CFexpress Cards Explained: What are Types A, B and C?

If you’ve been following the latest mirrorless camera releases, like the Canon EOS R5 and the Sony A7S III, then you’ve probably heard about CFexpress. The new memory card game in town, it’s fast becoming standard practice for new cameras to come sporting a CFExpress slot.

Big deal, you might be thinking. Why should I be excited about a memory card? Especially when you might have noticed that a CFexpress card seems to cost a bit more than a regular SD memory card.

You may also have clocked that CFexpress comes in three varieties – Types A, B and C – and wondered about the differences between them.

We’ve put this article together to provide a quick and straightforward explanation to what CFexpress is and what you need to know about it. So let’s waste no more time and crack on!

What is CFexpress?

CFexpress cards are the latest generation of what was once CompactFlash (CF card). These are high speed memory cards designed to keep up with the demands of the latest cameras in terms of both high-resolution photos and video.

CFexpress cards use an interface called PCIe 3.0, as well as NVMe 1.3 protocols. You don’t really need to know the ins and outs of how this stuff works – the bottom line is that this is the kind of tech you would previously have found in computers and solid-state drives (SSDs), which are typically much faster than SD cards.

So the main takeaway is this – CFexpress cards are fast. The maximum theoretical performance of a Type C CFexpress card (the fastest of the three speed classes) is 4,000MB/s; for context, UHS-III SD cards can theoretically manage a little over 600MB/s.

While there is an equivalent format for SD, which is called SD Express, camera manufacturers seem to have overwhelmingly plumped for CFexpress. Like the memory card version of the battle between VHS and Beta-Max, this is the format to focus on when thinking about the future.

Let’s take a closer look at the different types of CFexpress memory card on offer.

CFExpress Types A, B and C: What are the differences?

If you were to line up the three different types of CFexpress cards, the first thing you’d notice is that they are physically quite different. CFexpress Type A is the smallest, measuring 20mm (width) by 28mm (length) by 2.8mm (thickness, including label area). The Type B cards measure 38.5mm x 29.6mm x 3.8mm, while the largest Type C cards measure 54mm x 74mm x 4.8mm.

The main reason for this is because each of these types of memory card  has a different number of PCIe data transfer lanes. The CFexpress Type A card has just one lane, Type B has two and type C has four. This means the three memory card types of cards offer different transfer speeds – Type A Cards have a maximum theoretical transfer speed of 1,000MB/s, Type B cards can theoretically reach 2,000MB/s and Type C cards, as discussed, can reach transfer speeds of up to 4,000MB/s.

Of the three, photographers and videographers don’t need to concern themselves too much with Type C – these larger cards are designed more for use with computers and Solid State Drives. The types you’ll most typically find compatible with cameras are Type B – this is the type you’ll be able to use with the Canon EOS R5, Nikon Z6, Panasonic S1R and other cameras.

One of the main reasons for this is that CFexpress Type B cards are physically the same size as, and pin-for-pin identical to, another card type – XQD cards. So if a camera has an XQD slot, then usually all it needs to become CFexpress compatible is a firmware update.

Panasonic rolled out updates for their XQD cameras in 2019. Nikon have updated firmware for mirrorless Z6/7 and DSLRs D5 / D500 / D850 / D4S / D4 which all have XQD slots.

Meanwhile, the Sony A7S III, recently rolled out to big headlines, many of which focused on the fact that it takes CFexpress Type A cards. Which, you may recall, are actually the slowest type on offer. Why did Sony pick this size? Well, for one, the 1,000MB/s maximum transfer speed is still more than ample to record pristine 4K footage without any dropped frame.

But the other half of the story is that the smaller size of Type A means that a CFexpress Type A slot can also be used as an SD card slot. So users of the Sony A7S III can use its dual card slots with SD cards and CFexpress cards.  They can be used in any combination (though you can’t use both in one slot at the same time), giving a lot more flexibility.

