Discussion: How wide can you go?

Discussion in 'Open Discussion' started by pdh, Oct 11, 2010.

  1. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    I've seen a number of threads and articles, here and elsewhere, in which folk have said that they wouldn't suggest using a non-native lens with a focal length of less than 35mm (or so) on a mFT camera.

    This is put down to non-native lenses not being designed in such a way as to optimise perpendicular incidence of light on the 4/3 sensor, which apparently does not tolerate more oblique angles well.

    It is said that as a result, you get "poorer" results, but I haven't been able to find this evidenced (or perhaps I haven't researched enough) with sample images, or even descriptions of what the poorer results look like.

    Yet I also see plenty of images posted here using short non-native lenses (the CV 12mm Heliar for instance at one extreme) which look pretty good to me.

    With the relative paucity of primes in the mFT lineup, and the high availability of non-native lenses adaptable to mFT, both brand-new and "legacy", and costing between a few pounds and a couple of thousand, it felt like a useful discussion to initiate ...

    So, do you lose contrast? edge sharpness? DOF? all three? Something else? I'm not talking pixel-peeping here, but how shots look on a good screen or well printed.

    Thanks in advance for any and all contributions ...
     
  2. grebeman

    grebeman Mu-43 All-Pro

    Mar 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    I've been well pleased with my use of the Voigtlander 15mm, f/4.5 lens in both good and poor light, as a walk round and landscape lens. I have recently obtained the 12mm, f/5.6 but have only taken a series of photographs in poor, flat light. They looked a little less sharp than those obtained with the 15mm lens when printed out at A4 size, however I was using the hyperfocal technique and wonder if it would be better just to set the lens to infinity focus for landscape work, the loss of about 0.2 or 0.3 of a metre at the close end of the range probably won't impact on most landscape shots.

    [​IMG]

    15mm Voigtlander


    [​IMG]

    15mm Voigtlander


    [​IMG]

    12mm Voigtlander


    [​IMG]

    12mm Voigtlander

    All images are uncropped

    Barrie
     
    • Like Like x 4
  3. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    Thanks Barrie.
    I have to say I'm slightly surprised that no-one else has contributed yet ... but maybe I'm the only one who thinks this is worth talking about!
     
  4. bradc

    bradc New to Mu-43

    2
    Oct 6, 2010
    Calgary
    I recently picked up the Pro-Optic 8mm Fish-eye (180 degrees on a APS-C sensor, little less on m4/3) for my Canon mount system and also use it on my GF1 with an adapter. Since it is manual it is quite easy to use. That said - I find the sharpness lacking on the GF1, and it has some ghosting I don't see on the Canon. It isn't unlike what you get when shooting a wide aperture prime wide open (though it seems to happen when stopped down too). I've only had it for a few days so I'll try to post a couple of examples of what I mean when I get some time.

    Definitely a few of us interested in this topic! I have to say that I see the same thing with my 60mm Canon macro - can't seem to get a lot of sharpness out of it, but an old 50mm f/2 Pentax seems to work very nicely - so maybe it does have to do with the angle of the light...
     
  5. Brianetta

    Brianetta Mu-43 Veteran

    438
    Sep 5, 2010
    North East England
    Real Name:
    Brian Ronald
    No pdh, we're just waiting for your results...
     
  6. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    as I don't own a usable non-native prime of less than 35mm, Brian, you will be waiting a long time ...
     
  7. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
    Hi,

    I've not been in this topic yet, because I don't understand the question very well.

    Are we talking about the shortest usable FL on µ4/3 in general ? In that case, my answer would be 7mm, because I use the 7-14mm Panasonic lens quite often. It's an excellent performer, but judged rather expensive by some.
    Here's an example of a 7mm shot from last sunday. Purpose was to check for flaring of this lens in very difficult situation with the sun shining almost directly into the lens. I feel the lens performed great !

