To go for mechanical cameras as a travel photographer
for me was a long decision and testing process.
It took quite some time to evaluate the Nikon F501/F801s and F4
(the AF cameras that were available at that time)
until I decided that the old style mechanical cameras best suite
my needs. Although new high tech cameras like the
F5, F100 or even F90x offer great features, I have come to the
conclusion that most of these features make things more complicated
and more difficult to use. Photographic theory is easy and things
become difficult if you start to try to make things more
abstract like most of the program modes of new high tech camera's do.
There is no "point and shoot" program mode in any new camera,
that ensures that 100% of the images become "good".
You are the only person that can decide what point in the image
should be focussed on and what exposure value should be used as a reference
and what aperture or shutter combination should be used.
This is a creative process that can never be replaced by
a programmed decision process in a camera, no matter how sophisticated it may be.
The price of a camera plays no role in a decision process.
First you can buy used ones, like I did but
the most expensive part of a camera are the lenses,
at least when it comes to the good ones. So the price of a camera
plays a minor role.
One additional note on photo magazines: never ever trust any of the "tests" of a magazine. I've never found that one of this "tests" in this magazines contained any valuable information.
There are great auto focus (AF) lenses on the market,
but most of them do not reach the optical and especially mechanical
quality of the old Nikon AIs manual focus (MF) lenses, although some
of them (like for example the AF-DC Nikkor f2.0/135) come close.
Lenses with a poor mechanical quality are for example
the AF Nikkor f2.8/20mm and the AF Nikkor f1.4/50mm.
Although they are optically OK, they are made of plastic
and the focussing ring is loose and too easy to change.
It can be defocussed by accident.
Some lenses I prefer (like for example the PC Nikkor f3.5/28mm) are only
available in MF versions.
The main advantage of AF systems is the speed and accuracy of the focussing especially when you wear eyeglasses.
There are several reasons why I prefer old style mechanical cameras instead one of those fully electronical cameras for travel photography.
Electronics is more sensible on heat, cold, shock and humidity. If it's extremely hot, the commonly used LCD displays begin to smear, if it's cold they simply freeze. No matter what happens you can't use them anymore. If your FM2 accidently falls in salt water you can try to clean it simply with fresh water and let it dry, but afterwards you'll be able to use it again. You will of course have to send it to Nikon afterwards, but you will still be able to take pictures although no Nikon support is available.
Electronic cameras need batteries. Usually they run out of power in the worst possible moment. Some of them need cells that are not commonly available, especially in more remote areas. if the FM2 runs out of power, you can still select a shutter/aperture combination by simly guessing one and make a picture. If it's cold the batteries have a very limited lifetime.
The more simple a technical system is, the more stable it is. This is not only (but especially) true for photography, but for every technical system. Some of the newer electronic cameras have got lot's of very small buttons. You can't press them with your gloves on. Old style mechanical cameras share a very simple and easy to use user interface. If you're exchanging camera bodys it is quite inconvinient to get used to another user interface everytime you change the body.
There are excellent zoom lenses on the market, but they never reach the optical quality of the Nikon AIs fixed focal lenses, although some of them (like for example the AF Nikkor f2.8/80-200mm) come close. Fixed focal lenses almost do not create distortions in contrast to almost every zoom lens. Their maximum aperture is usually much bigger than of zoom lenses, which makes them ideal for available light photography but also gives you more freedom in controlling the focal depth. They reach the maximum resolution much earlier than zoom lenses. The maximum quality for example of an f1.4 lens will already be reached when it is closed to f4.0, a value that most of the time is maximum value for zoom lenses. A value where most of the zoom lenses create a poor picture quality.
The major disadvantage of the fixed focal lenses is the price and the weight of the equipment. As a backpacker you'll have to restrict yourself to a (small) selection of focal length lenses. If weight is most important, I use the f3.5-5.3/28-200mm although is has a poor picture quality. Most of the time I use one of the following sets depending on how much I'm able and willing to carry:
First of all both cameras are part of the same system, means you can exchange the add on tools like the MD12 motor drive, Nikon DR2 and DG2 and MF16 Databack but also the batteries between them.
Forget the program mode of the FA as soon as possible, it always selects a shutter time that will for sure not be short enough to take a picture with the camera in your hand. You will have to put it on a tripod. But the FA has got a better program mode called "automatic override". What does that mean? Well the camera is able to overide the shutter time you've selected under certain conditions. Let's give an example: you select f5.6 at 1/250s in S-mode (Shutter priority) instead of the minimum (for example f22). Now the camera cannot close the aperture to less than f5.6 when more light becomes available. Instead of this it'll change to shutter time to for example 1/500s or less. That gives you control over the maximum depth of focus in the picture although you're in S-mode. The same is true if less light is available. First it'll use the 1/250s - that you selected - as long as possible opening the aperture resulting in for example f1.4 1/250s (depends on your lens). What happens now if even less light is available? Well the camera will change the shutter time to 1/125s then 1/60s and so on. This "automatic override" is better than every program mode in any of the electronic cameras I know of. This somehow is a mixture of aperture priority and shutter priority. Unfortunately this camera needs batteries to work. It only has one time (1/250s) that can be used without batteries. Luckily the MD15 can replace the internal power supply. The FA can also be used with the MD12.
There's not much to say about this camera. In contrast to the FA it works fully mechanical, means every shutter time can be build without batteries. The internal exposure meter (of course) needs cells, but only tells you to open or close the aperture or increase or decrease the shutter time. The display only uses LED's no LCD's. I used this camera from -30 degree celsius up to +55 degrees, in a sandstorm and pooring rain and it worked with no problem at all in contrast to the FA where the LCD display proved to be the major problem.