Sigma 24mm f/1.8 EX DG Aspherical Macro
May 10, 2011
by Andrew Alexander
Surfing the internet doesn't give an easy indication of when the Sigma 24mm ƒ/1.8 lens was introduced, but its styling suggests that it isn't one of Sigma's recent designs. That said, it competes with much more expensive lenses from Canon and Nikon, as well as being available in Sigma, Sony, Pentax, and even Four-Thirds mounts.
The lens was designed to fit 35mm film or a full-frame sensor, and will provide an equivalent field of view of approximately 35mm when used on an APS-C-sized sensor. The Nikon version of the lens does not have a built-in motor, so it won't autofocus on consumer bodies such as the D3100 or D5100.
The Sigma 24mm ƒ/1.8 EX DG Aspherical Macro ships with a petal-shaped lens hood, accepts 77mm filters, and is available now for approximately $550.
Mounted on the sub-frame Canon 7D, when used wide open at ƒ/1.8, the lens provides fairly sharp results throughout the center of the frame, degrading to significant softness in the corners. Unsurprisingly, there is little difference between ƒ/1.8 and ƒ/2; however, stopping down to ƒ/2.8 provides an impressive increase in sharpness, with the same central area of the frame becoming sharp, and only slightly soft in the corners. Stopping down further to ƒ/4 and ƒ/5.6 provides further, but minor, gains in sharpness. At ƒ/8 there is some further reduction in corner softness, at the slight expense of central sharpness, but the numbers are fairly small at that point. Diffraction limiting sets in at ƒ/11, but there's very little to note; at ƒ/16 it's more noteworthy, with the image showing average sharpness across the frame. Fully stopped-down at ƒ/22, the lens is neither sharp nor soft.
Mounting the lens on the full-frame Canon 1Ds mark III tells a much different story. Shot wide open at ƒ/1.8, we note some impressive corner softness, though there is a small central ''sweet spot'' of sharpness. Again, stopping down to ƒ/2 provides very little improvement, but ƒ/2.8 transforms the lens into something much better: a large central sweet spot of moderate sharpness, edging to corner softness. Further sharpness gains are possible at ƒ/4 and ƒ/5.6, as above, but nothing that really gives you tack-sharp results from corner to corner - the center is good, but the corners are soft (though not terrible). At ƒ/8 and ƒ/11 you get sharper corners at the cost of some of the central sharpness, and diffraction limiting has truly set in at ƒ/16. Fully stopped-down at ƒ/22, the lens is slightly soft across the frame.
As we've come to expect from very fast glass, in addition to noting with transverse chromatic aberration (color shifts usually found in the corners of an image, in areas of high contrast) the Sigma 24mm ƒ/1.8 shows signs of longitudinal chromatic aberration - magenta / green color shifts that appear on either side of the focus plane, when the lens is used at its widest settings. CA is generally quite high for this lens, though the results are slightly more significant when stopped down - possibly because corner softness reduces the capacity of our testing softness to actually detect the CA in the first place. See our sample images for more detail.
Corner shading isn't an issue when the lens is used on the sub-frame Canon 7D, showing corners which are just over a quarter-stop darker than the center, when used at ƒ/1.8. Otherwise, it's negligible. On the Canon 1Ds mark III however, using the lens wide open at ƒ/1.8 produces corners which are over a full stop darker than the center, making corner shading quite noticeable indeed. Stopping down to even ƒ/2.8 drops this falloff to just a half-stop, and at any other setting it hovers at around a third-stop.
The 24mm ƒ/1.8 has about as much barrel distortion as you might expect from a wide-angle lens: around +0.5% in the corners, and easily correctable in image post-processing software.
The 24mm ƒ/1.8 uses an older-style electrical motor in the Canon-mount version we tested, producing a slight whine in focusing and average speed: about a second to go from close-focus to infinity. Sigma uses two switches to enable or disable autofocus, and they have to be set in the same assignment for either setting to work correctly. The Nikon-mount lens relies on a body-based autofocus screw, meaning you'll need a newer body such as the D90 (or pricier) to autofocus. In any case, the front element does not turn during autofocus.
The 24mm ƒ/1.8 is listed as a macro lens, producing an impressive 0.37x magnification at its minimum close-focusing distance of just over 7 inches (18 cm).
