cool off on its own a bit. Stock solution keeps for a couple months. A 1L packet makes 33.8 oz and I use 8 oz of develop at a time, so I basically get four uses per packet.

HC-110 concentrate: I put the few drops into a bottle and mix it with a bit of hot water at the time of development.

From the D76 stock or HC-110 mixture, I pour into a graduated cylinder. I add water up to about 12-14 oz and then measure temperature. This leaves me with ability to add ice or hot water to get the temperature to what i need it.

For developing, I either use D-76 1:1 (stock plus equal parts water) or

HC-110 Dilution B, which is 15ml in the aggregate 480ml (16 oz) solution
HC-110 Dilution H, which is 7.5ml in the aggregate 480ml (16 oz) solution. Might as well save money!

Developing
Some people "pre-wash" - basically soak the film in water and agitate for a couple minutes before developing. The need or benefit disputed, but it is claimed to prevent air bubbles. The effect on developing times is unclear: it may lengthen developing times (more diluted since water remains) or shorten developing times (more effective when wet) I skip this step and having noticed anything wrong.

Agitation during developing
After I pour in the developer, I agitate for 30 seconds to start and then agitate for about 7 seconds every minute. Kodak recommends 5 seconds every 30 seconds, but that seems like I'm constantly agitating and usually I am trying to do two things at once. There is professional justification for less agitiation. Someone else smart than me explains:

Allowing the developer to "soak" for 1 minute between agitation does something very simple: it creates what are called edge and adjacency effects, which is sort of like a type of "edge sharpening". Here's how it works: the developer exhausts itself as it develops the highlight areas,which have been heavily exposed. The less-exposed shadow areas though, exhaust the developer significantly LESS, due to their lower exposure. This means that the developer, as it soaks and gets exhausted, develops the edge transitions between highlights and shadows, creating microscopic "edge" enhancements at the "adjacent" areas between shadows and highlights. This exhausted developer/stronger developer edge and adjacency effect is made more pronounced by a longer soak time: if the developer is agitated every 30 seconds, fresh developer is more or less continually distributed,and the edge and adjacency effects do not develop to nearly the same degree.

Developing Time
Tri-X 400 at ISO 400

• D-76 1:1 - 68F: 9 3/4 minutes , 70F: 9 minutes
• HC-110 Dilution H - 68F: 13 minutes

Tri-X 400 at ISO 1600

• HC-110 Dilution B - 68F: 13.5 minutes

TMax 3200

• HC-110 Dilution B - 68F: 8.5 minutes

To adjust time for developing following this formula (where Exp = e^x):
New time = Old time × exp(-0.045 × (New temp °F - Old temp °F))

Stop Bath
Kodak makes stop bath to immediately stop development. Pour out the develop and adding a lot of water will do the same thing. Stop bath is claimed to save fixer life. It's pretty cheap, but it smells nasty. I tend avoid it because of the smell and I'd rather risk getting less chemicals on me.

Fixer
Pour in the fixer mix. Agitate continuously for the first 30 seconds and then every couple minutes. I tend to fix for 8-10 minutes. It’s hard to over fix. If the film has a heavy purple tiny, it may need more fixing. You can reuse fixer, so pour it back into your storage container.

Wash
The goal is to get the fixer off the film. You can agitate some our cycle water out. You can take top off and inspect film. No real technique, just make sure all fixer is gone.

Final rinse
Add a couple drops of Photo-Flo and fill with distilled water. Agitate a bit. Both these will make sure no hard water stains develop on the film.

Drying
Pull the film off of the reel, clip one end to where you will be hanging the film to dry. I've tied a bag clip to where we hang clothes to dry. Pull the rest of the film off of the reel and add weight the bottom of the film, with a clothes pin or a film clip. With a damp sponge, ever so gently, remove any water droplets. I slide the sponge down the film, barely touching it. Be careful to not scratch the negatives, they are very soft at this point.