How to Select the Right Photography Memory Card

How to Select the Right Photography Memory Card
Contact Us
Thought Leadership
News & Events
Thought Leadership
November 25, 2015
Picture This: How to Select the Right Photography Memory Card
Learn about the capabilities you should take into account when shopping for your next memory card
By:Tom Ando, general manager for Canon Inc. and Co-Chairman of the Compliance Committee and a board member of the SD Association
While the average consumer uses a smart phone to take pictures, professional photographers need the quality
and features that high-end digital cameras offer. But even the best camera will not perform at its maximum level
without the appropriate memory card. Certain characteristics such as speed are critical for capturing a valuable
image, especially for action photographs. Below are the most important considerations photographers should
consider when selecting memory cards.
Camera Model
Before beginning the search for the perfect memory card, make sure to read your camera’s user manual and
confirm what types of cards are supported. Characteristics such as maximum supported capacity (SD, SDSC,
SDXC) and/or minimum performance class are usually provided by the camera manufacturer. Sometimes the
manufacturer will even define several minimum performance requirements by usage (HD video capturing, still
pictures, etc.). The following information provides some clarification about the various symbols or marks used
to indicate the different classifications.
Recent posts
Why the SD Market Continues to
Focus on Capacity, Security and
How 3D NAND Can Continue
Gigabytes Scaling, Enhance
Picture This: How to Select the
Right Photography Memory Card
View all
If the SD memory card does not operate at the optimal speed for photography applications, it will most likely fall
behind and lose the race in number of images per frame– especially when shooting Full HD/4K video. Every
memory card operates with two actions: write and read (WR/RD). The two different types of speed parameters
are commonly provided by memory cards:
Minimum assured write performance – indicated by a Speed Class marking
Maximum possible WR/RD operation
Speed Class is a standard defined in SD
specifications (see table) to assure card
performance used by any device that
operates a specific Speed Class. It is
important to knowthatSpeed Class ensures
minimum performance as long as your
camera supports Speed Class (again, check your user manual) indicated on the card. It is
crucial that both the card and the camera must support the same Speed Class to
guarantee specific performance.
2016-03-03, 4:33 PM
Page 1 of 4
The maximum
supported write
and read speed
rates are not
by SD
These rates are
usually marked
in Bytes per
second [i.e.
95MB/s = 95
Mega Bytes per
second] and are provided by the memory card manufacturer. It’s important to know that each card manufacturer
uses their own criteria of measurements and may only provide a general impression about the card’s
capabilities to the consumer. If only a single rate is marked – it is usually the read capability of a card, so it is
recommended to check the card’s retail package for the read capability number.
Write speed is the rate that the memory card can save images. Choosing a card with the minimum required
speed is imperative for proper camera operation. In addition, high rates of maximum WR/RD speeds are highly
recommended for photographers who shoot many frames per second in continuous shooting mode. For
example, sport photographers cannot do their craft well without a high WR/RD speed that can handle bursts of
continuous shooting. It is equally important for recording HD video and shooting large files with high resolution
In other words, having a memory card that meets your camera’s Speed Class rates is the minimum requirement
to delivering on the full capability of your camera. However, using high speed write/read cards is also important
for an improved picture taking experience, which in some cases means the difference between catching a
specific moment or missing it. Most cameras take pictures faster than the image buffer can transfer them. When
this happens, the buffer fills up and the camera ceases shooting until enough images have moved from the
buffer to the card. Once this movement occurs, the camera resumes taking pictures. A faster memory card
helps move this process along to extend shooting time. The user can click away, taking as many pictures as
they want without worrying about missing a piece of the action. On the other hand, if the card is too slow, the
camera’s buffer memory will fill up and stop recording prematurely.
Read speed is measured by how fast devices, like computers and printers, can retrieve data from the card. The
faster the read speed, the faster the card will transfer images more quickly.
Of the two speeds, write speed is most important for photography and should be given priority over read
speed. You can find an SD memory card’s speed class on the card itself or its packaging, as well as an online
store listing.
