There are lots of different workarounds for this.
You're correct that Epson sized the framelines for what a 28mm, 35mm or 50mm lens will show
when used on the R-D 1, so the so-called "crop factor" already is taken into account.
Also, because the effective focal length of a lens increases, or "zooms in" slightly, as you focus closer (the lens has a longer focal length at its closest distance than it does at infinity) Epson made the framelines 85% of the nominally correct size to provide some safety margin.
This confuses a lot of people, so I'll explain it in more detail: Suppose they had made, say, the 50mm frameline cover exactly what a 50mm lens shows at infinity. Then, when you focused the lens at a distance of 1 meter, its effective focal length will be longer -- about 55mm -- so it would now show a "tighter" field of view than you see in the framelines. In fact, it would only show about 90% of what you'd expect.
That means that if you very carefully positioned an element of the scene exactly at the edge of the frame, you'd find out it had been cropped out of the final image -- just as if you'd framed it up exactly with a zoom lens, and then zoomed in a little tighter!
To avoid that, Epson made the framelines so they show only about 85% of what the lens covers at infinity. That means pictures made at infinity will always show quite a bit more subject than you saw through the viewfinder.
Then, when you focus down to one meter -- where the lens covers only about 90% of what it covers at infinity -- the 85% finder coverage means you'll still have a slight amount of "breathing room" around the edges of your picture. As long as your composition was within the framelines, you can be sure all of it will appear in the final image, and you can simply crop out any excess.
Incidentally, Epson didn't invent this idea -- every rangefinder camera with projected framelines sizes the framelines a bit "tight" with respect to what the lens sees at infinity.
So, as Sevres says, this 85% safety factor means the 35mm framelines will work fine for your 40mm lens at longer distances; in fact, they're a closer match for the 40mm focal length than they are for 35mm! I used to use a 40mm lens on my R-D 1, and I found that the 35mm frameline was a safe guide down to distances of about 8 feet. Once I got closer than that, though, the lens' effective focal length had increased enough that it was now seeing
less than the framelines showed -- so I had to remember not to compose my pictures too close to the frame edge, instead adding a bit of "air" at the edges of the image.
You can apply these concepts to use longer lenses without too much trouble on your R-D 1. One approach is to buy accessory viewfinders that were designed for lenses on 35mm cameras, applying Epson's 1.53x "crop factor" to convert the coverage for the R-D 1.
For example, suppose I want to use an 85mm lens on my R-D 1. 85mm x the 1.53x "crop factor"= 130.05... so if I use a finder designed for using a 135mm lens on a 35mm camera, it will show about the correct view field. In fact, if the finder is made correctly, it will show slightly
less than the lens sees... which is what I want, to provide that framing safety factor noted above.
In practice, it's not always that cut-and-dried, since the makers of accessory viewfinders often designed them with deliberately tight framing to provide a safety factor of their own.
For example, I've got a 100mm f/2 Canon lens that I often use on my R-D 1. Going by the arithmetic, that lens should need a 35mm-camera finder designated for a 153mm lens... of which there ain't no such animal! However, I've got a 135mm Komura brightline finder in which the frameline was designed so conservatively that it's actually a good match for the 100mm lens on the R-D 1! Fortunately, the fact that the R-D 1 is a digital camera makes it quick and easy to shoot test shots to see how your lens' coverage compares with your finder's.
Some people even use this capability to dispense with auxiliary finders altogether, and just use various "landmarks" in the finder (the rangefinder patch, the edges of various framelines, etc.) to help them visualize a particular lens' coverage. Shoot a test shot, check it, then look through the finder and note where the edges of the image line up. I'm a bit uncomfortable with this technique myself, but some R-D 1 users swear by it.
