Digital camera technology has "matured" enough for anyone who has any interest in photography to "go digital" -- this holds true for both SLR and Video Cameras. The initial investmnet cost for top end professional Digital SLR's (e.g. Canon EOS-1DS Mark II) and "prosumer" DSLR's (e.g. Canon EOS 20D or Nikon D70) remains high -- however, the new consummer level digital SLR camears are very competively pricesd (e.g. Canon EOS 350D (Digital Rebel) or Nikon D50) and offer exceptional value for money when one considers the long-term costs of film processing.
1. Image quality
In the not so distant past, I felt that the quality of a digital camera image for producing large (i.e., magazine page size) prints was still not quite as good as what was possible using high quality, fine grain film (like Fuji Velvia). However, since using the new Nikon, I now believe that digital images have finally caught up with film in terms of overall quality. This is not to say that ALL digital cameras will give the same results, but the high-end and even "prosumer" DSLR's (like the Canon EOS 20D or Nikon D70) have, I feel, now equaled the results of fine-grain film.
The CCD (or CMOS) technology used in DSLR's is, in my opinion, just as good in capturing tonality and details across the full range of light, as a high-end film SLR. DSLR's are perhaps even better at capturing details in the highlights. Some will argue otherwise, but almost all will agree that the technology is advancing and still has lots of room for improvement, while film has matured and will likely not go any further. One potential downside of the digital sensors though, is that they are far more "demanding" on your lenses and your technique. By this I mean that they are "less forgiving" than film in terms of picking up color or luminosity noise. Film has several layers of emulsion to absorb the light and so noise is more likely to be less noticeable on film. Result: Quality lenses are even more important when using a good DSLR.
2. Immediate Results
You can edit your shots and see the results immediately using the camera's built in viewer or on a laptop if you've brought one along for image editing.
3. Film and Developing Costs
I typically spent $1,000 or more for film and processing on one of my African safaris. This is based on about 4,000 - 5,000 images using slide film. This is not cheap, I'm sure you'll agree. Digital media is somewhere around $150 to $200 for a 2-gigabyte CompactFlash card. Even assuming you have two or three of these and a digital wallet to download the drives to when they get full, you save money almost immediately. No more film, no more running out of film, no more left over film, etc.
4. Transportation of film
Let's face it, carrying 100+ rolls of film in your carry-on baggage is not fun. Getting any amount of film through airport security and x-rays with a hand check is now virtually impossible. Even if you buy the film overseas and have it developed before coming home (which is what I did for my last few trips), you still have to lug it around in your luggage from camp to camp.
5. Post processing overhead
Scanning of my slides (to convert them to digital), labeling all the slides and filing them ...we're talking LOTS of hours. I'm happy to do away with all of this. The digital storage includes all details or metadata for the image (date, time, aperture, shutter speed, etc.); no more labeling, just download to your PC. Of course there's still a considerable digital work flow which will occur for digital images, but it is still less work than working with slides.
6. Existing Equipment
Most of the lenses I own and have used with my film cameras are compatible with the new Nikon digital bodies. Only my wide-angle lenses must be replaced due to the "field of view crop" factor (see item 6 below).
7. Image magnification
This one's perhaps a bit more complicated...
Most of the digital SLR's today use an imaging chip (CCD or CMOS) that's about 40 percent smaller than a 35mm film frame (which measures 24x36mm). The results of these smaller sensors being used in the digital SLR are a "field of view crop" or lens magnification factor of approximately 1.3 to 1.6 (depending upon the camera) times the focal length of your lens. I will not attempt to explain the physics of the reasons behind why this is true, but suffice it to say that the smaller sensors use only the center 2/3 portion of the image created by the lens.
Therefore, if you use lenses designed for 35mm cameras, the effective focal length of the lens increases by about 50% when used on a digital SLR. So, if you use an 80-200mm lens on a digital body, the lens will have a field of view of 120-300mm and a 300mm lens becomes a 450mm lens and so on. The effective aperture (maximum f/stop) remains the same. All of this extra magnification can be either good or bad (if you want wide angle shots, the additional focal length is undesirable), depending on your needs.
