Troy
Rent an M7 camera with a 35 Summilux Aspheric or 35 Summicron Aspheric: either lens reaches an optimum aperture by f/4. Real world MTF results show ( for both lenses ) 5 line pairs are 97 % contrast, corner to corner. 40 line pairs are 50% contrast. In a 35 mm lens, this is stunning, and at f/4 ( which is like f/ 32 in a 300 mm lens on an 8x10 ! )
Try the 75 Apo Summicron, or 90 Apo Summicron as well. 40 line pairs at 70% contrast at f/4 can be expected.
There are 3 important things going on here, and they all fight conventional 35mm thinking, especially in a heavily Large Format oriented forum such as ours !
First, don't stop down too far. Diffraction is a killer with these superb lenses. Shooting at f/8 instead of f/4 reduces your potential resolution by 50%.
Secondly, camera motion is the main culprit in the loss of resolution. At 40 line pairs , the lens is imaging a dot of .0125mm (1/80 mm) on your negative. The smallest thing a healthy, YOUNG human eye can see is about 1/15 mm. So a 14 year old kid with perfect vision would need a 5 1/2 x enlargement to see the smallest object you can put on a piece of film with these new Leica lenses. 50 year old eyes like mine, a 12 x enlargement... with reading glasses, close up.
So, shooting at f/4 lets you work at handheld exposures that at least give you a chance. And even shooting handheld, on a bright day, at EI 100, f/4 and 1/1600 threatens 8x10 performance at EI 400, 1/1oo at f/32. The tripod is nice on a view camera, but you sacrifice film flatmess, focus accuracy, tripod movement, and exposure to wind. Not to mention shutter accuracy. I've shot 8x10 for 35 years, and understand the need for a big trashbin in the darkroom.
Finally, your film choice is critical to get the most out of these lenses. While some folks have a religious fervor over Copex and other Technical films, I most certainly do not. If you are not concerned with tonality, color rendition and overall image goodness, not to mention having fun making pictures, Copex, Tech Pan, and others are an acceptable technical exercise. But not for me. Kodak TMX, developed in a gentle acutance developer like Paterson FX39 or mixing your own and using FX1, FX2, or even PMK or PyroCat, you will get the results you need.
Considering the limitations, you are still able to shoot handheld, with a 100 speed film, and approach Large Format imaging.
Putting all the factors together, you certainly can make big prints, fairly easily, if you have the right set up, from 35 mm. Scanning, the scanner is your limitation. Enlarging, your enlarger is your limitation. Either way, with careful work and reasonable viewing criteria you'll be satisfied with a Leica system.
Comparisons are problematic unless criteria are established, otherwise there is nothing to compare, right ? And when the criteria are set, there is no way to weasel back and forth between formats. Either its a big neg, or a small camera.
You have to deal with focus accuracy, film flatness, and camera movement whether you shoot 8x10 or 35mm, or anything in between. Diffraction is a problem regardless of the format. Since the focal length to film size will be a constant, we can balance out the magnification advantage vs depth of field comparing across formats. Anything between 8x10 and 35mm is a compromise. Bigger is better, smaller is better, and in between is in between. There are no comparable camera & lens packages to the new Leicas, in any format.
Accuracy of exposure swing the advantage to the Leica, as does convenience and portability. While I can make wonderful images in broad daylight with an 8x10 camera, or a 120 camera, I can take my Leica with me on my bicycle and make pictures that, at 16 x20 or 20x24, under normal viewing conditions, never make me think of Large Format. Hand held. A neat carbon fiber Gitzo would be even better.