Not a Guru - only a chela (student) but with 480mm of bellows draw, a 240mm lens (or shorter) will get you 1:1. Again, the Fujinon A, APO Ronar, APO Nikkor, fall into this category, as do the real Macro lenses like G-Claron, Macro Sironar, Macro Symmar, Macro Nikkor.
The Fujinon A lenses are a clever hybrid design: f/9 for compactness, plasmat design for wide coverage and excellent correction, corrected close enough to be suitable for macro, but also for infinity.
Process lenses have been described by some experts as optimal for flat subjects, and real macro lenses as best for 3-dimensional subjects. That's probably true, but may appear only under the most rigorous scrutiny. I've used both kinds interchangeably, and not been able to detect any difference, at my admitedly lower level of requirements. The f/5.6 plasmat macros will be brighter to shoot, easier to focus, with widest coverage and the ability to use the most view camera movements, as in table-top product photography. The f/9 process lenses will offer less coverage, and greater difficulty in focusing under dim light.
At double extension, image circle increases to 2x what we get at infinity: many "4x5" lenses will cover 8x10 at that point. The Nikkor Macro lenses don't even cover adequately until used at macro distance: they are really intended for macro only.
All that being said, with 8x10 your image quality will be very high and you may not notice the difference between ordinary lenses and those designed for close work, unless you enlarge a bit. If your prints are small, then almost any lens will do, like an old Tessar that opens to f/4.5 (helpful for focus).
One other consideration is the inter-relation of subject distance, focal length, and perspective. Shorter lenses will make it easy to get in close for higher magnification, but will introduce foreshortening. Normal-to-longer lenses are often preferred for that reason, even though they require more bellows extension.
For that reason, on 8x10 you might want to consider 300mm or longer, or simply shoot a smaller format and appreciate the greater depth of field you will get. If you stick a 5x7 or 4x5 adapter on that back of the Century, the same 480mm bellows will give you plenty of additional magnification.
Bookmarks