    [​IMG]

    If we're talking only non-native solutions, then for me, the shortest FL used in "normal" photography is 24mm, in casu the Nikkor 24/2.0 which is also a good performer but much more subject to flare than the Panasonic.

    Here's an example :

    [​IMG]

    I also own a c-mount 15mm lens, the Kodak Cine-Ektar 15/2.5. This lens does not cover the whole sensor of µ4/3, so must be used in special occasions only.

    He're an example :

    [​IMG]
    C U,
    Rafael
     
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  8. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    Ok Rafael, thank you.

    I am not asking about which wide-angle lenses can be used on mFT, but about whether adapted lenses of less than 35mm focal length produce inferior image quality results in some way, comapred to those with a focal length of 35mm or greater.

    A C-mount like yours will almost always vignette I guess, but I am perhaps thinking about more common lenses such as those designed for older 35mm film cameras, or for larger sensors such as APS-x or full-frame
     
  9. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
    Hi, pdh,

    I can only speak for the lenses I own and in that focal length range, this means the Nikkor 35/2.0 and the Nikkor 24/2.0. Both are FF because they were meant to be used on 24x36 cameras. Since on a µ4/3 you will only use the sweetspot of those lenses, they can both be considered as excellent performers. I could not indicate any qualitative differences between them, except that the 24mm flares more. But, that has to be expected from a lens with such a large FOV.

    Oh yeah, I forgot about my Zoom-Nikkor 28-45/4.5 :biggrin:
    But it's hardly relevant because I have never seen one for sale anywhere.
    I own mine from the 80s, and hardly use it (I'm a bit afraight of "loosing" it since it's virtually impossible to replace it) and anyway, the focal range is more than covered by the kitlens from Panasonic.

    Still, here's a pic from that lens :

    [​IMG]

    C U,
    Rafael
     
    • Like Like x 2
  10. grebeman

    grebeman Mu-43 All-Pro

    Mar 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    Edge Sharpness

    I started a new thread this morning having forgotten that this one was opened some weeks ago on much the same subject, indeed I contributed to it then, so I've copied my posting from that new thread to here, hoping this doesn't confuse people too much.

    I have posted photographs taken with both the Voigtlander 12mm, f/5.6 lens and the 15mm, f4.5 lens in various threads. My thread https://www.mu-43.com/f56/mattiscombe-sands-south-devon-7327/ has forked in a couple of directions, one being the edge sharpness of wide angle lenses.
    I've done some testing this morning and can confirm what others have reported, that there is a poor level of sharpness at the edge of photographs taken with wide angle lenses. I have compared the two Voigtlander lenses with the native Panasonic 20mm, f/1.7 lens. Of the two Voigtlander lenses the 15mm is somewhat better than the 12mm, both lenses have very poor edge sharpness at f/5.6 with improvement being shown by f/11. That can be further improved by judicious use of unsharp mask.
    As with all things it rather depends on ones own expectations and subject matter. It would be nice to be able to test and print from photographs obtained with either the Panasonic 14mm or the two wide angle zoom lenses to see how much difference can be detected in real world photographs. Printing at 300 dpi or 360 dpi would be the deciding test.
    Perhaps a forum member equipped with one of the requisite native lenses who is on holiday in the south west at some time might like an excursion that would make comparisons and answer the question as to how much one is sacrificing in dogged determination to use these old lenses.
    In terms of printing I printed this one some time ago and was then, and still am well satisfied with the result.

    [​IMG]

    This begs the question about comparing tests to demonstrate lens sharpness with the perceived sharpness in "real world" photographs.

    Barrie
     
    • Like Like x 2
  11. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    Maybe a little off-topic, but what about the sensor being reflective compared to film and lenses needing AR coatings on the BACK side for digital?
     
  12. OzRay

    OzRay Mu-43 Legend Charter Member

    Jan 29, 2010
    South Gippsland, Australia
    Real Name:
    Ray, not Oz
    I've had no problems using CV lenses down to 12mm, and if you consider 4/3s lenses 'adapted', then the same applies to the 8mm and 7-14mm, all work perfectly.