Which cameras are CFexpress-compatible?

Here is a partial list of current cameras that offer one or more CFexpress card slots:

Which brands are making CFexpress?

When it comes to CFexpress Type B cards, you have many brands to choose from. Here’s a quick rundown of some we’d recommend:

SanDisk Extreme PRO CFexpress Type B cards

These are often bundled with the Canon EOS-1D X Mark III. They come in 128GB and 64GB varieties, and the larger card is also faster, offering a maximum read speed of 1,700MB/s, compared to 1,500MB/s on the smaller card.

Delkin Devices Type B CFexpress cards

Delkin start out at 64GB and go all the way up to a whopping 2TB. Read/write speeds increase as the capacities do, although, of course, so does the price.

Lexar Professional CFexpress cards

A trusted name in memory cards, Lexar makes reliable Professional cards with capacities ranging from 64GB to 512GB.

When it comes to Type A cards, Sony is currently the only game in town, announcing a range of CFexpress Type A cards alongside the A7S III. Offering read/write speeds of around 800MB/s and 700MB/s, the Sony CFexpress Type A TOUGH Memory Cards are, as the name implies, tough enough to stand up to the rigours of professional use. They come in 80GB and 160GB varieties.

One thing that’s also worth noting is that your current memory card reader may not be capable of reading a CFexpress card – so that’s another thing you may have to sort in order to be able to get the cards onto your computer. Sony and Lexar are two reliable brands that have started producing the CFexpress card readers. However, there are others out there, so get in touch with the Fixation sales team and we can recommend you the best deals for you.

The future?

Current CFexpress cards use the PCIe 3.0 spec, and given that the PCIe 4.0 is on the horizon, we can only expect these cards to get faster and faster. It’s up to you when it makes sense budget-wise to upgrade, however we can safely say that CFexpress is a format worth getting to know for the future of image-making.


Nikon Mirrorless Z5

Nikon has announced a new camera body in its Z series Mirrorless range. The Nikon Z5 is a full frame 24.3 megapixel camera with two SD card slots for more shots or for a secure backup on important shoots. The Nikon Z5 is positioned below the Z6 and Z7 in the Z series lineup, but it is a powerful camera, and an ideal first full-frame body.

Nikon Z5

Nikon has put the most important mirrorless technologies in this small, light, but tough, camera body. The 24.3 megapixel CMOS sensor has ample resolution for stills and video recording up to 4K. Here are the features in detail.


Five Axis VR CMOS Sensor

The full-frame 24.3 megapixel CMOS sensor in the Nikon Z5 is mounted on a 5-axis VR system for in body image stabilisation. With any Nikkor Z lens your stills stay sharp and your video will stay steady. The sensor has an ISO range of 100-51,200 to cope with any lighting conditions, with excellent low-noise performance at higher ISO levels.

Small, Light, Solid

To keep out dust and moisture, the Z5 has a magnesium alloy body with weather sealing around seams, moving dials and buttons. The body is compact and weighs only 680g with the battery. The Nikkor Z 24-50mm f4-6.3 kit lens that comes with the camera is the smallest, lightest full frame zoom available on the market. It is admittedly not the brightest lens, however it is a handy wide to standard zoom that will perform well in good shooting conditions. The body has sensor stabilization which will help produce steadier shots at longer shutter speeds which may be needed with a smaller aperture lens.

Ultra-Sharp AF

The Z5 focus system has 273 AF points on the imaging sensor and includes Eye-Detect AF and Animal-Detect AF focus modes to lock on to a wide range of subjects. The Nikon AF algorithm will lock on to your subject quickly and track moving subjects for crisp action shots.

Dual SD card slots

Record onto fast UHS II SD memory cards and easily shoot to one with a backup saved to the second card. Or use one card for stills and a higher capacity card for video to make sure you never run out of space.

