The Irix 150mm f/2/8 MACRO 1:1 macro lens (x150) stands alone as the only long (over 100mm) macro lens still being sold today. The Sigma 150, 180, Canon 180, and Nikon 200, are all discontinued. You can still find clean examples of the older Sigma, Canon and Nikon long macro lenses, but after a quick search on eBay, it looks like they will you cost more than a brand new x150 with warranty.
For the record the Irix lens tested here was provided as a loan by a friend. I did contact the US and Euro distributor of Irix , TH Swiss Ltd., and they stated there are no press or loaner lenses available. This is a red flag in my eyes, but then again, maybe Irix will surprise me!
All of the equipment used in this test, other than the x150, were purchased using my own personal funds, without any sponsors, advertising, site membership fees, or featured product fees. I do not receive any income from affiliate links or selling you any products. All the information I post on this site is to share with friends, colleagues, and fellow macro photographers. Almost all photography sites today are run for a profit by using ads and affiliate links to generate commission.
Key Features of Irix 150mm f/2.8 MACRO 1:1
Claimed APO correction (see final test results below)
Claimed 1x Optimization (see final test results below)
Claimed Weather sealed
Claimed Nearly zero distortion (0.1 %) (see the 0% vs 6% section below)
Claimed Long 150mm focal length (at infinity)
Claimed 43mm full frame image circle (see final test results below)
In-Camera Focus Indication Support (camera will confirm the proper focus distance)
Detachable tripod collar with Arca Swiss foot included (see notes below)
AE- communication with camera (exposure parameters are saved in EXIF data)
TECHNICAL SPECIFICATIONS
Irix 150mm f/2.8 MACRO 1:1 Lens
Type: full frame format, 43.3 image circle
Focus type: manual (no autofocus)
Focal length at infinity: 150mm
Measured effective focal length: 68mm at 1x, 110mm at 0.5x
Maximum aperture: f/2.8
Measured maximum aperture: f/3.2
Minimum Aperture: f/32
Iris: 11 blades
Maximum magnification: Maximum magnification is 1:1 even though the USA Irix site claims otherwise; “When you use a camera with an APS-C sensor, due to the crop factor, the magnification ratio will increase to 1,5:1”
Optical design: 12 elements in 9 groups with four high refractive index (HR) glass, and three low-dispersion glass (ED)
Focus Ring Rotation: 270 degrees
Accessory threads: M77 x 0.75mm
Lens mount tested: Canon EF
Rear slip-on cap size: 42mm
Weight: 840g
Source: lens made in Korea
Design includes cover glass: yes
Mounts: Canon EF, Nikon F, Pentax K
Street price new: $495. (MSRP $595 USD)
Warranty in USA: 30 day Satisfaction Guarantee and 2 years warranty from Irix
Release date: late 2018
Note: “Dragonfly” is not the name of the lens, but the finish of this lens “a combination of reinforced metal and composite elements”. Irix actually makes three 150mm macro lenses models, the Irix 150mm f/2.8 MACRO 1:1 lens, and the Irix 150mm T 3.0 macro 1:1 Cine lens in both Metric (M) or Imperial (feet) marked models. The cine version offers a de-clicked aperture ring, and is available in more mounts; Canon EF, Sony E, Micro Four Thirds, Canon RF, L-mount, Nikon Z, and PL mount. Optics are the same for all the 3 versions of this lens.
Irix Lenses Are Not Made in Switzerland
The x150 is designed and sold by a polish company based in Baar, Poland that goes by the name of TH Swiss Ltd. Chairman and co-founder of 'TH Swiss AG' is Hubert Grzegorz Adamczyk, is also the founder and owner of the Polish company named Delta, which is the exclusive distributor of Samyang in Poland, and also owns the e-retailer Foto-Tip. Irix claims a headquarters in Switzerland (they are based in Poland) , and manufacturing facilities in South Korea, using Japanese optical glass (according to TH Swiss Ltd.). Irix is a Polish company with a mailbox in Switzerland. Irix lenses are not Swiss optics.
