Hernan Rodriguez is our next special guest writer this month brought to us from the incredible lineup of presenters at the upcoming conference, WPPI. Hernan discusses the fundamentals of color theory,...
There are countless digital compact cameras out there, many of which look much
the same and offer much the same functionality. So which one is right for you?
That depends on what you plan to use it for and, of course, your budget. There
are the most visible criteria, like the number of "megapixels", zoom range and
what type of memory cards they use. Apart from these factors you need to think
about, there are also more subtle distinguishing features that can greatly affect
your choice. In this article I will cover as many as I can think of.
Before you rush out to the
stores and spend a lot of money on it, you must decide what you want to get out
of a digital camera. Buying a digital and expecting your photos to come out like
they do in the magazine advertisements is like taking a roll of film to your
minilab and believing your pictures will be as good as the ones on display, taken
by professionals on professional equipment and certainly not developed at the 2
minute photo service in your local drugstore.
Digital has come of age and can certainly compete with 35mm film, especially
in the compact camera market. But without knowledge of how to use a camera, and
Photoshop, you will not achieve better or more consistent results. One major plus
is the LCD screen on the back of the camera, letting you see you have taken a
horrible picture and giving you an opportunity to try again, all without the
costs of extra film and developing. But to get that extra quality, you will need
to know and understand about resolution, white balance, levels/curves, cropping,
unsharp mask and many other things. They are not that hard to get to grips with
enough to make your digital photos look much better, but you will need to invest
some time in learning them. I plan to explain all these things in future
articles, but for now, there are many books out there to help you out.
All that said, if you are happy with the quality of your 35mm compact and
developing and printing at the local minilab but want a digital because you won't
have to worry about the expense of film anymore, share your pictures with others
across the globe and only print those you really want prints of, there is also no
need to shy away from buying a digital camera.
Cameras know as Single Lens Reflex (SLR), with interchangeable lenses
and used by professionals and discerning consumers alike, have been available in
digital variants for a couple of years now and with their prices coming down
fast, many consumers are tempted by them. It is not in the scope of this article
to explain all their details but you should know what you are getting into before
splashing out $3000 on a camera, memory cards and lenses. Many people have been
disappointed by the (in April 2003) new
Canon EOS 10D, the first digital SLR to
come close to a (rich) consumer's price range, simply because it is too complex.
It is designed as a professional tool and more than likely, if you use it as a
point and shoot automatic, your results will be less than those of a camera
designed for that purpose. In general, unless you have been using an SLR for
years as advanced amateur or professional, if you need to read this article to
learn about digital photography, you are not ready for a digital SLR. You have
There is a lot of things you can say about digital cameras, but nobody can say
that they are not a lot of fun. Just being able to snap away without worrying
about costs of film and see instant results is the greatest thing since the
invention of photography. But please do all your friends and family a favour:
just because you shoot more pictures, doesn't mean they want to see all of them
so pick out the best and only show those!
On most website as well as a
shop's shelves, cameras are lined up by their "megapixel" count. Megapixel
simply means "million picture elements", or dots that make up the image. While
35mm cameras have an aspect ratio of 3:2 (hence the 6x4" or 10x15cm prints)
digital cameras generally follow computer screen aspect ratio 4:3. The number of
pixels is simply the number of horizontal pixels multiplied by the vertical
pixels, 1600*1200=1,920,000 pixels, which any marketing department will happily
round off to 2 megapixels.
How many do you need, then? That depends on your use. If you only ever plan to
put your pictures on a web page, the image from a 1.3 megapixels is about 5 times
bigger than you need, if you want a decent quality 11x8" or 28x20cm print, a 4
megapixel camera is your friend. Below is a table showing the megapixels you need
for which print size and which screen resolution this gives. Print sizes are
given in 300 and 150PPI, or Pixels per Inch. 300 is generally regarded as the
optimal resolution, but bigger prints tend to be viewed from further away and you
can therefore usually get away with a lower PPI count.
Megapixels vs. Resolution and Print Sizes
4.3x3.2" (10.8x8.1 cm)
8.7x6.4" (21.6x16.2 cm)
5.3x4" (13.6x10.2 cm)
10.6x8" (27.2x20.4 cm)
6.8x5.1" (17.3x13 cm)
13.6x10.2" (34.6x26 cm)
7.6x5.7" (19.2x 14.4 cm)
15.2x11.4" (38.4x28.8 cm)
8.6x6.5" (22x16.5 cm)
17.2x13" (44x33 cm)
* Please note that resolutions given are ballpark figures,
there are slight fluctuations between brands and models.