Best in class EVF

The electronic viewfinder in the Nikon Z5 has a 3690k-dot display which shows exposure, ISO and white balance settings in real-time.


To place an order, or to find out more about the kit, contact our sales team on 020 7582 3294 or email


Using Canon EF lenses with EOS R bodies

Tempted by the new Canon EOS R mirrorless cameras but worried about all your Canon EF lenses gathering dust? In this article, we’re going to be running through the adapter options for mounting EF lenses to EOS R bodies and explain how you really can get the best of both worlds.

We know that it does sound too good to be true. The idea that you might be able to bring all any old EF lenses with you when migrating to a new system, and have everything work just as it’s designed to may seem a pipe dream.

Photographers have been swapping lenses between systems for many, many years now, but it is generally accepted that this will involve a trade-off in terms of features and functionality. Things like autofocus or image stabilisation will either work less effectively than usual, or simply not work at all.

Canon’s new EOS R system, however, is a different story.

With the introduction of the full-frame mirrorless cameras such as the Canon EOS R. Canon turned many heads and signified that it was taking mirrorless seriously. This was a serious tool for serious professionals, and was clearly built and marketed as such – but many pros worried about their considerable collections of EF compatible lenses. Was Canon asking them to effectively throw these investments in the trash and start again?

Short answer: no.

Do Canon EF lenses work with EOS R camera bodies?

It was a given that Canon would produce an EF to EOS R adapter, however what’s impressive is just how comprehensive a job they’ve done of ensuring the lens and cameras can communicate.

This is not a coincidence. Canon has specifically designed the EF and RF systems to be what it calls “bilingual”. When most lenses are adapted between systems, the device is converting the electronic signals from one device to the other.

Even when the communication is sophisticated enough for the devices to understand each other thanks to the latest firmware updates, it still has an inherent latency, which causes lag and impacts on performance. On EF-EOS R adapters, the information can pass straight through.

What this means in practice is that, for the vast majority of models, everything that your EF lens can do on an EOS body, it can also do on an EOS R body when they are connected using an adapter. Indeed, now that the cameras have been around for a couple of years, photographers have been able to test them out. Some are even reporting that, anecdotally, their EF lenses seem to perform better with the Canon R, with faster autofocus.

The Canon EOS R bodies are able to store a large number of lens profiles in their internal memory, allowing them to correct known aberrations and distortions in many EF lenses, back to the 1990s. This functionality can be disabled if you don’t require it and it won’t overpower the character of an old lens if you’re going for a specific “look” over technical perfection.

The compatibility really does extend right across the range of EF lenses. You might be wondering, out of more than 150 EF lenses made by Canon, how many have functions that don’t work when they’re paired with EOS R bodies? Answer: eight.

In all cases, it’s a pretty minor thing – the Canon EF 35-80mm f/4-5.6 PZ lens from 1991 can’t use its Power Zoom when paired with EOS R, and the AF Stop button doesn’t work on seven telephoto prime lenses from the late 90s and early 00s. In all other respects, EF lenses work on EOS R bodies exactly as they were designed to work on the original DSLRs.

From left to right: EF-EOS R standard adapter, Control Ring adapter, Drop-in filter adapter.
EF-EOS R adapters

The EF-EOS R adapter range is made up of three models, each of which is a little different. Let’s take a look at the main features of each one…

Canon EF-EOS R Mount Adapter

This is the simplest, most affordable mount adapter for converting EF lenses to EOS R bodies. It allows for full communication between lens and camera, meaning all functionality like AF points and image stabilisation will work as advertised.

Lightweight and compact, the EF-EOS R mount adapter contains no optical elements, so it won’t compromise the quality of even the sharpest L-series lenses. It’s also dust- and water-resistant, so if you’re using the more rugged lenses in harsh weather conditions, the adapter won’t be a weak spot in your setup.

