Film VS Digital Photography

Differences Between Film and Digital Cameras and Photos

How images are saved

Digital cameras save images as 1's and 0's in blocks, (pixels), on various storage media. The image is saved in a pattern that tells the appropriate program all the elements of the original image. How many 1's and 0's the camera can save the image in determines how much detail can be recorded. This is the resolution of the camera measured in pixels. Higher pixel cameras record more detail, but require more time to record the image, or more powerful or faster circuitry, and more storage.

Film cameras save images on a special material that is light sensitive until it is processed. Once processed, the image is recorded on the film as tiny blotches of colors in varying degree of brightness and intensity. How small these blotches are is based on the speed of the film used. The film speed is what determines how much detail can be recorded with a film camera. Lower ASA numbers record more detail, but require more light to do it.

Most digital cameras have an ASA setting so you can adjust its "sensitivity" to light, but be careful using that feature. Increasing its sensitivity by setting it to a higher ASA rating does reduce the quality of the photo, just like with film cameras. When you increase a digital camera's sensitivity, you're telling it to require less light to create the image, but the sensors require a certain amount of light to properly capture the image. As you increase the camera's ASA, it starts bundling the millions of sensors into groups so it can deal with lower light levels. This means your image blocks get bigger, therefore, picture quality goes down. The camera will come with a preset ASA setting. Usually that's the highest it'll go before it starts degrading the image quality. Unless you know what you're doing, like after this course, it's usually best to just leave that setting alone.

What about the end results?

This is what really counts, right? No matter how images are saved, we just want to be able to show our pictures to our friends and be proud to show them, so what's the difference between film and digital when it comes to the final picture?

First would be the range of quality possible. It used to cost a couple thousand dollars to get a digital camera with enough megapixels to match a film camera for detail captured, but now you can get one for a couple hundred. For low cost cameras though, like for children to have fun with, or to leave at the tables at a wedding reception, a $10 disposable film camera works just fine. You can't get a digital camera for that price.

It took a while for high resolution digital cameras to be affordable to amateur photographers, but they did have 2 advantages which made them grow popular very fast. The biggest advantage of course, is its digital format. You could snap a picture and email it to a friend right away. Even the early digital cameras were good enough for web use. The 2nd advantage, that you probably didn't know, is its dynamic range. Dynamic range is a measure of the range of light levels that can be captured or seen. Below a certain level, everything looks black, and above a certain level, everything looks white. The human eye, at any one instant, can see differences across a range much higher than any camera can capture, but when it comes to what a camera can capture, most digital cameras can capture a wider range than film.

Here is an example to show the difference. These pictures were not really taken with a film and a digital camera. It's just one picture I edited to show what dynamic range means.

Can you see the difference? There's less detail in the darker and lighter areas of the second picture. Which one represents a digital camera? When you want to capture as much detail as possible in a wide range of light levels, the digital camera wins the challenge. As for overall detail and quality, the digital camera has surpassed the 35mm film camera. An 8 MP camera captures about the same amount of detail as a 35mm camera with 400 ASA film, and a 12 MP camera captures about the same amount of detail as a 35mm with 100 ASA film. Go to 16 MP and a 35mm can't beat it even with professional film. Digital is now available even higher than that.

The second difference between the film and digital final picture, you probably already know, the image format. Digital files VS negatives or slides. They can both be printed and they can both be shared on the internet, but digital is already to go for internet use. Film needs to be converted to digital by scanning either the negative, slide, or print. As for printing, it used to be easier with films, but now there's no difference. You can bring your digital images to any photo-finisher and have them printed, or you can use a self-serve printer, or print them at home. So now you're thinking, why use film?

Film still lasts longer and is usable longer, until photo labs are gone, than digital. I still have a roll of film from when I was 13, a long time ago, that hasn't changed. Put your digital pictures on a CD and I can guarantee you that in 30 years it'll be useless, for 2 reasons. One, most computers probably won't have CD drives anymore. Probably won't even have DVD drives by then. Second, your CD won't be readable. Don't believe me? Wait and see. With digital, there's not much choice. You need to keep recopying or transferring your images to new media if you want to keep them for a long time. If you do a lot of picture taking, you're going to be very busy later.

A little about film cameras

Digital cameras have pretty much made film cameras disappear, for the amateur photographer anyway. Professionals still use film, just not all the time, and that is going away fast. Even in 2010, most professional 35mm SLR photographers still used film. Digital had surpassed film, but only at a high price. Only the serious pros could afford to go digital, but as prices went down, more converted. Now, most have gone digital because they are better, faster, and cheaper. Photographers using medium and large format cameras are also converting to digital, but at much higher costs and requiring powerful computers to do any editing with the huge digital file sizes.

