Things to Know Before Buying a Film Camera – SLR vs Rangefinder

PROS

Compact
Rangefinder camera generally compacts in size because of the lack of a mirror, therefore the focal plane sits much closer to the lens and allows the lens design to be smaller in size.

Quiet shutter
Since the camera generally using cloth shutter, it allows the shutter to be more silent. Also, with less vibration, you can use a much slower shutter speed handheld at 1/15th second or even 1/8 of a second.

Viewfinder
Rangefinder cameras always have a bigger and brighter viewfinder. Inside you got the frame line as an indication on what will be captured, which allows you to observe, adjust and decide when and where to pull the trigger. 

Filter
As you are viewing through the optical viewfinder, using a filter especially an ND filter will be much easier than SLR cameras does not have a direct impact on the viewfinder. Also, no viewfinder blackout whenever a shot is fired.

CONS

Shutter speed
Generally, rangefinder cameras have a slower shutter speed at around 1/500 or 1/1000 of a second which is much slower than SLR cameras that you can not use the camera at a wider aperture.

Wide angle lenses
Usually, the magnification of a camera is set at around 0.72x, which only contains the maximum 28mm frame line. If you like to use wide-angle lenses you may need to add an external viewfinder on the hot shoe to preview the frame line. But focusing still needs to be done inside the original viewfinder on your camera body.

Frameline is only approximate
It is not exactly the edge of the picture. When you get closer to the subject say at 0.7 meter or 1 meter, the actual picture is different because the position of the lens and the viewfinder is separate.

Minimum focus distance is limited
Because of the rangefinder parallax usually, 1 meter is the limitation of the camera. Some modern lenses are designed to use 0.7 meter which is still much far away from what SLRs can do.

Focusing Alignment
There are often focusing misalignment due to the age of lenses or camera bodies. It requires professional technicians to calibrate the focus shift on rangefinder lenses.

Lens cap
It is undetectable whether you have your lens cap on or off when you are focusing on the optical viewfinder. The only thing you will notice is the meter reading is messed up. You might end up shooting a roll of nice images in black.