Stupid question about focus lock on Arca-swiss cameras

[Rust Never Sleeps]

I got a F-Field not too long ago and I want to make sure I am locking the focus right since the Arca-Swiss manual is top notch and tells me exactly how to do this :rolleyes:.

Now I know the smaller outer knob is the focus and the bigger inner knob is the friction/lock, duh, but which way is it supposed to be turned to lock the focus?? Turning towards me or away from me?? The knob moves side to side depending on which way you turn it, either to the focus knob or to the rail. If I were to guess from playing with the camera I would say friction knob moves against the focus knob(turning friction knob towards me). I just want to be sure before clamping down pretty good, don't want to force anything and screwing something up. Thanks, wonderful camera BTW, me like a lot. Will post more on the camera once I figure it out and take some pictures.

[Sheldon N]

It should clamp against the rail, squeezing the rail tight to lock focus (turning knob away from you).

Often, I only halfway snug the focus lock down or even forget to lock focus. The carriers are sturdy on the rail regardless.

Congrats on your new camera!

[Rust Never Sleeps]

It should clamp against the rail, squeezing the rail tight to lock focus (turning knob away from you).

Often, I only halfway snug the focus lock down or even forget to lock focus. The carriers are sturdy on the rail regardless.

Congrats on your new camera!

Thanks, it seemed to lock a little better when I turned the knob toward me, that is why I thought that might be the right way. But like I said I never clamped it down too much for the fear of breaking something. I also thought this might me the right way because when the friction knob hit the focus knob the focus would shift a very small amount and I remember reading that is a problem sometimes. Is there any negative effect from turning the friction knob too far out from locking so it hits the focus knob?? Thanks

[Sheldon N]

I don't think there's any negative effect from backing out the lock until it hits the focus knob. It just wouldn't really accomplish anything.

What I typically do is back the lock knob just until it's loose, turning it any more than that doesn't make a difference. Once it's loose, it's loose.

When focusing I will snug the lock knob down partially so that the focus knob will work, but requires a little extra effort - then fine tune focus on the ground glass before locking it down fully.

I find that this helps to mitigate any focus shift when locking down the camera.

[neil poulsen]

You want to be careful about tightening it too much. Just enough to do the job.

It should tighten by turning it clockwise as you face the knob.

[vonstauren]

I got a F-Field not too long ago and I want to make sure I am locking the focus right since the Arca-Swiss manual is top notch and tells me exactly how to do this :rolleyes:.

Now I know the smaller outer knob is the focus and the bigger inner knob is the friction/lock, duh, but which way is it supposed to be turned to lock the focus?? Turning towards me or away from me?? .

Well, not that you would be more clear than the Arca Swiss manual:) - turning toward me or away from me is not really a clear description to say when you have a knob with an axis perpendicular to you...
But as said correctly - the clockwise (facing the knob) turning tightens the thing. The tightening is there just to prevent effects of inadvertent touches to the focus knob or strong pressure on the standard which, also as said, is firm enough in itself. If you avoid the two causes you don't even need to tighten it.

[Rust Never Sleeps]

Thanks for the tips guys. I had some time to screw with the camera and it indeed locks down pretty good after turning the friction knob all the way against the carrier. Not too tight but locked down pretty good. You can still do very fine focus too if need be or if the standard moved a little while locking. Rod at Photomark told me the newer carriers can still be focused while locked down pretty good without anything getting screwed up. Something about the old carriers getting messed up after doing this but he did not state the date when Arca made this switch.

Also it is very easy to see if the focus shifted by looking at the rail and noting the millimeter markings behind the rear carrier after focusing and look to see if the carrier shifts after locking. If it shifts a little just focus it back to were it was at before locking since you can still focus after locking. I will do what you recommended Sheldon and when focusing just locking down enough to still be able to focus with a little extra effort and then locking down further to lock down. I tried this and it works very well. The carriers hold very well even when not locked down just as people here have stated.

Got a 15cm extention rail and Arca lens hood coming and a 65mm Grandagon coming soon, so I am slowly but surely building my large format system. Can't wait to take it into the field this spring, summer, and fall and figuring this large format thing out.