There are currently
seven different basic memory card types made for use with digital
cameras, with some more popular than others. There is also another type
of storage used, Microdrive, which as its name suggests is a
miniature hard drive, which although popular in early digital camera
days when memory card capacities were low, seems today to have
almost disappeared, as with early
memory card formats.
As an
integral part of the digital camera system memory cards have a vital role
to play, indeed digital cameras are useless without them, so choosing a camera without paying close attention to the
type of card it uses can often lead to disappointment. It is also
the case that in these days of high resolution sensors and
fast frame per second rates - fps - choosing a memory
card with the right performance level, one that can read/write
at high speed, is as important as the performance
of the camera itself. Using a 'slow' card with a fast/high
resolution camera will hinder and restrict it's speed of use.
This
aspect is now of particular importance with regard to the
newer cameras that now increasingly offer HD video capture. In
order to be able to take more than a few seconds worth of
video a fast card is essential. Tests with Canon's new HD
enabled 500D DSLR for example have revealed that only about 8
seconds of video can be captured in one go with slower cards
under 60x.
Although
newer cameras need the higher transfer
speeds that some of the faster and more expensive memory cards provide, it needs
also needs a
compatible card reader to be able to transfer images as fast
as it is possible between memory card and computer, if
transferring shots to a computer isn't to end up take longer
than actually taking them in the first place.
Fast
cards - 10x, 40x, 60x, 133x, 300x etc. UDMA.
Most
memory cards sold these days are able to give high/fast transfer rates, usually written on the
card as either 4x, 10x, 40x etc, this referring to the speed increase over
a 'standard' card, or increasingly now the actual data
transfer rate, 15mb/s, 30mb/s etc. The standard card transfer rate is classed
as 150kb/s which translates as 9mb's a minute. Which isn't really very fast
when you consider the size images files are these days and is why large capacity cards with fast read/write rates are now
increasingly common. So a 40x card can read/write at
6mb/s, a 60x - 9mb/s, 133x - 20mb/s, 200x - 30mb/s, and 300x - 45mb/s.
The highest current rate, that of 300x or 45mb/s is only
achieved with the latest UDMA cards.
With the newer digital cameras with high
megapixel
sensors there is a need to ensure that you use the fastest
cards available in order to achieve reasonable read/write
rates. This is especially true of the professional DSLR's with
high frame per second rates. They need to be able to write
images to the memory card at very fast rates. This rate is
also applicable to the speed with which images can be
downloaded from the card to the computer. The
latest card standard to arrive is UDMA. This enables the
fastest transfer rates to date, but is restricted at present to
Compactflash.
To
enable fast transfer rates between the memory
card and the computer when downloading images the interface
used must also be capable of coping with the flow
of information. So it must match the card requirements or the
rates promised won't materialize. If you only have a USB1.1
card reader then fast rates won't happen whatever the speed of
the card. You need at least USB2. The latest spec cards, those
UDMA enabled, need a special UDMA reader using the firewire
interface to reach the maximum rates they are
capable of. Or one of the latest PCMCIA/Expresscard readers
used in laptop expansion card slots which offer the UDMA
interface.
There
are various other points
to be aware of and we'll deal with these also.
Compactflash:
[CF] - current.
This was one of the first types of
memory card made and is still the most popular to date, although
it's now being
replaced in most digicams and some consumer level DSLR's by the
smaller size SD card format. There are two
versions, Type 1 and Type 2 . Type 2's were originally introduced to enable higher capacities and are thicker, however even
Type 1's are now available in capacities up to 8Gb and beyond. The
latest CF standard is CF3, which supports CF1 & CF2 along with
PIO 0-4 and UDMA 0-6 standards. This allows the fastest transfer
rates of any card type to date.
Originated
by SanDisk, CompactFlash cards are now made and sold under many different brand
names, are the
preferred card choice for many, and standard fitment in many DSLR's,
especially semi-pro and pro types. The
latest versions now offer very high capacities to suit the high
pixel counts of many newer cameras as well as high transfer rates -
up to 300x - and 16Gb and 32Gb cards have been
announced recently.
Not
all cameras can support high capacity cards over 2Gb. Older cameras
need a firmware update from the camera maker, if they have released
one. So be careful when purchasing an older secondhand camera using CF.
Most older cameras have an upper capacity limit of 512mb or
less due to firmware limitations, and not all cameras support type 2's either, so beware on these points
also.
Microdrive:
[MD] - now obsolete (we
think)
This is, as its name implies, a
miniature hard drive, just like that used in a computer, and was
invented by IBM. It is the same size and uses the same interface as
a Type 2 Compactflash card. It requires more power to operate than a
memory card and not all cameras can accept it. Originally made with
a capacity of 340mb [considered huge at the time when memory cards
were 32/64/128mb], there are now
512mb,1Gb, 2Gb and 4Gb versions. As with all hard drives, they must
be treated with respect and not subjected to sudden shocks or
dropped. Such damage is fatal. Now largely redundant as a design
due to their vulnerability and the high capacity of current memory
cards we aren't sure
as to whether Microdrives are still manufactured, Hitachi
taking over
production of hard drives from IBM some time age, and before the IBM
computer division was sold to Lenovo.
