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Samyang / Rockinon 7.5 mm feedback + questions

Discussion in 'Native Lenses' started by SojiOkita, Apr 21, 2014.

  1. SojiOkita

    SojiOkita Mu-43 Top Veteran

    614
    Feb 23, 2014
    France
    I everyone.

    After giving up on Olympus body cap 9 mm (I found on samples that the soft corners were visible even in websize images), I finally bought the Samyang 7.5 mm.
    I was not a great fan of fisheye lenses... but: affordable price + good IQ reputation + no other wide prime + I think I'll have the use for it on my next trip... all this made the decision.

    I'm learning to use it properly.
    Never had neither a fisheye nor a MF-only lens before.

    The focus scale is not very helpful (very long from 0.09 to 0.25 meters, and then very short to infinity) and it's too bad there's no automatic zoom/focus peaking when using the focus ring.
    However, I like the "stiffness" of the ring: it will not turn easily against your will.

    I seem to get better results in setting the focus ring just before infinity, and aperture around f/8 or just a little wider.

    So far, I've been pretty impressed with the images produced by this lens.
    When defishing the lens with Lightroom, the corners are a little weird, but considering the ultra wide angle of view (it seems to be wider than a rectilinear 7.5 mm), if you reframe a little, it's totally usable.
    I don't plan to defish all my images, but it can be useful sometimes (and you can also use lower percentages if you want to lower the "fisheye" look a little)


    Anyway, as I'm just starting with this lens, I wondered if some more experienced users had some tips/hints about how to get the best of this lens.
    (how to use the lens, or the body with this lens, what mistakes to avoid when using it, etc... etc...)
    Thanks in advance for your answers.
     
  2. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    I love my "Rokfish". I can't say I'm particularly expert with the lens, but a few things I've learned:

    - If you keep the horizon dead in the centre, then on landscapes, you can often get a fairly regular-looking photo without defishing.

    - Hugin does a good job of correcting bent horizons (when you don't put it on the centre-line) without defishing it. I forget exactly now how to do it, but it's a question of dragging the image in one of the preview screens.

    - Focus ring calibration tends to vary from copy to copy. It's worth experimenting with yours to find exactly where the hyperfocal distance is for f5.6 and f8. Then mark the barrel with that setting and in future, there's no need for focusing when the light's good and you're not focussing close up.

    - If you're a Lightroom user, there's a nice plugin called LensTagger that runs Exiftool as a batch job on selected photos. It's a quick way to tag all your images with the correct lens (but no aperture setting of course).

    - If you see a rainbow, grab your Rokfish - you can get the entire arc in a single shot. Cool!
    9719899556_d42ccd817f_b.
    Fishie Rainbow by Paul Kaye, on Flickr


    Hope this helps!
     
    • Like Like x 22
  3. Harvey Melvin Richards

    Harvey Melvin Richards Photo Posting Junkie

    Feb 15, 2014
    Southwest Utah
    My main comments would be to make sure that your fingers, feet, shadow and dogs are out of the photo. I have had way too many photos with these problems.
     
    • Like Like x 6
  4. GFFPhoto

    GFFPhoto Mu-43 All-Pro

    Feb 24, 2013
    Someone in this forum posted defished lens profiles for LR a while back. You can do a search.
     
  5. kwalsh

    kwalsh Mu-43 Top Veteran

    775
    Mar 3, 2012
    Baltimore, MD
    If you are using LR be sure to have it correct for chromatic aberration - this improves the corners quite a bit. You can see CA around the leaves in Paul's image even at web size, it is pretty significant CA but corrects automatically very nicely in LR. (BTW, very nice rainbow shot Paul!).

    Ken
     
  6. SojiOkita

    SojiOkita Mu-43 Top Veteran

    614
    Feb 23, 2014
    France
    Yes, that's the profiles I'm using.
    They work well.
     
  7. Andym72

    Andym72 Mu-43 Veteran

    330
    Mar 4, 2013
    Reading, UK
    If you are using an Oly camera, don't forget to set the IS focal length manually (from the SCP, highlight the IS box and press the middle button, then INFO).

    If you decide to use Hugin to defish, set the focal length to 7.66, not 7.5, you get more accurate results.

    If you want to keep the image 'fishy', reproject to Stereographic. Still clearly fishy but somehow looks less odd.

    Sort out CA and apply any noise reduction *before* reprojecting.


    Sent from my iPhone using Tapatalk
     
    • Informative Informative x 1
  8. SojiOkita

    SojiOkita Mu-43 Top Veteran

    614
    Feb 23, 2014
    France
    Thanks for the tips. I'll try what I can get from Hugin.
    Hugin is the software I use for my panoramas... very powerful and efficient.
     
