9.5mm f/3.5 - Panasonic DMW-GWC1 Wide Converter on the 12-32 mm

Discussion in 'Accessories' started by wjiang, Jan 23, 2015.

  1. wjiang

    wjiang Mu-43 Hall of Famer

    So after the poor results I got from the GWC1 with the PL15 (wide angle converter for panasonic 15mm), I decided to sell the thing.
    But not before I did some more experimenting...

    The GWC1 comes with a 37mm adaptor for the 14-42 PZ, which also happens to be the thread size for the 12-32 pancake. Would it work?

    Basically, yes.

    12-32mm at 12mm + GWC1 (9.5mm), f/3.5:
    P1240072.

    There's unrecoverable vignetting, but only in the extreme corners. After correcting barrel distortion and cropping to 3:2, you don't even see it:
    P1240070.

    For comparison, here's what you get from the 12-32 at 12mm:
    P1240073.

    The really surprising thing is that this combination is still decent optically. It looks as good as any example I've seen from the 14mm + GWC1 - the centre is sharp and the corners aren't too shabby either. After seeing how much better this combination is, it's even more disappointing how poorly matched the PL15 is.

    Edit: I've cleared out Dropbox so the RAWs are no longer available...
     
    Last edited: Mar 21, 2016
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  2. ManofKent

    ManofKent Hopefully still learning

    789
    Dec 26, 2014
    Faversham, Kent, UK
    Richard
    That looks surprisingly usable.
     
  3. wjiang

    wjiang Mu-43 Hall of Famer

    I know, right? I don't have any use for it though as at f/3.5, I've got something better and wider - just needs a little software magic to re-project from fish-eye ;-)
    P1240076.
     
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  4. damienr8

    damienr8 Mu-43 Rookie

    11
    Apr 12, 2014
    What lens is this?
     
  5. tkbslc

    tkbslc Mu-43 Hall of Famer

    Wow, what software do you use to de-fish that shot as shown above? Assuming 7.5mm Rokinon/samyang?

    Since you have to crop in about 5-10% or so to get rid of the vignetting, I think you are back near the 10.5mm as promised from that adapter when used on the 14mm. Still nice to see how it works, thanks.
     
  6. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Guys, read the thread title, or the text above the first pic.
     
  7. wjiang

    wjiang Mu-43 Hall of Famer

    Samyang 7.5mm m4/3 fish eye.
    I use Hugin to reproject. I prefer the term reproject as I'm actually converting from one projection (fisheye) to another (here Panini General I think), not usually rectilinear which is what most people consider defishing to be.

    The crop with the 12-32 plus converter should still give a wider 3:2 result than with the 14mm, I only cropped the top and bottom, not the sides.
     
  8. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Oops, sorry!

    Barry
     
  9. LPG1964

    LPG1964 Mu-43 Rookie

    16
    Mar 20, 2016
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  10. Bruce McL

    Bruce McL Mu-43 Veteran

    The dropbox link in the first post does not resolve for me. I get an error message.

    As an option to cropping the WAC plus 12-32 to 3:2 or 16:9, I wonder if shooting at 14mm instead of 12 would get rid of the vignetting.
     
  11. wjiang

    wjiang Mu-43 Hall of Famer

    Sorry... I think I cleared out my Dropbox of random stuff so it's probably irretrievable now. As to your question - yes the vignetting was effectively gone by 14mm.
     
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  12. SojiOkita

    SojiOkita Mu-43 Top Veteran

    619
    Feb 23, 2014
    France
    Very interesting.
    I won't have the use for it either, as what I miss is an ultra wide prime (not an ultra wide zoom as I already have the 9-18) but I'm surprised by the results.
    As the 12-32 is sharper that the 9-18 I wonder how 12-32 + converter would compare to the 9-18.


    Yes, panini projection is much more pleasing than rectilinear for fisheye images.
     
  13. wjiang

    wjiang Mu-43 Hall of Famer

    Would have been an interesting comparison indeed... I eventually got a 9-18mm since this post, but I find corner sharpness really is lacking at f/4. It's decent by f/5.6 but never really gets to be great.
     
  14. LPG1964

    LPG1964 Mu-43 Rookie

    16
    Mar 20, 2016
    Good to hear this. I was also pondering buying the 9-11 because of its attractive price and small size. A pity that it isn't that sharp. The better Pana and Oly are much larger and costlier...
     
