Sam North
24th of February 2004 (Tue), 15:16
You may find the following of interest if you’re thinking of buying the Sigma 24-70mm f2.8 EX DG ASPHERICAL DF. Sometimes it’s very useful to get a user’s firsthand impressions.
Is it possible to produce impressive photographs using less expensive equipment? Yes, it’s possible, although much depends on your goals and even your style of photography. A landscape photographer shooting for high quality books will want to use the very best equipment available. If you’re a casual amateur or a dedicated enthusiast, a lower spec SLR and cheaper lens can deliver quality results, even at larger print sizes. It’s all too easy to get hung up on equipment, especially in the company of other pro/am photographers, on forums, for example. Arguably, when viewed at typical distances, software-enhanced prints from images produced by less expensive equipment will compare quite favourably to prints of images shot with the very best of SLR gear.
So, if you’re planning on shooting DSLR and you’ve a slimmer wallet than you would like, is it worthwhile combining the Sigma 24-70mm f2.8 EX DG and the Canon EOS 300D? Yes, it is.
My only real alternative to this Sigma lens was Canon’s EF 24-85mm f3.5-4.5, but I had questions about its durability and I doubted its image quality would surpass the Sigma, especially at wider focal lengths. I choose Sigma partly because of an older Sigma 28-70mm f2.8 lens I’ve used for around 7 years. It’s surprisingly sharp and reliable and, if it's possible, I'm considering having it re-chipped by Sigma for the most recent DSLRs. For a reasonable price I wanted useful performance, good bright optics and, with 1.6x cropping in mind, a versatile focal range for landscape and people photography.
When all is considered, this lens is fairly priced, although you must remember to include the cost of the 82mm filter - UV, skylight, 81A.
It’s worth noting at the outset that under average to strong contrast conditions, red and blue fringing around the edges of the image was obvious. If a shot with fringing is particularly important, it can be removed in image-editing software. Fringing at wide-angle settings can be caused by light striking the image sensor at a steep angle. However, in this case it is certainly evidence of chromatic aberration, a common problem with less expensive lenses, kept to a minimum by 1.6x cropping of the image.
As for general image quality, the 100% detail images below show that this lens performs reasonably well for the price, and compares favourably with my reliable Canon original Ultrasonic EF 70-210mm f3.5-4.5, a lens I have used extensively over the years. The Sigma results compared to those from my 35mm prime EF lens should make me want to throw my new zoom lens in the bin – and that’s with 1.6x cropping! But I just need to think a moment: I already know from experience that zoom lenses are not supreme optical performers (more so those from independent manufacturers), so the test results need to be viewed in context, with one eye firmly on image-editing techniques. I bought this lens with its limitations and the advantages of PHOTO-PAINT image-editing software in mind.
Unsurprisingly, regardless of aperture, my Sigma, at 24mm especially, gets nowhere near a prime lens, but I know that I can optimise results in the field by eliminating camera shake and shooting at f5.6 to f11. At 24mm at f11 the corners of the Sigma are less soft than at f5.6, but at f11 the centre of the frame is less sharp than at f5.6. So for optimal results I should, when possible, shoot at f5.6 to f8. To these typical zoom characteristics we should add the fact that barrel and pincushion distortion are quite noticeable, especially at extreme focal lengths. Independent zoom lenses need to be assessed in context - they will never perform as well as prime lenses.
Until I discover very good reasons not to, I shoot hi-res JPEGs and to get more neutral results I set the 300D to a customised parameter setting, although it’s worth remembering that when Contrast, Sharpness, Saturation and Colour Tone are set to zero, they are in fact set to 3 on a scale of 5. My neutral JPEG images are loaded into PHOTO-PAINT and immediately converted to a lossless format for archiving and editing. It’s a fact that image-editing improves the performance of your lens! It is definitely worthwhile spending time adjusting the contrast levels and the sharpening values. You will end up with very good images that will look acceptably sharp, even at larger sizes, all taken with a lens that costs a lot less than the Canon professional equivalent!
As expected, the Sigma’s build quality is more than acceptable, but not impressive. I feel it’s not quite on a par with the old 28-70mm, but it’s more than good enough and doesn’t give the impression it’s about to fall apart anytime soon. The finish is reasonably durable, too.
In practice, outdoors on bitterly cold days, I found the lens easy to use, and that includes switching from manual to AF, using the small button on the side along with the push-pull action of the focus ring. I don’t do a lot of manual focusing so it’s really not a problem, although if you do a search for this lens you’ll find lots of people who disagree: they are irritated by the push/pull focus ring action.
The auto focus is noisy, not unlike the 28-70mm, but it works quickly enough and so far I’ve had no problems on dull overcast days. Not having a lot of confidence in evaluative metering, I quickly got into the way of selecting and locking in a mid-tone, using the centre point, auto focusing, recomposing and firing off a shot. (I have my EOS 50 set up to do this.) If you’re into manual focusing you’ll like the feel of the generous focus ring. This is a heavy lens and the zoom ring needs a very firm grip, but if you’ve reasonably strong hands this combination won’t be a problem. However, the zoom ring is a little narrow for a man’s fingers, so a tight grip is essential. I like the weight of the lens on the camera – it’s manageable and very stable.
