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  1. #11

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    Voigtlander Rangefinder Alignment effect on depth of field vs. focusing accuracy.

    Quote Originally Posted by Lee L View Post
    The choice of a 90mm f:4 lens was based on the 18.9mm effective baseline (EBL) of the Leica CL (not the later CLE), and for good visual acuity is just over the limit for being focusable at f:4 (about 107% using the visual acuity model).

    The CLE had an EBL of 28.8 (over 50% longer than the CL), and with a 90 f:4 hits about 70%, and with a 90 f:2.8 is right at 100%. So the 90 f:2.8 on the CLE should be slightly better able to focus accurately than the 90 f:4 Leica chose on the CL.

    The R3A that the OP is using has a 28% longer EBL than the CLE, so hits about 78% with a 90 f:2.8.

    One reason that I recommended purchasing the 90 Summicron and testing is that the acuity of the photographer's vision comes into play, and someone with worse vision at given distances won't be able to use the rangefinder to it's maximum capability. Vanishing Point seems to have hit the wall earlier than the models, which points up the need to establish personal parameters with a given setup.

    In any case, there is no law against using a Summicron at f:2.8, or f:4, and as pointed out, that starts to get into the peak performance of the lens. I use both Leica and C/V lenses, and leaving image quality aside, would spring for the 90 Summicron over the 90 Lanthar because of build quality, longevity, and potential utility with future camera bodies and in lower light levels. If the OP can get reliable focus for himself at f:2.8, or even f:2, (the acuity model suggests f:2.2 as the limit, 100%, on the R3A) he's ahead of the game over the f:3.5 for isolating the subject.

    I wouldn't buy the more limited optic at the same price point as the one with greater capabilities, as long as the condition of the used lens isn't an issue.

    Lee

    (As info, I own and use a CL, CLE, R3A, and a 90 f:4 from Rokkor and one from Leitz, but haven't used a 90 Summicron, Elmarit, or C/V Lanthar.)
    Isn't there also an issue, specific to the Voigtlanders,
    of rangefinder alignment ?
    While this shouldn't effect the choice of lens, wouldn't
    a stopped down lens, or a slower lens, mean that if
    you are out of alignment, your images may still be sharp, which is the most important thing here.

  2. #12
    Lee L's Avatar
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    Quote Originally Posted by Vanishing Point Ent. View Post
    Isn't there also an issue, specific to the Voigtlanders, of rangefinder alignment ?
    Any assumptions about focusing accuracy obviously imply a properly calibrated rangefinder. I have used 5 C/V Bessas, two T's, one R2, and one R3A. One T arrived with a slight vertical misalignment and was returned for replacement. It focused fine on a vertical line or edge. The seller claims it was checked before shipping, nothing I have reason to doubt, and it was out far enough on arrival that I suspect it was dropped hard in shipment. The others snap into focus on fine texture, indicating good horizontal and vertical alignment, and on tests at 1 meter with a 90 f:4 and at about 6 feet with a 135 f:4.5 show very good rangefinder adjustment with an angled yardstick or scale. Many of the C/V rangefinders are user adjustable. I have seen the threads you mention on C/V rangefinder misalignment, but have no evidence that it's a chronic problem. I don't put a lot of stock in internet dog pile critiques, where the sample is self-selecting.

    While this shouldn't affect the choice of lens, wouldn't a stopped down lens, or a slower lens, mean that if you are out of alignment, your images may still be sharp, which is the most important thing here.
    Of course, which is why my personal choice would be the Summicron and seeing where the practical limits would be for that lens, the body in use, and my visual acuity. To be redundant: pick the stop that fits your own limits, not be limited by a fixed f-stop limit that may be overly conservative when you'd prefer more selective focus. But I don't see the point of using a rangefinder that's out of alignment and covering that error with DOF, as opposed to having the rangefinder adjusted properly, and that's very easily checked.

    Lee

  3. #13

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    I shot with 35mm rf's and use the 90mm Apo Lanthar and a 75mm Color Heliar. Both are excellent lenses and I have to say I prefer the 75mm feild of view. Before you buy either 90mm try a 75mm on you camera and see what you think.

    Best regards,

    Bob
    Best regards,

    Bob
    CEO-CFO-EIEIO, Ret.

  4. #14
    Lee L's Avatar
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    Quote Originally Posted by rpsawin View Post
    I shot with 35mm rf's and use the 90mm Apo Lanthar and a 75mm Color Heliar. Both are excellent lenses and I have to say I prefer the 75mm feild of view. Before you buy either 90mm try a 75mm on you camera and see what you think.

    Best regards,

    Bob
    I really like the 75 Heliar too, and it suits the way I see very well, and is an excellent lens as you say. It's my most used 35mm rangefinder lens. Luckily with a rangefinder all you have to do is click in and compare the 75 and 90 frames and see if you like the focal length before laying out the cash. The 75 works particularly well for me with a 1:1 finder.

    Lee

  5. #15
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    Vanishing Point Ent. wrote [QUOTE=In my opinion; the conclusion is to NOT go for the 90 mm f 2.0 Summicron, unless you are planning to buy a Leica m camera down the road, where you can take advantage of the f 2.0. .[/QUOTE]

    I disagree with this logic.....Foremost, just because you own a Summicron doesnt mean you need to use it a F/2 AND the Summicron at f/4 will be even sharper stopped down 2 stops. An F/4 lens is wide open at F/4..... Secondly, the Summicron will be far easier to re-sell in the future if you need/want to....

    Dan
    Antique and Classic Camera BLOG
    www.antiquecameras.net/blog.html

  6. #16
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    thank you again everyone. All very thought out and useful suggestions. I suppose one could say it is a testament to the system that I have so many options.

    I was lucky enough to find a photographer friend of mine who has a 75mm Heliar and he is going to let me borrow it for the weekend so i can make my decision if I like the 75 or 90 focal length better. I instantly gravitated to the 90mm thinking it would be best for me but the more I think about it, 75mm might be more my speed.

  7. #17

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    Aren't Rangefinder cameras as much about the " feel " ?

    I'm just going to finish with this.
    All of you have neglected the other part of my first post.
    Which is that I found that the 90 mm f 2.0 Summicron was very heavy
    & very front heavy compared to the f 2.8 or the f 4.0.
    When I looked at getting one, I could feel the weight of the lens, around
    my neck & every time I went to pick up the camera & lens combination,
    it felt relatively like I was doing curls.

    This is just my opinion, but it is a consideration.

    With the f 2.8, which I said I had, the whole combination of camera & lens
    felt very natural, like they were made for each other.

    You should pardon the expression, that this is why,
    I never shoot my Canon 85 mm f 1.2 L on my A2, or Elan camera.
    I hate that Tail wagging the dog feeling.
    It's much more comfortable on my Canon EOS 1n RS.
    The heavier camera makes controlling the lens easier.

    So, I repeat the 90 mm f 2.0 Summicron, may
    " feel ", too heavy for the Bessa, but not for a
    Leica, especially if you put a MOT, on it.

    Aren't Rangefinder cameras as much about the " feel " ?

  8. #18

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    The early crons are really heavy the modern crons a lot lighter the CV is even lighter still. If you take an early cron for a walk it will turn into lead.

    Noel

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