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Thread: Beyond Close Focus Accuracy

  1. #1
    Senior Member ecliffordsmith's Avatar
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    Beyond Close Focus Accuracy

    Hi All,

    I hope all is well. I have been off with a big work project of late so took advantage of the time I would be unable to take many pictures to do two things.

    1) Send in my M8 35 Summicron ASPH for calibration.


    2) Get myself a D-Lux 4.

    Well, on the first point I can only have praise for the way Leica handled my equipment. The camera came back looking embarrisngly clean and the back focus issue with the lens is now truly solved. As my 2 year warranty is now almost up it was a nice time for a good service.

    Now, while testing the lens/camera combination I have found that from 0.7 (as set from the '.' marked on the lens at all apertures through to infinity the focus is spot on. Usually I focus in a hyperfocalish manner but was stunned to see what a difference the adjustment made.

    What I have noticed now though is that when I focus beyond the 0.7 on the lens through to the near focus limit the focus patch does not accurately display what will be in focus. It would appear that things would front focus a few centimetres.

    My big question now then is whether this is the normal behaviour I should always have expected? I will dig out the 75 Summicron ASPH later and try with that. Before the lens went in the close focus was possibly the only truly accurate focus and I am wondering whether I have been missing something fundamental for the past 2 years!

    Many thanks for any assistance in helping me scratch my head!

  2. #2
    Subscriber robsteve's Avatar
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    Re: Beyond Close Focus Accuracy

    If you are asking if the rangefinder should work at distances closer than .7m, the answer is no. It decouples at distances closer than .7m, give or take a bit depending on how the rangefinder stop was set up.

    Robert

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    Senior Member ecliffordsmith's Avatar
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    Re: Beyond Close Focus Accuracy

    Hi Rob,

    I think that is exactly what I am asking, thanks.

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    Senior Member ecliffordsmith's Avatar
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    Re: Beyond Close Focus Accuracy

    Hi Rob/All,

    Sorry, me again. Do you know why there is additional throw beyond 0.7 then on lenses please?

    Is there a way people know when they are at 0.7 without checking the lens itself?

    I cant believe I have used this camera/lens for 2 years and had it so off that I did not know this!

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    Re: Beyond Close Focus Accuracy

    Quote Originally Posted by ecliffordsmith View Post
    Hi Rob/All,

    Sorry, me again. Do you know why there is additional throw beyond 0.7 then on lenses please?

    Is there a way people know when they are at 0.7 without checking the lens itself?

    I cant believe I have used this camera/lens for 2 years and had it so off that I did not know this!
    I've been bitten by this a couple of times as well. The only giveaway is when you move the focussing ring and the patch doesn't move. The best arrangement is something like the WATE, where the closer focussing range is selected by pushing past detent, or step.

    With wideangle lenses it's sometimes nice to be able to focus closer by scale, and the dof will cover you. I often shoot architectural models with Leica M's, and the closer focussing of some wides is a real help.

    Henning

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    Re: Beyond Close Focus Accuracy

    Quote Originally Posted by ecliffordsmith View Post
    Sorry, me again. Do you know why there is additional throw beyond 0.7 then on lenses please?

    Is there a way people know when they are at 0.7 without checking the lens itself?
    the easy answer is NO -- you have to check the lens. but, then, do you truly know how far 0.7m is? if you don't, why does it bother you whether or not it is exactly at 0.7m?

    as far as i'm concerned, the closer the better! it still kind of aggravates me that the M2 rangefinder coupling does, indeed, stop at 0.7m regardless of the lens. the M8 gets closer but not all the way on my SA 21/3.4....

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    Senior Member ecliffordsmith's Avatar
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    Re: Beyond Close Focus Accuracy

    Hi Henning,

    Thank you for the response and welcome to the forum.

    Hi Cam,

    I am not bothered as to whether I am at 0.7 or 1 etc but what I observe is that the rangefinder and lens are in perfect tandem focus wise until the lens marking states 0.7 but I have a good 5mm of movemnt beyond 0.7 after that where the focus patch moves but the focus indicated is no longer correct. This is marginal stuff and borne out of curiosity more than anything. Before calibration I could push to the lens limit and the focus seemed correct so I had not realised this 'soft' stop on the lens.

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    Re: Beyond Close Focus Accuracy

    My Zeiss 21/2.8 focuses down to 0.5 m and my CV15/4.5 goes all the way to 0.3m. I've used both for macro work with models, with an M8 on a tripod, chimping with the view zoomed up. I guess this is re-inventing the G-1. The parallax that occurs at such close distances is such that just moving the frame lines to cover the correct range at the plane of focus doesn't give a good preview of the resulting image.

    scott

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    Re: Beyond Close Focus Accuracy

    Scott:

    Just to clarify, you are not saying your lenses are rangefinder coupled at theses .5m and .3m distances?

    Robert

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    Re: Beyond Close Focus Accuracy

    Quote Originally Posted by robsteve View Post
    Scott:

    Just to clarify, you are not saying your lenses are rangefinder coupled at the .5m and .3m distances?

    Robert
    Of course not, Sorry if I implied that. Just as others have observed, the rangefinder spot stops moving at .7 m, so any closer focusing is by scale or by guesswork, greatly facilitated by review on the lcd.

    But they are both quite useable at the closer distances. I was shooting outdoors yesterday in a field of flowers. Setting the 21 at .5 m, I just shot a series moving through what I hoped was the correct distances. Some came out wonderful, some didn't. Isn't digital great?

    scott

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    Re: Beyond Close Focus Accuracy

    Here's an example of the Zeiss 21/2.8 used at about .5 m:

    scott

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