So I guess this is backlash?

SteveM(PA)

SteveM(PA)

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Going from infinity to subject, I'm getting front focus. Going from closest distance to subject I get back focus. Consistently, for about the last 100 test shots, both of my 135's (Canon and TE). I'm using a Nikon DG-1 2X mag, so I can't blame myself anymore. This isn't really fixable is it? Rats.
 
You mean to say the camera is fighting back? Or avenging something you said or wrote?

Sorry to hear about your trouble, though... :(
 
SteveM(PA) said:
Going from infinity to subject, I'm getting front focus. Going from closest distance to subject I get back focus. Consistently, for about the last 100 test shots, both of my 135's (Canon and TE). I'm using a Nikon DG-1 2X mag...
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At which aperture?
Due to the short base length of the rangefinder one cannot focus accurately a 135mm lens at wider apertures than f/8 without magnifier and f/5.6 with a 1.30x magnifier normally.
F/4 would be OK with a 2.0x magnifier, if any, but are you sure your Nikon DG-1 is a magnifier?
 
there's one advertised on this page (link)

- to the OP - yes, it sounds like backlash, the crucial question is how bad is the back focus?

I find I home in on the focus point by going back and forth with the focus ring, so I never really know whether I'm coming or going, if you get my drift :)

So, I do get some unpredictability in the focus, but it's never been a problem for me, as I don't use lenses longer than 50mm.
 
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SteveM(PA) said:
Going from infinity to subject, I'm getting front focus. Going from closest distance to subject I get back focus. Consistently, for about the last 100 test shots, both of my 135's (Canon and TE). I'm using a Nikon DG-1 2X mag, so I can't blame myself anymore. This isn't really fixable is it? Rats.
Click to expand...

Yep. One version of it. Magnifier might help or not - if the backlash is caused
by the mechanics of the camera (or lens), it won't help. As long as you
know how much you back focus it's not so bad: in a portrait situation you can
focus on the nose instead of the eyes for instance ....

Roland.
 
ferider said:
Yep. One version of it. Magnifier might help or not - if the backlash is caused
by the mechanics of the camera (or lens), it won't help. As long as you
know how much you back focus it's not so bad: in a portrait situation you can
focus on the nose instead of the eyes for instance ....

Roland.
Click to expand...

It seems like that is the simplest answer. Going from closest focus, I'll focus on the nose. Coming from infinity, focus on the ears or whatever.

I still don't fully understand it. Coming from either full direction, no matter how much I saw back and forth, I'll still get the predictable result (front or back focus as the case may be). But if, for instance, I'm coming from infinity, saw back and forth, and perhaps just touch the closest focus point, saw back and forth some more, go to subject...the focus is reset for "coming from closest focus" with the result of back focus.

It's all slightly voodoo-like, and maddening. And the chorus chants "don't use 135's." But the trouble is, I love these rangefinder 135's, especially the TE. They are, relative to SLR 135's, petite and lovely.

And now, with the Nikon DG-2 attached, I know what I'm looking at. The rubber eyecup is nice, comfortable. I can mash the camera against my face for a steadier shot. Can see only a hint of the 50mm frameline (mine are crooked, so I don't care anyway) and the red meter reading is out of the question. But just flip the DG-2 up, and your full view is all there, then flip it back down to focus. Nice. Like a modern Barnack (althought the Barnack has a longer baselength).

I just never realized before how much the R-D1 doesn't know what IT'S looking at with a 135.

A further observation: At the moment of exposure, with a 135 attached (and I couldn't really see this before I had the magnifier) there is an image shift or "snap" in my viewfinder, and I can see exactly what is going to be in focus. And it is, of course, never what I've actually focused on. But I guess this makes total sense, and I'm just seeing the manifestation of the backlash.

I need a drink. :) And probably a 90mm. Sorry, I'll shut up now...
 
I did not know this magnifier at all.
I'd like i could use it on my Nikon DSLRs but i'ts not done for them i guess.
 
Xmas said:
It is a mechanical fault, it should be addressable, it may be dust or grit particles.

Noel
Click to expand...


It's been said that backlash in this camera cannot be repaired or fixed through calibration. It is a defect of the mechanism which can only be eliminated if the offending part is replaced. My R-D1s is accurate if lens focusing starts at a setting closer than the targe5 object, with the lens racking in as it's focused. On the other hand, same camera would back focus if focusing movments starts at infinity then moves to the more immediate distance settings.

This (d)effect is readily seen on the focus scale of the lens. The scale will show different focus points, depending on which way it was turned.
 
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