Canon Control Ring Mount Adapter EF-EOS R

Similarly to the standard EF-EOS R Mount Adapter, the Canon Control Ring Mount Adapter EF-EOS R converts EF lenses to EOS R bodies with no lag or optical elements to compromise quality, and is also equipped with weather sealing.

The key difference, as the name implies, is that this Canon EF adapter comes with a customisable control ring, and it’s not hard to see why many photographers say this is their favourite of the three adapters. Adding a lens control ring to the setup makes using the lens incredibly intuitive. What’s especially good about this adapter is the extent to which the control ring can be customised to the individual user’s preference – essentially it mirrors the control ring found on native RF lenses.

The control ring can be programmed to adjust all the major settings, including shutter speed, ISO, aperture, exposure compensation and white balance. The ring can be set to change values positively or negatively when it’s turned to the right or left. It can also be set to only kick in when the shutter button is half-depressed, if you’re concerned about accidentally knocking it at a crucial moment.

Canon Drop-In Filter Mount Adapter EF-EOS R

The third option of mount adapters for EF-EOS R is an interesting one, allowing for the use of a select number of drop-in filters. This is especially useful if you’re planning to shoot with a lot of larger lenses or wide-angles with a bulbous front element that doesn’t allow for the easy attachment of filters on the front.

While it doesn’t have the control ring option, this adapter does have all the functionality of the other adapters – it retains full autofocus and image stabilisation capabilities of the attached lenses, and also has the same dust- and weatherproofing.

Below are the filters you can use with this mount adapter

Canon Drop-In Variable ND Filter A: This variable ND gives you tremendous flexibility in controlling the amount of light reaching the camera, with a variable ND effect that runs from 1.5 stops all the way up to 9 stops. Use wider apertures or slower shutter speeds even in bright light conditions, and easily alter the intensity of the ND effect with the rotating wheel.

Canon Drop-In Circular Polarizing Filter A: Minimise reflections and glare with this drop-in polariser, which also has a rotating wheel that allows the user to modulate the intensity of the polarising effect. Made with high-quality glass, it ensures that the final image is still pin-sharp

Canon Drop-In CL Filter: This is a clear filter that’s used if you want to use the adapter without any of the above filter effects. Made from high-quality glass, it’s designed to effectively transmit light without any additional effects. This is useful if you want to have the option of using or not using the Drop-In filters without having the hassle of buying multiple adapters.

So the reality is that the best of both worlds truly is possible! We hope you’re encouraged to see the possibilities of shooting with EF glass and EOS R bodies, but if you have any further questions, don’t hesitate to get in touch with our team! You can email or call 020 7582 3294


Sony FE 12-24mm f/2.8 G Master Lens

Sony FE 12-24mm f/2.8 G Master is an extreme wide angle zoom lens for full-frame Sony alpha bodies. It is perfect for getting close to the action, or capturing a whole scene in one image. The constant f/2.8 aperture is an industry standard for professional zoom lenses, it enables photography in low light at any focal length you select.

The Sony FE 12-24mm f2.8 G Master lens launches at £2899

To place an order, contact our sales team on 020 7582 3294 or email

Key Features

Innovative Optics – Sony G Master Precision

Sony has preserved incredible image details at extreme wide angles and wide open at f/2.8 by applying the full range of G Master imaging technologies. The FE 12-24mm f/2.8 features four aspherical elements in a complex build of 17 elements. Three are XA elements (extreme aspherical) to manage the distortion and aberrations that can come with wide angle glass. Not here, the combination of XA, Aspherical, ED (extra-low dispersion) and Super ED elements effectively reduce chromatic aberrations for crisp detail while a new Nano AR Coating II minimises ghosting and lens flare.

Bright f/2.8 aperture

The constant aperture of f/2.8 permits shooting at any point in the zoom range without having to resort to slower shutter speeds or higher sensitivity which could take away from the shot. Low light scenes which need low-noise such as night landscapes and astro photography are possible with this lens and the 12-24mm zoom range offers more framing options in one unit.

