Samyang 7.5mm vs DSLR 8mm; also Anglerfish software

Discussion in 'Native Lenses' started by RAH, Jul 6, 2015.

  1. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    Hi folks. I am a long-time Olympus 4/3 user (E-520) and recently bought an E-M10 (that recent sale was too good to pass up!). So I am looking at lenses for the new camera (I have a fair number of 4/3 lenses which I can use too).

    I just ordered a Rokinon (Samyang, Bower, etc) 7.5mm fisheye (m4/3 version). I already have a 8mm version which I use on a Canon and like pretty well.

    Of course, they appear to be fairly different, if not in specs, then certainly in appearance and size. I see that the minimum focus distance on the 4/3 version (3.5 inches) is much less than the DSLR version (12 inches). The lenses get different test results too, from my web searching. The m4/3 version seems to be even better than the DSLR version, which is no slouch.

    I am wondering if anyone has any experience using both and what if any difference they have found.

    On a related front, even before I ordered the new fisheye, I have been looking for good defishing software. My regular image editor, PaintShop Pro, has a built-in function which is so-so. I spent $25 for the PTLens plugin, but am not wild about it either - it doesn't seem to have many options or adjustments.

    I just tried using Hugin, which is normally a stitching program but can also do defishing on one image. I couldn't make much sense out of it so I watched a YouTube video on using it for defishing and MEGO (My Eyes Glaze Over) set in very quickly. Yikes! So it seems we have minimal control with PSP and PTLens, but mind-boggling control with Hugin. Although I don't know how good a job Hugin does, it better do a REALLY fine job after all that effort you have to make!

    I looked at the Fisheye-Hemi software too but after reading some posts on some forums, including this, I found Anglerfish:

    http://www.anglerfish.ajotte.com/index.php

    a standalone program which is $20 to buy. VERY nice! It has a lot of options and seems to do a much better job removing the fisheye distortion without distorting the rest of the image too badly, especially the edges. I figured I'd praise it here because I don't see it mentioned very often and think it works very nicely.
     
  2. gr6825

    gr6825 Mu-43 Veteran

    277
    Oct 10, 2012
    Personally, I do not understand using a FE and then "defishing." I think the fisheye effect is the reason for the fisheye lens. Anyway, just personal preference.

    With respect to differences (7.5mm vs. 8mm) you could look here: 7.5mm vs. 8mm

    The MFD is a big difference, which you already noted. The 7.5mm focusses very closely, and that is nice for a FE. It looks like the FOV of the 7.5mm is closer to 180 degrees versus about 167 degrees for the 8mm.

    I love these lenses. I had a Rokinon 7.5mm for M43, and it worked great. Actually for people shots, I wished for AF. But otherwise, it is a very sharp and capable lens. Nice projection too. Now I shoot with a Nikkor 10.5mm.

    Enjoy your lens!
     
    • Agree Agree x 1
  3. tkbslc

    tkbslc Mu-43 Hall of Famer

    The 8mm is designed to be 180 degrees on a 1.5x crop APS-C sensor. So on your Canon, you were getting maybe 168 degrees at 1.6x crop factor. On a 2x crop 4/3 sensor, that lens would only give about 135 degrees.
    The 7.5mm is designed to be 180 degrees on a 4/3 sensor and has a short flange depth to work around the m4/3 mount. So in terms of advantages to using the 7.5mm vs an 8mm on m4/3, the 7.5mm is smaller, lighter, shorter and gives a much, much wider and uncropped view. Compared to using the 7.5mm on m4/3 vs 8mm on your Canon, it will be significantly more compact and give a slightly wider view.

    Optically, they are both excellent. Not much there to worry about.
     
    • Informative Informative x 1
  4. tkbslc

    tkbslc Mu-43 Hall of Famer

    3 main reasons for me:

    1) The Samyang is about 1/4-1/3 the price of the cheapest 7mm rectilinear.

    2) Freedom to choose projection. I can shoot it fisheye and then decide later if it works better in rectilinear or any number of other in-between projections.

    3) The Samyang is about half the size of the 7-14mm f4 and maybe 1/3 the size of the 7-14mm f2.8.

    So cost, weight, flexibility.
     
  5. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    Thanks for the interesting feedback, folks. I actually didn't realize that the 7.5 would be somewhat wider than the 8 on my Canon. I agree that the closer MFD is nice to have because having something in the foreground is a common technique with such a lens.