  15. Egregius V

    Egregius V Mu-43 Regular

    127
    Jun 14, 2015
    Massachusetts, USA
    Rev. Gregory Vozzo
    One's mileage can vary depending on subject distance, shutter speed/stability, lens quality, and maybe other factors. I've seen counter-claims that the 9-18 is sharper than the 12-32. I don't have the 12-32, but do know that my 9-18 is capable of pretty sharp images edge-to-edge and is capable of beating my 14mm+ zooms at its wide end. Yes, it is weakest at 9mm f/4, where it is a bit soft at the far edges and corners. That's certainly not ideal. However, I find for my own use that the softness is minor. The 7-14 zooms have been tested extensively and can be sharper in the corners, but not always and not by enough to make me want to trade. Besides, there are reasons to prefer the 9-18 that have nothing to do with sharpness.

    On the other hand, I'm eagerly awaiting a review of Nikon's new (not-yet-released) 18-50 DL camera to see if it's worth having over the Oly. 9-18 for indoor shots.

    It's great to see what wide converters can offer as an alternative! I've often wondered. Lucas's media shelf images from the 12-32 + WAC look an awful lot softer than what I get with the 9-18 (also using a media shelf), but I'm not so sure about how the OP's outdoor images compare. My 9-18 at 9mm f/4 is more comparable to Lucas's 14-42 + WAC at f/8.

    FWIW, I have an album on Flickr for shots I took with the 9-18 lens. Pixel-peeping is encouraged. :biggrin: I doubt they're up to everyone's standards, but they all look fine to me. Admittedly, most of these are keystone-corrected and otherwise processed to some extent, but the EXIF info is there and the images are not resized at all.
     
  16. wjiang

    wjiang Mu-43 Hall of Famer

    The 9-18 is soft in the corners at 9mm f/4 but by f/5.6 I'm pretty sure it does noticeably better than the converter. I never felt the need to stop down past f/5.6 except to get more DoF. Centre sharpness isn't a problem for the 9-18, so unless I need across the frame sharpness for architecture or landscapes, I have no qualms about using it at f/4 (e.g. for UWA street, event and portrait shots).
     
  17. LPG1964

    LPG1964 Mu-43 Rookie

    16
    Mar 20, 2016
    Hi Egregius and Wjiang,

    Good to hear about your experiences with the 9-18 mm. I will look on Flickr to do some pixel peeping. What I particularly like about the 9-18 is its size and the possibility to add filters. In that respect the more expensive Pana and Oly have a serious disadvantage.

    I choose that shelve with cd's on purpose because it clearly shows the flaws in the edges and corners of the picture. If you do some landscape shooting you won't notice that much when the flawed area contains sky or grass etc. It really depends on what subjects you are shooting.

    What I forgot to mention about the Pana converters; the attachment of these converters to a filter thread is done through an included plastic bayonet adapter. That is unfortunately not so sturdy and accurate. It is a rather bad and foolish construction that does not guarantee a very precise positioning of the converter. Hence we see some asymmetrical vignetting in the 12-32 with the Pana WAC. It would have been much better if these converters just had a straight 37 mm thread (and a 46 to 37 mm step-down ring included). This is a real blemish for an otherwise excellent piece of glass.
     
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  18. LPG1964

    LPG1964 Mu-43 Rookie

    16
    Mar 20, 2016
    Hi Egregius,

    I looked at a few of your beautiful photo's in Rome on Flickr, but the maximum size I could download was 2048 x 1152... Is that right?
     
  19. wjiang

    wjiang Mu-43 Hall of Famer

    There are elaborate square filter holders for both 7-14 lenses, but I agree that it's more straightforward with the 9-18. That was my big reason for getting it.
     
  20. Egregius V

    Egregius V Mu-43 Regular

    127
    Jun 14, 2015
    Massachusetts, USA
    Rev. Gregory Vozzo
    Sorry, it looks like I had restricted who can download full-res photos. I've temporarily disabled that restriction, so you should be able to download full-res images now. (I wish that could be done more selectively!) For example, this one at 9mm, f/4 is 4616x3456. Interestingly, the out-of-camera JPEG is 4608x3456 - all I did was load the RAW image in DxO Optics Pro 9 and apply some lens-profile distortion adjustments (to taste) and some brightness/contrast/color adjustments.

    Full disclosure, a.k.a. TMI: For some reason, DxO is able to pull more pixels from the RAW file than most other converters, presumably from the far edges of the sensor. I believe I actually reduced the width a bit by applying distortion adjustments which reduced elongation at the far left and right edges. I also left in some volume distortion which makes the pillars look slightly curved. Call it an artistic decision or n00b clumsiness - I don't remember which was the greater influence. :D

    EDIT: time's up - I reset the access restriction for the time being. Not sure it's wise to leave it off.
     
    Last edited: Mar 28, 2016