Digital Photo Storage

Where should I store my photos? I’m asked this question a lot. On the road, my wife, Madeline, and I use portable hard drives and flash drives. But at home we use external hard drives. And we back up all of those portable and home drives to the cloud.

Those are short answers and probably create more questions. In this post, I’ll discuss storage needs; options for home, travel and backup; and their pros and cons.

How Much Storage Do I Need?

First thing’s first: Photos take up a lot of space. But how large is an average photo? That depends on when and with what device you took the photo. And we need to know the difference between a photos resolution and its size.

Photo resolution

Let’s start with how a digital photo is constructed. When you take a picture or scan a photo to digitize it, the resulting image is made up of pixels, which are colored dots. Each pixel can be one of 256 colors. A photo has a dimension expressed in pixels. Ever see 800 x 600 pixels or 2048 x 1536 pixels? The first number represents the width of the photo in pixels and the second number the height.

A digital photo’s resolution is expressed in total number of pixels in the photo. For a photo that is 2048 x 1536 pixels, its resolution is 3,145,728 pixels. That’s a lot of pixels! When it’s more than one million pixels, we express it in megapixels. One megapixel is one million pixels. Eleven megapixels is 11 million pixels.

If your camera shoots a photo with a resolution of three million pixels, we can assume the photo was taken with a camera with a capability of three megapixels. A photo with 5184 x 3546 pixels has a resolution of 18,382,464 pixels or 18 megapixels. We can assume the camera had at least 18-megapixel capability.

Your pictures’ resolution and size come down to your camera. (And this applies to phone cameras, point-and-shoots and digital SLRs.) These days, phones take photos between eight and 64 megapixels. Dedicated cameras, like a point-and-shoot or a DSLR can take photos up to 100 megapixels.

It’s important to remember, you don’t have to take pictures on a phone or camera at the maximum capability. You can adjust the setting to take photos in smaller resolution. Instead of shooting at a max of 5184 x 3546 pixels, you can set it to shoot at 2048 x 1536 pixels.

How many megapixels do you need? That depends on what type of print you want to make to preserve the picture. A typical 4x6 picture needs only two megapixels of resolution. An 8x10 requires seven megapixels. If you want to hang a 12x14 print on your wall, that photo needs to be 15 megapixels. The 16x20 family portrait you want in your living room needs close to 30 megapixels.

Also, if you work with your photos a lot, you’ll want a higher resolution. What do I mean by work? If you like to do a lot of editing, like removing power lines or people from a landscape photo. Or maybe you use your photos for a business or as art. And if you want to zoom in to create a photo of a closeup of a flower or animal, you’ll need more resolution.

Keep in mind, too, higher resolution photos are bigger in size. That means longer upload times to send photos via messaging and social media or to upload or download them to the internet. And some messaging services and social media limit the size you’re allowed to send or upload. If you shoot in high resolution, you might have to resize them for smaller size.

Note: Pixel often is abbreviated as px or PX. So, you might see someone write, “The photo is 1024 px wide.” Likewise, megapixels is abbreviated as mp or MP. Samsung advertises their new Galaxy S20 phone as having a 64 MP camera. For this post, I won’t abbreviate pixels or megapixels. In the next section, I’m going to discuss photo size expressed in bytes and megabytes. With the abbreviation for megabytes being MB, I want to minimize confusion.

Photo size

Now we can talk about size, or how much space on a computer drive a digital photo takes up. As the resolution of your pictures improves, your photo size increases and takes up more space. In other words, the more pixels you pack into an image, the bigger the image is, and the more space you need to store it.

Digital file size is expressed in bytes, which are units of computer information. Because bytes are so small, one file quickly can grow to millions, billions or trillions of bytes. Below is a how we refer to those sizes:

 Most people shoot between three and 15 megapixels. A three-megapixel picture ranges in size between .5 MB and three MB. A 15-megapixel picture ranges between two MB and 10 MB.

If you assume your pictures could be 10 MB, you could fit 100,000 photos on a one TB drive. You will likely need an external drive for your computer because you’ll need a lot of storage as you produce and save photos.

Luckily, the price of storage has significantly dropped over the years. For the past four decades, storage prices have gone down from around $500,000 per gigabyte in 1981 to less than $0.03 per gigabyte today!

I’ve purchased quite a few external drives over the years and continue today. An average external drive will run for between three and seven years.

What Do I Need?

Now you know about photo file size and space needs, here are the devices and services you need.

Portable External Drives

If you travel and want most of your data to travel with you, you’ll need a portable external drive. These drives are categorized many ways. But the easiest way to classify them is by drive type: 1) solid state drive (SSD); or 2) spinning disk or hard disk drives (HDD).

In the old days, these drives held 256 MB of storage. Today, you can purchase drives of 256 GB or bigger. SSDs are memory with no moving parts. Instead, they have chips that store your data. Without moving parts, they are more reliable of your taking it with you. And SSDs are more compact.

An HDD has multiple platters that spin really fast. An arm reaches out to the specific area and reads the data you’re looking for. (Think of it as a record player for data.) SSDs are more expensive than HDDs per GB of storage. But SSDs are also much faster than HDDs.