Beginner’s guide to photographic films
The vast majority of photographer’s nowadays use digital cameras due to the ease of use, instant preview gratification, straight forward storage, the ease of making many copies and sharing, and many other reasons. But even so, many remain faithful to film and swear by it mainly because of its high quality and dynamic range, nostalgic and true feeling, as well as lower equipment cost.
With film, it all comes down to an emulsion with silver components that act as a coat on which images are recorded, and it has made significant improvements in quality and characteristics since the early days when it was used.
Emulsion is a light-sensitive coating on photographic paper or film that consists of fine grains of silver halide salts (suspended in gelatin) with variable crystal sizes that determine the sensitivity, contrast and resolution of the film. When film emulsion is exposed to light it forms an invisible image, from which a visible one can later be extracted through a series of chemical processes during development.
The size, shape and closeness in position these silver halide salts have directly affects the size of grain and film sensitivity to light, from fine grain (less sensitive to light) to coarse grain (more sensitive to light).
Film mainly falls into one of two categories: color film and black and white film. With color film, the image is more like what the eye sees and relates to in reality, but one must be careful of major color cast and hue variations. With black and white film, the image is more of an interpretation of reality. It requires more thought when it comes to light and image components (such as forms, shapes, texture … etc), but is more forgiving in terms of exposure.
Once a film is processed, the image can be printed on chemically coated paper, as well as scanned for further digital manipulation and sharing online, then digitally stored.
Film Size
The most popular color as well as black and white film size is the 35mm film, which is considered full frame. Cameras usually create 24 x 36mm frames on a long roll of film, with enough length for 12, 24 or 36 frames.
It is also known as 135 film which is a term Kodak introduced, and comes as rolls packed in light-tight metal cassettes which allows for loading in day light. 35mm film can be processed in all labs everywhere, and 35mm cameras, lenses and equipment are the most available of all film camera types.
A larger film size is the 120 medium format film and comes backed in opaque paper and tightly rolled on a plastic spool. 220 film is the same size as 120, but lacks the paper backing allowing more film to fit on the spool. The lack of protection means that most medium format cameras are not equipped to handle 220..
Medium format film is shot in many aspect ratios depending on the camera or frame insert used, with the most popular being 6×4.5cm, 6x6cm, and 6x7cm formats.
6×4.5cm is a rectangular format. The actual image size of this format is about 56 x 42 mm, with 16 exposures per 120 roll.
The slightly larger 6x6cm format is a square format. The final image can later be cropped to a more preferred format (with a vertical or horizontal orientation). Actual image size of this format is 56 x 56 mm, with 12 exposures per 120 film roll.
Larger format cameras exist, including 6x7cm, 6x9cm, 6x12cm and even 6x17cm. These cameras are less common, but can produce stunning images.
Sheet film is typically large film format that comes in separate sheets instead of rolls. These sheets are packed in boxes as 10, 25, or 50 sheets per box. Most common sheet film sizes are 4×5 inches and 8×10 inches, though other sizes can also be found.
Sheet films are fitted into holders and inserted into the camera so that exposures can be made. Each sheet has an edge-notching on one side which helps the photographer determine which direction the film should be at when inserting and changing in the dark.
When the exposure is made, the holder along with the film are removed from the camera, and another new sheet is inserted for the next shot.
Film Sensitivity to Colors
A film’s sensitivity to colors is set during the manufacturing process, and it differs between color film and black and white (monochromatic) film.
In black and white film, the emulsion is usually sensitized to all colors of the visible spectrum and even to shorter ultra-violet (UV) wavelengths as well. This, of course, is different from what the human eye is naturally accustomed to and sees.
In color film, emulsion is made in multiple layers stacked up one on top of the other so that part is sensitive to blue only, part is sensitive to blue and green, and part is primarily sensitive to red color. Most manufactured color films are set to give an accurate color balance under day light shooting.
Film Speed
Film speed is usually expressed in the US-based ASA rating or the European-based DIN rating. For all intents and purposes, ASA is identical to ISO rating. Film speed serves the exact same purpose that the ISO does in digital photography.
The higher the film speed (commonly known as fast film), the more sensitive to light it is and the coarser image grain will be. The lower the film speed is (commonly known as slow film), the less sensitive to light it is and the finer image grain will be.
