Portable storage round-up

What’s the best way to move your images from camera to computer and then to other storage options? Memory cards, portable drives, tablets and laptops provide temporary storage while you’re on the move but, once you’re home, files should be backed up to high-capacity desktop storage, with copies on separate drives, optical disk or in cloud storage.

As camera pixel counts and frame rates increase and video streams require increasing storage capacity and data transfer rates, photographers must seriously assess how and where they will store their images and movie clips.

Choosing the right storage is essential when you’re on the move, when reliability, capacity, speed and device footprints will be key considerations. With the latest high-end cameras, photographers find memory cards fill up faster than before and their computer’s hard drive can hold only so many files.

In this round-up we look at portable storage solutions you can use both at home and while travelling. Our main focus is on backup options which allow you to store photos and movie clips in multiple locations.

The importance of backing-up

Everyone has lost computer files at one time or another, whether through computer crashes, memory card and disk failures or the theft of a laptop or storage drive. Any of these events will cost you precious records so it’s important to back up files regularly to ensure you have copies that can be accessed if disasters occur.

Professional photographers recommend a ‘3-2-1’ rule: make three copies, store two on different types of media and one in a different location. For travellers, this could mean keeping images on memory cards and backing up to portable HDD (hard disk drive) or SSD (solid state drive) as well as to the cloud. Stay-at-home photographers could write images to their computer’s internal drives, to external HDD/SSD, and to the cloud.

Choose technologies that meet your individual requirements and resources, taking account of storage capacity, data transfer speeds, cost and convenience. For travellers, devices with fast start up and read speeds can save a significant amount of time.

Memory cards

Your camera will determine the type of memory card you need and its resolution, video capabilities and the extent to which you use continuous shooting will dictate the card speed required. Having multiple memory cards is one storage option, particularly if your camera provides two card slots.

The latest high-end interchangeable-lens cameras often provide dual slots that can be used to back-up files on the go. The Nikon D850 shown here has slots for SD and the relatively new XQD cards.

Dual-slot cameras can be configured to store on both cards automatically and most will let you store different file types on each card. The most common situations involve storing JPEG images on one card and raw files on the other or still images on one and video clips on the other. Most cameras can also be configured to use the second card as a backup for anything photographed with the camera.

The main disadvantage with relying on memory cards is that they’re relatively small (particularly SD cards) and, therefore easy to misplace. It’s also risky to locate all the files in one device (the camera) until you back them up elsewhere. You may also need to use fast, high capacity cards if your camera records high-resolution images or 4K movie clips.

Most current cameras use either Secure Digital (SD) or CompactFlash (CF) cards. Fast, high-capacity versions of both are available since the maximum data transfer rates of normal SD and CF cards may not be adequate for the latest professional cameras, particularly those that can record 4K video.

For cameras that use Secure Digital (SD) cards, you can choose from three types: standard-capacity SD cards (which have almost disappeared from the market), high-capacity SDHC cards and high-speed SDXC cards (which include UHS-II cards that have an extra row of contact pins for fast data transmission). They differ in capacities, data transfer speeds and applications, as shown in the table below.

Card type	Min. write speed	Max.write speed	Max. capacity	Applications
SD	2 MB/second	25 MB/second	Up to 2GB	SD video recording
	4 MB/second			HD video recording (from 720p to 1080p/1080i)
	6 MB/second
SDHC	10 MB/second		2GB to 32 GB	1080p/1080i video recording
	10 MB/second	104 MB/second		Broadcast standard 1080p/1080i video recording (UHS bus)
SDXC	30 MB/second	312 MB/second	32GB to 2TB	4K video files (UHS bus)

Most SD cards carry a speed class rating between Class 2 (minimum write speed of 2MB/s), Class 4 (4MB/s), Class 6 (6MB/s) and Class 10 (10MB/s). Many SD card manufacturers also list a specific speed alongside the Class rating, so a card can be Class 10 but also be listed as ‘up to 80MB/s’. The wording indicates the best you can expect but not necessarily what you’ll always obtain.

Some cards also carry an ‘x’ rating, based on multiples of the speed of an old CD-ROM (150KB/s). For example, 533x represents 533 x 0.15 = 80MB/s (there are 1,000 kilobytes in a megabyte). Currently the highest capacity SD cards is SanDisk’s 1TB SDXC UHS 1 card, which was announced at Photokina in September, 2016 but is not yet available.