For myself, I think the biggest advantage of film is the long life. Until they come up with digital storage that will last 100 years, film does have that advantage. But then, you probably don't care if your pictures last that long. For anything longer than 5 years, you will need to keep backup copies of your pictures and keep making new backups, if you want to be sure you don't lose them.

Film cameras use 2 different film options, negatives or slides, and they come with variations like color or black & white, or even infrared film. Films also come in different ASA or ISO ratings. This determines the light sensitivity, or how much light the film needs to create a good picture. Digital cameras let you set your ASA number to mimic film, but unless you need a higher ASA for low light, or you know what you're doing, you're better off using the system default setting.

With film or digital, ASA 100 is generally used for outdoor shots or indoors with a flash. ASA 400 requires less light and can be used indoors without a flash as long as there is average lighting in the room from either a window or a light fixture. If you have lots of lighting and want to make large prints, you can get ASA 25 film, or if you are taking shots with action or very low light, you can go the other way and get ASA 1600 film, but 1600 isn't good for enlargements. You can see the grain in a standard 4x6 photo, whereas with 25 you can get sharp 20x30 posters.

The difference between digital image formats and sizes

All but the entry level digital cameras have ASA settings, and these work similar to 35mm cameras and the film used. A higher setting means the camera will take photos under lower light levels, or at higher shutter speeds to capture action, and a lower setting means it will capture it's highest possible quality. Beyond that, most digital cameras also let you choose an image size and format.

Image Size

This is usually the most important decision when it comes to the settings before taking pictures. Do you want to capture the cameras full potential, or will smaller do? If you only plan to email the photo or use it on a website, and it's only for viewing, not printing, smaller will probably be good enough. Generally, 640x480 to 1200x1600 is big enough for that. If you want to print the photo, or email it to someone to print, you need bigger. How big depends on the size print you want to be able to make. A good quality photo requires 200 to 300 dpi (dots per inch). Over 300 is a larger than needed file and under 200 you will see a lack of sharpness in the photo. This means if you want to print a 4x6, you want at least 800x1200 and have no reason to go beyond 1200x1800. That means a 1 to 2 megapixel image. If you want to print an 8x10, you need from 1600x2000 to 2400x3000. That means a 3 to 6 megapixel image. You might want to print a 20x30 poster? That requires a 24 megapixel camera, or a 35mm camera with ASA 25 film. Then of course, posters aren't usually looked at from right in front of them, so a slight loss in quality wouldn't make a difference. A 6 megapixel camera can make a fine 20x30 poster to be viewed from 6' away, plus, there are photo editing programs that can "improve" the quality of an image.

Image Format

Pretty much all digital cameras have at least 2 options here, jpg and raw. Jpg is a compressed image format. It looks for pixels next to each other that are almost the same and makes them the same. This makes it possible to save the image as a smaller file size, which means more images on the camera. This means reducing the quality of an image though, but remember before how I said digital records a wider range of colors and brightnesses than film? Jpg basically reduces that range, so with only slight compression, the digital still captures more than film. Some cameras let you choose different compression levels. You need to decide how important the quality of the image is. Experiment with your camera at different levels of compression to get an idea of what is acceptable to you. If you choose to save your images in raw format, you preserve full quality, but you also don't get a lot of pictures unless you add a high capacity memory card, if your camera has that option. Most do.

Most cameras have at least one more option. It's a manufacturer chosen, and sometimes custom, compression format. Some of them compress the image with no loss in quality; others do have some loss in quality. You can usually get details from your camera manual. Many users like this option because it was designed for the camera. The main problem with manufacturer format is sharing the digital image. Unless your camera has an option to send the image to the computer in a standard format, or your computer has a program that can convert it, others may not be able to see your photo. If your camera doesn't allow you to change the format when transferring to the computer and you don't have a program to do the conversion, you probably want to save in jpg format if you plan to share it with others. Just remember, low compression if you want full quality; higher compression if you want to use it on the internet or take many pictures at once.

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Well, that's it for the basics. Not much fun here, but knowing the basics will make the course much easier to understand and gain knowledge from. The actual course will get into lighting, exposure, and actually taking pictures. If this material was new to you, go over it again tomorrow, then again a few days later, then it'll be in more permanent memory.

See you when the course starts. :-)