Digital Single Lens Reflex Camera - why?

A Digital Single Lens Reflex Camera, or DSLR, is a camera that in theory has only one advantage over a compact camera or the camera in your phone: when you look through the view finder, you see the same thing as the camera will see when the photo is taken. You use the same lens.

In many cases, this is completely irrelevant. In many settings a compact camera that fits in your pocket takes as good pictures as a DSLR. Besides, the compact camera is usually easier to use: point, click, and you are done.

However, there are some other advantages with DSLRs compared to compact cameras.

With a DSLR, not only you, but the camera itself sees through the only lens. That means that all automatic settings (auto-focus, shutter-speed, aperture, ISO, white balance...) are done in the exact same space as the picture will be taken. For example, there may be a slight difference between the distance the camera measures and the the actual distance to the subject, so the auto-focus may be slightly off in a compact camera. That will not happen with a DSLR.

Next, the DSLR has removable lenses. You can buy lenses with much bigger magnification and much better precision than you will ever get with a compact camera. You can change lens depending on the circumstances, so you have one glass for wide angle photos and another for zooming, for example.

As the DSLR tends to be bigger than compact cameras, it often has an image sensor that is much bigger than in compact cameras. It seems any of the current Nikon DSLRs have an image sensor that is at least ten times as big as the one in my pocket Canon Digital IXUS 970 IS. A bigger sensor means more light, more data and better pictures - if you only use the data right.

DSLRs usually give much more flexibility to the user. All the basic things can be set manually, like shutter speed, ISO, aperture, white balance, and so on. This is not always an advantage, as it is much easier to really mess up the settings on a DSLR. However, if you know what you are doing, you can often get a much better result than with a compact camera.


Compared to an older SLR with film instead of electronics, the DSLR also has a number of advantages.

With a film SLR you need to develop the film. With the DSLR you get the picture straight away on the built in monitor.

With a film SLR every photo has a certain cost. With a DSLR you can take as many pictures as you want and erase them, if you do not like them. It costs virtually nothing.

With a film SLR you have to carry around rolls of film, if you wanted to take many pictures. With a DSLR, you can easily fit hundreds, sometimes thousands, high resolution pictures on one memory card. If you decide that you want to take tens of thousands of photos, the memory cards hardly take any space at all compared to the film rolls.

With a DSLR you can easily modify the pictures on a computer and improve colours and quality within seconds. If you mess things up, you can just go back to the original picture and start again from scratch. With a DSLR it is much easier to make a stitch of several pictures together, to get a huge photo.

With a DSLR you can send your picture to your friends on five continents within seconds. With a film SLR you had to wait not only for the development but for the post to arrive.


However, there are also still some advantages with the old film SLRs.

In really cold climates, electronics will not work. A mechanical film SLR can work at much colder temperatures.

In low light situations, a DSLR will produce noise, individual pixels that are of the wrong colour. This is a fairly unattractive thing. With a film SLR, you instead get grain, which are bigger dots, which in some cases look artistic and have a certain attraction.