Comparing Fish-Eyes : Rokinon 7.5mm vs Zuiko 8mm (FOV and look)

OK, call me stupid, but I bought a second fisheye lens.

I already owned the digital ZD8mm FE in FT mount.  Great lens.  Love working with it, also on E-M5.

And yet I got seduced and, on impulse, purchased the (manual) Rokinon 7.5mm FE in µFT mount.

I've tried rationalizing my reasons here : http://forums.dpreview.com/forums/post/50727693

Being now in the position to show some stuff from both fish-eyes, I thought to post a few things that might be interesting.

Don't expect pixelpeeping or essays on relative sharpness or chromatic abberations from me.

I don't do that stuff.  You  can trust the various reviews that float the www.

What I can show you, is a view of both lenses mounted on my E-M5 (shot with iPhone).

The ZD8mm requires, of course, the MMF-3 adapter, so that makes the combo still bigger.

Build quality of the Zuiko is legendary.  And it is of course weathersealed.

But the Rokinon also feels very solid and well made.

The difference in size and weight is pretty spectacular (and one reason for my purchase).

In fact, the size of the Rokinon is SO SMALL that I will really need to adjust how I hold my camera-lens combo, or I am going to get an awful lot of shots with my finger in the frame...

With the Zuiko, I had to watch out for my own feet, but at least my left hand had ample room.

This is particularly the case when the horizontal grip is mounted.  The extra grip real estate extends almost as far as the front element of the lens.  Hard to get rid of another finger (of left hand) in that area without it showing up in the frame.  This continues to amaze me.

Another thing I can show is the relative FOV : I wanted to know if that 0.5mm really makes a difference.

Well yes, it does.

Here is the tripod shot of our meeting room with the Rokinon.  I lined up the shot to get the top arch of the lighting fixture and the side of the right-side painting next to the edges of the frame:

And here is the shot, from the same tripod position (maybe with a bit of wiggle from the mounting/dismounting of lenses, but basically the sensor stayed in the same spot), with the ZD8mm:

Note how that top arch and the right side of the painting are not in the frame anymore.  Also significantly less plant on the left side.

Now, I did figure out that this difference is NOT ONLY the result of the 0.5mm difference.

The front element of the lens is also roughly 6 or 7 cm more removed from the sensor plane, and I supposed that this also accounted for some of the difference.

So what I did, is realign my viewfinder view with the top of the lighting rail arch and with the right side of the painting (by moving my tripod a few centimeters backwards):

The result is a shot that looks more like the first, but is still noticeably a bit less wide.  Pay attention to the left and bottom sides, of course : the left side painting is closer to the edge of the frame and there is less plant visible.

So that 0.5mm extra does indeed make a difference.

And there is also a practical issue : the ZD8mm needed to be 6 or 7 cm further away from the scene to capture a view that was as close as I could get it.

This does not matter much in most shooting conditions, but it does make a practical difference, when one is trying (as happens to me quite frequently) to get as much as possible of an interior into the frame by pressing one's back against a wall or in a corner of a room.  In those circumstances, the Rokinon will really show more.

Anyway, I thought this might interest some.

I hope to show more interesting fisheye shots soon.

I also already figured out that the Rokinon will be much easier to handhold with one hand only, for those contortionist angles that I sometimes employ.  Easier for video too, but that is not really my concern.

Nevertheless : the Zuiko (for those people lucky enough to already have it) remains a great lens, also for use on µFT.

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

You can say that again. You really have to be careful with this. I was out shooting with the Samyang on the E-M5 a couple of days ago and had my gloves on since it was -10 C. This wasn't a such a good idea. I came home with quite a few shots where the corners were blocked by a glove or two.

Once your fingers know how to the proper walking, I hope/think you'll have every reason to be happy with your new lens.

ThankThank I you for sharing. Very interesting.

Another thing that you can notice when looking closely, is that the extra 0.5mm also creates a bit more curvature/distortion.

Look at the top of the frame.

The curve of the lighting fixture is realigned in the 8mm shot to just touch the top of the frame again.

But the two claws with which that fixture is attached to the ceiling, are better visible in the 7.5mm shot than in the 8mm shot.

It is subtle but it is there, that difference.

If you want to look at much larger versions (monitor wide up to 2400pixels long side), look here in this gallery and use slideshow view:

http://roelh.zenfolio.com/p516385498

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

Really appreciate that comparison, as I decide if and when to go for the rokinon myself.  Since I used to own the ZD fisheye, that is very useful for me.

Using a FishEye with gloves: ouch, you lead the dangerous life!

I'm sure I will be. I'm already getting used to holding my left hand under the camera after a few short minutes of test shooting.

There is no need for hand on lens anyway : no weight to support, and once aperture is set, there is hardly a need for more manipulation.

Focus can be set to infinity for almost anything. The next focus stop is 0.25 meters.

Only for really really close focusing, does one need to use the focus ring, but then it will be a matter of careful shooting anyway.

In fact, I think this lens-camera combo lends itself well to one-handed operation, with fluid results.

