The Canon 30D vs. the 20D

It's not easy to compare the Canon 30D vs the 20D.

Why? These two cameras are very similar to each other. At first glance they appear to be identical.

In this head-to-head comparison of the Canon 30D vs. the 20D I'll explain the differences. By the end of this page, you should be able to determine which camera is right for you.

Three Key Differences

First, it helps to realize how similar these two cameras are:

  • They both have the same number of megapixels and the same digital sensor.
  • They are equally responsive, and both feature a 9-point autofocus system.
  • They use the same batteries and the same memory cards.
  • There's no difference in weight or in size.

Seems like the 30D is the same as the 20D with a different name. Almost.

There are three key features that distinguish the Canon 30D vs. the 20D:

  1. Spot metering
  2. Buffer size
  3. LCD size

Spot Metering

The Canon 30D has a spot meter while the 20D does not.

Every digital SLR camera has a built-in light meter that detects the amount of light reflected off the subject you are photographing.

Hence the name: reflected light meter.

The light meter tells you what aperture and shutter speed you need to use to get a correct exposure.

The three most common digital SLR metering modes are evaluative, center-weighted and spot.

  • Evaluative metering checks the entire scene (everything you see in the viewfinder)
  • Center-weighted only meters a small circular area in the center of the viewfinder
  • Spot meters just measure reflected light from a small spot in the center of the viewfinder

A spot meter is useful if you photograph scenes with extreme contrast (where you want only your subect to be correctly exposed) and if you want to meter precisely from a distance.

For example, with a spot meter, you could judge exposure on a person's face from several feet away.

If you don't ever see yourself playing around with metering modes, then you don't need a spot meter.

Buffer Size

The Canon 30D has a larger buffer than the 20D.

Large buffers are useful for action photographers.

Every time you take a photo, it is first stored in the camera's buffer (internal memory) before it is saved to the memory card.

When you take photos in rapid succession, it creates a backup in the buffer since the camera can take photos faster than it can write to the memory card.

Once the buffer fills up, the camera slows down substantially. Here's the comparison between the Canon 30D vs. the 20D:

  • Canon 30D Buffer - 30 JPG or 11 RAW
  • Canon 20D Buffer - 23 JPG or 6 RAW

You'll never fill up the buffer on the 20D unless you get in the habit of taking rapid consecutive shots.

LCD Size

The Canon 30D has a larger LCD than the 20D.

The LCD on the 30D is 2.5 inches while it is only 1.8 inches on the 20D.

Even though this seems like a tiny difference it is significant.

Once you see a digital SLR with a 2.5" LCD, a 1.8" looks positively tiny in comparison.

But who needs a large LCD?

If you like making sure that the photo you just took turned out, a larger LCD is a real benefit.

You can zoom in on your image and check to make sure that everything is in focus.

If you're used to using a film SLR (where you can never check images after you take them) then having a huge LCD might not matter all that much.

I find that I rarely use the LCD to look at photos, since even a 2.5" LCD can't compare to my 19" monitor.

Since I review all of my photos on my monitor for color and clarity, I don't often check them on the LCD.


It always comes down to this in the end doesn't it?

The 20D was released back in 2004 (ancient history in the world of digital SLR cameras). Even the 30D has now been replaced with the more advanced 40D.

You can still get your hands on a new 20D, but you're going to have to hunt around a bit. Your odds are probably better of finding someone selling a 20D since they've upgraded to the 40D.

Finding a used 20D will obviously save you a bundle over buying a brand new 30D, but the camera will be well out of warranty - should anything go wrong, the repair costs will come out of your pocket.

I'd advise you to spring for the Canon 30D if one or more of the following applies to you:

  1. You want to meter your subjects precisely, and have used spot meters before
  2. You want to take rapid consecutive action photos without having the camera slow down
  3. You want to review the photos you take on an LCD before you check them on a computer

If you don't see yourself doing these three things, save your money and get a 20D while you can.

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