    As far as defishing, as tkbslc said, it's nice to have the flexibility, and the lens is very much smaller than most other ultrawides and cheaper too - except for the Canon 10-18, but that's a whole other thing ;)

    I do have a 4/3 9-18, and it works pretty well on the E-M10, but it's much bigger, of course. I am not really saying that a defished fisheye is a perfect substitute for a non-distorted ultrawide, but I do want to give it a try...
     
  6. Whtrbt7

    Whtrbt7 Mu-43 Regular

    195
    Jan 7, 2014
    I use a Sigma 8mm F/3.5 at work for 360 work. It is a completely different beast since it is a circular 180 degree fisheye lens on 135 format. So the image looks like a circle when it comes out and then I stitch 6 frames together to get a full 360 spherical view. Canon crop bodies cut off some of the circle but it still does pretty well. The M43 fisheye lenses are currently full frame fisheye lenses that don't create a circle. I just got the Olympus 8mm F/1.8 and it has been quite awesome. The main difference for me is that I need to take 8 images in order to do the 360 sphere but I end up with higher quality final images due to DOF advantages as well as pixel level sharpness. I use the 8mm/1.8 for creative use too so I de fish images as I see fit and can compare them to rectilinear lenses as an after product.
     
  7. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    I think the Samyang 8 mm fisheye has a nearly stereographic projection, something that is very rare for a fisheye lens.
    (I nearly always transfor my Samyang 7.5 mm images to stereographic projection.)
     
  8. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    You can, but the corners will be very poor.
    The most difficult thing is related to perspective.
    A 7 mm rectilinear lens gives images with a very exagerated perspective. I need to see in the viewfinder this perspective to be able to obtain interesting rectilinear images.
    I find than defished images are nearly always disappointing.
     
  9. Paul80

    Paul80 Mu-43 Veteran

    254
    Jul 6, 2014
    Hi

    Don't have that lens but use Anglerfish with my 8mm Olympus lens and find it easy to use with good results.

    Like the OP I gave up trying to figure out Hugin and fisheye-hemi only works on verticals out of the box so no good for bent horizons without a lot of messing about.

    Give Anglerfish a go, well worth the small charge made for it.
     
  10. tkbslc

    tkbslc Mu-43 Hall of Famer

    I think it is funny that people would give up on Hugin so quickly, but they will shoot RAW muscle through learning the nightmare that is Lightroom. The workflow is actually quite simple once you know the 5 buttons to click. I found anglerfish to be far too simplistic and gives up 90% of the control I want.


    The corners are so much wider than a rectilinear shot that you can crop them out and still have a shot as wide. So I don't see that as a major issue. It depends on which projection you choose, again, as to how far they stretch.

    I do agree it can be difficult to mentally frame for different projections. I have the same problem with panoramas. But I work around it due to not wanting to drop $1000 on a 7mm rectilinear and for the flexibiility that I like. I kind of think of a fisheye shots as a "RAW" wide angle. I can tweak it to any projection and even slightly different perspectives later.
     
  11. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    If you found Anglerfish too simplistic, the SINGLE slider in PTLens for the actual defishing operation would seem unbelievably primative!

    Perhaps I could give Hugin another try, but my first impression of it was that it sure needed a lot of user effort to get anything worthwhile. The YouTube video showing how to use it that turned me off to it spent a lot of time showing how the user would mark vertical edges to help the program. I can see that if you did that carefully, you would undoubtedly get even better results than any fully automated program would give you, and you have a lot more control.

    I guess it depends on how much effort you want to make and how much control you need. Anglerfish seemed to me to give just enough control to get good results.

    I looked a little harder at Hugin's panorama stitching, just to see if I would like it for that (after I decided I didn't like it for defishing). It's pano abilities made me feel the same way - that it needed a lot of help from the user. This was a good test since I had some good input to try with it.

    I have a series of shots taken from a tripod which Microsoft's ICE (Image Composite Editor) did a PERFECT job of stitching together without ANY help from me. When I ran the same set of images thru Hugin, it did a terrible job and said it couldn't find any control points (which I guess are common areas in successive images that it looks for to help with the matching).

    I should say that my pano series of images are not perfect - I wasn't perfectly level, I had not even tried to find the nodal point, etc. But it didn't seem to bother ICE much at all. Even pixel-peeping I am unable to find any boundaries where things didn't get matched perfectly.

    I see that Hugin has a lot of tools to help you move the various images around to help it match things up, etc. But my feeling is if I am going to resort to that amount of effort, I might as well do it the way I used to - using PaintShop Pro layers, fading the edges of one layer into another, some cloning and careful erasing, etc.