Many recent SD cards carry a UHS (Ultra High Speed) Speed Class rating, sometimes in addition to the class rating. It’s denoted by either a 1 or 3 inside of a bucket U symbol.

The SD Association has two UHS Speed Classes: UHS Speed Class 1, which supports a minimum 10MB/s write speed, and UHS Speed Class 3 with a write speed of at least 30MB/s. Most cameras that support 4K video require at least a U3 rated SDXC card.

CompactFlash (CF) cards have been around since 1994 and are still supported in a few high end cameras but are being superseded by faster, more robust cards. The CF standard is based on a  50-pin  interface that supports data transfer speeds of up to 20  MB/s. Modern UDMA-7 enabled CF cards support data rates up to 160 MB/s, which is barely fast enough for recording video clips. Current capacities range from 4GB to 512GB.

CompactFlash and CFast cards have the same form factor, even though they are not compatible. The illustration above shows the sizeable differences in data transfer speeds.

A relatively new addition is CFast, which uses the CompactFlash physical body, but is not physically or electrically compatible with CF cards. CFast cards are based on the Serial ATA bus  and support read speeds of up to 540MB/s and write speeds of 450MB/s. Currently, 64GB, 128GB and 256GB capacities are available.

Another new card type is XQD, which was first announced in November 2010 by SanDisk, Sony and Nikon. Physically, these cards are slightly larger than SD cards but they use PCI Express as a data transfer interface. Sony is the only manufacturer of XQD cards at present.

Initially XQD cards supported transfer speeds up to 500MB/second but the latest version (v. 2.0) allows 1000MB/second. Currently available cards come in 32GB, 64GB and 128GB capacities and support up to 440MB/s read, 400MB/s write speeds.

In September 2016, the CompactFlash association announced the successor of XQD,  CFexpress, which uses the XQD form-factor and interface with the NVMe protocol for higher speeds, lower latencies and lower power consumption. The first cards were released in June 2017 in 32GB, 64GB, 128GB and 256GB capacities, with up to 1 terabyte in the future. We have yet to see these cards appear in cameras.

Toshiba FlashAir cards provide a wireless way to transfer photos from card to backup storage.

What speed do you need?

Because card prices increase with increasing speeds and capacities, photographers should ask themselves what card speed do you really need. The answers are simple:
1. If you seldom (or never) record movies, you can happily settle on slower (or medium-speed) cards. But if you want to record 4K movie clips, a fast card is essential.

2. Large image files from high-resolution cameras (including raw files and RAW+JPEG pairs) will take less time to store on faster cards, an important criterion for photographers who often employ burst shooting.

3. If you only record the occasional HD or FHD (1080p/1080i) movie, Class 10 is recommended as the minimum speed. UHS 1 cards should deliver smoother video footage.

When determining memory card capacity, check the retail prices for the type and speed class you are considering, noting that the highest capacity cards with the fastest transfer speeds are expensive and only sold by specialist shops.

Use the table below to estimate the shooting capacity you will need. (When shooting RAW+JPEG pairs, add the raw and JPEG file sizes, using data from your camera’s manual if you shoot reduced-size JPEGs or raw files.)

Effective resolution	File Format	Image size	File size
16 megapixels	JPEG	4608 x 3456 pixels	5-11MB
	RAW		21-32MB
18 megapixels	JPEG	5184 x 3456	6-7MB
	RAW		22-25MB
24 megapixels	JPEG	6000 x 4000 pixels	8.6-12MB
	RAW		25-33MB
36 megapixels	JPEG	7360 x 4912 pixels	10-16MB
	RAW		29-74MB

It’s usually cheaper to buy several cards with a capacity of 8GB or 16GB than a single high-capacity card. It’s also safer. While you have to change cards more frequently and you can run the risk of losing a card, if that occurs ““ or the card ‘crashes’ ““ at least you won’t lose all your image files. Reputable manufacturers like Panasonic, SanDisk, ProMaster, Angelbird, and Verbatim usually bundle their high-capacity cards with file recovery software that can retrieve images from a card if it fails

External drives

External hard disk drives (HDDs) have been popular back-up devices for at least a decade and today’s units come in different sizes, capabilities and capacities. Stay-at-home photographers can purchase desktop drives with around 4TB of capacity for approximately $200 or 8TB backup drives for around $400.

