Samyang 14mm f/2.4 premium vs. Rokinon 14mm f/2.8 comparison

Introduction

I should probably preface this review by saying that I loved the Rokinon 14mm f/2.8 when it first came out. It was inexpensive, ultra-wide, and the best part, especially for a photographer like me who spends his nights out under the stars, is that it wasn’t afflicted with coma, an aberration that’s the bane of night-sky photographers (or at least this night-sky photographer). I bought my gold-ring Rokinon 14mm f/2.8 in 2011, and it’s been a workhorse of a lens ever since, although it’s suffered a fair amount of abuse at my hands. Despite me having no relationship with Samyang/Rokinon/Bower (all the same company, in case you were wondering), I’ve long recommended the brand to photographers who have taken my night-sky photography workshops and lessons.  

 

Hopes and dreams

I was pretty excited when I heard that Samyang was releasing a “premium” version of this lens, the 14mm f/2.4. On their website, Samyang Lens Global boasted that this lens was a “premium manual focus photo lens designed for high resolution photoshoots.” And then they continued, “It has the unprecedented resolving power, matched with 50 megapixels photo and 8K video productions. The resolving power contains abundant pixel information.” Wow! Sign me up, right? Never mind the fact that I’m shooting with my old Canon 6D, with its puny 20-megapixel sensor. 

What I really wanted from the lens were the following:

1. A reduction in astigmatism/field curvature, which was my main criticism of the original Rokinon 14mm f/2.8. The old lens tended to really elongate stars near the corner of the frame, which required either cropping or a lot of cloning work in post-processing.
2. A usable wide-open aperture. When I first began shooting with my old 14/2.8 I wasn’t terribly bothered by the softness at f/2.8, but as my skills as a photographer grew over time (and I began making larger prints) I realized the limitations of that lens at f/2.8 and began to shoot at f/4 more often, gaining a sharper overall image but losing a stop of light in the process.
3. A brighter overall frame (less vignetting). Making panoramas from my old 14/2.8 was problematic, as the edges of the frame were considerably darker than the center (even at f/4, unfortunately). 

And that’s pretty much it. Although these seem like modest requirements, I hadn’t yet found a lens that met them in this price range ($999). And all this language about “unprecedented resolving power” made me wonder if I should open the lens’s box with gloves, lest I cut myself on the sharpness of the lens.

 

Initial thoughts

As mentioned before, the Rokinon 14mm f/2.4 SP  retails for $999, versus $299 for the old f/2.8 version. Although this might sound like a big difference in price, I was willing to pay a premium (pun intended) for a lens with even small improvements over the older f/2.8 version. The first thing I noticed when I received the lens was the designation “SP” on the box, which I had somehow missed when ordering the lens. The SP stands for Special Performance. Perhaps the word “premium” didn’t fare as well in focus groups? (That pun not intended.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From an aesthetics standpoint, which I honestly care almost nothing about, the 14SP is a nice-looking lens and was clearly designed with Zeiss’s external look in mind. The focus ring is rubber, like the older version, but doesn’t have the grippy ridges of the old version. The front element is also larger, which probably accounts for the extra 200 grams of weight from the f/2.8 version to the f/2.4 version. The lens isn’t overly bulky, though, and feels fine on my Canon 6D. Unlike the older f/2.8 version, the SP version doesn’t have a manual aperture or manual aperture ring: The aperture is controlled electronically via the camera body.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Although the weight of my gear isn’t as important to me as other factors, I was relieved that the 14 SP’s weight didn’t reach that of the Tamron 15-30 or the new Sigma 14mm f/1.8, which are around half a pound heavier.

Also worth noting, unfortunately, is that the lens does not mount smoothly to my 6D, unlike any other lens I’ve owned or have tried. Instead, there’s some metal-on-metal friction that eases halfway through the twist before becoming sticky again. The closest comparison I can make is when, years ago, I bought the cheapest set of macro tubes I could find on amazon. This is not a good sign.