Grain in film photography is the equivalent to noise in digital photography, though grain is sometimes considered to have an aesthetic appeal and sometimes even sought for its interesting visual effect.
In general, film grain affects the sharpness and fine details of the image with higher grain sometimes breaking continuous tonal gradation and edge contrast.
The main challenge for film manufacturers is increasing film speed thus making it more sensitive to light, without increasing the graininess and decreasing the sharpness of the image, so as to preserve minute image details and local contrast.
Professional and Non-Professional Film
The main difference between professional and non-professional film is that professional film is designed to give its optimum performance upon leaving the factory and should be refrigerated immediately until used. It should also be processed as soon as being exposed.
Non-professional, or amateur, film on the other hand is designed in such a way to allow for extra storage time while being kept at camera shops and at home or the studio until exposed. It can be stored at room temperature, and doesn’t have to be processed as soon as being exposed.
Professional film is slightly more expensive than non-professional film for the same film speed and size. Non-professional film is by no means inferior to professional film. Each type has its own uses, purposes, and audience with non-professional film being used by professionals all the time.
In each case, some of the most common causes of damage to film are humidity, storage in bright light or exposure to chemical fumes. Color film and fast film are particularly more prone to damage than black and white film and slow film. In general, if you keep the film sealed in the fridge, it should be fine even past its expiration date sometimes.
Keep in mind that film once taken out of the fridge should warm up to room temperature. Un-packaging the film and shooting too soon might cause condensation to form and ruin the film. Also when shooting outdoors in cold weather, make sure you keep the film warm in your pocket until it is time to load and shoot.
If film is not processed straight after exposure make sure you keep it in a dry, cool, dark place away from humidity and bright light, such as in a closet. If you want to put it back in the fridge, make sure you seal it in an air-tight box or a zip foil bag with a packet of silica gel.
Conclusion
Digital photography has taken the world by storm lately, and more and more photographers have been switching to the new trend, some of whom may never look back.
To others however, film remains the real deal. Every medium has its own strengths and weaknesses. In the end, it is always up to the individual and their taste to decide which way to go. It doesn’t really have to be one way or the other, though. Whether you like film or you like digital, you can still experiment and play with both.
Source: http://photo.tutsplus.com/articles/hardware/a-complete-beginners-guide-to-photographic-film/
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All about lens fungus
nce a month, we bring you a tipster from Lomography.com. Their ever-growing database of film knowledge offers tricks, tips and techniques that often outside the realm of mainstream photography.
Fungus can slowly take over and destroy your precious lenses and film. If you are still not aware of this problem that could be growing on your gear, get acquainted with this guide which explains, among other things, what fungus is, what it does to your equipment, and how you can prevent it.
What is this dreaded fungus?
If you buy new equipment and take good care of it, you may not encounter fungus. But if you own any vintage cameras or old lenses, this could be a problem and you may not even know it!
When you think of fungus, you may think of mushrooms, yeast, alcohol fermentation, traditional Chinese medicine or even fungal skin infections (ack!), but mould can be deadly for camera equipment and film.
Fungus is a tiny organism that can grow on film and lens surfaces, inside lenses, between the elements, and under lens coatings. It sets down its “roots” very quickly and multiplies even faster. It is very hard to remove fungus completely once it has taken hold, so it’s best to start prevention before it appears.
How exactly is it bad for my equipment and film?
As it grows on glass, it can permanently etch the surface, causing your photos to become “soft”, less contrasty, have more flare, or slightly darker. On film, once it sets in, the same thing happens. As it has “set roots” in, even if you wipe it away, there are still marks remaining. The effects of fungus may take years to become visible on photos though.
How does fungus get on my lenses and film?
High humidity is the main cause, so if you live in the tropics, or often go shooting in the rain, beware! Fungus is among the most abundant organisms in the world, and it mostly multiplies by teeny spores, which are everywhere. They can find their way into lenses because they are so small. Moisture (from rain, or the high humidity) then helps it grow at super speed.
How do I spot it and what does it look like?
Take out your lens, open it to the widest aperture (biggest hole), and hold it up to bright light. You can also use a torch light and shine it on the lens. Look through the lens. If you see something that looks like dust, but more spidery and in blobs or clumps, you’re in trouble.
Here are a few examples:
Image from photo.net
The image above shows it in early blob stage. It’s past the part where it could be mistaken for dust, as it’s clumping together and multiplying.