Professional build and control

Shoot anywhere with weather sealing for resistance against dust and moisture. The Sony 12-24mm f2.8 G Master also features a focus hold button for locking on to your subject without taking your hand from the lens. Alternative functions can be assigned to the focus hold button in the camera menu for more control options.

XD Linear motors – Four of them

Count ‘em four. Two for the main focus movement and two for the floating elements which correct chromatic aberrations as lens elements are moved further apart. XD linear motors are quiet with minimal vibrations for smooth focusing and precise focus tracking. Floating element groups allow lens designers to engineer more compact lenses. Another benefit is that the focus is made faster by reducing the distance traveled by each element group

To place an order, contact our sales team on 020 7582 3294 or email


Canon EOS R5 and EOS R6

With the R5 and R6 Canon announced its biggest update to the mirrorless EOS R system to date. Two new full frame bodies: The 45 megapixel EOS R5 and the 20 megapixel EOS R6. Alongside the camera bodies Canon also announced four new RF mount lenses, and two teleconverters.

Both cameras are compatible with the Canon RF mount converters so you can use your stable of EF lenses with these new bodies.

[gdlr_stunning_text background_color=”#f3f3f3″ button=”Contact us” button_link=”/contact-us/” button_background=”#009bc1″ button_text_color=”#ffffff” button_border_color=”#009bc1″ title=”£200 Trade in Bonus” title_color=”#009bc1″ caption_color=”#a0a0a0″]Save on a new Canon EOS R5 or R6 when you trade-in any working interchangeable lens camera. Canon are offering a £200 trade-in bonus on top of the value of your traded in kit.
Contact our sales team for a free quote. Offer ends 14/07/2021

To speak to the sales team about how these cameras can work for you, or to place an order, call our sales team on 0207 582 3294 or email

Full release info on the two camera bodies below. Read our article on the new Canon RF lenses.

Canon EOS R5: Photography without compromise

Launch Price: £4199

The Canon EOS R5 is a high resolution full-frame mirrorless camera body with high speed AF tracking technology pioneered in the EOS 1DX mark III. The EOS R5 is not only a stills machine, it can record up to 8k DCI video, and offers 4K recording up to 120fps for cinematic slow-motion footage. The camera is built around a magnesium alloy body, built to withstand heavy professional use. The Canon EOS R5 is built without compromise.

Canon EOS R5 key features
  • 45 megapixel full-frame CMOS sensor : Capture extraordinary detail, right up to ISO 51,200
  • 20 fps : Silent electronic shutter. Shoot faster and capture the perfect moment.
  • Full Frame 8K RAW video : Superb resolution and dynamic range
  • 4K video up to 120fps : For outstanding slow motion effects
  • Up to 8 stop Image Stabilisation : Shoot handheld with very long shutter speeds
  • Wi-Fi and Bluetooth built in : For wireless LAN image transfer
  • Magnesium Alloy body and chassis

Canon EOS R6: High speed for every story

Launch Price: £2499

The Canon EOS R6 is a lower resolution body, with a higher sensitivity range. Ideal for low light photography and video. The in-body image stabilisation system works with Canon Image Stabilisation lenses to offer up to 8 stop stabilising power for smooth footage, and pin sharp images. The EOS R6 is compatible with the Canon RF lens range and the wider EF range (with a Canon mount adaptor) which makes up to 68 current full-frame optics available for limitless creative expression.

Canon EOS R6 key features
  • 20 Megapixel full-frame CMOS sensor : ISO up to 102,400 for superior low light images
  • High speed continuous shooting
  • 20fps Silent electronic shutter. 12fps Mechanical shutter
  • 4K UHD Video
  • Up to 8 stop IS
  • Shoot handheld with confidence
  • Magnesium alloy chassis with poly-carbonate body

For expert advice on the full Canon range, or to place an order call the sales team on 0207 582 3294 or email us at

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