If you’ve never worked with digital file formats, the word gigabyte probably doesn’t mean much to you.
Whether you’ve just gotten your first camera or you’re shopping for a new memory card, you’re faced with dozens of options that can be extremely puzzling if you’re not familiar with them. A 16GB card may be the same price as a 64GB card, but they’re far from the same.
32GB memory cards are a popular choice, but you’re probably asking yourself, how many pictures can 32GB hold?
Comparing JPEG, RAW and DNG
One aspect that determines the number of pictures that a 32GB memory card can hold is the file format. This includes JPEG, RAW, and DNG. On a computer, you’ll typically see these after the file name, like this: BeachPhoto.JPEG
JPEG Quality Settings and File Size
JPEG stands for Joint Photographic Expert Group, after the committee that developed the standards for the format. JPEG is also shortened to JPG.
JPEG is a standardized lossy compression format for digital images and is one of the most common picture types you’ll see when browsing the internet or anyone’s computer. They’re popular because they save more space than older formats, but there is some loss of quality between the original picture and the final JPEG.
A 32GB memory card can hold a maximum of 22,888 JPEG photos. This number changes depending on the picture quality or the number of megapixels. If all of the pictures have 22 megapixels, then a 32GB card would only hold 4161 JPEG photos.
RAW File Size
You’re probably not familiar with RAW picture formats unless you’ve been working with cameras for a while. RAW files are uncompressed images that come directly from the camera with minimal to no quality loss or interference from other digital factors. Typically, RAW files are processed through a photo editor like Lightroom before being turned into another format and printed.
A 32GB memory card can hold a maximum of 2,228 RAW photos with 4 megapixels. If the RAW images have 22 megapixels, a 32GB card will only hold 416 photos.
DNG File Size
DNG photos are also considered to be a RAW photo format, but there are some differences. Even though RAW files can be processed through programs like Lightroom, DNG files can be imported and edited in all Adobe applications regardless of your camera brand. They take up the same amount of space as a RAW photo.
Your camera’s resolution is one of the largest factors in determining how many photos you will be able to store. For example, if you have a smaller, cheaper camera, your photos will be lower quality than someone with a professional high resolution DSLR, and your photos will take up less space.
Determining Your Camera’s File Size
Most of the time, you’ll be able to determine your camera’s file size by reading the manual, but once you start adjusting settings and functions, it may deviate from the norm.
There are some steps you can take to calculate your camera’s file size. This will help you keep track of how much space you’re filling on your memory card and when it’s time to unload some pictures onto a USB or external hard drive.
First, determine how many vertical and horizontal pixels your camera detects. Multiply these together to get the total number of pixels.
Then, multiply the number of pixels you got in the first step by the number of bits your camera has (such as 8 or 16 bit). Finally, divide your answer by 8 to get the number of bytes. Divide this number by 1,024 to give you the answer in kilobytes, and then divide one more time to finally get the number of megabytes.
Memory Card Calculator
An easier way to figure out the size memory card you need for your camera is with a memory card calculator. These will ask you to input your camera model, preferred file format, and memory card size and tell you how many photos will be stored before it’s full. You can use these results to decide if you need to buy a larger card or if you’re okay with what you have.
Types of Memory Cards
Along with the total size, memory cards are classified into three different categories: Compact Flash, Secure Digital, and MicroSD.
Memory cards used to be extremely fragile, and everyone in the market was excited when SanDisk came out with the CompactFlash (CF) card in 1994.
The CF card offered high performance and durability compared to its counterparts. CF Type-I and CF Type-II are still offered today, but they are no longer popular as faster cards have replaced them.
SD (Secure Digital)
You may have heard someone call a memory card an “SD card” once or more, and this is because of the Secure Digital (SD) card. SD cards rose quickly in popularity in 1999 as they had low production costs and small size.
Nowadays, SD cards are obsolete as the largest size they offered was 2GB of data. Today, you’ll run into SDHC (Secure Digital High Capacity) and SDXC (Secure Digital Extended Capacity) instead.
SDHC cards were the first upgrade to the original SD cards. The manufacturers doubled the read and write speeds and increased the maximum size up to a 32 gig SD card. When 32GB wasn’t enough, they came out with the SDXC card. The SDXC size was increased to a theoretical 2TB (2048MB) with extremely fast read and write speeds.
MicroSD cards are very similar in size to sim cards and were created because regular SD cards were too large for mobile phones.
MicroSD cards are typically found with sizes of 32, 64, and 128GB. Very rarely, smaller cameras will require a MicroSD card instead of a regular-sized one, and phones as well. There are also adapters that can be purchased to use a MicroSD card in place of a regular-sized SD card.
What Size Memory Card Do You Need?
Some photographers prefer to work with the largest memory card available to them, while others just need enough to get by.
To determine the ideal memory card size for you, think about the quality of photos you’ll be taking, the file format you plan on using, and the amount of time you’ll take in between offloading images to an external location like a computer or USB.
Even if you’re using the lowest quality file format, you’re bound to fill up your memory card eventually. Use a memory card calculator or calculate your camera’s file size by yourself to determine the ideal size for you.
If you’d like to avoid sitting in front of a computer screen for hours, waiting for it to process your high-quality photos, then you need to be aware of the reading and writing speed of your memory card.
MicroSD cards can read and write at a speed of 100MB per second, while SD cards can read and write three times faster.
A memory card with lots of storage and a high reading and writing speed will be considerably more expensive than a small, slow card. If you do invest in a high-quality card, then consider purchasing a protection plan in case anything happens and you’re out of luck. If you’re on a budget, then try and find a sweet spot—reasonable storage with speeds that aren’t too slow.
Quick Tip: Read Your Camera’s Manual
The caveat to how many pictures can 32GB hold? You should always read the manual. This applies to both your camera and the memory card you’re considering buying.
Take into account the file format you’d like to shoot in (JPEG, RAW, or DNG), your camera’s resolution, and the type of memory card you’re looking at. Different memory cards have different speeds and benefits to each.