Smartmedia:
[SM] - now obsolete
The second original type of card,
these were used in cameras made by Olympus and Fuji. At one time the
second most popular type, with a maximum capacity of 128mb, these
cards have now been superceded by the smaller xD picture
card, which new Olympus and Fuji cameras are now designed to
accept. When buying a secondhand digital camera using Smartmedia be
careful. The design meant that the camera controlled the
maximum capacity of the cards that could be used in them,
which is some cases seem very low these days. Often just 32mb
or 64mb. These cards weren't brilliant in use, the main
problem being the connection design, which caused many issues
and lead to them being replaced. As far as we are aware they
are not available new anymore.
Secure Digital:
[SD] - still current
These
were a new smaller card format with additional security originally
designed for use in multi-media devices such as mobile phones,
PDA's and personal players, which camera makers then started
using to enable smaller cameras to be produced, and they are rapidly
replacing Compactflash in a wide range of digital cameras. They
are available in sizes up to 2Gb, their maximum capacity
design limit.
Secure
Digital High Capacity : [SDHC]-
current
These are a new
high capacity version of SD designed to overcome the maximum
design capacity of
2Gb. Only cameras that are SDHC compatible can use these
cards. Recently new high capacity cards up to 8Gb have been
announced, with fast transfer rates that approach that which
some of the faster CF cards can achieve. The fastest SDHC
cards are currently 'Class 6' at up to 20mb/s with new 'Class
10' at up to 22mb/s just arriving in capacities of 4, 8, 16,
and 32Gb. Although many cameras now use SD/SDHC in preference
to CF - particularly in
consumer level cameras, you'll note that write/transfer speeds
aren't as fast.
Multimedia:
[MM]- still current - but
uncommon
These are identical to Secure Digital
in most respects, the difference being they don't have the built-in
security features of the former, and are thus slightly cheaper and
less restrictive in their use. In reality these cards seem to have disappeared
from the marketplace given the rise in popularity and availability
of SD cards.
Memory Stick:
[MS] - still current
Designed by Sony and used exclusively
in cameras made by them, Memory stick slots are often to be found in
Sony's laptop computers. As with Smartmedia, maximum capacity
limitations has led to new variants, Memory Stick Duo and Memory
Stick Pro. As with other types, older cameras cannot accept the
newer cards. Some Sony cameras, and their DSLR's, use CF cards.
xD picture card: [xD] -
still current
The new standard card for
many Fuji and
Olympus cameras, a replacement for Smartmedia. They are the smallest
of all cards currently made. Many Olympus and Fuji cameras use this
format alongside CF.
Comments
The type of memory
card a camera uses can
play vital role in how well, or badly, a camera may perform,
and how easy it is to transfer images for long term storage. All the
different types of cards have their good and bad points, but there
are some that have stood the test of time better than others. As a
general rule the two most common card formats are CF and
SD/SDHC. If you see cheap/bargain price digital cameras for
sale be aware this might be because they use a less common or
obsolete card format for which it is more expensive, difficult, or impossible to
obtain cards.
One
point that should be made is that although it is not terribly common
these days, memory cards can and do corrupt and fail, and it is for this
reason that many digital camera users prefer to use a number of
smaller capacity cards on which to store the images they are taking, rather
than one large one. Some even swap the cards about as they shoot, so
that should a card fail, not all images, nor all those from one
particular scene or event, are lost. To lose some images would be
bad enough, to lose all would be, for a professional, a
disaster. Microdrives are also known to fail, and must be
treated with care and respect. Although the current versions are now
apparently much better than the original versions in this
respect, the high capacity of current flashcards means the
need for them no longer really exists, especially as they
consume greater amounts of power than a normal memory card.
To prevent the chance of a card
corrupting, care should be taken when inserting one, and you should
never try removing one whilst the camera is writing to it. Not only
will the images being written be lost, but it will almost certainly
corrupt the card as well, rendering it unusable. It may well also
damage the camera's electronics. Indeed it is best to make
sure the camera is turned off before inserting and removing
memory cards.
Although all cards of any particular
type are made to set standards, cards from different sources have
sometimes been found not to work with particular camera makes or
models. It is therefore recommended that you take care when buying new memory cards for a camera, and if you can, take the camera along
and make sure that the cards will work in it. If
you can't, perhaps because you are buying by mail
order/on-line, then stick to well known makes. These include
Sandisk, Fuji, Lexar, Delkin, Viking, and Kingston.
