65

Photo films and papers are made from salts of silver that naturally only darken when exposed to violet or blue light. In the early days of photography, this was all that was available. Therefore these films and papers are able to be handled under any light source that does not radiate blue light. By the way, the violet and blue frequencies of light are the ...


33

In the darkroom, place a piece of the material you will be developing, flat, face up, on the work space. Place a handful of coins on this material. Using a timer, remove a coin every 5 minutes. 12 coins will cover 1 hour. At the end of the time span, develop the film or photo paper. A perfect darkroom will leave no evidence. An unsafe darkroom, reveals ...


31

Make negatives specifically for the course: Ask yourself what you want to actually teach in your class, and come up with negatives to function as aids to those lessons. If all the students are going to learn is how to mix chemistry, expose photo paper, and what order/timing to dunk the sheets in the tanks, then why on earth is anyone Paying for that when ...


23

It's likely to fog your paper. You need a specially designed red or amber filter or bulb. But... there's an easy test. Place a large coin on a sheet of unexposed photo paper. Expose the paper to your safelight for, say, twice the amount of time you expect the paper to be typically exposed to the safelight. The safelight should be in its intended location. ...


20

If you are talking about locating a light leak in a changing bag for loading film into magazines and cameras without a darkroom available… Periodically, to check the condition of your changing bag, put a bright light inside the bag through one of the sleeves. Close up the bag. Sit in the darkroom or a closet with no light for a few minutes to let your eyes ...


15

Conventional wisdom says yes, you should use a stop bath. The stop bath is a very weak acid (similar to white (distilled) vinegar) and is used to neutralise the developing agent. This guarantees two things: You can be sure that you won't have any additional development happening after the developer bath. You won't contaminate your fix with developing agent. ...


15

it seems a little odd that there is a type of light that doesn't affect film or developing paper etc. There are types of light that don't affect the rods and cones in your retina, too. You can't see infrared or ultraviolet light even though some other animals can. It's the same idea with photographic materials: they vary in their sensitivity to different ...


13

This looks to me as if you have botched loading the film onto the spiral, so that two wraps of the film were touching or very close to each other. When that happens you tend to get marks on the negs where developer hasn't really reached them properly. (I tend to get this with 5x4 negs processed in a mod54: huge negs like that are very flexible so if you ...


11

Most commonly, you used paper with different contrast grade. There are fixed grade papers, normally available in grade 0 to grade 5. There are also variable grade papers (aka Multigrade), where you change the contrast with different filters that gave different colors. See: http://en.wikipedia.org/wiki/Photographic_paper#Contrast_control


11

Dedicated safelight is the best. But when unavailable you can work with red bicycle light or red LED Christmas tree decoration. Colored LEDs have a narrow emitting band and are usually safer than colored regular bulbs. But beware - some have an invisible narrow blue band which will ruin your work Always remember no safelight is truly safe and keep your ...


10

Yes, if the room is truly dark and you work quickly, you'll be fine. But the room has to be totally dark. If you have a bathroom or walk-in closet with no windows, and you make sure no light is coming in through under the door, you shoudl be fine. Wait a few minutes in the dark for your eyes to adjust, to make sure you can't see any light around the ...


10

Te test proposed by @bvy is a nice one. I would just add a couple of tips. Put the light the furthest away you can. If the light does not heat, try using some layers of red cellophane paper https://www.google.com/search?q=red+cellophane+paper. Photographic paper reacts to the blue component of white light. The amber light needs to have a very thick layer ...


9

The first generally known case of taking two different exposures of the same high dynamic range scene and combining the results was around 1850. Gustave Le Gray did it to render seascapes showing both the sky and the sea. Le Gray used one negative for the sky, and another one with a longer exposure for the sea, and combined the two into one picture in ...


7

In the darkroom, one can use an unsharp mask to achieve effects similar to the digital tool of the same name. Yes, "unsharp mask" was a darkroom technique before it showed up on your computer. You start with your negative, and copy it onto another negative (forming a "mask"). The mask is dark where the original negative was clear, and clear where the ...


7

Yes, they can. The darkroom I work in uses the strips of red LEDs you can get to put in car rear windows, all run from a 12 volt supply, as safelights and they work brilliantly. I believe that fairly extensive tests were done before I joined: leaving paper out for hours & then checking for fogging. I'd encourage anyone planning on doing this to do ...


6

Push processing (extending the time the film spends in the developer) increases the contrast of the negative or slide. If you're shooting roll film, you pretty much have to push or pull the whole roll. But for sheet film shooters like Ansel Adams, it was a pretty good way to adjust contrast—terms like "N+1 development" in the Zone System refer to this ...


6

Wet silver color printing is slow, tedious, and requires trial and error to get the color balance right. I don't miss those days. Even if you want to cling to film for some reason, scanning the film then printing digitally is much easier, repeatable, and faster. My process went something like this (it's been 20 years or so): Turn off all the filters to ...


6

With a grain focuser, compose with the lens wide open. Now stop down to the aperture you will be using. Now use the grain focuser. It is likely that you are focusing wide open, it is likely that the focus is shifting as you stop down. This is not uncommon. Also, check and see which is sharper, grain focuser on easel, no paper on the easel or, sacrificial ...


5

Xtol is less stable and is liable to fail without giving notice. Other than that, it's got an excellent reputation. Kodak provides this comparison between its developers: The main difference between D-76 and Xtol when you develop at rated speed is the fineness of the grain. The other metrics (shadows detail and sharpness) are very much in line. Of ...


5

The process involves the following steps: Remove the film from its roll(s), load it onto reels, and insert the reels into their tank. This must all be done in the dark. (Good to practice on some old ruined film so that you can learn to load the reels by touch.) Once the cover is on the tank, you can turn on the light. Pour developer solution into the tank, ...


5

Photo prints will yellow if improperly washed. We wash prints after the fix bath to completely remove residual chemicals. Try to save these prints by re-fixing and then washing in running water for about 15 to 30 minutes in gently running water. If water is scarce, use a washing agent like "hypo clear" followed by a brief wash. If this doesn't work, let us ...


5

Using an ND filter is the best option however, if this lash-up is for black & white printing, you can install a common lamp dimming switch. Only do this if the lamp operate at line voltage and only if the lamp is the only thing on that circuit.


5

Photo paper is ordinary paper coated with light sensitive chemical. These are crystals consisting of silver combined with iodine, or chlorine, or bromine. In their natural state they resemble table salt except the crystal are much smaller. When these crystals are exposed to light, the chemical bonds holding the crystal together weakens. Normally we only ...


5

Before making assumptions on monochromaticity with LED lights that aren't built for this purpose, test and/or measure. LEDs are often overdriven, and/or allowed to get reasonably hot, and/or used in pulsed modes in these applications. All this can affect their spectral behaviour (compared to datasheet values) a lot.


5

A big fun factor in seeing the darkroom at work for the first time (and all other times) is seeing your own image appearing on the paper So... Let them have fun then! There are several projects they can do without taking the source images themselves, for example, a photo collage. Let them expose several images together. Let them make masks with cardboard, ...


4

I have seen the same problem when photographing a red laser spot, the spot came out white, not red. In my case it was an exposure problem, the small intense dot on a dark background, the dot was severely overexposed.


4

As John states, the camera may be compensating for the monochromatic light, or it could be saturation, if the point is much brighter than the background. Have you tried intentionally underexposing, i.e. set compensation -2 or more EV? Have you shut automatic white balance? You might also include a print of the spectrum in the photo, lighting the paper a ...


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