 

Comparison methodology

For these comparison tests, I shot with the lenses on my Canon 6D. Mirror lockup was used, as was my tripod. Neither the camera nor the tripod were moved between shots. Focus was achieved manually, with live view zoomed in 10x on the same focus point for each lens. I was extremely careful not to touch the focus ring at all after achieving critical focus. I also used a wireless remote with my drive set to a 2-second timer to eliminate any chance of camera shake.

The photos below are both completely boring (it’s Oregon in the winter, what can I say?) and unedited, save for the default settings applied by Lightroom. All photos were exported as web-res jpegs with no output sharpening.

 

Initial tests

All right, let’s get to the good stuff. We’ve been cursed with cloudy skies for quite a while in my part of Oregon, so instead of taking the lens out for some star photography, I took the Rokinon 14mm SP for a quick trip down to a local park. For this first set of comparisons, I chose a particular tree far beyond the bridge, which is where I focused the lenses (see below). I did that to simulate the technique of focusing on a faraway object (like a star, for instance) while shooting at night.

The red arrow shows my focus point for all 3 lenses, and I’m estimating  the focus point was around 70 feet away. 

Here’s a comparison of the two photos, both taken at 1/25th of a second, ISO 100, f/2.8. I know many of you are probably wondering, why f/2.8? Well, I’m a star photographer, and this would primarily be a “star photography lens” for me. I have to see improvement in these wide apertures to justify making a purchase like this. If the full resolving power of the lens doesn’t kick in until f/5.6, it’s useless for my needs (although clearly not useless for most other needs, including landscape photography).

On the image below, move the slider right to see the 14SP’s photo, and move the slider left to see the older f/2.8’s photo. 

Right away I noticed the following:

1. Slightly different fields of view (FOV), despite both lenses being 14mm, which could have to do with…
2. …less distortion for the 14SP. My next series of photos will better illustrate that the 14mm f/2.8’s infamous “moustache distortion” has been greatly reduced in the new lens. Strangely, the bridge structure appears flatter and more squat in the 14SP version, despite the fact that the older version seems to be a slightly wider lens. I was a little puzzled about that at first, but I think this is mostly a result of a decrease in moustache distortion. If you think about it, moustache distortion causes objects in the middle of the frame to arch upwards slightly. Since that’s been eliminated, I can only assume that buildings, mountains, and other tall, prominent objects will appear more diminished and flatter than the older version of this lens. The fact that moustache distortion could actually benefit landscape photographers who enjoy shooting mountains with an ultra-wide-angle lens was something I hadn’t really considered before.
3. The 14SP is a brighter lens, I’m estimating around 1/3 of a stop, with more contrast. The brightness may be partly due to the vignetting on the older f/2.8 being so extensive, which leads to my next point….
4. …less vignetting on the new lens, although some still exists.

I wanted some straight lines so that I could better see the differences between the two lenses as far as distortion goes, so I took the photos below, both shot at f/2.8, ISO 100, 1/30th of a second. The background was intentionally slightly blurred because I focused on a point on the far side of the bridge, which was only about 4 feet away: much too close for infinite depth of field at f/2.8, even at 14mm. Again, pull right to see the 14SP’s results.

Okay, so the new 14SP version clearly has less distortion. But something that really puzzled me on these were the out-of-focus (OOF) areas in the background: The SP’s OOF areas were far more OOF than the old 14’s, but only at the edges of the frame. The center background wasn’t quite as OOF. This inconsistency was my first real indication that something may have been wrong with the Rokinon 14mm f/2.4 SP.

I proceeded anyway, with the following photos, both taken at f/2.8, ISO 100, 1/250th of a second. Once again I focused on the same very far-away object for both photos, which meant I lost a little depth of field at the very front edge of my foreground. Again, pull right to see the 14SP.

 

 

Once again, we see that the 14 SP is brighter, with better contrast and less distortion. But when I started pixel peeping, I noticed some weirdness, which I’ll get to in just a moment, below. But to be honest, and this may sound a little foolish, I really didn’t buy this lens to shoot at f/2.8. I was really hoping to shoot the night sky with its wide-open aperture, f/2.4. After all, if this lens is indeed 1/3 of a stop brighter than the non-SP 14mm f/2.8, and if this lens is usable at f/2.4, we star photographers are gaining nearly a full stop of light (1/3 + 1/2 = 5/6). 

So before we hang it up, let’s make this already highly unscientific comparison even more unscientific: Let’s take a look at f/2.4 on the new lens vs f/2.8 on the old, below. First some notes: Both shots metered the same. The exposure on the 14SP was 1/400th of a second; the exposure on the old f/2.8 version was 1/250th of a second. That’s 2/3 of a stop difference in shutter speed. These two photos were taken about two and a half minutes apart, so it’s entirely possible that the scene lightened or darkened slightly in that time. Again, slide to the right for the f/2.4 version.

I think the old Rokinon may have a slight edge in center brightness, but it appears that the new Rokinon 14mm f/2.4 SP may have a slight edge in the vignetting department. I thought about comparing 100% crops of these photos to illustrate what seemed to be a negligible difference in sharpness, but we should probably just go straight to…

 

The weirdness

Okay, back to the weirdness, and this is where this comparison is probably rendered useless. Here’s an approximate 100% crop from the area that I focused the lenses. Pull right to see the 14SP. (Note: The crops don’t line up exactly because the field of view and distortion in each lens are slightly different.)

So I thought these crops were pretty similar, with the 14SP again having slightly better contrast and being slightly brighter overall (which is a good thing for star photography). Here’s where things get weird. Again, pull right to see the 14SP. (Note: The crops don’t line up exactly because the field of view and distortion in each lens are slightly different.)

 

 

Huh? Clearly the Rokinon 14mm f/2.4 SP has a problem with the right side of the frame. If you look closely, just to the right of the playground equipment you can almost see the line where the resolution turns to mush.

 

Here’s a crop from the same photos, far-left side. (Again, pull right for the new 14SP.)

 

 

Okay, so the 14SP is still brighter and has a little more contrast. I think that the sharpness here is fairly comparable, and not at all like the right side of the frame, although the 14SP looks like it may be slightly worse as far as sharpness goes. Which begs the question: Is there also something wrong (just not as badly wrong as the right side) with the part of this lens that renders the left side? Or is this how this is supposed to look?

I’m not going to go to great lengths pondering those questions here because I returned that particular lens and will get a replacement. When I receive the replacement I’ll definitely continue comparing it so that I can upload the results from that. Suffice it to say that this was a disappointing experience.

*Update*  I never did follow up to receive a second copy of this lens after sending the first one back. However, I’m leaving this incomplete review in place because I thought it might be of some small use to photographers considering purchasing this lens.

 

My wholly incomplete conclusion

The results here may lead to more questions than they’ve answered. I’m not sure we can assume that this particular lens only performed badly on the right side, although that may be the case. It very well could be that the entire lens underperformed due to some optics being out of place.

Regardless, we’ve gotta wrap this up with something. So let’s revisit my earlier hopes and dreams for this lens, as follows:

1. Less astigmatism: Maybe? Less distortion, for sure, but we don’t know if that means less astigmatism for star photography yet. Mark this one “unresolved.”
2. A usable wide-open aperture: Also “unresolved.” I would need a better copy of this lens to say for sure. On this copy, f/2.4 seems to resemble f/2.8 on my old Rokinon lens pretty closely as far as vignetting and sharpness go, although the new lens has better color and contrast. If I considered f/2.8 on my old lens to be unusable, I would probably have to consider f/2.4 on the new lens unusable, although f/2.8 on the news lens seems to be a clear improvement. But is that enough?
3. A brighter overall frame: This is true at apertures f/2.8 and narrower. But again, not true at f/2.4. However, I’m not sure how much vignetting can be influenced by out-of-alignment optics, so again, I’ll mark this “unresolved.”

Look, I know it’s unusual to have a usable wide-open aperture on an ultra-wide angle lens, and many photographers assume that they’re going to have to stop down for best performance. Truly, only star photographers hope to use these wide-open apertures. But interest in star photography and Milky Way photography seems to be growing at a pretty rapid rate, and Samyang will continue to have more competition in the fast, ultra-wide-angle lens market, as we’ve seen over the past year. If you’re only going to improve upon an existing product by an aperture value of a half stop, you’d better hope that half stop is usable.