Photo sizes demystified

By | March 5, 2018
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I’ve got a mixture for you today – some info about photos that you might find handy if you use a digital camera of any kind (whether it’s a stand-alone or one on a phone) and some news – but first…

If you read last week’s email, you’ll have noticed the bit about taking “screenshots” on a Windows PC and the new shortcut for it.

Well, a few people have tried it out and found it didn’t work for them. If this happened to you and you’re wondering what’s going on, it doesn’t mean your PC is playing up.

As I mentioned, it’s a new shortcut that Microsoft have only recently added to Windows. That means only people with a new version of Windows will get it. If you have Windows 10, your PC should automatically keep you up to date and you should get this shortcut. But if you have an older version (eg Windows 7 or even an older version like Vista), then you won’t have it – since it’s a new shortcut, it’s only on the new versions of Windows.

Photo sizes demystified
If you’re ever choosing a digital camera or a mobile phone or tablet that has a camera in it (most have these days), you’ll notice it saying it has a “12MP camera” or a “5 megapixel Camera” or something like that.

Here’s what it means – and why it matters.

First of all “MP” and “megapixel” mean the same thing – MP is just short for megapixel.

It’s a way of measuring how high quality the photos it can take are – in general higher is better.

It means how many million pixels, or dots, go to make up each photo. (If you’re pedantic like me, each megapixel is actually 1,048,576 dots, not exactly a million).

So a 5MP camera takes photos that have 5 million dots in each of them.

The more dots used, the more detail you can see in the picture.

So why wouldn’t you want as high a number as possible? Well, for one thing cameras with a really high number tend to be more expensive. But it’s not as simple as that.

Because a 12MP photo has more dots than a 5MP photo, the file that stores that photo takes up more space.

That means it can fill up the storage on your phone or camera more quickly – in fact on some you can tell it to work at a lower quality level to avoid this – but there’s not a lot of point in having a 12MP camera if you only ever use it at 5MP!

The larger files can also take longer to email or to upload to send to people on Facebook or Flickr or however you like to share them… not to mention longer to back them up safely.

The other thing to bear in mind is that it all depends what you’re going to do with the photos.

If you’re only ever going to look at them on a phone screen, 3MP will probably be fine – you simply wouldn’t be able to tell the difference between that and a photo taken at 12MP.

If you’re going to print them out on a home printer at a normal size, 3MP is probably about as good as anything, too. If you want to print them a bit bigger or will get them professionally printed, you might notice a difference up to 5 or 6MP.

And if you want to print the photos as posters or to zoom in on just one part of the photo after you’ve taken it, then 12MP or even higher might be better.

One more thing I should say, though. Phone makers in particular tend to make a big deal of how many megapixels their cameras are – particularly if there’s is high!

It can be important – but it’s not the only thing. Imagine taking two photos – one on a camera that’s only 5MP and one on a camera that’s 12MP… but the 12MP camera has a smear of grease across the lens. The one taken on the 5MP camera will be better!

Similarly, how good the photos actually come out depends on the quality of the lens, the quality of the light detectors inside the camera, how well it adjusts for light levels and so on. It’s not ONLY about the number of megapixels.

Do you use your smartphone (or tablet) for taking photos?
Part of the reason I’ve been thinking about all this lately is I’ve been working on a book called Smartphone Photography One Step at a Time. I’m not quite ready to announce all the details about it yet – and it’s not available to order yet.

I’m hoping to be ready to tell all later on this week.

I can tell you that if you use a smartphone to take photos (or come to that, a tablet, as it works in basically the same way, just bigger), or if you’ve got one and have thought about using it as a camera, then you might find this interesting… and possibly very useful.

After all, the quality of photos you can get from a phone now is pretty stunning. Mine takes better photos than my stand alone digital camera – and it’s not like my phone is a particularly expensive one. And I’ve usually got my phone with me when I’m out and about, so if I see something I want to get a photo of, I can.

But like with so many things on phones and tablets, many of the options you need are hidden away and unless someone shows you how to use it, you simply can’t work it out. Even if you know how to take a quick snap, you might be missing a few settings that would give you much better results… or struggling with sharing them… or printing them… or even doing basic editing to straighten a wonky photo or crop out an unsightly pole…

Anyway, I’m getting ahead of myself. As I say, more info later in the week!

2 thoughts on “Photo sizes demystified

  1. David Cathcart

    Looking forward to a book on taking photos with a smartphone. I’m knew to smartphones and would like to know more about the camera.


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