Canon Digital SLR Cameras
The Digital Single Lens Reflex (DSLR) camera gives you the ease of use, features, and interchangeable lens of a standard film SLR coupled with all the advantages of digital. This means that with a modern DSLR you will get a bright Through The Lens (TTL) viewfinder, fast operation, the ability to fit good quality lenses, no more film to buy or developing costs, view and delete photos as soon as they are taken, and can quickly download the images to a computer where they can be processed and viewed.
Canon's first affordable DSLR was the popular D30 which was a 3 megapixel camera, which was replaced by the D60 which was a 6 megapixel camera and then the 10D which was also a 6 megapixel camera with a few subtle changes. Canon then brought out their entry level DSLRs with the Canon 300D 6 megapixel camera which was cheaper than the 10D. The Canon 10D was replaced by the 8 megapixel Canon 20D while the 8 megapixel Canon 350D replaced the Canon 300D. The 8 megapixel Canon 30D has now replaced the Canon 20D and recently the 10 megapixel Canon 400D has replaced the Canon 350D. There is also a professional series of Canon DSLRs called the 1D(S) and the 5D DSLR camera. The Canon 40D, 10 megapixel camera has now replaced the 30D. The 12 megapixel Canon 450D replaces the 400D. A new entry level affordable 10 megapixel Canon DSLR called the 1000D is now also available which has a slightly lower spec than the 450D but is a step up from the older 400D.
The main differences between the entry level Canon DSLRs (300D, 350D, 400D, 450D, 1000D) and the more expensive Canon DSLRs (10D, 20D, 30D, 40D) are that the entry level cameras are smaller and the casing is made of plastic rather than magnesium alloy, which helps to keep the costs down.
Batteries
It is a good idea to get a few extra batteries for your DSLR camera and as Canon batteries are expensive it is worthwhile purchasing third party batteries which are considerably cheaper and work just as well as a genuine Canon battery. A Canon battery grip is also very useful and fits under the camera and can take 2 batteries. The grip which screws into the tripod thread of the camera also has buttons for various functions and is particulary useful on the smaller entry level DSLRs to make them larger, heavier and to get a better grip of the camera.
Memory Cards
Memory cards for Canon DSLRs come in the form of Compact Flash cards or more recently SD cards which have dramatically dropped in price over the last few years as well as increased in size. There are many different makes of Compact Flash cards but i would recommend SanDisk Extreme III or IV cards of 1Gb - 8Gb or more. SanDisk Extreme III or IV cards have a very fast read/write speed and usually come with a recovery disk and small pouch for the card. It is usually preferable to use several smaller cards than one very large card in case the card becomes corrupted or damaged however if you are shooting in RAW mode then a large memory card will be neccesary.
Cleaning Equipment
Cleaning equipment is essential in keeping your camera and lenses clean. To clean lenses you should first use an air blower/brush to blow away any dust or grit and then use Eclipse lens cleaning fluid with a Pec-Pad to remove smudges or fingerprints, alternatively you can use a lens pen. Only clean your lenses if they need to be cleaned as repeated cleaning can lead to the lens coating being worn away over time and the risk of tiny scratches. A good anti-static cloth can be used to wipe the camera body.
One of the most annoying problems with Digital SLRs is that over time the camera's sensor will attract dust which will eventually show up on some of your photographs, especially if your photo contains a lot of sky as in airshow photography. Canon has now started to address the problem of dust on the sensor by adding automatic sensor cleaning on the new Canon 400D & 40D cameras which works well. To minimise getting any dust on the sensor it is advisable to take a few precautions of switching the camera off before changing lenses as a charged sensor can attract dust, quickly change lenses with the camera mount face downwards, and never leave the camera without a lens or body cap on. To check for 'Dust Spots' shoot the sky using an Aperture of f/22. View the image using Photoshop Elements or Paint Shop Pro and select 'Equalize' and the 'Dust Spots' should reveal themselves. Be aware that the dust you will see will not usually show up at wider apertures. Only clean the sensor with recommended 'sensor cleaners' & 'Eclipse fluid' and only if they show up in your everyday photography. You can purchase sensor (CCD) cleaning equipment from Warehouse Express who are highly recommended. There are many websites available which explain how to safely clean your camera's sensor. Another option is to take your camera to a reputable camera shop and let them clean the sensor but it is much cheaper and satisfying to learn how to do it for yourself.
Sensor size
Many of the affordable Canon DSLR cameras (300D, 350D, 400D, 450D, 1000D, 10D, 20D, 30D, 40D etc) have a smaller sensor size than a Full-Frame (FF) camera or standard 35mm camera. These cameras have a 1.6x crop factor which means that you will have to be aware of this when you purchase a lens. A 300mm lens will have an effective field-of-view of a 480mm lens (300X1.6=480) or a 15mm lens will have an effective field-of-view of 24mm (15X1.6=24). So for airshow photography a wide-angled lens of about 17mm will be useful for static aircraft and museum aircraft and a telephoto lens of 300mm-400mm will be useful for taking photos of aircraft in the air.