Pros and Cons
What I really like:
150mm Focal length at infinity
No in-lens image stabilization (less things to break)
Easy to find stock online (this is not the case with a lot of new macro lenses)
Lens packaging very complete and well though out
Tripod collar included
Extra rear cap included
Very good tube lens performance (28mm image circle)
What I can do without:
Soft rubber coated magnification ring (rubber never works long term on a lens)
What I didn’t like:
Very inconsistent image quality across the frame
6% distortion at 1x
150mm focal length measured only 68mm at 1:1
Maximum f/2.8 aperture is measured as f/3.0
Lack of a manual aperture ring
Poor tripod collar design: missing upper Arca-Swiss QR bevel
Poor tripod collar design: extremely short foot length
Poor tripod collar design: non-removable foot
Heavy corner shading when used as a tube lens
How to determine effective Focal Length (EFL)
Measuring the effective focal length (EFL) is simple with a handy formula. You can determine the effective focal length by measuring the magnifications at two different known extensions.
EFL = (ext 1 - ext 2) / (mag 1 - mag 2)
In other words, the difference in extensions divided by the difference in magnifications, gives you the EFL. The x150 EFL measures in at 110mm at 1:2, and just 68mm at 1:1 using this formula. Thanks to Rik at www.Photomacrography.net for this formula (and most of the other formulas I use).
why is my 150mm macro lens only 68mm at 1x?
The focal length (FL) engraved or printed on a macro lens is stated for infinity focus and almost all will decrease in focal length as you focus closer. This is known as focus breathing and is a change in focal length (angle of view) as the focus changes. In almost all cases the small differences are usually insignificant but with macro lenses that focus closer than standard telephoto lenses the change can be significant. Almost all modern lenses exhibit some degree of focus breathing and the Irix 150mm f/2.8 1:1 lens is an extreme example. At infinity the FL is 150mm but by the time the focus moves to 1:2 the lens is now 110mm FL due to the change in angle of view, and by 1:1 the lens is effectively only 68mm lens!
Other examples: Sony FE 90mm F2.8 Macro G OSS, at infinity 92.61 and 45.88 at 1:1. Sigma APO Macro 150mm F2.8 EX DG OS HSM is 149.99 at infinity, and 78.23 at 1x. The new Canon RF100mm F2.8 L Macro IS USM is 100.80 at infinity and only 36.0 at 1:1. See: https://www.photonstophotos.net//GeneralTopics/Lenses/OpticalBench/OpticalBench.htm# to use the optical bench for more info.
Changing focal length during focusing is not what causes focus breathing but rather it's the changing angle of view during focusing. Modern lens designs reduce the focal length, in effect by “zooming out” when focusing closer. The downside to this kind of design means reduced working distances and widens the angle of view creating a busier background.
Almost all lenses are optimized for moderate distances (1:10) to infinity. To prevent a loss in image quality when focused to their minimum distances, modern lenses typically focus internally by moving floating element groups position in relation to each other to control various aberrations as you focus closer, each lens group moving independently using a cam sleeve or motor(s).
Why do most modern macro designs use internal focus with floating elements? Focusing only by extension can be impractical for long focal lengths so it's easier and more practical to correct for various aberrations by not keeping the focal length constant.
Is it possible add extension tubes to reach 1:1 to keep the FL constant? Yes, but the internal floating elements were designed to keep aberrations in check and using extension only to focus to 1:1 magnification will result in lots of aberrations (unless the lens is specifically optimized for 1:1).
Irix 150mm f/2.8 MACRO 1:1 Lens 1x Test
1x Test Wafer Target with center crop section highlighted with an arrow.
Uncropped 1x test image showing the crop outlines in blue: center, APS-C or 28mm IC, and full frame corner (upper right)
100% View Center Crops at 1x
To compare against the x150 lens, I chose two lenses truly optimized for work at 1x, the Schneider Makro-Symmar HM 120mm f/5.6 (MS120), medium format line scan lens, and the Canon MP-E (MPE) 65mm 1-5x f/2.8 Macro lens, also definitely designed for 1x and larger. All lenses were used at their sharpest apertures; f/5.6 for the x150, the MS120 was shot wide open (f/5.6) and the MPE was best at f/5.6. All three of these lenses are limited by their sharpest aperture of f/5.6. A lens that optimized to be sharpest at f/4, or even f/2.8, will be at a higher level of sharpness due to less loss due to diffraction.
Click to open each image in a few full size window or right click (two finger click on mac) to open in a new tab or save to download.
Irix 150mm f/2.8 MACRO 1:1 (x150), left (top on mobile): sharp, some slight red CAs around highlights and edges.
Schneider Makro-Symmar HM 120mm f/5.6 (MS120), center: this is a 35 year old design with a 90mm image circle with sharpness is similar to the Irix center but without any trace of CAs anywhere across the full frame sensor.
Canon MP-E 65mm 1-5x f/2.8 (MPE), image on the right (bottom on mobile): very sharp and only a slight trace of red CAs.
Verdict: All three images show similar sharpness which is not surprising since they were all shot at f/5.6. The Makro-Symmar image has just about perfect CA control.
100% View APS-C / 28mm IC Crops at 1x
Click to open each image in a few full size window or right click (two finger click on mac) to open in a new tab or save to download.
X150, left (top on mobile): this crop area shows a disappointing drop off in sharpness is already a problem. It gets worse, CAs are a problem here and this is not a single frame, the x150 image is not flat field corrected. This is different frame from the center image.
MS120, center: image quality here is almost identical to the center or maybe a bit better. Zero CAs and sharp. The MS120 field is completely flat, all crop are taken from a single image.
MPE, image on the right (bottom on mobile): very sharp here, some CAs, but not too bad. All crops are taken from a single image.
Verdict: MS120 is sharpest without any trace of CAs. MPE is very sharp. The x150 will not cover a 28mm IC circle at 1:1 with a sharp corrected image.
100% View Full Frame Corner Crops at 1x
Click to open each image in a few full size window or right click (two finger click on mac) to open in a new tab or save to download.
X150, left (top on mobile): TH Swiss Ltd. / Irix claim 0% distortion for this lens, but it’s obvious there is a lot of distortion here the distortion at 1x is actually 6%, not the 0% claimed but the manufacturer. . The i150 is not corrected for a flat field so all the crop areas are from different files, and this file was the best in the stack!
MS120, center: clean, sharp and CA free here. This lens is corrected for field flatness so this crop was taken from same file as the center.
MPE, image on the right (bottom on mobile): sharpest of the three but some red fringing on the edges. You can see the CAs even in the thumbnail image. This lens is corrected for field flatness so this crop was taken from same file as the center.
Verdict: Poor image quality in the full frame corners from the x150. The MS120 and MPE both cover full frame corners with a sharp image.
0% or 6% distortion?
Irix (TH Swiss Ltd.) claims 0% distortion and 1x optimization for this lens. These claims are false, just as this lens is not a Swiss lens, TH Swiss Ltd. is not a company in Switzerland. You can clearly see the distortion in the test images. Looking at the Photons to Photos Optical Bench brings up these interesting numbers:
Irix 150mm f/2.8 Macro 6% distortion at 1x
Canon RF100mm f2.8 L Macro IS USM 1% distortion at 1x
Canon EF100mm f2.8L Macro IS USM: 5% distortion at 1x
Nikon AF-S VR Micro-Nikkor 105mm f/2.8G: 5% distortion at 1x
Sigma Macro 70mm f/2.8 EX DG: 2% distortion at 1x
Sigma Macro 105mm f/2.8 EX DG OS HM: 3% distortion at 1x
Sigma APO Macro 150mm f/2.8 EX DG OS HM: 2% distortion at 1x
For more: https://www.photonstophotos.net//GeneralTopics/Lenses/OpticalBench/OpticalBenchHub.htm
1x test setup details
Camera: Sony α7R IV, model ILCE-7RM4, also known as: A7R4
Sensor size: 35.7 x 23.8 mm. 42.91 mm diagonal. 3.73 µm micron sensor pitch, 35 mm full frame 9504 x 6336, 60 MP), APS-C, 6240 x 4160, 26 MP
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block
Test images were taken in a stack in 6 µm steps. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, edge, and corner if needed. Each image was processed in PS CC with identical settings and all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images.