But this isn't all there is to it, manufacturers do not put their best quality
CCD or CMOS censors (the light sensitive component behind the lens that records
the image) and best lenses in their lower resolution cameras, so it is quite
possible, even when your picture is scaled down to only 600x450 for web page use,
you can tell the difference between a 4 and 1.3 megapixel camera. In most cases,
however, if you buy a 2 MP camera and make 6x4 prints from it, you will generally
have a quality similar to, if not surpassing, a 35mm point and shoot. And you can
email these images or post them to a website.
first question you have to ask yourself is: to zoom or not to zoom? Like their
35mm compact counterparts, zoom lenses for digital cameras can be of questionable
quality and often a fixed lens is the higher quality option. Fixed lenses are
really only offered on the lower resolution models and those are usually cheaper
and much higher quality than their zoom versions and you should really consider
this if you are looking at a 1.3 or 2MP camera for your family snapshots.
Because digital cameras have a much smaller image area than a big 35mm
negative, they only need a very short focal length lens to achieve the same
magnification. Quite often you will see lenses in the single digits on the wide
end, but usually, the 35mm equivalent focal length is given, so a 35-70mm zoom
lens will act the same as it did on your 35mm point and shoot.
There are two big drawbacks these short focal lengths have: the fact that it
is hard to make a really wide lens, a 37mm focal length equivalent to 35mm film
is often the widest you will find except on the more expensive "prosumer" models.
(Those that look like an SLR, but without interchangable lenses) The second one
is a massive depth of field. Although the 35mm equivalent is the same, you
actually have a 7mm lens, so even at f2.8, this will mean almost everything in
the frame is in focus, which usually does not make for the most appealing images.
If you want true wide angle, 28mm, you will need to go for a camera at the higher
end of the scale, although for some mid-range cameras you can get a wide angle
adapter which is mounted in front of the lens.
I mentioned "f2.8", if you are new to photography or never used an SLR, this
may be gibberish to you. What it means is how much light a lens lets through, the
one specified means the maximum for your lens with its iris or diaphragm
completely open, the less light a lens lets through, the higher the number. This
is called a lens' aperture, Latin for "opening". 2.8 is about the lowest you will
find and this number usually increases with the focal length of a zoom, so a
35-100 zoom may be f2.8 at 35mm, but slower at the long end. Maybe not entirely
surprising is that because the actual focal length of these lenses for digital
cameras is so short, compared to 35mm compacts, they are surprisingly fast at the
long end. Typically, you should see about f3 on the wide end and f4-5 at the long
end. Although such a thing exists as fixed aperture zooms, you won't find them on
digital compacts and when someone specifies 35-100/f2.8, you can be sure they are
letting you in the dark about the probably shameful aperture at 100mm. Sometimes
you will find 4 values in the specification, like f3.1-8 and f4.6-11.3. This
means that on the wide end the maximum aperture is f3.1 and the minimum is f8,
the same for the second range, which applies to the long end. In this case the f8
means how far the camera can close the lens to get a proper exposure and is
really not all that important. With the exception of a few, lower numbers usually
mean a better lens; not only does it let through more light, resulting in less
use of the flash and less noise in the image, they usually are also sharper,
offer better contrast and are less likely to cause flare.
Before taking the
actual picture, a camera needs to focus, work out exposure and do many other
things to be ready to record the image. The time it takes from pressing the
shutter release to taking the picture is called shutter lag. It is a
problem in many compact cameras and even more so in digitals. This delay is
different in all cameras and you should check it in store before you buy as long
shutter lag will make you miss the "decisive moment", an object may already have
moved out of frame by the time the picture is taken. The way to minimize this
with any camera is pre-focussing. When you press the shutter release half way,
the camera will focus, set exposure and if needed charge the flash, indicating in
the display or viewfinder when it is ready. Keep the shutter depressed half way
until the best moment and then press it fully; your camera should now take the
picture almost instantly, if it doesn't, move on to the next model.
The short advice is: deal with whatever is on your camera. If you buy a better
camera, you may want one that has a connection for an external flash, which will
be vastly superior to whatever you find built into any camera.
There is an ever increasing number of memory card formats available and in all
honesty, for general use they don't differ that much. You may want to keep in
mind that more than one person in your household has a camera or memory card
equipped MP3 player and settle on one format, but other than that you should be
more interested in how much the cards are to buy, and even there the price
difference is decreasing fast.
SmartMedia: Ironically, the technically dumbest card is called "smart".
Maybe the smart refers to its price tag; it used to be the cheapest and you will
find this format on the cheapest cameras. But because of the popularity of other
formats, the price advantage seems to be gone, in some places CompactFlash cards
are now priced lower than SM. That is not to say it is bad, for the small images
created by 1.3 and 2MP cameras, its transfer speed is adequate and there is no
reason to shy away from them.
