Ultra-Wide Manual Lenses

Discussion in 'Adapted Lenses' started by OzRay, Apr 4, 2010.

  1. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Real Name:
    Ray, not Oz
    I commented once before that I was pretty happy with the Voigtlander 15mm f4.5 lens on the Pen. I've been using it a more bit lately and I must be looking at it more critically, as the corners just aren't in focus as well as I'd expected. For a lens designed for 35mm sized film/sensor area, it's quite pronounced, even stopped down slightly. It makes me wonder how this lens would perform on a 35mm sized sensor and whether anyone would be happy with its performance.

    This was really bugging me, as I'd read many reports where this lens worked fine on both film and digital Leicas. So I did some further tests. First, I took off the B&W filter, but this didn't change a thing. Then I focussed using the maginfication option to ensure that I was getting things in focus, no change. Then I started to experiment with aperture settings and bingo! You wouldn't think that with a lens of this wide a focal length and inherent depth of field (moreso when used on m4/3s) that you'd have to stop down much at all. In fact I'd stopped down to f16 before things at the edges became sharp.

    I'd like to note that my tests in this instance were done where parts of the scene were quite close, so for scenes where the subject matter is all within a resonably compresed field, it may not require going down so far in the aperture setting. So to see how fair this was, I decided to compare this lens to my 4/3s 7-14mm at 14mm. It wasn't exactly the same field of view, and the extra 1mm does make a difference at the wide end, but it's all that I had.

    So I started at f4 on the Olympus lens and moved up the same stops as I did with the Voigtlander. The Olympus was not in focus at the edges when set to f4, but improved noticably at f9 and at f16, things were sharp, but still, not as much as I'd expected. Fully open, the Olympus is better than the Voigtlander and this is surprising, as I'm only using the centre part of the Voigtlander lens, compared to the full image circle of the Olympus.

    But the ironic part of all of this was that using AF with the Olympus lens, no part of the subject that should have been in focus was in focus, even at f16. So what does this mean? I guess I'll still be happily using the 15mm, but with the knowledge that if there is subject matter near and far, especially at the edges, stop down sufficiently so that the edges are reasonably sharp as well, so that it doesn't look like a whole bunch of smearing is going on.

    My only concern now is that I was considering buying the Voigtlander 12mm, now that it's available in the M mount, but if the 15mm has this problem, what will the 12mm have?


  2. Bokeh Diem

    Bokeh Diem Mu-43 Top Veteran

    Mar 14, 2010
    Frankly, I don't think the Nokton 50/1.1 does a much better job on the M4/3rds format than what you are experiencing with your 35... it appears to me from images posted in this Site that the problems of adaptation are chronic (angle of sensor incidence, small sensors being asked to mate to lenses designed to allow that much more information into a space designed for something entirely different as a take up mechanism. I am almost am starting to think the problems become more pronounced the more you spend on the adaptive lens (LOL).

    Come on Pany Leica, blow us away with some more fast primes! I am saving up now for the Leica DG Summilux 4/3rds mount 25/1.4, having seen what the PL 45/2.8 can do. And, gimme a fast prime 9 and 14, like that 20 pancake.
  3. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Real Name:
    Ray, not Oz
    Oops! I think you misread my post. I'm talking about a 15mm, ultra wide angle lens, designed for 35mm film (it'd need to be a 7.5mm in m4/3s terms).


  4. cosinaphile

    cosinaphile Mu-43 All-Pro

    Dec 26, 2009
    new york city
    ray as i understand it the 12 has a better build quality and optical quality than the 15 , [which i own and like in spite of edge softness] this referring to the screw mount version of a year ago. which i was looking into at the time ...............

    i know what you mean since m4\3s is a crop of 35 you would expect really good performance since only the center is used , could be the angle of the light waves
    i was wondered the same thing ,

    but i dont mind he 15s performance too much i love its dof and the look of the images it makes, imperfect as they are
  5. doc-mud

    doc-mud New to Mu-43

    Apr 5, 2010
    12 vs 15 mm heliar on GF-1

    I own both lenses (as screw-mount versions) and tested them (so far non-systmetically) on the GF-1. From my impression, I can confirm the soft edges to be more prominent on the 15 mm pics as compared to the 12 mm which appears to have both a better build and optical quality.
  6. laptoprob

    laptoprob Mu-43 Regular

    Jan 28, 2010
    ... but both the 15 and the 12 can hardly be called ultra wide angles anymore on a m4/3 camera. I sold both when I got Panny's 7-14. The 12 is slightly better in corners than the zoom, but slooow and not quite ultra wide.