Zoom, Zoom, Zoom - Part I

This is the second post in my basic photography series about  10 Cool Features of Your Digital Camera You Should Learn and Use.  Since every camera is different I recommend you have your camera's manual handy to read what it says about your zoom features.  Check in the index at the back of the book under "zoom" or "optical zoom" and "digital zoom".  Not all cameras have both optical and digital zoom.

I was reading my granddaughters Facebook post the other day and she said “I love, love, love, the rain”. Well I could post that “I love, love, love, zoom”. Before I bought my digital SLR (the changeable lens type) I probably bought 4 or 5 “point & shoot” cameras primarily to get a better zoom. I love having the POWER to zoom in and get close.

When you bought your camera it may have been similar to my wife’s and advertised something like 24x zoom. When you looked a little closer you saw that it had 6x Optical and 4x Digital zoom. When I wrote the intro to this series I suggested you turn your digital zoom off. Why would I say that?

The net result of digital zoom is that it simply makes the dots bigger. This ain't like diamonds - bigger isn't better. What I mean by that is that your photo is made up of tiny square dots. If you have a “5 megapixels” camera, like the one I'll be using for my examples, that means that there are somewhere around 5,000,000 dots -that’s a lot of dots- making up that photograph and as long as you are in optical (lens) zoom mode you’re using all of them, but the instant you go into digital (electronic magic) zoom all you are really doing is making the same size photo with fewer dots. If you use fewer dots to make the same size photo each dot has to be bigger to fill the same space.  In other words, more pixels (optical zoom) means more clarity and fewer pixels (digital zoom) means less clarity.  For example:

Here I have taken a square about 27 pixels wide from one of the photos below and dramatically enlarged them just to show how the pixels make up the photo.

This shows what happens if you do just a 3x digital zoom on those pixels to fill the same space. Notice how large each pixel is and that you get much less detail. This is essentially what happens when you do a 3x digital zoom in your camera.


The camera I used to shoot my example photos is the one I described above with a 6x optical (lens) and 4x digital (electronic) zoom, making a combined zoom of 24x. If you zoom to the maximum of 4x digital then you now have the same quality as if you had taken 5,000,000 divided by 4 or about 1.2 megapixel. So if you have a 5x or 6x digital zoom you will have even fewer pixels. Why would you pay for a 5 megapixels camera and then intentionally choose to take 1 or even less megapixels photos?

Perhaps you are not planning to print the photos, you’re just going to email them to friends or post them on Facebook.  So, maybe it’s not all that important, unless you get that once in a lifetime great photo that you would just love to make into a large print to hang on your wall.  You decide, but just so you can make an informed decision I’m going to show you some more examples.

(Please note that if you want to compare the photos below even better you can see them enlarged by  clicking on each photo.)

Shot at full wide angle we're using all 5,000,000 pixels.  (This is also an example of composition. . .  really bad composition, but an example nonetheless.)

Zooming in to the maximum optical zoom of 6x and I still get to keep all my megapixels*.

By using the maximum digital zoom I’m able to get in very close, at an equivalent of 24 times closer than on the first photo above and 4x closer than with the optical zoom. Pretty impressive. Remember though that I now have the same quality as if I were using only 1.6 megapixels* and as long as you keep it small like this it really doesn't look too bad.

But by picking up my camera and walking that same four times closer to the subject I can stay in optical zoom mode and get essentially the same view and I’m back up to the full 5 megapixels*. Can you see the difference?  HINT: look at the wood grain and the ends of the boards on the roof. You'll see it much better if you click on the photo and enlarge it.


Okay, maybe there are times you can’t just pick up the camera and get four or five (depending on your camera’s digital zoom) times closer, so there may be times when you can actually use the digital zoom but I think those would be the exception. Open your manual and learn how to turn digital zoom off and on so that you don’t accidentally use it when you don’t have to.  (HINT:  It's probably somewhere in the menus not on some button or dial on the camera body.)

Zoom is too important to end here. Stay tuned for a few more tips on using zoom in a follow up post – Zoom, Zoom, Zoom, Part II. I think this post was a little more technical than I like to get so future posts will be less about how your camera works and more about having fun with your camera. Meanwhile get out there with your camera (and manual) and practice, practice, practice. Here is the assignment for this post:

1. Learn how to turn digital zoom on and off.
2. Make a few photos at full wide angle, full optical telephoto and full digital telephoto and study them for the effects.

This isn’t part of the assignment, but I’d love to hear your thoughts and invite you to leave a link to your photos if you put it online so we can go look at them.


*Just for clarification, even if you clicked on the photos above to see them larger you still weren't getting all 5 megapixels.  I reduced the photos down (equally) to a much more reasonable size so they didn't take forever to load on your computer.  I just wanted you to see an example of the difference.

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