Leica Is my rangefinder off?

VINCETAN

Top Veteran
I sent my M to Leica NJ last December asking them to clean and recalibrate the RF. Since it came back, I am not sure if the RF is actually more off or it just normal. So here is what's happening. When I am focusing on a straight line holding the camera perpendicular to the line, no issue. I can line up the RF. When I am holding the camera at an angle, say 45 degree to the line, in the patch, the line will not line up. One image will be straight while the other will be at an angle. When I focus, the 2 line never really merged but is always a little off, one has a slight angle while the other is straight.

Not sure if this is just normal.
 
Using a line as a target, with the camera at a 45degree- the line should "line up". At an angle parallel with the line- that's a problem.

Focus on the line with the camera held level. Then turn the camera 45 degrees. If the coincidence shifts, would indicate something is loose in the RF mechanism.
 

VINCETAN

Top Veteran
Brian

Thanks for the explanation. No wonder I've been having such a hard time trying to get a good focus. I have sent Leica NJ an email regarding this.

Regards
Vince
 
Vincetan, when you point at a line in, let's say a wall, and you point at it with your camera parallel to the focus plane (the wall) there should be no issue as I understand there is not.
If the line is, let's say, in the floor running away from your feet to infinity, an you point at it tilting the camera 45º down, the lines must not align at all, except for one point, your focus point is where the lines cross with each other and it is how it must be. In the wall case, all the line is in the same focus plane, in the floor case, the focus plane is only the cross point, from there onwards the line must be at one side of the straight one and from there towards you the line must be on the other side (obvious, is closer to you... ;-)).
Obviously, if when you move the camera the coincidence shifts, there is an issue with the rangefinder as Brian points out.
 

VINCETAN

Top Veteran
AlbertTRAL, For most object, it is really hard to see but if I am focusing a very high contrast thin black line on a white piece of paper, the line never merge in to one line. It is close but you can see definitely see that it is not a straight line but more of a very narrow x.

Anyway, hope Leica can turn this around quick as I have a vacation coming up in July.

Regards
Vince
 
Vincetan, maybe I am not understanding you correctly but to me your rangefinder is perfect. It is doing what is supposed to do. The only way that both black lines merge together is when you look through the rangefinder completely perpendicular to the paper, this means that the paper (and the lines it contains) are all in the focus plane, thus with the sensor or image plane in the camera completely parallel to the paper.

You can do a test, put a white paper with the black line in the floor and focus the line with the paper between your feet. The lines should merge perfectly. Then you step back, and as you go away from the paper (and from 90º you need to tilt the camera upwards to 45º), you will see that both lines become an X. The focus point is where the lines cross and obviously will never merge...

This "X" effect becomes more evident when focusing to close distances because the patch covers a distance more comparable to the base line of the rangefinder.

Sorry in advance if I am not understanding you... English is not my mother language... ;) :)
 
Last edited by a moderator:

VINCETAN

Top Veteran
"You can do a test, put a white paper with the black line in the floor and focus the line with the paper between your feet. The lines should merge perfectly. Then you step back, and as you go away from the paper (and from 90º you need to tilt the camera upwards to 45º), you will see that both lines become an X. The focus point is where the lines cross and obviously will never merge...

This "X" effect becomes more evident when focusing to close distances because the patch covers a distance more comparable to the base line of the rangefinder."

The description that AlbertTRAL described above is exactly what I'm experiencing. Maybe my description was not clear. So, no issue here?
 
No issues at all. If you think a little bit how a rangefinder works, you will see that is working as it should.

1. When the two lines merge completely? When all the line is at the same distance from the camera (the distance at which you are focusing) obviously contained in a same plane, the plane you are focusing.

2. When the two lines generate an "X" and only "merge" at one point? When the line comes towards you or/and goes away (thus is not contained in the focus plane). The part of the line closer to you cannot merge because you are not focusing at that distance. The line more far away cannot merge because you are not focusing at that distance either. You are focusing at the distance where the two lines cross, this means that the rangefinder image in front must be at one side of the viewfinder image and the image at the rear must be at the other side (one is front focus and the other is back focus, just the crossing point is in focus -as per the rangefinder, let's forget now about depth of field-).

Hope I have been able to explain myself... ;) ...in any case I suppose Leica will clarify the issue.
It's curious though that you have just realized now about this issue after sometime with a rangefinder... the reality is that usually everything we focus is roughly "apparently" in the same plane because we see this effect only from time to time (close up pictures, where the rangefinder patch covers a length "comparable" to the rangefinder base line, that include a "long" line).
 
Last edited by a moderator:

brusby

Regular
Focus on a single small dot rather than a line. If you always get 2 images of the dot, even at the best focus, your vertical alignment is probably off.

And if it is off, focusing on a vertical line probably won't let you know it.

Good luck.
 

VINCETAN

Top Veteran
Thanks guys for your input. I guess no issue with this camera. I sent Leica an email Saturday but have not heard back from them. So glad I don't have to send the camera in. There is always a risk of delays or other issue when you send a camera in to NJ. I think they are much better than before. I remember the mid 90s, there was one occasion when I send them a M4-P for cleaning, it came back clean but when I remove the bottom plate, a screw came falling off. Never knew what that screw is for since everything seems to work ok.
 

Latest posts

Latest threads

Top Bottom