Irix 150mm f/2.8 MACRO 1:1 Lens Test FINAL RESULTS
The Irix 150mm f/2.8 Macro 1:1 lens performs well at infinity and moderate distance but I would not recommend this lens for macro photography, even with the $500 USD price tag. Honestly those funds would be much better spent on the awesome Sigma Art 70mm f/2.8 DG Macro Lens, or the also excellent Laowa 100mm f/2.8 2:1 Ultra Macro APO, both of these will give you sharp, clean, detailed CA free images across a full frame sensor from infinity to 1:1. The Irix 150mm f/2.8 Macro 1:1 lens cannot.
The Irix distributor TH Swiss Ltd. promotes the excellent chromatic aberration control as a major selling point of the lens. The attention to CAs is nice to see, if it is true, and I had the highest hopes for this lens but unfortunately this lens seems to not be optimized in the 1:1 range even though Irix claims it is. Now I understand why TH Swiss Ltd. does not loan lenses for testing! Due to the disappointing results I decided to cut this test short and not run another tests on this lens.
These results are a perfect example of why I started this site in 2017. That is to save other macro photographers the time, money and disappointment that I experienced after buying lenses following online recommendations. This Irix lens is a great case in point, before I contacted TH Swiss Ltd. for a test sample, I read at least a dozen online reviews and found nothing but praise for the excellent sharpness, perfect APO performance, and zero distortion! These were just repeating the talking points found on the Irix web page. The problem is that not one reviewer was never bothered to actually test the x150 lens at 1:1! Why would they do this you might ask? Almost all photo sites use affiliate links to generate income through sales commission and the better the performance of a lens being tested, the higher the recommendation, the more money the site will generate through click-through links on the site. In my eyes these websites as guilty as Irix for publishing false statements and misinformation!
Why is the Performance of the Irix 150mm so Poor at 1:1?
Why is the performance of the Irix 150mm f/2.8 MACRO 1:1 so poor at close-range? The optical design of the x150 does not use a floating correction group often called “floating elements”. This type of correction works so well that almost every macro lens sold since the 1980s utilizes it. The “floating elements” correction design compensates for aberrations that cause image quality to deterioration as you focus closer; such as field curvature, corner softness, and chromatic aberrations.
Take a look for yourself, load the x150 in the Photons to Photos optical bench database:
Moving the focus slider to the minimum you can see the focus group shift as you move to 1:1.
Now load any modern lens, this is a link for the Sigma Macro 105mm f/2.8 EX DG OS HM that uses a floating element group:
Moving the focus slider on the Sigma to the minimum distance and you can see the focus group shift as you focus and a second floating aberration correction group move at the same time. Load any modern Canon or Nikon lens into the Photons to Photos optical bench database and do the same as these all use a floating group for macro range correction.
Don't expect good results in the photomacrography range from a lens that do not use a floating aberration correction group even if the lens is labeled as a 1:1 macro lens.
Industrial lenses
Not all lenses have floating elements controlled by a focus ring. Special ultra-high performance industrial “Float” lenses use a geared ring to move floating elements inside the lens to suppress and correct aberrations at a desired magnification. This float ring is usually geared so the setting and adjustment to be externally motorized in an automated inspection line or factory. These float ring lenses are corrected at a much higher level than the consumer macro lens, and produce exceptionally consistent image quality over a very large image circle, These lenses are usually made to order in small batches and are priced to match. Examples of this type of lens are the Schneider Macro Varon, Printing NIKKOR 150mm Float Ring version, and the Rayfact VF to name just a few.
Irix 150mm f/2.8 MACRO 1:1 Lens as a tube lens
This lens does make a very sharp and CA free tube lens over a 28mm field (Sony APS-C). The full frame image will have issues with heavy corner shading. Minimal space between the objective and tube lens works best. The Mitutoyo 5x I tested was 1 or 2mm away from the front tube lens glass. More space made the issue worse.
LINKS FOR MORE INFORMATION:
The Irix 150mm f/2.8 Macro 1:1 on the official Irix site:
In this section I normally fill this space with as many useful and interesting links but in the case of the Irix 150mm there are no reputable webstes out there to share. I could not find a single website that called out Irix false statements and misinformation, like the 0% distortion claims, Irix not being a Swiss company or even worse the very poor performance, red fringing and soft details at 1x, not a single website! Why? Affiliate Program! An affiliate program through which you can earn money by publishing a unique discount code that will be assigned to website reviewer to get a commission on each sale using the code. Publishing false statements and misinformation makes these websites as guilty as Irix.