Image from clubsnap
This image above is how it looks when it has taken over the whole lens surface, which is bad news.
Image from pentaxforums
On rare occasions, it could look like bacteria. As shown in the example above, fungus usually starts from the edge of the lens and grows inwards.
The example above is how it could look like on film, which is in blobs as well. The fungus was spidery too, but that can’t be seen here.
How do I prevent its growth?
There is no definite way of keeping fungus out given its tiny and effective spores. I have had lenses kept in dry conditions yet they magically grew fungus. However, there are some good ways to lower its chances of taking hold. Fungus thrives in humid (and dark) places, so the best way would be to suck its life-giving moisture out. So take your lenses and film out of your drawers and boxes right now!
Some ways to keep humidity low:
- Silica gel
- Dry cabinet
- Dehumidifier
Image from madeinchina.com
Silica gel is not really a gel. It is most commonly sold in the form of tiny beads (above), and is useful for controlling humidity. If you buy stuff and see packets saying “do not eat”, it most likely contains silica gel beads. Please, do not eat it. To use it, buy a dry box (sealed or airtight case) first – then pour the beads in and keep your equipment or film in the box. The beads will change colour when they absorb moisture.
Keep an eye on them and when they show water saturation, you should either buy a new pack of beads or heat them up until they return to their original colour (meaning they are highly absorbant again). Some people have stir-fried the beads in a pan, baked them in an oven, or even microwaved it. Just don’t reuse that pan or baking tray for food! You could also try sunning them for reuse.
The dry cabinet is probably the best option as it gives you more control over the humidity. It comes with an analogue dial or tells you digitally (above) what level the humidity is, and you can also choose your humidity level. Camera equipment is best stored at 35-45% humidity.
About humidity: Don’t keep levels too low as cameras and lenses are lightly lubricated and low humidity could dry up that oil quickly, making your lenses zoom slower than normal, for example.
Otherwise, the dehumidifier also sucks out moisture, but this would have to be an enclosed room. Aircon is also an option, because cold air holds less moisture, but it consumes lots of electricity and is expensive.
Another way to fight fungus growth would be to use your equipment regularly. Keeping it for too long in a dry cabinet won’t help as cameras should get some fresh air from time to time. Cameras used daily are much less likely to get fungus (but more dust) than those which are kept even in less humid conditions.
How do I get rid of fungus?
Once it has grown on the lens or film, it will likely return even after being removed. Thus it is best to follow the prevention methods above. However, if your lenses have caught the fungi bug, you can either clean it yourself, or send it for professional cleaning.
Self-cleaning is more possible when the fungus is on the exterior of the lens. Use hydrogen peroxide, bleach or rubbing alcohol to wipe the glass surface gently, which will likely kill as well as remove the fungus. Lens cleaning paper, like this one below, is best as it is lintless and soft, making it less likely to scratch your lens.
Professional cleaning is the best, and sometimes only, option, when the fungus has grown inside the lens. These specialists will give it a thorough cleaning for a certain price. In Singapore, it costs about $80-100 to get a lens cleaned at a camera shop. If the fungus has etched the glass surface, the lens may need to be polished and require a new coating as well.
Alternative methods (which have both worked and failed for people)
Some have tried sunning their lenses by leaving it in the open, or putting their fungus-infected equipment under UV lamps. This has worked for some, and also boosted fungus growth for some, so please be wary if trying it.
For film, some have recommended putting it in the freezer and then wiping off the fungus gently when there is condensation. I have tried this and it worked but temporarily only as the fungus came back.
It won’t go away…
However, as mentioned earlier, please note that fungus can make a dreaded return, even if you store it in a dry cabinet after cleaning. Certain items are just more prone to fungus. I kept all my lenses in one dry cabinet in the past, and two showed signs of fungus (they were moved to a separate dry cabinet) while the rest were, and still are, fine. This has been the case for many other photographers as well. In the case that fungus starts growing on your lens again, please keep it separately from the rest of your equipment.
To sum it up!
Use your equipment as much as possible. After each use, let it air dry then store it in a low-humidity environment. The same goes for film – keep it in a dry cabinet if possible, or years down the road your memories could be etched with fungus.
Please leave any comments if you have any other suggestions on how to keep fungus at bay or how to remove it!
Source: http://photo.tutsplus.com/articles/hardware/all-about-the-dreaded-fungus-lomography-tipster/
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