Build Quality and Handling
The lens is finished in Sigma’s matte black rubbery-feeling material, weighing in at a solid 485 grams (17 oz), with a metal lens mount and plastic 77mm filter rings. The lens features two controls, both of which are used to enable or disable autofocus. The first switch is what you might expect - a simple toggle switch which enables or disables autofocus - but the second and less intuitive switch is that to manually focus you must physically move the focusing ring rearward. You'll know you can then focus manually because you expose a macro magnification scale. However, there's no doubting that the arrangement is potentially confusing, and neither manual nor automatic focusing will work if the switches aren't aligned to the same setting. Otherwise, the lens is fairly bare, with only a distance scale under a window providing distance information in feet and meters. There is no depth-of-field scale, nor is there an infrared index (at least, on the Canon-mount version: Sigma's website seems to show a Nikon-mount version, with depth-of-field scale, and an honest-to-goodness aperture ring).
The focusing ring is fairly large at 1 1/4 inches wide, a rubber ring with ribs running lengthwise. The ring turns ninety degrees through its range, and ends at hard stops at the close and far points. The ring focuses slightly past infinity. There is some slightly lens extension, about a half-inch, as the lens focuses towards infinity.
The LH825-03 lens hood is a short petal-shaped hood, which can attach to the lens via a bayonet mount for storage.
Canon EF 24mm ƒ/1.4L II USM ~$1,800
The Canon is sharper than the Sigma at all apertures, and exhibits much less chromatic aberration. However, corner shading is substantial, especially on full frame. Distortion is about the same. Better build quality and more straightforward focus options; the Sigma costs substantially less.
Nikon 24mm ƒ/1.4G ED AF-S Nikkor ~$2,200
Similarly to the Canon, the Nikon is much sharper at all apertures, and exhibits much less chromatic aberration. Corner shading is also well-controlled, and distortion is slightly less than the Sigma. Better build quality and more straightforward focus options; the Sigma costs substantially less.
Pentax 24mm ƒ/2 SMC P-FA ~$?
We haven't tested this lens, and you probably will have a fairly tough time finding a copy, but in Pentax mount, this is closest. In its prime (pardon the pun) it actually cost much less than the Sigma.
Sony 24mm ƒ/2 SSM Carl Zeiss Distagon T* ~$1,250
We haven't yet tested the Sony 24mm, but it is close in specs to the Sigma. Uses 72mm filters instead of 77mm.
There's a lot to like about the Sigma 24mm ƒ/1.8 - while it's not a stellar performer (when used at ƒ/1.8) for sharpness, chromatic aberration or corner shading when used wide open, especially on full-frame, it's actually fairly decent - especially when you consider the major manufacturer options cost vastly more money to get into the same ball park.
The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.
As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.
Sigma 24mm f/1.8 EX DG Aspherical Macro User Reviews
8 out of 10 points and recommended by jedy (2 reviews)Price, macro, pleasing bokeh, 1.8 apperturefocus ring travel, lens breathing, no HSM, CA.
I'm using this with a Canon 600D/Rebel T3i.reviewed April 5th, 2013 (purchased for $400)
For the price, this lens is a true bargain. It offers wide angle (or wide-normal on crop) and macro (not true 1:1) which is a welcome bonus. The bokeh is pleasing enough and shallow depth of field great for arty shots. On the downside, the front element extends when focusing meaning you get quite extreme lens breathing. Also the focus ring travel (rotation) isn't that great (about 90 degrees), meaning manual focus is fairly tricky as slight movements will throw the focus out easily (this issue applies to other Sigma's I've owned). The lack of a silent focus motor (HSM) means this lens is both noisy and slow to auto focus. There's also a fair bit of CA at higher f numbers but this can also apply to other fast primes regardless of price so cant complain too much here.
Overall I am pleased with this lens. The only main gripe for me is the focus travel issue as it would be nice to be able to better control manual focus. Other than that, I can't fault this lens too much as all lenses at lower price brackets will have their issues and compromises. I cannot justify the price for Canon L series lenses and the macro and f1.8 make this 24mm the best non-L alternative.
9 out of 10 points and recommended by RGSphoto (1 reviews)Sharpness, bokeh, speed.erratic AF in low light but not always.
