The Epson R-D1 framelines are deliberately tight, so photographs will show more of the scene than is enclosed by the framelines: a maximum of 85% of the captured image at 3 m (~10 feet), this percentage increasing as the distance to the point of focus increases (because the focal length decreases slightly). Presumably, this generous safety factor (Leica M, 93% at 2 m) is to accommodate the multitude of lenses made over the last half century that will fit this camera: the stated focal length of a lens is often not its exact optical focal length, so the field of view of different lenses with the same nominal focal length will vary.
For anyone used to SLRs, this inaccuracy is annoying, since many photographs will need to be cropped; not to mention the wasted pixels, effectively reducing the resolution of the R-D1.
An additional problem is that the R-D1 only has three sets of framelines, for 28, 35 and 50 mm lenses.
I use the following rules of thumb for increasing the accuracy of framing. The width highlighted in red should be added to or subtracted from the framelines as described (an asterisk indicates that the R-D1 has no framelines for that focal length). In each case, the field of view is for 3 m focus. For focus at infinity, add the width of three framelines to compensate for the increase in the field of view.
Owing to the 1.53 R-D1 crop factor, many accessory finders are unsuitable, as their field of view will not match most standard focal lengths. Two exceptions are 35 and 135 mm finders: the former is suitable for 21 mm lenses (= 32 mm on the R-D1), and the latter for 90 mm lenses (= 32 mm on the R-D1). Also, Cosina Voigtländer manufacture wide-angle finders designed specifically for the R-D1 that take account of the ×1.53 crop factor, for 12, 15, 21 and 25 mm lenses.
A zoom finder is probably the most convenient and cost-effective solution, and the use of accessory finders is covered here.
Modifying the Epson R-D1 frameline masks
A more drastic solution is to modify the R-D1’s rangefinder mechanism by drilling holes in the frameline masks. This procedure is described in the adding framelines article.