Wide Angle Voigtlander "D" framelines questions

[Sailor Ted]

I just got my 12 D and 21 D viewfinders for my RD-1s and have some questions.

1. I notice the brightlines are only visible when my eye is slightly away from the viewer- is this normal?
2. I see color fringing on the edges of the brightlines- blue and yellow with blue on one side of the lines and yellow on the other. Again is this normal?
3. Lastly on the 12 D is it conservative with it's framing of the image or is it showing the full frame at a distance. If it is conservative could it be used to frame my 21mm lens on my R3M with reasonable accuracy (will a conservative 18mm field of view actually be closer to an actual 21mm field of view on my film camera)?

Thanks in advance

 

[jlw]

The only D finder I own is the 21mm one, but I think everything you're seeing is normal.

1. The finder framelines are reflected, rather than projected via a frosted window as in the camera's built-in viewfinder. The lines themselves are etched onto the finder's rear lens, and are reflected by a mirrored area at the outer edges of the front lens. If your eye is too close to the finder, the reflections may miss your eye.

2. This is normal and I think it's inevitable, given that the finder has to cover a very wide area in a very compact space with a simple optical system. The rear lens of the finder not only has to bring the front lens' field of view into correct focus, it also has to focus the reflections of the framelines (which, as you can imagine, are at a considerably different apparent distance) so some compromises are required in the optical design.

3) I don't have the 12 D finder, but I'm sure its coverage is fairly conservative. I know the 21 D finder is quite conservative (shows less within the framelines than you get in the final image.) This is a necessary safety feature. If you haven't done so already, you'll discover by a bit of experimentation that the finder's framing area varies considerably depending on your eye distance, the angle you look through it, etc. They had to design it to take these variations into account.

A projected-frameline viewfinder (like the one in the camera) could be designed to avoid or reduce most of the compromises -- its more complex optical system gives the designer a wider range of choices for optimizing the view. However, such a finder would be quite a bit larger and probably more expensive. For example, the new Leica Universal Wide-Angle finder for M cameras covers three focal lengths and uses a projected frameline system, but get a load of its size: