Does my buffer look big in this – my camera buffer that is. The world of
digital photography can be a confusing one. It is a jargon-laden medium that
seems made to order for techno-nerds and computer junkies, for people –
mostly men (like me) – who can talk the talk but often can’t walk the walk.
We snappers love to bamboozle friends and family with tales from the world
of megapixels and RAW files, with anecdotes about focal length and burst
rates. However, reading between the lines it’s all just digital noise and
shutter lag.
Still, today’s photographer – amateur and pro alike – needs at least a passing
understanding of the technicalities of digital equipment. For better or
worse we now live in a film free society, well almost at least.
When pictures were still being made on film there were a few proven formats
that photographers worked with: 35mm (the most popular), medium format,
large format and a small handful of others. Each format had its place in the
photographic food chain. Then along came digital, and everything changed.
Although film is still being used, and will continue to be used, digital has
taken over, especially in the consumer market.
So what’s replaced film; how do we get those terrific holiday snaps from the
camera to hanging on the kitchen wall? The one thing common to all digital
cameras is the need for some kind of image storage mechanism, generally
referred to as a memory card.
What is not common though is the format. Having said that, however, there is
one or two that are becoming common, almost industry standard:
The Compact Flash Card (CF) is a memory card that uses Flash Memory to
store data. Since flash memory is very stable and can store a large amount
of information in a small area it is one of the most popular kinds of cards
used by camera manufacturers. But because it is, in relative terms,
physically larger than other formats it is usually only used in Digital
Single Lens Reflex cameras (DSLR’s), cameras that have bigger housings than
their point and shoot cousins.
Secure Digital, or SD cards, are also extremely popular with
manufacturers, especially for small point and shoot cameras. SD cards also
use Flash Memory, making them as stable as CF cards. However, they are about
half the size of CF cards, allowing camera makers to stream line their
products. Not long ago SD cards were limited in how much data they could
store, but with recent improvements SD cards ranging from four gigabytes to
as much as 32 gigabytes of memory are now available. These new cards are
called Secure Digital High Capacity cards (SDHC) and are on the market now.
oth CF and SD cards are made by a number of different manufacturers.
The most popular are Sandisk, Lexar and Fuji. How they are priced is based on
how much data they can store – the number of gigabytes – and how fast the
write speed is.
Write speed is another one of those digital traps. Basically the faster
the write speed of a card the quicker it will store an image once the
shutter button is pressed, thus allowing the photographer to keep shooting.
But there is a caveat. Write speeds are designated in a numerical way: 16x,
40x, 80x, 133x and now 300x. Sure, the average High Street camera store
salesman will probably steer you towards the faster cards, but the simple
truth is that unless you are using a relatively high-end DSLR all the write
speed in the world will not make your pictures store faster. The speed of
storage is dependent on the camera’s buffer, a holding tank for pictures
that have been shot. It is the buffer that allows the camera to write the
pictures to the card and still let the photographer shoot. But not all
buffers are created equal. Some have a greater capacity to hold pictures –
DSLR’s – while others are limited. So there is no reason to spend a lot of
money on a 300x memory card when your camera can’t handle it.
To illustrate, the average point and shoot camera will be able to shoot one to
three pictures before the camera needs to stop and store the images. A top
end professional camera can shoot up to 110 images before it needs to store
the pictures to the card.
CF and SD are not the only formats on the market. Some camera manufacturers
have their own dedicated memory cards. Sony developed the Memory Stick in
1998. Since then it has gone through a number of improvements and is now
used in all Sony cameras, as well as mobile phones.
There is a whole raft of memory card formats – mini-SD cards, xD-Picture
cards, multi-media cards, etc – but they all perform the same task: storing
data, in this case pictures. The only real thing to take note of is that
different camera manufacturers use different card formats. So when
purchasing a new camera make sure you know what kind of card it uses. And at
the same time be sure you understand how fast the camera can write pictures
to the card. There is no need to by a 300x card if the camera can’t handle
it.
Like any new technology, digital photography is constantly changing. It is
also becoming more popular month in month out. The combination of these two
factors has significantly reduced the price of memory cards.
Not long ago a one-gigabyte card would have cost close to £200. That same card
today can be had for as low as ten quid.
So the key things to remember about memory cards are: they are compact storage
devices that are, simply put, the digital equivalent to film; the more
gigabytes the more room for pictures; cost is usually determined by size of
memory plus write speed; a fast write speed may not be a necessity (depends
on camera model); there are lots of formats but probably only one that fits
your camera.
Memory cards are sold everywhere now, but the best prices are still on-line: www.memorybits.co.uk;
www.digitaldepot.co.uk; www.memoryforless.co.uk;
www.play.com
sony lost its way a long time ago, its insistence on proprietary memory cards discourages a lot of consumers from buying their cameras. It is also worth noting that a lot of computers and TVs can read CF and SD cards so that is another reason for going with them.
Ian, Frederick, USA MD
A point to note is that usually a smaller buffer will also mean slower write speeds due to the camera probably costing less and having less technical features.
JN, Warks,
A point to note is that usually a smaller buffer will also mean slower write speeds due to the camera probably costing less and having less technical features.
JN, Warks,
I'm not sure if I understand your write speed and buffer size comment. All else being equal, I would have thought a camera with a smaller buffer would benefit more from a higher write speed card, as the buffer is more likely to be filled and therefore needs to be emptied as fast as possible? If the camera itself can't exploit the 300x write speed, fine, but how is that directly related to buffer size?
CpC, London,