Photographers on the move have a wide choice of portable HDDs, with 1TB drives available for less than $80, 2TB drives at around $100 and 3TB drives for $140-$170. Most will slip into a laptop case and the majority have fast USB 3.0 interfaces.

Desktop drives utilise 3.5-inch disks and require separate power supplies. Portable drives use 2.5-inch disks and draw their power from the USB cable connecting them to a computer. Expect to pay more for ‘ruggedised’ models with anti-shock protection, slim and lightweight drives and drives with wireless interfaces.

Shock- and moisture-resistant portable hard disk drives are worth paying more for when you need to back-up images and video clips in challenging environments.

Solid State Drives (SSDs), which use flash memory (like memory cards and USB thumb drives) are worth considering, particularly if you don’t require much storage capacity. They are smaller than the smallest portable HDDs and, with no moving parts are also more robust. They also offer faster transfer speeds and use less power. The capacities range from 256GB to 2TB and they cost a lot more than normal HDDs. Expect to pay more than $500 for a 1TB SSD.

Solid State Drives like the Samsung Portable SSD T5 shown here are more expensive than HDDs but are smaller, faster, more robust, have no noise/vibration and use less power.

Other storage options

Optical disks used to be a good backup solution but, although they’re still available, most photographers prefer easier, more reliable options. The 4.7GB storage limit on a standard 12cm DVD won’t hold enough files to make it viable for backing up movies and high-resolution images and even though products are in development with greater data storage capacities,  these will require special players when they eventually reach the market (assuming they do).  HDDs provide higher capacities and are cheaper and more reliable.

USB thumb drives can be a convenient place to ‘park’ files while transferring them between different storage devices. Prices vary with capacities, transfer speeds and manufacturers. Their maximum capacity is limited to 1TB but such drives are hard to find. The most useful capacities for imaging are 64GB and 128GB.

Third party cloud storage

‘Cloud’ storage is something of a mixed bag with lots of players and a variety of prices, ranging from ‘free’ bundling of storage with a subscription service to $10/month for up to 1TB. Dropbox, Flickr, Bitcasa, Google Drive, Microsoft OneDrive, SmugMug, Canon Irista, and Amazon  are among the market leaders.

The main problem with cloud storage is that you are entrusting your files to a third party that also deals with a lot of other customers. Your data may be stored on a server farm, which is usually located offshore. If the network connection is disrupted, it will become inaccessible. Data transfer speeds also depend on the speed of your internet connection, which can be painfully slow and erratic in many parts of Australia.

Most service providers place limits on how much capacity they offer before they charge you to store files. Advertising is often a ‘given’ with plans that are free.

Making server-based cloud storage work isn’t as simple as it seems. File transfers can be interrupted, the provider’s servers might crash or somebody may interfere with your data. And even when things run according to plan, you need a reliable way to access the files you’ve stored at the sizes you want when you need them.

Some services assume you are uploading images solely for the purpose of sharing them online and will automatically re-size the files accordingly. Most place limits on movie files and many won’t accept raw files. Privacy is an issue with services that make their galleries public, such as Instagram and Facebook, although you can often restrict who can view your pictures.

Personal cloud storage

One way to circumvent the issues of third party cloud storage is to have ‘personal cloud’ storage, which is a hybrid between an external drive and a cloud service. Files are stored on your local networked drive, which is usually a Network-Attached Storage (NAS) device beside your home computer.

Several hard disk drive manufacturers have developed storage devices that support ‘private’ cloud storage that you can access from your smartphone and tablet computer. Photographers with Wi-Fi enabled cameras can back up their images and movie clips to their home storage with this system ““ provided the Wi-Fi network is capable of handling the amount of data involved.

These systems are generally free, although you must set up dedicated user accounts and apply encryption to protect your data. Reliable internet access and fast upload speeds are critical for private cloud storage to be practical.  

Hard drive products that support ‘personal’ cloud storage can range in capacity from very affordable 2GB to network-attached devices, such as the one shown above, which has four drive bays and can handle up to 40 terabytes of data.

Personal cloud storage can be very convenient. It can be accessed from any networked computer or device, or remotely using Wi-Fi or Internet connections on your phone, tablet or laptop. You have complete control over your files; they can be password protected and encrypted, and when you delete something you know it’s gone. And after you buy the equipment, there are no annual storage fees.

Article by Margaret Brown

Excerpt from  Photo Review Issue 74      

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