Most African safari photographers will usually benefit from additional focal length since good quality telephoto lenses are both expensive and heavy to lug around on African safaris and we all wish we had a bit more magnification to get closer to our wild subjects.
A few final comments:
One less obvious benefit of all this is that since a digital sensor is capturing only the middle portion of the image, the image quality will (should) be better (all other things remaining equal) since camera lenses typically have better optical performance (sharpness and contrast) at their centers than at their outer edges.
For those photographers who would still like to be able to get those beautiful wide angle landscape or people shots (this includes me!), the additional focal length is not always good news. A 20mm ultra-wide lens becomes a not-so-wide 30mm lens. You'd need a 13mm lens to get that same ultra-wide coverage on a digital SLR, but no one makes such a lens. A few companies make 14mm lenses, but they are very expensive. Camera and lens manufacturers have responded by introducing new lenses that are made specifically for use on digital SLR's and do not result in any lens magnification.
Finally, there are now at least two digital SLR cameras (Canon EOS-1DS Mark II and Kodak DCS-14n) which offer a "full frame" digital sensor. These cameras have 24x36mm image sensors (the same size as a frame of 35mm film) without any field of view crop (focal length multiplier). Simply put, a 16-35 mm lens on these two digital SLR's will provide the exact same field of view as it would on a "traditional" SLR with film. Note that these are top-of-the-line cameras - not cheap!
The ultimate lens for wildlife photography is probably a 600mm F4. At 600mm you get an impressive 12x magnification. However, this is a huge piece of equipment weighing 6 kilos or more and unfortunately carries an equally hefty price tag - at local prices equivalent to a perfectly acceptable new car! Apart from the very wealthy or a person intending to make a living from photography, I think few could justify this kind of expenditure.
I have certainly never been in the very wealthy category (and as a wildlife photographer equally certainly never will be!) and had to wait almost ten years before I could save enough to part pay for a 600mm F4. I borrowed the rest and repayments kept me poor for the following three years.
Fortunately there have been some remarkable advances in optical technology in recent years. This means it is now possible to get quality super telephoto magnification at a fraction of the cost of a hefty 600mm F4.
Today most of the main camera manufacturers are producing teleconverters matched to their tele lenses of such superb quality that it is difficult to tell if a teleconverter has been used. If you start with a 300mm F2.8 lens and add a 2x converter, the combination effectively becomes a 600mm F5.6 lens. At F5.6 it still has enough light gathering power to shoot action.
The cost should be less than one eighth of the 600mm F4 lens. It is possible to put a 2x converter on a 300mm F4 but the two stop light loss from the converter makes the combination a 600mm F8 which is a bit slow for anything other than static portraits. If you buy new or at least latest technology equipment made by a prime camera manufacturer, this ouftit will also give outstanding results.
Autofocus is a topic I would like to discuss at length in a later feature. However, with so many keen photographers changing to autofocus, it means that there are a lot of perfectly good manual focus lenses on the second hand market. These could be a worthwhile option for those on a tight budget but always insist on testing a second hand lens thoroughly before purchase. It might look OK but a bad knock may have upset the alignment of internal optics. Remember also that very old equipment will have old technology and so may not work well with a teleconverter which is our "cheap" way of getting super-magnification.
For supermagnification at a real budget price, you should look at a second hand Novaflex. Once the mainstay of many wildlife photographers, the Novaflex, which incidentally is a long focus lens rather than a true telephoto, has been somewhat overtaken by the new generation optics. There are many perfectly servicable second hand Novaflexes on the market and in the right hands can still produce very acceptable results. In fact, I know of quite a few photographs published in this magazine that were taken on a Noveflex.
The last word on lenses is that if you are at all serious about bird photography or think you may become so in the future, always buy the best you can afford. Otherwise you are pretty sure to want to upgrade in the future. I have done a lot of buying and selling of lenses in the past and, goodness knows, it can become an expensive business!