Thanks everyone - i really appreciate the advice!
I'm hoping to learn more about the DOF being compressed with the "longer" focal length of the 180mm at wider apertures (realizing that i'll tend toward stopping down a bit?). This approach, as compared to the "sweeping vista" more characteristic of say the 50mm (or 65mm for that matter), is at the heart of my question.
Sorry to reference a smaller format, but it's my 'frame of reference' ;-). On 35mm format, the FOV of a 24mm is almost too much for what i like to see and honestly for what i can capture well given my pathetic skill level. I have a superb 24mm f2.8 lens in Minolta SR mount, but it's approaching too much width whereas my 35mm f2.8 is just about perfect for what i usually "see". I also have the 28mm f2.8 "in-betweener", but for some reason (user error probably) it's just not there for me - knowing that i can simply move to alter what's in the frame.
Thanks again - this is all so new to me - i greatly appreciate your responses and look forward to learning more!
Just a couple of observations here - they aren't intended as criticisms.
Your reference to depth of field is a bit confusing.
For a given subject image size (on the film) and f/stop, different focal lengths will give the same depth of field - because in order to get the same subject image size with a longer lens, you need to move farther away.
The factor that changes with focal length (for a given subject image size) is perspective - to get the same subject image size with a longer lens, you need to move farther away, thus creating more depth "compression" in your image.
Sometimes, with landscapes, we tend to pay more attention to field of view than perspective. By that, I mean we tend to strive to get the entire vista in, and therefore lean to the shorter focal length lenses. Sometimes this ends up in a disappointing result.
There are an infinite number of landscape subjects out there that will benefit from a longer focal length, just not
all of them.
If you have only one lens, you are going to have to choose appropriate subjects anyways.
As for your "frame of reference", don't discount it, because it is important!
There is at least one long and interesting thread her on APUG where the question is asked: "What do you consider to be your 'normal' lens?" (I'm paraphrasing the title). It is interesting, because it highlights how different people are most comfortable with different "frames of reference". So, subject to a couple of considerations, I would suggest that you trust your experience with 35mm when you consider what to do in larger formats.
What are those considerations?
First, the aspect ratio of an RB67 is close to 6x7, rather than the 2x3 aspect ratio of 35mm. To me, 6x7 looks less wide than 35mm when using lenses with equivalent "wide" angles of view. Most likely this is because the format is less rectangular.
Second, the differences in handling (bigger! camera) and viewing (bigger! view screen) seem to subtly affect my perception, and thus affect my photographic choices as well. I cannot really describe why this happens, but I'm sure that at least some of this is due to the fact that I only use a WLF on my RB67, whereas my 35mm (and 645) cameras are almost invariably used with an eye level prism.
FWIW, my favourite lenses on 35mm are 35mm, and on 645 are 55mm. For my 6x7 work, I really liked the 58mm on the Koni-Omegas I just sold, and find that the 50mm on my RB67 is very satisfactory, although the 90mm gets a lot of use too.
Hope this helps.
