Advantage of digital SLR cameras over compacts - are there any?

Already own a compact digital camera? What are the advantages of digital SLR cameras then?

They're big, heavy and expensive when compared to compact digital cameras. So wouldn't you be better off with a compact? Well, not necessarily.

This page outlines the key differences between the two.

And will hopefully show you that there are good reasons why keen photographers carry bulky SLRs around with them!

It's difficult to pin down just one advantage of digital SLR cameras, because there are so many of them. I've outlined the advantages in the following three categories: is updated regularly. To learn out about the updates as they happen subscribe to the digital photography blog, and this site’s RSS feed.

NB: Many links on this page lead to explanations of key digital photography terminology. These links will open in new windows. Other links will open as normal.

Advantage of digital SLR cameras – Photo Quality

Many compact cameras these days have a huge number of megapixels. More in fact than a lot of digital SLRs. You could be forgiven for thinking that this must mean better photos?

Unfortunately you'd be wrong. More megapixels doesn't equal better quality. The problem is the image sensors on compact digital cameras are just too small. When 10 million pixels are crammed onto them the individual photosites on the sensor are too small, and too close together.

This closeness and their size means they suffer from interference. When you look at photos closely they have speckles on them. This is called digital noise. The effect is worse in low light.

The lack of noise in photos is one advantage of digital SLR cameras when it comes to picture quality, but not the only one. Another advantage is SLRs' ability to shoot in RAW mode.

By shooting in RAW mode the camera captures more detail, and allows for far more flexibility when it comes to editing photos later on.

Overall photo quality is one advantage of digital SLR cameras over compact digital cameras.

Read more on why the number of megapixels isn't a good guide to photo quality.

Advantage of digital SLR cameras – Speed

When I talk of "speed", I am referring to the speed of camera operation.

There are a number of factors that contribute to the overall speed of a digital camera.

First, there is the speed of focusing. When composing a shot, cameras clearly need to focus first.

In any given situation a digital SLR camera will focus on the subject faster than a compact digital camera.

This speed advantage of digital SLR cameras is even more obvious in low light conditions.

I've lost count of the times I have seen out of focus low light shots from compact digital cameras. Mind you, sometimes I look a little better when I'm out of focus!

Second, there is the frame rate. Frame rate is the number of frames per second a camera can take.

Digital SLR cameras are usually good at taking a sequence of photos of a moving subject; and will be able to keep re-focussing as the subject moves too. Have a look at the photo below to see the effect.

 advantage of digital SLR cameras - speed

This sort of photo would be impossible to take with a compact digital camera because they can't take photos fast enough, and the few that can (in things like "burst" mode), they can't focus fast enough to keep up with the moving subject.

Another element of speed is how long the camera takes to switch on. With a digital SLR, especially the more recent Nikons and Canons, as soon as you turn the switch, it's on. That's it. No lens to extend. No motor whirring. It's just on, in an instant.

If you are interested in capturing a moment, this "on" speed might be the difference between getting your shot, and missing out. This is a definite advantage of digital SLR cameras.

A final note on the speed of operation is the speed of zooming. When a compact camera zooms the motor whirrs and the lens slowly extends. Digital SLRs don't work in this motorised way. You zoom the lens by turning the lens barrel. This gives you an instant zoom.

With this type of manual zooming it is also easier to nudge the zoom in or out a little if you need to – just a little flick of the wrist is all that's needed, and you're there.

Speed of operation is therefore a clear advantage of digital SLR cameras over compact digital cameras.

Advantage of digital SLR cameras – Flexibility

When we talk of flexibility of cameras, we mean how well can it handle a range of situations. Here the advantage of digital SLR cameras over compact digital cameras.

With a digital SLR you have the choice of hundreds of different lenses and a huge range of flash options.

Why should you care about the lenses, after all, compact digital cameras come with good zoom lenses, don't they? Well, yes, they do. But the quality of the lens is poor in relation to the lenses available to digital SLRs, and there is no comparison when it comes to aperture.

Lenses on digital SLRs have wide apertures, much wider than the zoom lenses on compacts. This provides two advantages of digital SLR cameras over compacts.

First, this means that shutter speeds can be faster because more light can enter the camera. (read more on understanding aperture)

Second, it means you are able to control the depth of field in your photos. A shallow depth of field is particularly flattering in portrait photography, and is impossible to achieve with a compact camera because the lenses just aren't up to the job. (read more on depth of field)

And then there's the flexibility of the flash on offer. The small flash on top of compact cameras is no match for the powerful flashguns that are available for digital SLRs.

Not only are flashguns more powerful, but they also able to "bounce" the flash off of ceilings and walls. This diffuses the flash, and eliminates red eye.

Click to read more on red eye and what causes it.

Flexibility is another area where the advantage of digital SLR cameras over compacts is clear.

Advantage of digital SLR cameras
– The Verdict . . .

The advantages of digital SLRs over compacts I have listed here represent some key advantages. But this list is not exhaustive. Use a digital SLR for a bit (borrow one if you can), and then try a compact; you'll certainly see the advantages of digital SLRs if you do.

Ready to learn more? Find out how to use your digital SLR like a pro, and start taking sensational photos today!