Rangefinder Vs. Live View

[G Dogg]

Hello all,
I am a "newer" member and have decided to muster enough courage to post a question to this group of experienced individuals. This question has likely been addressed previously, though I could not find it in my searching. Please forgive me if this is already dealt with elsewhere, and perhaps you could point me in the direction.

I notice that when I focus with the RF patch on either the M240 or the M246, and compare to the image to the "sharpness" in the electronic viewfinder, they don't agree. I either have the focus lined up with the patch, or I focus (with or without peaking), and they do not agree with each other. I am the original owner of both cameras, no trauma to either one. I am using an older 50mm summicron at 5.6.

Is this difference typical or does this mean I need to have things calibrated? Any insights are greatly appreciated. Thank you in advance.

 

[JPSuisse]

I am no expert here either. But based on my experience with focus problems I am going to make the wild guess that the problem is with the lens. Why?

When I bought my MP new in ca. 2007 I bought also about 5 lenses new too. No problems. When I got the M8 in 2009, I had big troubles getting sharp pictures. Finally, ALL the equipment went back to Leica...

Leica informed me that the camera was ok but that the lens mounts were corrected and from then on, all was fine with the M8. I sure did have a lot of unsharp pictures at first. :-(

Apparently, since the focus accuracy must be better for a digital sensor, the mounts needed to be adjusted to better tolerances. The thickness of film allows a certain forgivingness with the focus and thus also the tolerances of the rangefinder mechanism.

Good luck clearing that up!

EDIT:
I was assuming that the camera was new and hasn't been knocked out of alignment. That is of course a possibility. My experience with new lenses just prior to Leica's digital maturity (?) was that even they all needed a adjustment by the factory in order to work satisfactorily on a digital M. So, why wouldn't older lenses need the same thing? Since then, however, Leica seems to have gotten the tolerance issue cleared up, because the other lenes I have bought have worked right out of the box.

 

[G Dogg]

Thank you JPSuisse. I guess I will need to do the same as you have done. I don't notice the problem with the newer lux 50 however, so maybe that lens is more calibrated for digital? Thanks for the insights.

 

[JPSuisse]

Exactly. If the 50 Lux works, then your rangefinder mechanism should be ok!

 

[Vince Lupo]

I'd suspect it is with the lens too. I thought I was having an issue with my 0.95 Noctilux on my 246, but in comparing focus with the EVF, both the rangefinder focus and the EVF focus line up. So I think it must be me!

 

[Ronald M]

I'd suspect it is with the lens too. I thought I was having an issue with my 0.95 Noctilux on my 246, but in comparing focus with the EVF, both the rangefinder focus and the EVF focus line up. So I think it must be me!

The 1.0 Noct has focus shift. The corners sharpen up like a Summicron if you adjust focus when using 5.6. Don`t know about the .95. Test yours

 

[G Dogg]

So the interesting thing is I have completed side by side comparison , with the 50 summicron, first with the rangefinder then with live view. I was around F8, did close and far shots. I could see a bit of difference between the two approaches. When I imported into Lightroom, I then compared at 2:1. Granted, I am using a 27 inch IMAC, so the screen resolution is a factor...but I could not detect any real difference. Maybe very slight in terms of sharpness. I then printed out 20x24 of a sampling and cannot see any difference. Hmmm

 

[G Dogg]

Guess what I am seeing is not enough of a difference in the real world setting...in practical terms.

 

[Vince Lupo]

The 1.0 Noct has focus shift. The corners sharpen up like a Summicron if you adjust focus when using 5.6. Don`t know about the .95. Test yours

F/5.6? On a 0.95? Hmm, didn't know it had other aperture settings other than f/0.95.

 

[rscheffler]

So the interesting thing is I have completed side by side comparison , with the 50 summicron, first with the rangefinder then with live view. I was around F8, did close and far shots. I could see a bit of difference between the two approaches. When I imported into Lightroom, I then compared at 2:1. Granted, I am using a 27 inch IMAC, so the screen resolution is a factor...but I could not detect any real difference. Maybe very slight in terms of sharpness. I then printed out 20x24 of a sampling and cannot see any difference. Hmmm

At f/8 even with a 50, the depth of field will probably mask focus disagreement between the two focusing methods in most situations.

For best peaking/live view critical focus, it's better to focus at a wider aperture, then stop down. But if the lens has focus shift, then at the working aperture might be better (not sure if the Cron has focus shift), though by f/8 that should be pretty much moot.

RF/live view focus disagreement will be most apparent at wider apertures. If you typically shoot stopped down a fair amount, then you should be able to get by using the RF even if the lens doesn't agree with the camera's calibration. At wider apertures it will be more difficult, but even here if you test for it, you can intentional misalign the RF coincidence to achieve correct focus. In fact this is what I'm doing with most of my lenses now that my M240 seems to be slightly back focusing everything...

IMO, best way to determine if it's the camera or a specific lens is to test as many lenses on the camera as possible. And on another camera, if possible. With one or two lenses, it's difficult to determine which is at fault for missed RF focus.

 

[G Dogg]

Great insights rscheffler. I will definitely test more lenses against the rangefinder coincidence and the live view.