Sigma 180mm F2-8 EX DG OS APO Macro-Robert-OToole-Photography-2017.jpg

The Sigma 180 is longest macro lens in Sigma's lineup and the fastest 180 macro on the market, in fact, this is the only fast f/2.8, 180mm, 1X macro lens available on the consumer market. The sharpness of this lens wide open is impressive

TECHNICAL DETAILS

Type: Macro lens Focal length: 180mm at infinity Aperture: 9 blades

Magnification range: 1X - infinity

Coverage: Full frame Working distance: Long

Chromatic Aberration (CAs): No problems wide open but lateral CAs increase as you stop down unfortunately. This lens is labeled an APO lens, but the images that it makes says that it is not.

Lens mount: The lens tested here was in G-type Nikon F-mount (no aperture ring)

Optical design: 19 Elements in 14 Groups, including 3 FLD elements.

Sigma's FLD glass is the highest level of low dispersion glass that Sigma uses with extremely high light transmission. FLD glass helps correct chromatic aberration, or color fringing, caused when different light wavelengths do not converge at the same point after passing through optical glass.
FLD is used over ordinary optical glass to ensure high definition, high contrast images, even at maximum aperture. Also the density of FLD glass is lower than traditional optical glass, so this helps make large aperture lens designs lighter.

Coverage: Full frame.

Filter threads: 86mm!

RATING

Why 180?
The strength of the 180 macro are narrow angle of view, that creates smooth soft backgrounds and makes it easy to avoid distracting background objects. This really helps extract the subject from the background. The biggest negative of the 180 is the lenses size and weight, thanks ro the lenses fast aperture. This means that my 180 gets left on the shelf more often than not, especially when I am traveling.

What I like about the lens
Image Quality
Small angle of view
Build quality
Bokeh
Tripod mount

Things that I dislike about the lens
Lateral CAs increase at smaller apertures
The longer working distance can be too long sometimes
Extra large front element

Things I don't need
Extra large size
Extra weight
Huge price
f/2.8
Image stabilization for macro photography.
Weather sealing. After more than 10 years of experience photographing wildlife professionally in all kinds of weather, I think the need for weather sealing is really more of an internet myth than a true professional feature.

The Bottom Line

This lens works best chasing skittish subjects like reptiles, and in those special cases when you need even more reach, the lens works great with the 1.4X and 2X teleconverters. For general macro photography the extra long working distance can be more of a hindrance than an advantage when it comes to the basics, like lighting for example. For this reason and others, the Sigma 150, or 105 makes more sense for the average photographer.

After owning a Sigma 180mm f/2.8 Macro lens for about 5 years, I can report that it is a very sharp lens with pretty bokeh but I ended up selling it in 2018. The reason is simple, the lens was just not convenient to use, so it sat on the shelf rather than my gear bag, more often than not. The Sigma 180mm is just too large and too heavy for an every day macro lens. A fast maximum aperture gives you a nice, sharp, snappy viewfinder image, but I never shoot at f/2.8, so I would rather not have to carry around the extra-large glass necessary for that maximum aperture. An f/3.5 or f/4 maximum aperture would be a better choice. The same situation with optical stabilization.

Another disappointment with this lens, other than the weight and size, and OS, is lateral CAs. This lens is not a true APO and worse of all, the CAs increase as you stop down, believe it or not.

When you look at the shortcomings of this lens it's clear that the lens is really a fast 180mm that can focus to 1x, rather than a true purpose built macro lens. Sigma's marketing and design for the last few years is to aim at the large aperture crowd and not the professional photography market. Remember I don't make any money selling lenses, or getting commission from links on this website, I am a professional nature photographer that has been using Sigma macro lenses for more than 15 years.

Image Quality

Note: Canon owners that shoot jpeg need to turn off Peripheral Illumination Correction in the menu. Otherwise there is a problem with vignetting.

Sharpness Test

This 6 inch silicon wafer was shot at 1X, Nikon D810 ISO 64 Nikon MM-11 stand. Image shown are 100% or actual pixel crops. A highly detailed, high-contrast test target like the wafer used here, will tend to reveal sharpness differences and chromatic aberration much more strongly than a real-world image. The target is a silicon wafer shot at 1X, the un-cropped full frame image is below with the crop target areas highlighted in blue.

Center crop at 100% magnification view below. Click on an image to see larger version in a new window.

Test setup notes

-The Nikon D850 camera was vertically mounted on a Nikon MM-11 stand for this test.
-For each lens and each aperture setting focus was bracketed and the sharpest image was chosen at 100% view in photoshop.
-Manual mode was used at ISO 64.
-To avoid any sharpness loss due to vibration a Nikon SB-R200 flash was used at 1/16th to 1/2 power. -The flash remained in place for the entire test to avoid changes in light angle, the flash was mounted on a flash bracket bolted to an optical breadboard.
-RAW NEF files were processed in Photoshop CC with all noise reduction and lens correction turned off, all settings were zeroed out and the same white balance setting used for all the images.
-All crops are shown here at 100% actual pixel view.
-All of the test result images are single frames.
-To avoid focus shifts with aperture changes, 10-15 shots were made at 40 micron steps at each aperture.
-The sharpest images were chosen at 100% actual pixel magnification, cropped and saved in Photoshop.
-Each lens was shot in full stops from wide open down to f/8 or f/11.

Image Quality in the Center; 100% Crops

In the center image quality peaks at f/5.6 and is also very good at f/8. There is softness in the center at f/2.8 and f/4. Overall very good in the center, stopped down.

Image Quality, Edge; 100% Crops

The edge crops tell a different story than the center. Wide open the edge crop is a little soft so f/4 is best. The problem here is that chromatic aberration is not a problem at f/2.8 but they increase as you stop down. Overall sharpness is good in the edge crops but the CAs are poor at f/4 and smaller.