  9. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    FYIs, RawTherapee (free) can do lens correction, CA correction, etc.

    DarkTable probably can too (also free).

    Barry
     
  10. LowriderS10

    LowriderS10 Monkey with a camera.

    May 19, 2013
    Canada
    It's a great lens...I usually focus it to just shy of infinity and forget about it. Every now and again I have to tweak it a bit, but for landscapes, etc, it works perfectly, regardless of the aperture.
     
  11. tjdean01

    tjdean01 Mu-43 Top Veteran

    842
    Feb 20, 2013
    I like to set it at 16:9 for "panorama mode" :)
     
  12. zensu

    zensu An Old Fool

    Aug 8, 2012
    Southeastern USA
    Bobby
    As a senior I love the "Rokfish" nickname! The're probably not a lot here who remember Issac Hayes on "The Rockford Files".
    Bobby
     
    • Like Like x 1
  13. inkista

    inkista Mu-43 Veteran

    332
    Jan 13, 2012
    San Diego, CA
    As with any fisheye, horizon placement is key in determining how "fishy" the image is going to look. Put the horizon in the center of the frame if you want less distortion:

    8668786909_c6abba5a59_z.

    Put it at the edge if you want more:

    8668802381_f46c1aee71_z.

    And if you're into panos, consider getting a tripod, a Nodal Ninja, and learning to stitch 360x180s.
     
    • Like Like x 3
  14. SojiOkita

    SojiOkita Mu-43 Top Veteran

    614
    Feb 23, 2014
    France
    After a (very) few weeks of use, I must say I love my fisheye ;)

    The horizon indicator on the camera is very useful with this lens (especially if you want to correct later)

    The most difficult thing I found in using it is my fingers/hand/elbows that are sometimes in the corner of the frames.
    (in the bottom left, as there is the mode indicator (P/A/S/M) I often don't see them in the viewfinder).

    I took a lot of pictures with it on my trip (maybe a little too much ;) ), I'll post some in the image post section when they'll be processed.
    It's a very fun lens to use.
    I was going to buy a 9 mm BCL but as I was going on a cruise on boat interiors are mainly made of curves, I thought this was probably the best time to buy a real fisheye. I don't regret it.

    I find the Lightroom correction "Samyang stereographic" very useful especially when there are people on the image.
    It gives a very "natural" look even if the lines are curved.
     
  15. davidp158

    davidp158 New to Mu-43

    9
    Dec 1, 2011
    Rokinon 7.5 won't focus - options to fix this?

    I bought a used Rokinon 7.5 fisheye lens, and suspect I have a bad copy. My problem is that images are extremely soft, while many reviews claim this to be a fairly sharp lens. I have tried all apertures with my GH4 and GH3 cameras, but the lens won't focus closer than 5 or 6 feet. Even at that distance, images are very soft. I have read posts about the infinity focus being uncalibrated with this lens, and that some brave souls have modified their lenses somehow. Is there a way to fine tune the lens myself, or do I need to send it back for repair?
     
  16. janneman

    janneman Mu-43 Veteran

    414
    Dec 6, 2012
    Netherlands
    Jan (John) Kusters
    Check the back side of the lens (the bayonet side). I have seen a few reports where the back element had been loose. Simply turn the metal ring to lock that last element again, if its loose.
    The focus is not automatic of course, but most people get excellent results with the lens just short of infinity and f5.6 or 8. For closer work, make sure not to focus too closely, the lens can be turned to focus very close up.
     
    • Like Like x 1
  17. Vivalo

    Vivalo Olympus Loser

    931
    Nov 16, 2010
    Finland
    The back element might be loose. Just screw it carefully clockwise so that it is tight. But try not to touch the glass surfaces.
     
    • Like Like x 1
  18. ahinesdesign

    ahinesdesign Mu-43 Veteran

    432
    Dec 6, 2011
    NC, USA
    Aaron
    Check the rear lens element - it comes loose on some copies of the fisheye, and can simply be screwed back into the lens body.

    I supposed its also possible a lens element has been knocked out of place from a drop, but I would check the rear element first.
     
    • Like Like x 1
  19. davidp158

    davidp158 New to Mu-43

    9
    Dec 1, 2011
    Thanks for all the replies. I removed the metal mount and checked the rear lens element, which appears to be snug.
     
  20. zensu

    zensu An Old Fool

    Aug 8, 2012
    Southeastern USA
    Bobby
    Mine is tight as a drum. Make sure if you mount the lens on a body with IBIS that you set the focal length to 8mm. They don't have a 7.5mm focal length but the IBIS will ruin your shots if it's turned on and you haven't set the lens focal length to 8mm.