Hi Tom,
I was on the grill so I beieve I am slightly past the point of focus on the finder so my mental note is to back it up a bit. I also am having a very hard time finding the point of best focus on the GG. I think I am "seeing" the best focus as past the object or I am picking the far end of the range of more or less in focus areas.
I found infinty using a tripod and a water tower about 1/4 mile away. I am confident the iniifnity is correctly set more or less but again, I have a range and there is a point in the range that I just cant tell if it is better or worse focus 🙂.
Using a tripod and a 4x and 8x loupe. What i need is a DSLR with a long lens!
A trick with the ground glass focus is to blink. What happens if you stare at it is your eye tries to adjust, and it becomes hard to tell what is going on. Or just look away from the ground glass and back again. You first impression is usually the correct one. Also, you sometimes get the impression of two images one the ground glass. With a properly set up Pacemaker Graphic the one on the front surface of the GG, nearest the lens, is correct.
The thing you need to change on the rangefinder is the focal lenght of the lens. That would be a bit on the high side of the 9.5 with your lens. The numbers are not precise and you can be off a bit and get a decent setting. Once you tweek the focal length, you need to reset the infinity, and close focus (6ft) points. The midpoint (15ft) is just a check that you got it right.
One of the problems is, I think, trying to be too damn precise. Close enough is close enough. The other thing is not understanding that these cameras were not used like 35mm, they used small f-numbers and slower shutterspeeds (f/16 1/100 was common, 100 speed film was about as fast as was available back in 1950), so they had quite a bit of depth of field to play with. Those were the day of flashbulbs, not available light (f/22, 1/50 with a #5 clear flashbulb at 10ft is what I use a lot with my 4x5. You will note that that is also the correct exposure in bright sunlight with ASA 100 film).
An interesting point is that in 1959, they about doubled all the film speeds for b&w film. Actually, they only doubled the numbers, there was no change in the emulsions, just the way they measured it. Actually, that was the second time they did something like that. In the 1930's they used Weston film speeds, then they went to ASA, raising the numbers by about 1/3 of a stop, then they went to the new ASA raising the numbers by about a stop. Great way to seem to make progress without actually doing anything. So, the 1935 40 speed film, became the 1950 50 speed film, became the 1960 100 speed film.
Ain't it interesting, the things you learn reading old books.