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

I sold my Nikon 10.5mm f/2.8 fisheye, which I mostly used on my Nikon DSLR but also on my m4/3 cameras. The Nikon fisheye was a superb lens, but by all reports so is the Rokinon. And since I mostly shoot m4/3 these days, I wanted a wider native fisheye. So I sold the Nikon for $450, bought the Rokinon, and put the other almost $200 towards a used Oly 9-18mm. Now I've got the m4/3 ultrawide kit I have wanted for more than two years

I had used the Nikon Fisheye for something like five years. The Rokinon seems every bit as sharp, and actually seems to have less of a purple fringing issue. That's correctable in Lightroom anyway, but it seems like the Rokinon does not exhibit as much fringing before correction. It's hardly been an issue so far.

The Rokinon is of course smaller as well, and like you I discovered that it's diminutive size is both a blessing and a curse. I am sure I will get used to it, but I frequently discover that my finger is in the frame.

Sean

Thank you very much for sharing. I've been mulling over getting this lens for a while and lately I've been leaning toward the Rokinon.

Your comparisons help a lot. Have you done much PP in de-fishing either lens? There are times when the fisheye effect is perfect and other times I'm curious what effect straightening things out a bit has on the image.

Bobby

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Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

Thank you for doing this!  And for all those that have this lens, I too had the finger issue.  First one I shot, my finger was in the lower part of the frame!  I was really surprised at just how wide this lens is!

Couldn't agree more. Been there, done that, and my thoughts are exactly the same as yours.

I'm sorry that I cannot help on that subject.

Because I never use de-fishing software.

But I wonder if such software would discriminate between lenses used.  I think it would use optical information found in the image itself.  Or is the process of de-fishing purely mathematical, regardless of actual content, and are the algorhythms written to match with specific lenses?

Really, I would not know.

But you could ask in one of these threads, where people are talking about de-fishing in a very informed manner :

http://forums.dpreview.com/forums/post/50722127

http://forums.dpreview.com/forums/post/40689446

Or maybe ask KenW or AndersW.

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

Hi Bobby,

Roel PM'd me to point out your question here.

There are really two kinds of de-fishing commonly done.  The "classic" approach is to change the "fisheye" projection (usually close to an equal area projection) into a "rectilinear" projection (gnomonical projection) which is what we are used to with "normal" lenses.  This will turn the 7.5 or 8 mm into looking very much like the 7-14 at its widest end (and actually will be a bit wider).  This type of transformation is rotationally symmetric, that is all directions are treated the same (horizontals, verticals, diagonals).  When we do this kind of de-fishing and then crop to a rectangular final image two things happen:

• We lose quite a bit of the corners
• The image is stretched quite a bit on the edges of the final image which lowers resolution and can turn circles into ellipses which can be very unflattering for faces

Both the 7.5 and 8 are nice sharp lenses and resolution wise they actually handle the stretching of a de-fishing quite well.  They will act a bit like a 6mm normal lens (rectilinear) but the extreme edges might be a bit ugly.  You can of course crop just a bit more and get a perfect match for the 7-14 at 7mm as far as perspective goes.  You can see some examples in the threads Roel linked to.

This fisheye to rectilinear de-fishing can be done with almost any lens correction software out there, including Lightroom lens profiles.  There are freeware options as well.

The other kind of projection that has recently become more popular is not symmetric at all and is based on how architecture painters of the past represented wide angle perspective in their paintings.  These guys of course didn't do any math, they eyeballed what "looked right".  In doing so they effectively corrected horizontal lines differently than vertical lines (e.g. they made sure verticals stayed vertical, but allowed horizontals to curve).  Recently people have come up with some tunable projections that reproduce what this artists did by eye years ago.  Besides being good for architecture they are also great for images with people in them as they tend to not distort faces as badly.  One of the common projections of this family is the Panini projection you can read a bit about it here:

http://wiki.panotools.org/The_General_Panini_Projection

Again there are freeware options for this, or there is the Hemi tool which uses it and the most recent version of Photoshop includes such a projection as well.  I think Martin Evening even did an article here on DPR about the new defishing and panorama projection settings in Photoshop.

Both the 7.5 and 8 handle this projection nicely as well.

Anyway, hope that was helpful.  I'm rarely around the forum these days so if you have more questions best to PM me.

--
Ken W
See profile for equipment list

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

For those of you in the US of A, $242 at overstock.com. Everyone buy it so they go out of stock and then I won't need to resist.

Thanks for info on price at overstock.com.  I had been thinking about buying at B&H for $280, but decided to pull the trigger at overstock.com, when I saw your post.

Just to be clear: I have no affiliation with Rokinon nor do I benefit in any way if any of their lenses get sold.

If anything, there will be more people using fisheye, and the look will become more common.

Bad news for me, because I depend on fisheye to help me make shots that are halfway decent.

BTW: I bought mine from amazon, because the lens is hard to find in Belgium and not that many online stores are reliable and ship to Europe.

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

You're welcome.

And what did it make you decide? And why?

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html

I think that may be the final push over the cliff for me to get the Rokinon as my next UWA.  I still miss my ZD fisheye and I will miss the weather sealing, but that Rokinon looks significantly smaller than I expected.  Seems like a great tool to throw in the backpack for when I find myself in an unplanned situation that just screams fisheye.   And if I buy the Rokinon instead of the panny fisheye, I can easily keep saving for a 7-14 for when I'm feeling like a rectilinear lens, while still have some options on the UWA side of things.

The zuiko really does look the business on the om-d!  Is it really weather sealed?  My copy doesn't have any sort of silicon/rubber gasket at the lens mount like the 12-50 and like the pentax weather sealed lenses do.