    I really do wish I liked Hugin better, since I very much like using open-source software. Maybe if Anglerfish proves wanting, I'll look at it again.

    I agree with you about cropping out any offending edges after defishing, still leaving you with a very wide result.
     
  12. gr6825

    gr6825 Mu-43 Veteran

    277
    Oct 10, 2012
    Yes, but there is still the problem of the de-fishing process. If you are moving the image around, that is going to degrade the image. Of course the amount of degradation may be small, and it sounds like you are able to make this process work effectively. This is the personal nature of photography - finding what works for you.
     
  13. budeny

    budeny Mu-43 All-Pro

    Mar 4, 2014
    Boulder, CO
    @RAH@RAH - have you tried LR profiles for 7.5mm? I found stereographic projection plus ~30-40 pts distortion correction the most satisfying for me.
     
  14. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    Yes, I agree - moving the image will degrade it. A bunch of years ago I would NEVER adjust an image to straighten the horizon (or rotate it for any other reason), because I worried about the slight image quality loss you suffered. Maybe image editors have gotten better since then, but nowadays a don't worry about it and kind of forgot about it, since it is usually pretty important composition-wise to have straight images, at least as far as landscapes. Like you said, whatever works for you! :)
     
  15. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    I don't use LR (the last holdout!), hence my use of alternate software.
     
  16. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    These profiles are very good and easy to tweak.
    And you can change the settings anytime you want.
    I wouldn't use my Samyang so much without these profiles.

    Concerning Hugin, that's a very powerful program (for panoramas also), and not so complicated to use in the end, once you understand its logic.
    (I admit the first time I use it... I also found it horrible).
     
  17. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    I never used Hugin to defish (it's my favourite panoramic software when Lightroom doesn't work), so I made a test today.

    It's quite simple.
    1. Open your image
    step1.

    2. At the bottom of the screen, select "full frame fisheye":
    step2.

    3. Select 7.5 mm with ratio x2:
    step3.

    4. Go to the sticher tab.
    Select the projetction you want (rectilinear, cylindrical, stereographic):
    step4.

    5. Click on "calculate filed of view" / "calculate optimal size" / "fit to crop images".

    6. Click on "stich" at the bottom right

    Warning: with rectilinear projection, the size calculated is too high. You may prefer to export at 70% or 50% size.

    If you want to visualize the projections, you can click on the "GL" icon.
    You have several tabs and can play with your image.

    The correction are a little better in Lightroom (it's a profile specific to the Samyang), but Hugin allow more projections.
    The "cylindrical" is sometimes very good. It gives a "panoramic" feel.
     
    • Like Like x 1
  18. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    Some examples:

    Image #1
    - original
    Low_P1020211.

    - Hugin cylindrical
    Low_P1020211_Cyl.

    - Hugin rectilinear
    Low_P1020211_Recti.

    - Lightroom rectilinear
    Low_P1020211_RectiLR2.

    Image #2
    - original
    Low_OLY02461.

    - Hugin stereographic
    Low_OLY02461_Stereo.

    - Lightroom stereographic
    Low_OLY02461_StereoLR2.
     
    • Like Like x 1
  19. RAH

    RAH Mu-43 Veteran

    271
    Dec 1, 2013
    New Hampshire
    Rich
    I think I gave the wrong impression about how difficult I was finding Hugin for defishing. I found it difficult because I didn't much like the results I was getting by doing what is described in the post above. I mean, it was OK, but not a good as I could get with Anglefish (IMHO). So I was looking to see how it could be adjusted (ntot just picking different projections, etc). That was when it seemed to get rough. It's OK, I guess.

    I do wish that ICE, which I mention above for stitching, would allow using ONE image the way Hugin does - then you could use its projection techniques for defishing, just as being done with Hugin. But ICE won't do anything unless you give it at least 2. Oh well...
     
  20. SojiOkita

    SojiOkita Mu-43 Top Veteran

    620
    Feb 23, 2014
    France
    I just tested anglerfish software.
    Nice options, miss stereographic projetction.
    There is a profile for the 7.5 mm Samyang fisheye, which is good.

    I tested cylindrical projetction, it does a better job than Hugin imho.
    For rectilinear, the 3 (Lightroom, Hugin, Anglerfish) are very similar.
    The difference is on the corners, where I like Hugin best, then Anglerfish, then Lightroom.
    (Hugin has to be set to 50% size)