    Cheers

    Ray
     
  13. grebeman

    grebeman Mu-43 All-Pro

    Mar 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    I don't consider that idea off topic, there was a web site I looked at some months ago, (in French and I'm failed O level), but the basics were clear. This person proposed a light baffle to be fitted a certain distance behind the rear element of adapted lenses, distance and diameter of circular hole in the baffle dependant on, if I remember rightly, the focal length of each lens. Others I believe have disputed the necessity for this arrangement.
    On a similar topic Ansel Adams in his book Camera and Lens talks about the problem of wide coverage lenses, in other words those with a much larger image circle than the area of the negative, giving rise to flare and subsequent fogging of the negative due to light bouncing around off the interior of the camera, in his case obviously large view cameras.

    Barrie
     
  14. grebeman

    grebeman Mu-43 All-Pro

    Mar 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    I agree with you Ray, I've been happy with the prints I've made at A4 size, however if you photograph small print for example the quality at the edge looks poor when examining the file in photo editor software, thus it would score low on a lens test, however the prints as perceived by the eye pass the test, at least to my eyesight.

    Barrie
     
  15. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    I guess that's true - if the photons aren't being captured by the sensor and turned into electrons, they have to bounce off and go somewhere ...
     
  16. OzRay

    OzRay Mu-43 Legend Charter Member

    Jan 29, 2010
    South Gippsland, Australia
    Real Name:
    Ray, not Oz
    Talking about wide lenses, for those who have the Voigtlander 12mm and/or 15mm, looking at the aperture when fully open, does it appear as if the aperture could actually open even more, but is intentionally limited?

    The 12mm especially looks like it could potentially open significantly more, but has been limited for some reason. Maybe the image quality (as it's designed for a Leica) drops off dramatically if allowed to open more than the f5.6.

    Cheers

    Ray
     
  17. Luckypenguin

    Luckypenguin .

    Oct 9, 2010
    Brisbane, Australia
    Real Name:
    Nic
    I recently saw some film lenses being sold on eBay as 'modified for M4/3' where it looked as though a small plate had been fitted across the rear element to reduce the image circle. It seemed like an interesting idea but still doesn't stop the excess light entering the lens in the first place. I have no evidence to suggest that it makes an improvement but on my Canon FD lenses I've been using a step down adapter (52-37mm) as well as a hood to achieve the same effect on the front of the lens. I've been meaning to do some back-to-back testing to see if it actually makes a noticeable difference.
     
  18. grebeman

    grebeman Mu-43 All-Pro

    Mar 13, 2010
    South Brent, south Devon (UK)
    Real Name:
    Barrie
    rear baffles

    I've found the web site that relates the experiences of a French guy using baffles behind the rear element of the lens. My french is virtually non existent sadly so all I could determine is that different lenses required different diameter holes in the baffle. Also he didn't have any examples of wide angle lenses.
    www.esperado.fr - Les baffles pour les optiques manuelles 24X36 ou moyen format sur APN APSC ou four third

    It generated some correspondence in the dpreview forums but no definitive conclusions that I could make out. There was some doubt being expressed as to whether the idea could actually improve the sharpness or whether it was just an improvement in contrast as a result of cutting down on the stray light.

    Barrie
     
  19. Luckypenguin

    Luckypenguin .

    Oct 9, 2010
    Brisbane, Australia
    Real Name:
    Nic
    Thanks for the link, Barrie. I put it through google translate - some of it comes out a bit X-rated, but anyway...I would tend to agree that if anything it would improve contrast more so than actual sharpness, but then a higher contrast image will appear sharper than a low contrast image. It would be an interesting experiment to test out the theory.
     
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  20. Rudi

    Rudi Mu-43 Top Veteran

    574
    Aug 16, 2010
    Australia
    The Canon EF-S 10-22mm seems all right at 10mm on the E-PL1... :biggrin:

    [​IMG]