Continuing our series of posts dispelling myths commonly repeated in some corners of the internet (or by less scrupulous retailers), we come up to the last of our entries based on a misunderstanding of the digital world and how it works, as opposed to the analog film world. Today’s myth:

A faster SD card will let your camera take faster photos, resulting in shots with less blur.

While a lot of you may be rolling your eyes at this, we have heard it come up before. So, for those of you who don’t know, there’s only one aspect of any camera that ultimately controls all blur in a photograph: shutter speed. A faster shutter will stop both blur from your own shaky hands, as well as from moving subject. Other things can help you get faster shutter speeds, like bigger apertures, or higher ISOs. Image stabilization can help reduce blur cause by you holding the camera, but not for moving subjects. But, your memory card never plays a part in this.

In film, a faster film really would have helped images have less blur. That’s because in the film days, film was both the determiner of your ISO as well as your storage medium. While memory cards are your storage medium in digital, they no longer play any role in determining ISO. That’s all down to the sensor. When you take a digital photo, your camera records some data into a temporary buffer that’s built into the camera. Then, to be saved, that data has to be written to a memory card. This is where the speed of a memory card really comes into play. The faster the memory card can write data, the faster the camera can empty its buffer. The faster it empties the buffer, the faster it can add new photos to it. So, a faster card can help, but it helps you take more photos in a continuous burst.

But it can’t make your photos have less blur. There’s a lot of stuff that can help you there, including faster lenses, flashes, or a camera with a sensor that can use faster ISOs. But not your SD card. So, be wary of anyone trying to tell you differently. Because we have heard of it happening.

Show of hands– who reading this remembers film? You know, film, that plasticky stuff you used to load into cameras that let you take pictures? Yeah, that stuff. In general, it was easy to know where you stood with film. The more it cost, the better it probably was. Sure, you could get a $5 roll from Wal-Mart, but the $8 roll from a camera shop like, say, us was probably going to be better stuff. Better colors, better detail. You could have the best lens going, but if you were using cheap film you’d have a softer, grainier photo than with the good stuff.

And then digital came along and messed everything up. In digital, the “film” is essentially baked in as a function of the sensor, and the image isn’t comfrotingly recorded as corrosion of silver particles, but instead as a series of 1s and 0s called binary. Which eventually leads us to this being a thing:

The Myth: Image Quality is Correlated to the Quality Of My Memory Card

Better film yielded better photos, and the memory card (be it SD or CF) serves a similar purpose in digital, so, it should also dictate quality too, right? Wrong. Film was an anlalog medium. The images was made up of corroded silver grains. The better the emulsion, the finer the silver grains, the better the color packs, the better the image got. The digital equivalents of all of that are in the camera’s sensor, and the maximum quality you can achieve with those is decided the moment you buy the camera. All the memory card lets you do is write those 1s and 0s somewhere else, but a 1 is a 1 no matter how much you paid for the memory card. There aren’t better 1s and better 0s to be had.

So then, why do some memory cards cost a lot, and some not? If it’s not about image quality, what’s it actually about? Well, it comes down to a few things. One is stability. More expensive cards are often more “stable,” or less likely to become corrupt or damaged over repeated use or the occasional drop. If a card becomes damaged or corrupted, then images will be unrecoverable, so, more stable is good. Another factor is speed. A good memory card can write the image from the camera much faster, and a computer can read it back off the card much faster. This lets you take more pictures in a burst, record longer video clips, and spend less time importing photos. A third factor that sometimes comes up is actual build quality. Some high-end cards like Hoodman’s Raw Steel line are made from metal instead of plastic, and are ruggedized and water-sealed to keep them safe from harm through trying situations.

But, what a good card can’t do is give you a higher quality image. In digital, that’s down simply to your lens and sensor combination (and, you know, your skill, but we’re focusig on the gear end here). If anyone tries to tell you different, trust us, you’re getting taken.

Hello everyone, and welcome back to Roberts Raw! It’s a bright and shiny new year out there, and we’re in the dark, cold land between major shows and product announcements. As such, we thought we’d take some time while we can to do a short series of posts covering some common myths and misconceptions about the modern (ie, mostly digital) photo world. And, since everything in digital comes down to the file, we thought we’d start with this doozy:

The Myth: Opening and closing a JPG repeatedly degrades the file and causes data loss.

Often seen as a explanation for why JPGs are called “lossy” compressions, this is one of those assertions that betrays a poor grasp of the underlying technologies that make digital photo possible. The simple truth is, a JPG to your camera and computer is just a series of 1s and 0s that make a file. When you open it they get read off the disk into memory. But, they don’t wear out. They’re still just ones and zeroes. There are some things that can cause a JPG to lose data (or, as it’s called, become “corrupted”), but those are usually things like bad memory cards or hard drives, things that cause bits of the data sequence to be forgotten. But, while that’s a good argument for keeping backups of all your photos, it doesn’t lend any weight to the idea that opening your JPGs will slowly make them look worse. Open and close and move them around as much as you want to, they’ll be exactly the same each time.

So, what does lossy mean then? And why are TIFF and other raw formats that are “lossless” better? Well, lossy means that some information is being thrown away while that series of ones and zeros is being calculated. This is done in various ways, but always for the same reason: to save file size. JPGs do it by looking at small chunks of your photo and merging very, very similar spots of color into one bigger field of the same color. This means there’s less data to write, and that means smaller pictures. Plus, as a bonus, if done well most people in most situations won’t see the difference anyway. Lossless files don’t do this. They keep everything about the original photo. Every color at every pixel is recorded. This means that you have a lot more to work with in post-processing, truer colors, and smoother gradients. But, depending on how it’s done, you will have larger to much, much larger files than with a lossy format like JPG.

But, they’ll all still open as many times as you want without any loss of quality that wasn’t decided when they were written*.

*Again, if the disk the file is on gets damaged during reading or writing the file, the corruption can occur, but that’s unrelated to actually reading the file, it’s just because where the data used to be went away. Also, if you edit a file in an editor like Photoshop and then save it over the original, you can make changes that will reduce quality. But only if you choose to save them. Simply having opened the file will not alter the original data in any way.