How to choose black and white photographic paper

If you want to take black and white photos, you must choose the right black and white paper. The author likes black-and-white photography, and has been using many brands of black-and-white photographic paper since the 1960s, such as the domestic Aokun brand; Slavic languages imported from Yi Erfu, Hungary and Russia, etc.

Black and white photographic paper is generally divided into two categories: printing photographic paper and enlarged paper. The difference is that the former has lower sensitivity and the latter has higher sensitivity. Now there are some black and white photographic papers, the sensitivity is between photographic paper and enlarged paper, and they can be printed and enlarged.

The validity period of black-and-white enlarged paper is generally two years, but the actual validity period of printing paper is much longer than two years. I have used printing paper that has expired for 10 years, and I don't feel anything obviously bad.

Black-and-white photographic paper is generally divided into 1, 2, 3 and 4 according to contrast, and the larger the number, the higher the contrast. The higher the contrast, the lower the sensitivity and the longer the exposure time. It is customary to regard No.2 photographic paper as neutral and suitable for dealing with negative films with moderate contrast.

Black-and-white photographic paper can be divided into two categories: ordinary paper and plastic-coated paper. Ordinary glossy paper can be dried and polished by glazing machine after washing, or it can be dried and polished naturally by laying flat on the glass. Its advantage is that the photos are kept for a long time, but its disadvantage is that it takes time, effort and medicine. Plastic-coated photographic paper does not need drying and polishing, which has the advantages of saving time, labor and medicine during processing, but the photo preservation is poor.

The film surface of black and white photographic paper is different from smooth surface, fine suede and coarse suede. The contrast of glossy paper with the same number is often greater than that of textured paper. In the domestic photo papers with the same number, the contrast between AD and Xiamen University is large, while the contrast between Shanghai and Le Kai is small. The contrast between Hungary and Yi Erfu is higher in the same amount of imported photographic paper, while the contrast between Russian-made Slavs is smaller.

Except a few black-and-white photographic papers are full color (such as the early Slavic carbon amplification paper), most brands of black-and-white photographic papers are color-blind and can be operated under weak red light. The purchased black-and-white photographic paper must be tested for color blindness before it can be used to ensure safety.

For the selection of different photographic papers, according to personal experience, we should first choose photographic papers with different film surfaces and contrast numbers according to personal use. For example, if you are a photographer who likes to write freely, then I suggest you choose glossy paper. This kind of photographic paper is very suitable for newspaper plate making and printing. If you only enlarge a photo of about 7 inches, then No.2 glossy printing paper is more suitable. Although the exposure time is long, the printing paper is not afraid of storage expiration, so there is little waste. Of course, although the texture of carbon amplification paper from Le Kai and Slavic is fine, it does not affect printing and plate making. The black and white photos published by the author in newspapers and periodicals in recent years are almost all made of carbon fine velvet paper, and they can be used without finding anything bad.

Limited by economic conditions, it is impossible for ordinary cinematographers to buy all the photographic papers with different contrast numbers, only the photographic papers with the same contrast number (such as No.2 or No.3), and adjust them with different concentrations or different formulations of developer to obtain different contrast effects. Its law: taking D-72 as an example, the greater the concentration (such as developing directly with the original solution), the higher the contrast; The higher the content of hydroquinone and potassium bromide in the formula, the higher the contrast; The higher the PH value, the higher the contrast. On the contrary, the contrast will decrease.

If you are a small business owner of photography, cotton wool paper is more suitable for making portrait commemorative photos-soft contrast and rich layering will impress customers. Especially for small flaws (such as acne, moles, etc. ) on the negative or the face of the subject, it will be softened less obviously by the suede. Of course, rough textured paper (such as cloth or livzon) is not suitable for plate making and printing, and photos made with it are not suitable for submission.

Boxed or bagged black and white photographic paper should be stored in backlight and dark place. Before cutting, you must wash your hands and keep them dry, and then take the photo paper. You can't put skin cream on your hands, so as not to leave traces on the film surface of the photo paper and cause uneven development. In particular, plastic-coated photographic paper is more likely to leave a hidden danger of mildew in the future. Therefore, don't cut too much photo paper at a time, so as not to touch the photo paper moldy.