Who knows how the film type photos were developed in the past?

This process is carried out in the dark bag, all the parts of the development tank, ready to develop the film, scissors into the dark bag, then you can begin to roll film and canister, roll film action must be slow and even, a roll of 135 film just to use up a spool of film, rolled up with scissors after cutting the film. Before this step, it is best to use the used film in the bright room under the practice a few times, skilled, so as not to formally * work failed.

The film is positioned through the axle track, and the winding film is isolated from each other to ensure that the development fluid can flow freely and evenly between the film gaps:

2, the preparation of the liquid

The preparation of the developer liquid: I use Rockefeller SHD100 black-and-white film, so I chose to use Rockefeller's HB-17 concentrated developer liquid. You can choose different dilution ratios according to the actual situation, usually the bottle containing the solution have instructions. I chose a program of 1:12/24 ± 1/5 minutes and 30 seconds. Because it takes 650ml of potion to develop two rolls of film in an AP canister, you can calculate that it is 50ml of concentrate + 600ml of water, I used tap water, of course, you can use distilled water if you have high requirements.

The preparation of fixing solution: I use fixing powder. 10 measuring spoons + 650ml water. You can prepare according to the specific instructions. Here to remind you, if the fixing powder preparation, add water evenly, while adding water and stirring to dissolve, otherwise it will be easy to cause the powder into lumps.

Three, the steps of the film

After the completion of the preparation of the water, you can begin to develop the film, which is also the most critical step.

First, measure the temperature of the developing solution to ensure that the temperature is consistent with the nominal temperature.

At that time I measured the room temperature was 23 ℃, basically in line with the requirements of the development, if in the summer or very cold winter, in the air-conditioned room there is no problem, if not to be through the ice or hot water to regulate the temperature of the potion. Development temperature is higher than the standard development temperature provided by the film manufacturer, there will be excessive development of the phenomenon, the density of the negative contrast increases, the particles become thicker, gray fog increased; development temperature is low, it will result in insufficient development, the negative becomes flat gray and soft, unless you need to achieve a special effect, it is not recommended to violate the requirements of the development temperature.

After the temperature is right, it's time to fill the developer tank. There is a filling hole at the top of the developer tank, and the filling process should be even. From the beginning of the injection of water, you can start timing. Generally 650ml of water all injected need 30-60 seconds of time, after pouring the beginning of a minute constantly stirring the water. AP canister on the top of a rotatable stirring rod, it can drive a piece of axle in the tank up and down, if you use the canister does not have such a device, you will have to pick up the whole canister to shake it.

Then it is stirred for 5-10 seconds every minute for the rest of the time, until the development is complete. This is *required* so that the potion can contact the film sufficiently to complete the development chemistry thoroughly.

Since it takes about 30-60 seconds to pour out the solution at the end of development, it is important to start pouring out the solution half a minute before the end.

The development temperature is important, but so is the development time. Because the development time is too long, the density and contrast of the negative increased, the development time is too short, the negative will be underdeveloped. Although modern black-and-white films have a certain degree of tolerance, but in the process of developing temperature and time control is not appropriate, or will affect the tone and level of the negative.

Immediately after developing, pour water into the developing tank, stirring constantly for 1 minute, and then pour off the water.

Next, you can pour the prepared fixing solution into the developing tank, stirring continuously for 1 minute and then every 1 minute. Under the condition of 20 ℃ about 10 minutes of fixation. Higher temperature, shorter fixing time, lower temperature, longer fixing time, the requirements are not very strict. I use 23 ℃, the fixing time is 9 minutes.

Four, washing steps

Finishing fixing, you can wash. The purpose is to completely remove the residual liquid on the film in order to preserve the film for a long time. Open the lid of the development tank, placed under the faucet, connect a hose on the faucet, the other end inserted in the center of the film axis, open the faucet to moderate running water rinse 20-30 minutes.

In the final water at the end of the rinse, add one or two drops of detergent as a wetting agent, in a thorough stirring for half a minute to complete the washing process. This is done to eliminate any water stains that may have formed on the film.

Fifth, the drying of the film

The negative will be hung in a ventilated dust-free room, the lower end of the film on a clip with a certain weight to prevent the film from curling in the drying process. Both sides of the film should be gently wiped with a soft, damp sponge to remove excess moisture and ensure that the film dries quickly and evenly.

The above is my first black and white film development process and experience, I hope to be useful to you, but also welcome criticism and correction, together with the practice of discussion.