Card Interface Type
As mentioned above – the Speed Class relates to the interface type supported by your memory card and
device. The interface type allows maximum bit rate transmission over the interface. There are three interface
types defined by the SD standard:
Basic/Normal – up to 25MB/s
Ultra High Speed 1 – UHS-I – up to 105MB/s
Ultra High Speed 2 – UHS-II – with up to 312MB/s
Consult your owner’s manual to ensure your camera supports UHS-I. If the camera was made in the past
couple of years, it might already be compatible. Today, there are cameras in the market that also support the
UHS-II interface.
You may be asking yourself why anyone would want to buy UHS-II cards and cameras. Especially when already
affordable SD memory cards (such as UHS-I with up to 90MB/s write speed) can capture a standard JPEG
image file even while using the perpetual burst/continuous shooting. But there’s another image quality issue to
2016-03-03, 4:33 PM
Page 2 of 4
consider. JPEG formats typically only
come standard with eight bits per
pixel. But while digital cameras come
pre-set to produce the best images
possible, their factory settings may
differ from individual user
preferences, such as when he or she
wants to manipulate white balance,
brightness or other settings.
In this scenario, JPEG files simply don’t have the bandwidth. As a result, most DSLR camera manufacturers
offer RAW formats, typically with 12-to-14 bits per pixel. The RAW format is nearly universal for professional
photographers and high-end camera lovers, so maintaining original quality with wider range of post-processing
options becomes the focus as RAW files tend to be larger. A good rule of thumb is that every 20M of pixels
require 250 megabytes of storage.
Because of the larger RAW file size, users may reach the buffering limits on their camera sooner than expected,
particularly when shooting in bursts, as perpetual-burst photography can command more than 250Mbytes per
second, even on cameras with shutter speeds as low as 10 frames per second. In these cases, UHS-II cards
and their interface allow for smooth, and continuous, burst shooting without the risk of missing that special
Again, it is important that your camera supports the UHS-II feature. A few such cameras already exist today and
it is expected that UHS-II feature will be supported for non-professional users at an affordable price, due to
lower internal camera memory buffering requirements, in the future.
Higher memory storage levels equal larger video file storage capabilities – so the more gigabytes a memory
card can store, the more video it can shoot. This is an important differentiator for photographers who shoot long
HD or 4K videos. And for photographers who focus on still shots, more memory capacity is still a win. Of
course, regardless of needs, the rule remains the same: it is always select a memory card compatible with your
All SD memory cards are not created alike. The following information can help you determine, according to
capacity, which type of memory card fulfills your needs:
SD – up to two gigabytes
SDHC (SD High Capacity)– two gigabytes to 32 gigabytes
SDXC (SD Extended Capacity)– 32 gigabytes to two terabytes
Most devices support SDHC, while SDXC is newer to the market and most new cameras and professional lines
support SDXC.
HD and 4K video consumes significantly more storage space than standard video – about twice as much – and
will fill up a memory card at a faster rate. This makes storage capacity a key factor in determining how much
video you can capture on a card. Make sure to look for higher memory capabilities if you are going to shoot in
HD and 4K. Higher gigabyte cards offer longer recording times, so always remain aware of the time length you
2016-03-03, 4:33 PM
Page 3 of 4
need from your card. The last thing you want is to run out of space in the middle of a project.
When you consider all of the above factors, your chances to select the best memory card for your photography
needs will be quite favorable. And in capturing every memorable moment, you will also capture opportunities
that benefit your photography business.
Tom Ando is a general manager for Canon Inc. He is in the ASIC development division and specialized in image
processing, video codec and storage media interface. Ando is the Co-Chairman of the Compliance Committee
and a board member of the SD Association.
©SD Association. All rights reserved. SD, SDHC, miniSDHC, microSDHC, SDXC and microSDXC Logos are
trademarks of SD-3C LLC
Back to top
Recent posts
*SD, SDHC and SDXC Logos are trademarks or registered trademarks of SD-3C, LLC in the
United States, other countries or both. Also, miniSD, microSD, miniSDHC, microSDHC,
microSDXC, smartSD, smartSDHC, SDIO and miniSDIO Logos are all trademarks or registered
trademarks of SD-3C, LLC in the United States, other countries or both.
Contact Us
Privacy Policy
Copyright (c) SD Association. All Rights Reserved.
2016-03-03, 4:33 PM
Page 4 of 4
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF