Samyang 24mm f/3.5 Tilt-Shift Lens on GFX: a deep dive

Started 5 months ago | Discussions
Rob de Loe
Rob de Loe Senior Member • Posts: 1,354
Samyang 24mm f/3.5 Tilt-Shift Lens on GFX: a deep dive
9

This is a series of posts about the Samyang 24mm f/3.5 Tilt-Shift Lens on GFX.

My adaptation of this lens is a bit unusual, but the optics are the same as the stock version.

The post is long, so here's the short version: Hmmmm, not as bad as I've been led to believe... In fact, I can use this lens for serious work on my GFX 50R!

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Overview

Main entrance, Basilica of Our Lady, Guelph, Ontario, Canada. Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens with 12mm of rise, f/16, on GFX 50R. Click on image for full resolution JPEG.

There was a lot of excitement when the Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens was released. This lens, which also sold under the labels Rokinon and Bower, promised tilt-shift movements for a fraction of the cost of the Canon TS-E 24mm f/3.5L II Tilt-Shift Lens.

If you read the numerous reviews published since the lens was released, you’ll know why initial excitement at the prospect of an inexpensive tilt-shift lens for many different mounts was followed by some disappointment.

  • Reviewers typically described image quality as poor until f/8, or even f/11. Several reviewers said that the Canon TS-E 24mm f/3.5L II Tilt-Shift Lens is better at f/3.5 than the Samyang is at any aperture.
  • A lens meant for shift is often used by architectural photographers, so distortion should be minimal. The Samyang has strong barrel distortion.
  • Tilt-shift lenses are hard enough to use with well-design controls. The tilt-shift controls on the Samyang are described as hard to use and feeling flimsy.

With problems like that, why would anyone be interested in this lens, especially someone using a demanding 33mm x 44mm sensor? There are other options:

  • GFX users who need the focal length but don’t need tilt and shift have the superb Fuji GF 23mm f/4 R LM WR.
  • People who need movements can adapt the Canon TS-E 24mm f/3.5L II.

The Samyang competes mostly on price. You get an image circle large enough to cover the GFX sensor and allow for some shift, at a fraction of the cost of the much better Canon TS-E 24mm f/3.5L II (but with a lot of compromises).

I need movements on a wide angle lens, but I can’t use the Canon on my GFX 50R + Toyo VX23D digital view camera. Despite its well-documented flaws, I took a chance on the Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens. I’m glad I did because it’s much better than I was expecting. This is by no means a first class lens, but with some care it’s possible to get excellent results.

In this thread I provided information – and files – you can use to judge for yourself if the lens will meet your needs. Many of the images are full resolution JPEGs. I’ve also provided some sample RAF files in this Google Drive folder .

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Backstory

I’m not really a wide angle person, so my SMC Pentax-A 645 35/3.5 has been meeting my needs up to now. However, I’m increasingly needing a wider lens, and flat stitching with the 35/3.5 is not something I enjoy doing or find reliable.

I bought the Samyang after studying the disassembly post on the Lensrentals blog , and reviewing some GFX 50R RAFs provided by a generous forum member (thanks Matt!). On that basis, it seemed worth a shot.

For my needs, the fact that the lens comes apart easily is ideal because it makes remounting simple. I bought a used Canon EF mount version from the local classifieds, removed the shift mechanism, locked down the tilt mechanism, and attached it to a Toyo recessed lens board. Removing the shift mechanism bought me the extra flange distance that allows the lens to work well on my Toyo VX23D. With this arrangement, tilt and shift now happen on the VX23D rather than via controls on the lens.

Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens mounted to a lens board for my Toyo VX23D.

Even though I’m using a custom mount, most of this post remains relevant to people using the unmodified lens. The key difference between my setup and using it natively is that I do tilt and shift with the VX23D. The optics are the same.

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Sharpness

When I bought this lens, I started from the assumption that image quality would be poor until f/8 or f/11, and even then not particularly good. After putting the Samyang through its paces, I’m puzzled by the consensus in the reviews I read. On my setup, the Samyang does much better than I’ve been led to believe. Getting the best results form this lens is not easy, so I wonder if some of the bad experiences people have reported are due to user error (e.g., not focusing in the best spot in the scene, misalignment due to the tilt mechanism not being perfectly zeroed).

Is there anything more uncharacteristic for me than a colour car shot? I don’t think so. This is f/5.6 so you can see sharpness at the point of focus (orange reflector), and you can evaluate how the lens transitions to out of focus. Click on image for full resolution JPEG.RAFs for f/5.6, f/8, f/11 and f/16 are in the Drive folder.

When I’m evaluating a new lens, I make a set of images from the same location in the city where I live. It’s a high point of land that looks over the downtown. I’ve used it so much I can quickly spot problems.

View of Guelph from Catholic Hill. Samyang 24mm f/3.5 ED AS UMC Tilt-Shift at f/11

All the reviews I’ve read say this lens is unusable at f/3.5. The comparison pair below is f/3.5 and a 100% crop from my long distance test scene on a sunny afternoon. This part of the scene was in full sunlight. The point of focus is the chain on the fence in the foreground. The uncorrected image (left) is low contrast and looks unsharp; I can see why reviewers describe image quality as poor. However, a few simple adjustments in Lightroom produce a dramatically improved result (right).

The “Before” image at left is the f/3.5 RAF at 100% following import into Lightroom. The “After” image at right is the same file after basic corrections.

Sharpness increases noticeably at f/4 and peaks in the central part of the image at f/5.6; edges and corners are a bit softer than the middle of the frame at f/5.6. Diffraction starts being noticeable at f/8 on my GFX 50R, but f/8 provides the best overall sharpness across the whole frame.

Uncorrected f/3.5 (left) and uncorrected f/5.6 (right) at 100%. The soft hazy look is gone by f/5.6 and the image is as sharp as it’s going to get in the central part of the frame.

RAW samples from f/3.5 to f/16 for this scene are available in the Google Drive folder . I didn’t provide f/22 because diffraction makes it too soft.

In terms of sharpness, “Not as bad as I’ve been led to believe” is not exactly a ringing endorsement. If you need strong performance from wide open, this is not your lens. But I usually shoot a lens like this at f/8 and smaller apertures anyway, so image quality at those apertures works for me.

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Shift performance and field flatness

People buy this lens because they need shift and tilt. One thing to get out of the way from the start is that the native tilt-shift controls on this lens really are as bad as reviewers say. Shift is OK, but tilt is the weak link; the controls work, but they’re not robust. I suspect that many people who bought it for shift and tilt find the controls frustrating, and move on to something else. Thankfully, tilt and shift on my setup are done with the VX23D, so I don’t have to suffer the built-in controls; I removed them to mount the lens on the Toyo board you can see in the picture (above).

I was happy to discover that the image circle of the lens is surprisingly large, and allows a very useful amount of shift on a 33mm x 44mm sensor. The lens is designed for 12mm of shift on full frame, which requires a minimum 64.6mm image circle at infinity. Samyang seems to have been conservative, because the circle of good definition (the part of the image circle that is usable, rather than just illuminated) actually allows for 10mm of good shift on the long edge on my GFX 50R before vignetting appears in the extreme corners. For that to be possible, the circle of good definition needs to be around 72mm. The full illuminated diameter of the image circle looks to be around 80mm (although only a small part of the area beyond 72mm has good definition).

To illustrate the size of the image circle, and the point where vignetting starts, here’s what 15mm of shift on the long edge at f/11 and infinity looks like on my GFX 50R. Image quality at the 10mm mark is good. Image quality near the hard vignette is surprisingly good. To be on the safe side, you shouldn’t expect good definition beyond 10mm. However, if you don’t need the detail in the far shifted part of the frame (e.g., darkness, clouds) then a 12mm shift is fine.

Uncorrected panorama created from +/-15mm shift showing position of unshifted GFX frame and the position of shifted images.

Corrected panorama made from +/-10mm shifted images. Flat field correction was used in each source image. Click on the image for full resolution JPEG.

Light falloff increases towards the edge of the image circle on every lens. The uncorrected +/-15mm panorama shows that at f/11, light falloff is modest until mechanical vignetting occurs. A lens cast correction (LCC) frame is an excellent way to manage light falloff. You have to remember to shoot an LCC frame each time you make a shifted exposure. Lightroom (or any other tool that can process LCC frames) will use the LCC frame to remove light falloff and correct any colour cast that occurs during shift. Note that I’m not seeing any colour cast issues during shift with this lens, so LCC correction seems only to be fixing light falloff.

Depending on the scene, shifting a bit more than 10mm is possible. The image of the main entrance of the Basilica of Our Lady in Guelph at the top of this post was shifted up (rise) 12mm. The image quality at the top corners of the frame in that image might not be good enough for the most demanding applications when 12mm of shift is used, but this will be case-by-case.

In this uncorrected image of the source file for the picture at the top of the thread, light falloff towards the edge of the image circle is evident, and the corners show the darkness you’d expect. A LCC frame would have gone a long way to correcting the light falloff; I corrected it in Lightroom. In a situation like this you have to be careful because any mechanical vignetting will cause the Flat Field Correction tool in Lightroom to fail.

The uncorrected version of the image at the top of the post showing where the top would have been without shift, and where it was at 12mm of shift.

My ideal shift lens has a perfectly flat field across the entire image circle. Some of the lenses I use on my VX23D come close to meeting that ideal. I evaluated field curvature at f/4 using the technique Roger Cicacla described recently . As these images show, my copy of the Samyang does not have a perfectly flat field at f/4, but for the way I’d use it (f/8 through f/16) it’s fine.

The “Find Edges” filter in Photoshop reveals the amount of field curvature at f/4.

Find Edges filter applied to an f/4 panorama created using +/-10mm of shift. The shape of the field doesn’t change significantly during shift.

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Distortion, flare and other considerations

Barrel distortion is another “feature” of this lens (see the before and after comparison, below). Fortunately, it’s simple barrel distortion rather than complex moustache distortion. That means it tidies up very well. In Lightroom, no pre-defined profile is available (which is not surprising because embedded shift information would be needed to apply an automatic correction, and this is a fully manual lens). However, as a starting point, the profile for the Samyang 24mm f/1.4 ED AS IF UMC lens does a good job.

Before (left) and after (right) comparison showing unshifted distortion, and how much room I had to leave around my simple test target to allow for correction.

For some people, the amount of distortion could be a deal breaker – but I don’t shoot a lot of buildings so I can work around this flaw. As the examples in this post show, as long as you plan for the correction (leave some room at the edges), and can live with the fact that lens correction is destructive, it doesn’t have to be a deal breaker.

The “Before” image is the uncorrected RAF after import into Lightroom. The “After” image is the corrected file (full version at top of this post). The distortion to the heads of the figures at left and right in the row of saints is not due to a flaw in the design of the Samyang 24/3.5; that’s what wide angle lenses do in situations like this.

Some reviews I read suggested chromatic aberrations were a problem. If there’s any in the images I’ve made so far, it’s extremely minor. You can see for yourself in the RAW samples in the Google Drive folder .

The lens has a large, bulbous front element that is very prone to flare and ghosting; this is not surprising for a 24mm lens with a large image circle. When the sun is in the frame, some amazing flare artefacts can appear. I’ve seen this in many lenses so I don’t consider it unusual.

The sun was fully in the upper-right hand corner, creating this lovely flare artefact at bottom-left.

Flare also kills contrast, as this example shows. In these images, the strong evening sun was inside the frame, in the upper-right hand corner. Contrast was reduced over the entire image in the left-hand frame. Blocking the sun with my hand (right) eliminated the flare and dramatically improved contrast. Unfortunately, my hand had to be in the picture to do this!

The sun was inside the frame, which caused flare across the entire image, and destroyed contrast in the unshaded version (left). Blocking the sun in the frame with my hand (right) brings contrast back.

Interestingly, some reviewers and users have reported especially bad and uncontrollable flare with versions of this lens for specific mounts, notably the Sony E mount version which has a long tubular mount because of the E mount flange distance. Switching to a shorter Canon EF mount eliminated the problem for that user. On my setup, there is no adapter, so there’s no internal flare at the rear. Users of this lens experiencing flare and reduced contrast even with good protection from stray light at the front should flock the inside of the mount part to deal with the problem.

Other than the tilt-shift controls, the mechanics are good. The focus ring is smooth and well-damped. I found it easy to focus precisely. The aperture is nice too, although I find it’s too close to the focus ring.

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Conclusion
1

The Samyang 24mm f/3.5 ED AS UMC Tilt-Shift is a lens with some significant shortcomings. Nonetheless, if you’re willing and able to play to its strengths, it’s a lens that is capable of making high quality images on a GFX camera. I’m sure that if Fuji ever releases a 24mm tilt-shift lens, it will be superb. But Fuji may never release a 24mm tilt shift lens, so we have to consider every option.

If you need the best possible 24mm tilt-shift lens currently available, get the Canon TS-E 24mm f/3.5L II Tilt-Shift Lens. I haven’t tried one so that’s not a personal recommendation, but this is the advice you get from people who have tried both . If you only need what a tilt shift lens can do occasionally, or you’re like me and have a setup where you can’t use the Canon, the Samyang is worth a close look. It’s a demanding lens to use, and the tilt shift controls will be a source of frustration. But used carefully, it can produce good results.

The Basilica of Our Lady in Guelph on a cloudy spring day. If you make pictures like this a lot perhaps you could get a similar result by pointing up and correcting the verticals in post. I prefer knowing that I have what I need when I make the picture. This was 12mm of rise at f/16 with the Samyang 24mm f/3.5 ED AS UMC Tilt-Shift. Full resolution image available, but for this picture I had to crop in, so it's not the full GFX 50R resolution.

Rob de Loë
Guelph, ON

bobby350z Regular Member • Posts: 251
Re: Conclusion
1

Nice review, thanks.

Snap Happy Senior Member • Posts: 1,595
Re: Conclusion

Thanks for the detailed assessment Rob.

My conclusions after using this lens for a month on a dumb adapter were similar - much better than you might expect (especially at f/8), and but it became obvious when comparing 2ft-wide prints of the same scene to those taken with a hired GF 23mm, the Fujifilm prints had more detail, especially out to the edges (and so it should, given the difference in price).

I would be interested to see how the Canon 24mm TSE compares.

 Snap Happy's gear list:Snap Happy's gear list
Fujifilm X-T3 Fujifilm GFX 100S Canon EF 400mm f/5.6L USM Fujifilm XF 10-24mm F4 R OIS Samyang 12mm F2.0 NCS CS +26 more
Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Re: Conclusion

Snap Happy wrote:

Thanks for the detailed assessment Rob.

My conclusions after using this lens for a month on a dumb adapter were similar - much better than you might expect (especially at f/8), and but it became obvious when comparing 2ft-wide prints of the same scene to those taken with a hired GF 23mm, the Fujifilm prints had more detail, especially out to the edges (and so it should, given the difference in price).

I would be interested to see how the Canon 24mm TSE compares.

My pleasure!

Keith Cooper did a detailed comparison of the Canon vs. Samyang lenses. www.northlight-images.co.uk/review-samyang-24mm-tilt-shift-lens/  His conclusions are similar.

matteroner
matteroner Senior Member • Posts: 1,189
Re: Samyang 24mm f/3.5 Tilt-Shift Lens on GFX: a deep dive

Very nice write up. I'm glad everything worked out for you.  Can't wait to see what else you have planned for this setup.

 matteroner's gear list:matteroner's gear list
Fujifilm GFX 50R Fujifilm GF 110mm F2 Fujifilm GF 45mm F2.8 Canon EOS 6D Canon EOS 80D +11 more
Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Re: Samyang 24mm f/3.5 Tilt-Shift Lens on GFX: a deep dive
1

matteroner wrote:

Very nice write up. I'm glad everything worked out for you. Can't wait to see what else you have planned for this setup.

Thanks Matt. It all started with your willingness to share some RAW files.

I'm looking forward to using it in serious work. Putting that post together exhausted any desire I had to shoot pictures of churches, cars, city vistas and test charts!

jean-pierre peretti Regular Member • Posts: 134
Wow !

Hi Rob.

What a review !!

Congrats and a lot of thanks.

Regards,

Jean-Pierre

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
That's more like it

Cedar trees find a way to keep going. Fall over into the river? No problem! Grow sideways it is.     Samyang 24/3.5 Tilt-Shift lens, f/16.

Eggplantt
Eggplantt Forum Member • Posts: 98
Re: That's more like it

Excellent review and testing process- you should try out more gear!

Do you have any notes or pictures on how you attached the lens to your Toyo board? It looks very clean- wonder what you got up to. I assume using the mounting screw holes for the whole T-S mechanism, but not sure if you had to use longer ones instead to go through the lens board.

 Eggplantt's gear list:Eggplantt's gear list
Lenovo Vibe Shot
Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Re: That's more like it
1

eggplanted wrote:

Excellent review and testing process- you should try out more gear!

Do you have any notes or pictures on how you attached the lens to your Toyo board? It looks very clean- wonder what you got up to. I assume using the mounting screw holes for the whole T-S mechanism, but not sure if you had to use longer ones instead to go through the lens board.

Trust me, the last thing I need to do is try out more gear!

Mounting this was fairly straightforward. Here's the deal for the mount solution you see in the pictures (which is temporary):

  1. Remove the four screws that hold the shift mechanism onto the tilt mechanism.
  2. Remove the knobs for the shift mechanism
  3. Lock down the shift mechanism. My temporary solution is Gorilla tape. My permanent solution will be to drive a couple screws through the two pieces of the tilt mechanism.
  4. Cut a spacer template that fits over the four curved guides that hold the shift mechanism centred (see picture below). A spacer is needed otherwise it stands proud and lets in light. For my temporary mount, I cut a spacer out of a piece of 4-ply mat board I had handy. It was the perfect thickness.
  5. Drill holes in the Toyo mount board for the mounting screws. This is the trickiest bit because you have to use a template to locate the holes used to screw the tilt part to the shift part, and then transfer their position to the Toyo board.
  6. Attach using original screws, or replace with heavier and longer screws. It hold with the original screws, but they're M1.6 and not quite long enough. I had some M1.7 screws that were much longer, so I used them for the temporary mount; the part I screwed into is a tough plastic, so the slightly larger screws "self-tapped".

Red lines mark the four curved guides that centre the shift mechanism on the tilt mechanism.

Now that I know it's a keeper, I'm going to modify as follows:

  1. Sand or cut off those four curved guides so that the tilt mechanism lays flat on the lens board.
  2. Drill and tap some screws to lock the two pieces of the tilt mechanism together.
  3. Tap the existing mount holes to M2 and replace the M1.7 screws with heavier M2.

My "temporary" mount solution is rock solid, but the lens deserves something even stronger.

By the way, note the lens cap on the rear. It's just a touch loose, but fits fine.

Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Final mount solution implemented
1

To follow up on the previous post, the permanent mounting solution I described there worked very well. The only thing I still need to do is replace that bit of electrical tape that currently covers the hole for the tilt knob with a nicer cover.

Samyang 24mm f/3.5 Tilt-Shift lens mounted to Toyo lens board for VX23D

DMillier Forum Pro • Posts: 22,855
Re: Final mount solution implemented

You're pretty handy, Rob. There's a few jobs around the house that need fixing if you're passing by :-;

Particularly the darn back on the office swivel chair. Home working for a year has done for the locking mechanism...

-- hide signature --
DMillier Forum Pro • Posts: 22,855
Re: Samyang 24mm f/3.5 Tilt-Shift Lens on GFX: a deep dive

Do you consider the unmodified lens useful for full frame and smaller formats? Better than adaptors?

-- hide signature --
Rob de Loe
OP Rob de Loe Senior Member • Posts: 1,354
Re: Final mount solution implemented

DMillier wrote:

You're pretty handy, Rob. There's a few jobs around the house that need fixing if you're passing by :-;

Particularly the darn back on the office swivel chair. Home working for a year has done for the locking mechanism...

There's more than a few jobs around myhouse that need fixing! I'm like the car mechanic who drives a crappy, beat up car.

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