hamradio
Well-known
I'm in the process of aligning a Kalart sidemount RF with something a little outside the recommended range, an Ektar 203/7.7. The camera in question is a B&J 4x5 press.
Is there a specific reason the sliding distance scales on these cameras are set up in a way that allows one to focus beyond infinity, according to the scale? The B&J's rail can move about 1/8" beyond infinity, according to the scale, before hitting some sort of stop. Every crown graphic I've used was the same way. I'm contemplating setting the infinity stops to correspond with the most rearward position of the focusing rail, and not infinity according to the scale.
The reason the scale becomes an issue for me is because the bellows extension with the Ektar 203 is far enough that it covers up the distance scale.
I feel that setting the camera up so that infinity is the most rearward position of the focusing rail would be optimum for nighttime usage, as then one could simply retract the rail as far as possible and pull the front standard out until it hits the infinity stops, rather than have to peek under the bellows at the scale or look at the ground glass with a loupe. Would this arrangement somehow limit the usage of movements? It seems a lot more convenient than using the scale.
Thanks!
Is there a specific reason the sliding distance scales on these cameras are set up in a way that allows one to focus beyond infinity, according to the scale? The B&J's rail can move about 1/8" beyond infinity, according to the scale, before hitting some sort of stop. Every crown graphic I've used was the same way. I'm contemplating setting the infinity stops to correspond with the most rearward position of the focusing rail, and not infinity according to the scale.
The reason the scale becomes an issue for me is because the bellows extension with the Ektar 203 is far enough that it covers up the distance scale.
I feel that setting the camera up so that infinity is the most rearward position of the focusing rail would be optimum for nighttime usage, as then one could simply retract the rail as far as possible and pull the front standard out until it hits the infinity stops, rather than have to peek under the bellows at the scale or look at the ground glass with a loupe. Would this arrangement somehow limit the usage of movements? It seems a lot more convenient than using the scale.
Thanks!
rjbuzzclick
Well-known
Do you have the correct bed focus scale for the 203 lens? If not, it won't be usable anyway with the 203 so you can set your infinity stops wherever you want. The focus scale for the 203mm is P/N 30881-27 I believe. Look on the underside of the scale you have for the part number.
Both of my Graphics are set up the way you described with a little bit of play beyond infinity. I don't why that is but I like being able to go past both sides of infinity when fine tuning focus on the ground glass. I only have the focus scale for the 135mm lens on my SG. When I set up the stops for my 203 Ektar lens, I set them to agree with infinity on the 135 scale just so there's only one infinity reference on the camera. It's kind of a moot point though, since I can only focus through the GG with the 203 on my setup. My rangefinder isn't calibrated for it.
Both of my Graphics are set up the way you described with a little bit of play beyond infinity. I don't why that is but I like being able to go past both sides of infinity when fine tuning focus on the ground glass. I only have the focus scale for the 135mm lens on my SG. When I set up the stops for my 203 Ektar lens, I set them to agree with infinity on the 135 scale just so there's only one infinity reference on the camera. It's kind of a moot point though, since I can only focus through the GG with the 203 on my setup. My rangefinder isn't calibrated for it.
mdarnton
Well-known
I think when you try to move the RF feeler stop you will find that it doesn't slide like the infinity stops, but is screwed directly into the rail, and is butted back even with the back end of the rail. Too much work to move, and if you're really into drilling and tapping, the scale might be easier to move. Probably the play was there initially so that in production they could screw it down permanently and always know that it would work on any camera, regardless of production variations. These things weren't made by CNC.