Rangefinder vs SLR, winter thoughts
Rangefinder vs. SLR is usually not the first criterion on my mind.
Here are some of the things I consider first:
1. Manual/mechanical vs. automatic/electronic - I prefer battery independent cameras.
Here are the cameras I would seriously consider using because they may need batteries for the exposure meter but they to not need batteries to take pictures:
Fuji 6x9cm medium format rangefinder
Fuji 6x7cm medium format rangefinder
Leica M6 35mm rangefinder
Nikon F2 35mm SLR with non-metered finder
Pentax Spotmatic 35mm SLR
Mamiya RB67 medium format SLR
Nikonos 35mm waterproof underwater camera
Calumet 4x5 inch large format view camera
The first three are rangefinders, the second three are SLRs, and the last two are neither.
2. Image quality - I prefer the image quality of large format and medium format cameras more than small format. Therefore, I would select a medium format SLR or rangefinder before I would select a 35mm SLR or rangefinder.
3. Lens focal length - if I need a long telephoto lens to shoot birds or winter sports, I am limited to my 35mm SLR cameras because I do not have long lenses for my rangefinders or my larger format cameras.
4. Lens angle-of-view - if I need to shoot winter landscapes, I prefer to use a lens with a 75 degree diagonal angle-of-view. I do not have lenses with this angle-of-view for all my cameras. For example, I have a 28mm for my Nikon F2 and Pentax Spotmatic but I do not have one for my Leica M6.
5. Aspect ratio - when shooting winter landscapes, I prefer the 2:3 aspect ratio used by 35mm cameras and 6x9cm cameras. My Fuji 6x9cm medium format rangefinder is my personal favorite.
6. Weather resistance - I like cameras that resist snow, rain, sleet, spray, condensation, etc. My Nikonos is my most weather resistant camera.
7. Filter availability - I may need a certain filter that will only fit a certain lens for a certain camera. For example, if I need to shoot infrared, I am limited to using a lens that will accept the only one I own, a 720nm infrared filter with a 52mm filter thread. Since most of my Nikon lenses accept 52mm filters, that is the camera I would select for winter infrared shots.
8. Filter usage - it is easier to focus a rangefinder with dark filter vs. an SLR with a dark filter. Therefore, if I needed to shoot a winter scene with a 10-stop neutral density filter, I would select a rangefinder.
9. Size, weight, and ergonomics - my 4x5 inch view camera is too big, too heavy, and too slow for me to use in cold weather.