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Preferences in characteristics of a rectilinear UWA lens?

Discussion in 'Open Discussion' started by maritan, Feb 12, 2015.

  1. maritan

    maritan Mu-43 Veteran

    388
    Oct 30, 2014
    Like many of you, I'm in a quest for a relatively fast rectilinear UWA lens for the m43 system. Something wider than 12mm. My wants are specifically for landscape and night landscape photography.

    There are certain characteristics that seem unavoidable. Distortion for example. Vignetting too. Many of these characteristics can be corrected during post processing, sometimes automatically if it's a native lens.

    I'm thinking more in terms of adapted/ non electronic native lenses (Voigtlander for example) - basically a lens that the camera (E-M1 in my case) doesn't communicate with. Here are the main characteristics that Lenstip uses to review a lens:

    • Image resolution (center and edge sharpness)
    • Chromatic and spherical aberration
    • Distortion
    • Coma
    • Vignetting
    • Flaring

    If you were looking for a rectilinear UWA lens, performance in which of the above characteristics are most important to you? Put another way, which of the negative characteristics can be corrected easily in post processing without too much of a price to pay? For example, distortion can probably be fixed without too much of a penalty. That would imply distortion would fall towards the bottom of your list if you could just check a box in LR and have it corrected.

    Anybody care to share your thoughts?
     
  2. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Minor vignetting is simple to fix.

    Has anyone reviewed the Kowa 8.5mm?

    Barry
     
  3. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Absolutely no coma.
    low chromatic/spherical aberration
    Image resolution (doesn't matter if it's high if there's stupid amounts of the above aberrations)
    Vignetting minimal and gone by one stop down.
    Flaring doesn't worry me.
    Distortion worries me even less, I'm happy for a moderate amount as long as the first two are basically gone.


    What's useful for one thing can be useless for another, the hardest to find though is a lens that has amazing coma performance as the only brand that seems to be minimize it is Rokinon/Samyang. I've been looking at their 16mm f2.0 in Canon/Nikon mount lately and wondering how it would cope with being speedboosted (if it regains the performance of it's unboosted nature by one stop down when boosted I would find that acceptable due to the gain in view).

    Wider would be good, however I prefer usable performance over figures on a spreadsheet and currently I can't see many lenses which are of very high quality.
     
  4. maritan

    maritan Mu-43 Veteran

    388
    Oct 30, 2014
    • Like Like x 1
  5. maritan

    maritan Mu-43 Veteran

    388
    Oct 30, 2014
    Good points. You are right about Samyang lenses actively trying to minimize coma. Per Lenstip, the Sigma 10-20 f3.5 also minimizes coma but at the longer end. At the shorter end, it is pretty significant. I also have my eye on the 14mm f2.8 Samyang in Canon/ Nikon mount with a speedbooster. Per Lenstip again, the Samyang 14 mm f/2.8 ED AS IF UMC has virtually no coma on an APS-C sensor! Chromatic aberration was deemed "quite good."

    The reason I want wider than 12mm, is because I already have the 12-40mm Pro lens. I'm having trouble figuring out how much I'd gain by say a 16mm f2.0 speedboosted back to 11.36mm f2.0 (stopped down one). The view would be very similar to 12mm, but of course brighter.

    Edited to add: Why not just an Olympus 12mm f2.0 at that point? Native lens, no need for speedbooster etc.
     
  6. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    I have the 12-40mm however the Oly 12mm has never really impressed me. The native lens part doesn't worry me at all, I already have the speedbooster etc.
     
  7. Biro

    Biro Mu-43 All-Pro

    May 8, 2011
    Jersey Shore
    Steve
    Is the Olympus 9-18mm that bad?
     
  8. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Nope, it's a very good compact lens. It's just the maximum aperture is pretty slow and you're going to be pretty limited when shooting in no light conditions.
     
  9. christofp

    christofp Mu-43 Regular

    135
    Jul 21, 2012
    Maybe it can help here, at least it could make buying a 10 or 11mm lens obsolete:

    the 12-40 is a 10.9-40mm lens actually.

    Currently I use CaptureOne instead of LightRoom or OlyViewer. C1 is using its own lens correction data and does not do the aggressive cropping.

    On most lenses there is no big difference but the Oly12-40 is heavily cropped by default. I am wondering why Oly and Adobe decided to do so because vignetting and corner sharpness is quite OK even at 10.9mm.

    Christof
     
    • Like Like x 1
  10. maritan

    maritan Mu-43 Veteran

    388
    Oct 30, 2014
    Christof, thanks for that piece of info. I did read on here before that there was some cropping going on, but wasn't aware of how much.

    I guess I really am just looking for a really bright lens at this point (G.A.S.) or just learn how to use the f2.8 lens to the fullest of its ability (probably what I should do).