Card
Readers - USB, PCMCIA, Expresscard
USB
card readers
Nearly
all cameras come with the software
and cables needed to connect the camera to a computer, usually via
USB2 these days, and to download the images, to view, print and save them.
However, this means using the camera's batteries along with the
supplied software, which you might not like, and many consider a
better, quicker, and more convenient method is to use a separate card
reader and download the images from a memory card directly into a folder of your choice
on the computer using either the copy
or move options. Many
computers of both laptop and desktop design now have integral multi-format
card readers these days. However these don't usually cover all
memory card formats, with the most notable exception being
that of CompactFlash. In this case, or if the computer being used
doesn't have an integral one, then a separate card reader of
some kind is then needed.
Card readers that read just a single
card type have been in use for many years, and if you have, or
expect to use, only one type then they are a good buy. They are
available for most types, although those for the popular cards are
the easiest to obtain as well as being the cheapest.
Illustrated below on the left is an
early USB1.1 Compactflash card reader from SanDisk able to read both
CF1 & CF2 cards. This means it can also read Microdrives. On the right is a
USB1.1 multi-card reader
from Dazzle*. It can read all card types currently on the market,
with the exception of xD, which were introduced after it was made.
If you have a number of different types of card, or think that you
may use a different type in the future, then a multi-card reader is
worth considering, especially as they aren't much dearer than single
type readers and in some cases cheaper.
These
days it often makes sense to buy a newer USB2 card reader
(about £10 today) since
transfer rates will be much higher, depending on the card
rating, and will be backwards compatible with older computers
that still exist and use a USB1.1 interface. For example,
transferring 2Gb of images via USB1.1 is slow, taking about
35-40mins, but via USB2 might be around 5-10mins with a fast
card.
USB
memory card readers
SanDisk
Dazzle*
PCMCIA
slot readers
The
PCMCIA slot arose for use in laptop computers as a means of
providing a measure of expansion capabilities similar to that
enjoyed by desktop computer users via the integral PCI slots
fitted on computer motherboards. At the time the PCMCIA slot
first arose the USB interface didn't exist at all, and
connection via serial and VGA ports was slow. Using the PCMCIA
interface enabled much faster rates.
A
vast number of different accessories have been produced over
the years for use with it, and one area where this proved
useful was in providing memory card readers. PCMCIA
card readers have been made to suit both single card and
multi-card format use. Here is a one dedicated for use with
Type 1 Compactflash cards. It is shown on it's own, with a
Compactflash card fitted, and inserted with the card fitted
into the laptop's PCMCIA slot.
The
PCMCIA slot is now an old standard, superceded by
the Expresscard 54/34mm dual slot standard which replaced it a few years ago.
Most laptops now have Expresscard slots - see further on - but
some laptops are still supplied with PCMCIA slots, Sony's
often are, and PCMCIA accessories are still in plentiful
supply, and often easier to get then Expresscard one's.
If
you have a laptop with a free PCMCIA slot, fitting it with a
dedicated memory card reader is a definite asset. They are quite cheap,
ours cost just £9.99p, and they are still available at this
price today. The main advantage is the transfer rate of around
10mb/s meaning 2Gb of files can be moved in around 5mins.
Expresscard
slot reader
The
Expresscard slot standard was designed as an improved version
of the PCMCIA slot, and has two sizes, 34mm and 54mm. The
narrower slot is intended for laptops where space is at a
premium, and 54mm, the same size as the original PCMCIA slot,
for where there is more to spare. As it's a staggered
dual-slot interface design, 34mm Expresscards can fit into
54mm slots, but obviously 54mm designs can't fit 34mm slots.
Although many Expresscards are made to suit the 34mm standard
we have yet to see any laptop fitted with one. They either
have a 54mm slot, or none at all. This is of course the best
policy since it gives the greatest versatility over which size
to get since either Expresscard size can be used in it.
Here
is a 54mm Expresscard CF reader made to the very latest CF3 standards by
Apiotek. It's also made in a 34mm version. Although it's the same width as a PCMCIA card it's not only a
different shape but actually works differently in respect of
insertion and removal using a sprung action. Push once to
insert and lock in place. Push again to release.
This
particular reader supports CF1 and CF2, PIO mode 0-4, and UDMA mode 0-6. In other
words it can cope with the latest and fastest CF cards made, and is
rated for transfer rates of up to a blistering 2.5Gb/s. All
you need is the cards to go with it. Actually it's still
a huge advantage over any other card transfer method whatever
type of CF card you have. For example using Sandisk Ultra
2 CF cards (60x) we can move 2Gb's of files in
under 5mins. Mind you with a Sandisk Extreme 3 (200x) we can
move 6Gb's of files in roughly the same time.
We feel sure the multi-format Expresscard readers
available in the 34mm size will offer similar speed transfer
advantages for users of card formats other than CF.