Lenses
For airshow photography it is usually advisable to use zoom lenses so that you only have to carry a few lenses with you and change lenses less frequently.
For a Canon DSLR you have the choice of a range of Canon lenses or various third party lenses from Sigma, Tamron etc which are available with Canon mounts. Canon has a professional range of lenses which they designate as the 'L' series (Luxury) which are usually a distinctive white colour with a red stripe and Sigma's professional series is designated 'EX' (Excellence). These professional series lenses are usually well built, fast aperture, fast auto-focus, very good IQ (Image Quality), and are more expensive then other lenses.
A wide angled zoom lens will be necessary for close static and museum aircraft. The Canon EF-S 18-55mm f/3.5-5.6 kit lens is certainly wide enough or if you are looking for better IQ and image stabilisation then there is the Canon EF-S 17-85mm f/4.0-f5.6 IS. For excellent IQ and build quality then there is the more expensive Canon 17-40mm f/4.0L professional lens. Please note that EF-S lenses will only fit certain DSLR camera such as the 300D, 350D, 400D, 20D, and 30D. Good third party wide angled zoom lenses include the Sigma 15-30mm f/3.5-4.5EX, Sigma 18-50 f/2.8EX, and Tamron 17-35mm f/2.8-4.
A mid-ranged zoom lens will be useful for static aircraft that are further away. The Canon 28-135mm f/3.5-5.6 IS covers a good mid-range focal length, has image stabilisation, and although not an 'L' professional lens is a reasonably good lens.
A telephoto zoom lens will be necessary for aircraft in the air. A good starter telephoto zoom lens is one of the Canon 75-300mm f/4-5.6 lenses which are relatively inexpensive, light, and have just enough reach. If you get a Canon lens with USM (Ultrasonic Motor) or Sigma lens with HSM (High Speed Motor) then these lenses will autofocus much more quickly which is useful for fast moving aircraft. A more expensive Canon telephoto zoom lens which is a common lens at airshows is the Canon 100-400 f/4.5-5.6L IS which has image stabilisation, a long focal length, USM, and professional quality build. Alternative third party lenses are the Sigma 80-400mm f/4-5.6EX OS which is much cheaper than the Canon 100-400L, has image stabilisation, long focal length, and professional build quality however it does not have HSM so is slower to autofocus. The Sigma 50-500mm f/4-f6.3EX is cheaper still and has an excellent focal length range, HSM, professional build quality, but lacks image stabilisation and is relatively heavy although along with the Canon 100-400L is a popular airshow lens. Cheaper still is the Tamron SP AF200-500MM f/5-6.3 which has good focal length and is designed for digital SLR cameras. A much more expensive fast lens is the Sigma 120-300mm f/2.8 which is big and heavy but has excellent image quality, flexiblity of a zoom and f/2.8 aperture which also gives good results with an extender.
With most of the above telephoto zoom lenses including the Canon 100-400IS f/4.5-f/5.6L you will find they will produce a slightly softer image at their maximum focal length and will have better image quality (IQ) if you shoot them at a slightly shorter focal length and stop the lens down to f/8 on an f/5.6 lens which is usually the sweet spot of these lenses and which produces the best IQ. If you are trying to get the best IQ that you can then i suggest a Canon telephoto prime lens such as the Canon 300mm f/4.0L IS or the Canon 400mm f/5.6L lens as these lenses have exceptional IQ even with a wide open aperture and extremely fast autofocus. However if you use one of these lenses then you will need to complement it with a good zoom lens to cover all the focal lengths that you need and you may find that a second DSLR camera body is needed.
Another option, if you can afford it, is the Canon 300mm f/2.8L IS which is an exceptionally sharp and fast lens and still retains good sharpness and speed with an extender for more reach. This lens can be used handheld which is useful for airshow photography. The Canon 500mm f/4L is another very expensive but also extremely sharp and fast lens with plenty of reach but is very big and heavy and would be very difficult to manage handheld for the duration of an airshow. This lens would be more suitable for a tripod or monopod but you will miss a lot of shots due to the limitation of a tripod and also a fixed focal length.
Using you Digital SLR camera
In order to use a Digital SLR you need to understand how Exposure works with the Aperture and Shutter Speed, different Exposure program modes, metering etc. More information on using a Digital SLR can be found here.
Software & Post Processing
With a modern digital SLR you will be required to do some post processing to your photographs in order to straighten, crop, add contrast, colour, resize, and sharpen your photographs for printing or displaying on a monitor or website. Your DSLR camera should come with appropriate software but it is preferable to use either Photoshop (Elements) or Paint Shop Pro. Before post-processing it is essential that you calibrate your monitor either by using various websites, calibration software or better still a hardware calibration device. More information on post-processing can be found here.