CompactFlash: One of, if not the,
oldest standards around, they come in type I and type II versions. The type II
cards are thicker and all microdrives are type II. Not all cameras can take both
type I and Type II drives so if you intend to use a microdrive make sure your
camera is compatible. CF cards the defacto standard in professional cameras
because they are fast. You need this speed to transfer from the camera's internal
memory to the card. You can buy them in different speeds (2x, 4x, 10x, 25x and
such) and their price increases with their speed. For snapshooting, the cheap
standard speeds will be fast enough, only professionals letting their cameras rip
at 4 frames per second in the highest quality at the Oscars' red carpet will need
a 25x speed one. Note that card speeds do not directly relate to their
performance in a camera. The time required to take and store an image depends as
much (probably more) on the camera than on the speed of the CF card. On high end
DSLRs the fastest cards may allow images to be written 50% faster than on a
slower card, but in a typical comsumer digicam you may not really see any
difference. Last year Lexar introduced a WA (Write Acceleration) feature on their
high end professional CF cards, which allows up to 20% faster operation when used
with certain WA enabled camera bodies. The WA process requires that both the
camera and the card have WA enabled firmware, so using a WA card in a non-WA body
will not result in improved performance.
MicroDrive: This is an actual harddrive with moving parts the size of a
CompactFlash card! While from time to time questions have been raised about their
power consumption, heat generation and reliability, the bottom line seems to be
that though these issues may exist, in real life use they don't seem to
cause many problems. At one time microdrives were much less expensive than
equaivalent sized solid state memory but with the price of solid state memory
coming down, their price-per-megabyte advantage is getting quickly wiped out,
even the at the biggest size currently available (1Gb), they are only 10-20%
cheaper than CompactFlash. You should also be aware that there are compatibility
issues; even though they should work in any CF type II compatible camera, in
reality, they don't, so check with your camera's manufacturer if they are
Memorystick:This is Sony's proprietary format. It is reliable, fast and
not that much more expensive than competing standards. The only problem is that
you will need new memory cards if you decide to sell your Sony camera and go with
another brand; while third party manufacturers now make Memorysticks, no others
make cameras that take them.
MultiMedia and SecureDigital: These cards are closely related. They are
the smallest cards and both use the same case, but the SD card has more
connection pins. The SecureDigital card differs from the MMC in that it offers
(or tries to, anyway) digital rights management inside the card. This is a good
reason to never buy any devices that use them, especially MP3 players. You can
use a MultiMedia card in a device that is equipped with a SecureDigital card
slot. However, you can not do the opposite; SD cards will not work in an MMC only
xD Picture Cards:Developed by Fuji and Olympus, xD stands for "eXtreme
Digital", how original. Like MMC/SD, these cards are tiny but will support up to
8Gb of memory, though currently 256Mb is the maximum available size. Olympus says
adapters will be available to use xD cards in CompactFlash equipment but I fail
to see the point of that as CF cards are currently much cheaper than xD.
To answer the question of what size memory card you need, I have created the
table below. These are estimates because it depends on many factors, most notably
the difference in JPEG compression in different models and the content of the
scene. (ie: a nice landscape is easier to compress and results in smaller files
than a shot taken with flash at night.)
Number of Images per Memory Card and
camera offers a JPEG option and in general I recommend using the highest JPEG
quality setting at the cameras highest resolution. This will result in reasonable
file sizes and quality. Most more expensive cameras also offer TIFF or RAW files.
TIFF is an industry standard non-compressed (or light lossless compression using
the LZH protocol) file format. It produces giant files, though. RAW is
implemented differently by different manufacturers and really is the raw data
from the CCD, which also tends to be quite big but nowhere near the size of TIFF.
You will need the camera's software/drivers to create a TIFF or JPEG image from
it. The upside is that the image is not processed inside the camera at all,
allowing you to set white balance and other things at a later time.
Some cameras work with AA size batteries, others come with a rechargeable
Lithium-Ion battery and adapter to charge it. Both systems have their merrits.
You can buy pretty powerful rechargeable AA batteries (2000mA), but still a
Lithium-Ion battery specificaly designed for your camera is likely to give better
performance. If you choose a camera that uses a special battery with it's own
charger, getting a second one is probably the smart thing to do; you will one day
forget to charge, stay away from a wall socket too long or take more pictures
than anticipated. For other cameras you can get very powerful, but expensive,
lithium disposable batteries, if you go away for longer, carrying one of those as
backup could be a good idea. Personaly, except for the most casual of shooter, I
recommend a camera that comes with rechargable lithium-ions, but be sure to buy a
spare (or two) if you do heavy shooting.