I needed a standard walkaround lens for my Olympus E510 which can be use indoor and near to macro to take pictures.reviewed August 23rd, 2010 (purchased for $303)
I give two links
8 out of 10 points and recommended by newworld666 (1 reviews)Sharpness, bokeh, speed, macro, priceerratic AF in low light condition a bit soft in the edge
I don't know if it will really help some other people :o but here is my story. (you can open photos in a new tab to make direct comparison in fullhd, by clicking on them)reviewed April 19th, 2010 (purchased for $400)
I needed a standard walkaround lens for my 50D which can be use indoor and near to macro to take pictures of shops, bags, shoes .I would say to take picture of all luxury accessories for a web site.
It was very difficult to get good information about Sigma 20F1.8, 24F1.8 and 28F1.8 .. canon 28F1.8 seems also just acceptable .. and anyway just too long for an APSC.
I could see some reviews were the sigma 20F1.8 was really really soft .. So I decided to buy on ebay a 24F1.8 for 300€.
I own a 24L1.4II which is probably the best lens that exist for FullFrame sharp from edge to edge and an amazing aperture of F1.4..
So I wanted to compare how far is a sigma from a 5 times more expansive canon.
First I had to make an AF micro adjustment otherwise lens is almost unusable :confused: ..(+15 for sigma and +13 for canon) the only lens I can use without adjustment is 85L1.2II ..+0 :cool: ..
so at minimum focus distance I get
So macro capabilities are really sufficient and good for what we am looking for.
First manuel focus with sigma is very very difficult canon is very smooth and precise..
but sigma AF is working rather good even if sometime you need to put to infinity first and then refocus. Canon has a perfect AF ..
I tried to take "real" pictures in the day time, but in spring wether is changing every 10 seconds, so made all pictures incomparable. So I decided to take night pictures which is also interesting as we want to use this lens indoor, nights and almost of the time wide open with no flash.
So first general test
Focus was made on the church in front, and we can see that canon at f1.8 is much sharper, but sigma results are already quite good ..
If we go in some more detailled pictures
I don't think sigma is a real F1.8 ... if I want to get some background sky I have to adjust luminosity to become equivalent to canon
This time, Sigma softness is to noticable on the edges .. even in the general picture feeling. But still acceptable ;)...
Sigma can't reach canon sharpness .. and some flare appears ??...
Some other comparison with very acceptable sigma results
Some other details with colors
Sigma colors are less shiny than canon, not that bad, but difference is quite significant ..
100% crop .. wich shows a very big difference between two lenses ..
In the center, it's acceptable, but outside center, it makes almost impossible to crop heavily
I never use a zoom because I prefer to take time to move my feet to the right place and angle and then use my PC to correct the frame .. with sigma it will give quite limited possibilities to crop
(already 50D limits a lot comparing to my 5DMKII)
I love my 24L1.4II ..
but in real life this sigma, when AF is correctly adjusted, is really impressive.. with a 50D .. it really makes a very affordable couple
As my own conclusion, I would recommand the sigma 24f1.8 EX DG .. it's five time cheaper than canon 24L1.4II and results are more than acceptable.
On my 5DMKII difference is more significant, but for 50D, I imagine to be possible to get, in the real life, very good results unless you have to crop a lot. I made several pictures stopped down, and sharpness became even better, but not really significant if not cropped, so I think sigma can be used mainly between f1.8 and F2.8 unless you need more DOF ..
We are going use that lens as a walkaround lens attached to the 50D .. not very heavy, quite fast, with a good macro capability ..
8 out of 10 points and recommended by Wolfini (10 reviews)IQ, build, pricesize and weight, performance wide open
I use this lens on a Canon 30d and like the range as a "wide normal" (38mm equivalent) very much.reviewed January 5th, 2007 (purchased for $360)
Because of the large aperture you can shoot indoors at normal lighting without flash - although I usually stop down to at least f2,2, as 1,8 is very soft (hazy).
In very low light the AF is not very reliable, and manual focus is hard, too, when you´re using a large aperture. At least the manual focus ring is very good, and personally I like the clutch mechanism and do not mind the two-step progress for MF/AF.
Apart from 1,8 IQ is great: very sharp and wonderful contrast and colors. Shooting directly into the sun or lamps will produce some small flare spots, but contrast hardly suffers.
My gripe with the lens is the size - a normal prime should be small and light to carry, and this one is neither. So I do not use it very often, also because I have a very good Sigma 18-50/2,8, which is almost the equal in IQ.
Still: for those moments, when you need the fast lens or just feel like shooting prime I can recommend this.