Image Quality in the Corner; 100% Crops

Image quality in the corner isn't the strength of the Sigma 180 OS. The sharpness is not the greatest at f/2.8 and f/4, and stopping down doesn't help. CAs are an issue from f/2.8 and get worse stopping down. Overall corner image quality is poor.

Longitudinal Chromatic Aberration 1X test; 100% crops

What are LoCAs?
Longitudinal chromatic aberrations or LoCAs are ugly purple and green fringing seen in the out of focus areas in front of and behind the focus point of an image. LoCAs are common, especially with fast lenses, so chances almost all of your lenses have at least a trace, you just never noticed. The problem is that LoCAs are extremely difficult to correct with complex designs using special glass to fully correct the aberration, the Scanner-Nikkor for example has 14 elements, 6 of those being ultra low dispersion.

Test Setup
D810 camera was mounted on a Newport PRC-3 rail carrier and Arca Swiss style quick release clamp and moved back and forth to accommodate the different focal length lenses set at 1X. The Newport PRL dovetail rail system was bolted to a Thorlabs aluminum breadboard with a printed target set at 30 degrees on a tilt head. A single Nikon SB-R200 flash and the tilt head remained in place during the test.

LoCAs are pretty well controlled with the Sigma 180 OS and gone by f5.6.

Lateral chromatic aberration 1X test; 100% Crops

What are Chromatic aberrations (CAs)
Chromatic aberrations (CA) are one of several aberrations, or imperfections, that degrade image quality. These occur because glass bends different colors by different amounts. This phenomenon is called dispersion, and this is why you see some high performance lenses have labels such as, SD, UD, ED, SLD, ULD. These acronyms all refer to different types of low-dispersion glass types used in the lenses.

Lateral CAs appear in images as purple and green fringing, mostly seen on near-vertical hard edges on the left and right corners of the image. This results in softening of edges in the corners of an image. CAs occur because the different wavelengths of light are magnified by slightly different amounts by the lens.

Since this lens is labeled APO, the lateral CA correction is poor with the Sigma 180 OS. If it did not have the APO label it would be an average performance.

CA correction
Minimizing chromatic aberration is one of the most important goals of a lens manufacturer. Lens design correct for CAs by combining different lens elements with different dispersion properties, or different refractive indexes. But CAs remain a big problem for lens manufacturers in ultra-wide lenses, long telephoto lenses, and extreme zooms. Most manufacturers offer some level of correction, some can completely correct CAs, with in-camera correction. Over the last few years some manufacturers have become really sneaky with the use of Opcodes.

Opcodes

According to Adobe, Sony, Olympus, Leica, and Panasonic have an agreement in place with Adobe to allow automatic chromatic aberration correction (and distortion correction) before RAW file conversion by tagging the RAW files with Opcodes. The sneaky part is that Opcode force corrections in Lightroom and Adobe Camera Raw before you even even open the image. Opcodes cannot be disabled but you can delete the codes with certain apps. Opcodes also corrects for distortion (and vignetting) which means the image will be enlarged slightly then cropped to correct for distortion so there could be some effect on sharpness.

Lateral chromatic aberration is reduced by the lens design to a certain degree by combining different lens elements with different refractive indexes. There are lenses that use very complex designs using expensive low-dispersion glass to completely eliminate CAs. Examples of these types of lenses would be the Printing Nikkor, Scanner Nikkor and Schneider Macro Varon.

Test Setup
D810 camera was mounted on a Newport PRC-3 rail carrier and Arca Swiss style quick release clamp and moved back and forth to accommodate the different focal length lenses set at 1X. The Newport PRL dovetail rail system was bolted to a Thorlabs aluminum breadboard. The laser printed test target was taped to a Newport 460P XYX micrometer controlled setup. A single Nikon SB-R200 flash was used for lighting and has bolted to a articulating flash arm.

Alternatives to the Sigma 180 OS

Any of the other Sigma macro lenses are a better choice, the 150OS is sharper and has much better CA correction.

If you are just interested in 1x image quality with a longer focal length and price/performance ratio is important you can get much better performance for about a 1/5th the price of the Sigma 180 OS. The If image quality and price/performance ratio is important you can get much better performance for about a 1/5th the price of the Sigma 180 OS. The Schneider-Kreuznach Makro-Symmar 5.9/120mm Makro Iris Lens can be found in excellent condition on the used market for about $300. The Makro-Symmar is a high-end professional quality line scan lens on another level compared to the consumer market Sigma 180 OS macro.

Sigma-180mm-f-2-8-vs-Schneider-Makro-Symmar-120-at-1X-Robert-OToole-Photography-2017-Center.jpg

Sigma-180mm-f-2-8-vs-Schneider-Makro-Symmar-120-at-1X-Robert-OToole-Photography-2017-Corner.jpg

External Site Links for more info:

More info on the Sigma USA website: https://www.sigmaphoto.com/apo-macro-180mm-f28-ex-dg-os-hsm

Sigma 105mm test at Objektivtest.se : http://www.objektivtest.se/tester/test-sigma-105-mm-f28-ex-dg-os-hsm-macro/

Sigma 105 tested on a Canon full frame DSLR, at Photozone, now called Optical Limits.com:http://www.photozone.de/canon_eos_ff/743-sigma105f28oseosff

Sigma 105 tested on a Canon APS-C DSLR, at Photozone, now called Optical Limits.com: http://www.photozone.de/canon-eos/747-sigma105f28oseosapsc

Lenstip.com test of the Sigma 180: https://www.lenstip.com/355.1-Lens_review-Sigma_180_mm_f_2.8_APO_Macro_EX_DG_OS_HSM__Introduction.html

Sigma 180mm F2.8 EX DG OS APO Macro Test Review