After you have taken the shots, you will probably want to transfer them to
your computer for editing, emailing, printing and archiving. Most, if not all,
cameras connect to your PC or Mac via USB. (Universal Serial Bus) The way they do
this comes in two flavor, however. Some only connect with special drivers, which
you have to install and probably contain bugs, need to be kept up to date with
newer versions of your operating system in a few years time and are therefore a
general pain in the butt. The better way is if your camera acts as a "USB Mass
Storage Device"; all you need to do is plug in the cable and it appears in
Windows 98se/Me/2000/XP and MacOs as a removable drive from which you can simply
copy the image files. I have never even opened the driver CD that came with my
Olympus C-2, just plug it in and go. An added bonus is that these devices let you
copy any file onto your memory card, so if that Power Point presentation you need
to take to the office is too big for a floppy, just bang it onto your camera for
Another option is to buy
a USB memory card reader. These come in simple ones that only read one type of
card or ones with a number of different slots supporting more, if not all,
popular formats. These also act as a USB Mass Storage Device, freeing you from
any proprietary drivers and some people like them because during transfer you
don't drain the camera's batteries.
USB 1.1 vs. USB 2.0 vs. Firewire
Although at the time of writing none but professional models have anything
other than USB 1.1, in the future this may be different and you should probably
know what these different standards are.
USB 1.1 transfers files at a maximum of 11Mbit per second. This
theoreticaly means a little over 1Mb per second, ie: a 128Mb card would take just
over 2 minutes to transfer to your computer. Unfortunately, this heavily depends
on the camera and how fast you memeory card chooses to release it's data so
actual transfers are usualy half to 75% of that speed. Still, more than fast
enough to not be anoying. Most current (april 2003) and somewhat older PCs will
have USB 1.1 ports.
USB 2.0 uses the same cables and connectors as 1.1 but transfers at a
much higher speed of 480Mbit, theoreticaly zapping a 128Mb memory card to your PC
in less than 3 seconds. That probably will never happen in reality, but, unless
you are using slow memory cards, transfer times should be measured in seconds,
not minutes. USB 2.0 is found on most new PCs, although not all. If you don't
have it, you can buy PCI cards that give you some ports.
Firewire, also know as "IEEE 1394", is an older standard than either
USB variants, but certainly not a lesser one. Transfering at speeds up to 400Mbit
it is fast and used for many applications other than just cameras. This is also
the standard used to transfer digital video into a PC for editing in packages
like Adobe Premiere and it is very popular with high-end digital cameras and
scanners, in the latter case it took over more and more of SCSI's reign ever
since Apple, a graphics industry favourite, started putting firewire ports on
Macs as standard a long, long time ago. It is not easy to find a PC that offers
it as standard, but again, you can buy PCI cards to give your PC this
After shooting your images, you will need to get them to your PC, edit,
archive and then print or email them, or put them on the web. You'll need
software to do these things, some of which may already be included with your
camera. Although it is beyond the scope of this article to give you the fine
details on how to best use this software, here are some pointers:
Elements is Photoshop's little brother. Same quality, but less features.
Still, it probably has more of them than you will ever need.
Paint Shop Pro has a
great following, which must be for a reason. And it's affordable too, so this is
probably the reason Adobe decided to enter the low cost market with "Elements" to
Archiving and Sharing:
To create a photo album on the web or CD-Rom for your friends to enjoy, you
will need a "thumbnails" package. Both Photoshop Elements and Paint Shop Pro have
basic functionality, but to make the most of it, a specialized package may be
required and there are also packages available for you to keep track of all the
images you have taken. Tucows's
multimedia section has more of both categories of programs listed than
you can imagine, so I suggest you start there.
cameras offer special effects and other tricks, most notably movies, sometimes
even with sound. I guess movies are an added little extra, but don't expect too
much of it. As for special effects, those are nothing you couldn't do in
Photoshop afterwards at a better quality and with more control.
A nicer touch is the ability to manually control exposure settings. (aperture
and shutter speed, some higher end all in one models even feature a manual focus
option) While this is fiddly at best compared to a proper SLR, for more advanced
shooters it is a nice thing to have.
On the zoom side, most cameras only offer the usual "zoom in" and "zoom out"
buttons for motorized zoom, which is usually to fast too get your composition
exactly right quickly. Again, on the higher end of the spectrum you will find the
all-in-one kind-of-SLR type cameras that offer a zoom ring on the lens for
Very important is how easy it is to use all these functions and if the camera
can remember all of them or goes back to factory default every time you turn it
off or change the battery. When you go into a shop, play with it and see if it
feels good to you. So go at a quiet time if you can and if the sales people don't
seem very interested in spending time on you, they do not deserve several hundred
of your hard earned dollars!
Digital photography is actualy not that much different from using using film
so any photography source designed to help you take better pictures will be just
as valid for either technology. And there is enough of that information right
here on photo.net. There is one place that is perfect for helping you choose a
Digital Photography Review is
constantly updated with information on new and older models, it has
specifications, reviews and user comments and ratings.