The included lens hood (Canon claims lens hoods are "optional"!) will help to prevent flare, and so far I've had no serious problems. However, some have complained about flare with this lens. It’s interesting to note that the camera’s 1.6x cropping means the lens hood could be a little longer without appearing in the shots.
Conclusion: I got what I expected for the money I paid. To put it another way: 6 out of 10, but 8 out of 10 with the help of subtle software techniques. Please don’t let the limitations of less expensive independent zooms stop you from taking truly impressive shots!
Hope this text is useful to someone out there.
Sam
Is it possible to produce impressive photographs using less expensive equipment? Yes, it’s possible, although much depends on your goals and even your style of photography. A landscape photographer shooting for high quality books will want to use the very best equipment available. If you’re a casual amateur or a dedicated enthusiast, a lower spec SLR and cheaper lens can deliver quality results, even at larger print sizes. It’s all too easy to get hung up on equipment, especially in the company of other pro/am photographers, on forums, for example. Arguably, when viewed at typical distances, software-enhanced prints from images produced by less expensive equipment will compare quite favourably to prints of images shot with the very best of SLR gear.
So, if you’re planning on shooting DSLR and you’ve a slimmer wallet than you would like, is it worthwhile combining the Sigma 24-70mm f2.8 EX DG and the Canon EOS 300D? Yes, it is.
My only real alternative to this Sigma lens was Canon’s EF 24-85mm f3.5-4.5, but I had questions about its durability and I doubted its image quality would surpass the Sigma, especially at wider focal lengths. I choose Sigma partly because of an older Sigma 28-70mm f2.8 lens I’ve used for around 7 years. It’s surprisingly sharp and reliable and, if it's possible, I'm considering having it re-chipped by Sigma for the most recent DSLRs. For a reasonable price I wanted useful performance, good bright optics and, with 1.6x cropping in mind, a versatile focal range for landscape and people photography.
When all is considered, this lens is fairly priced, although you must remember to include the cost of the 82mm filter - UV, skylight, 81A.
It’s worth noting at the outset that under average to strong contrast conditions, red and blue fringing around the edges of the image was obvious. If a shot with fringing is particularly important, it can be removed in image-editing software. Fringing at wide-angle settings can be caused by light striking the image sensor at a steep angle. However, in this case it is certainly evidence of chromatic aberration, a common problem with less expensive lenses, kept to a minimum by 1.6x cropping of the image.
As for general image quality, the 100% detail images below show that this lens performs reasonably well for the price, and compares favourably with my reliable Canon original Ultrasonic EF 70-210mm f3.5-4.5, a lens I have used extensively over the years. The Sigma results compared to those from my 35mm prime EF lens should make me want to throw my new zoom lens in the bin – and that’s with 1.6x cropping! But I just need to think a moment: I already know from experience that zoom lenses are not supreme optical performers (more so those from independent manufacturers), so the test results need to be viewed in context, with one eye firmly on image-editing techniques. I bought this lens with its limitations and the advantages of PHOTO-PAINT image-editing software in mind.
Unsurprisingly, regardless of aperture, my Sigma, at 24mm especially, gets nowhere near a prime lens, but I know that I can optimise results in the field by eliminating camera shake and shooting at f5.6 to f11. At 24mm at f11 the corners of the Sigma are less soft than at f5.6, but at f11 the centre of the frame is less sharp than at f5.6. So for optimal results I should, when possible, shoot at f5.6 to f8. To these typical zoom characteristics we should add the fact that barrel and pincushion distortion are quite noticeable, especially at extreme focal lengths. Independent zoom lenses need to be assessed in context - they will never perform as well as prime lenses.
Until I discover very good reasons not to, I shoot hi-res JPEGs and to get more neutral results I set the 300D to a customised parameter setting, although it’s worth remembering that when Contrast, Sharpness, Saturation and Colour Tone are set to zero, they are in fact set to 3 on a scale of 5. My neutral JPEG images are loaded into PHOTO-PAINT and immediately converted to a lossless format for archiving and editing. It’s a fact that image-editing improves the performance of your lens! It is definitely worthwhile spending time adjusting the contrast levels and the sharpening values. You will end up with very good images that will look acceptably sharp, even at larger sizes, all taken with a lens that costs a lot less than the Canon professional equivalent!
As expected, the Sigma’s build quality is more than acceptable, but not impressive. I feel it’s not quite on a par with the old 28-70mm, but it’s more than good enough and doesn’t give the impression it’s about to fall apart anytime soon. The finish is reasonably durable, too.
In practice, outdoors on bitterly cold days, I found the lens easy to use, and that includes switching from manual to AF, using the small button on the side along with the push-pull action of the focus ring. I don’t do a lot of manual focusing so it’s really not a problem, although if you do a search for this lens you’ll find lots of people who disagree: they are irritated by the push/pull focus ring action.
The auto focus is noisy, not unlike the 28-70mm, but it works quickly enough and so far I’ve had no problems on dull overcast days. Not having a lot of confidence in evaluative metering, I quickly got into the way of selecting and locking in a mid-tone, using the centre point, auto focusing, recomposing and firing off a shot. (I have my EOS 50 set up to do this.) If you’re into manual focusing you’ll like the feel of the generous focus ring. This is a heavy lens and the zoom ring needs a very firm grip, but if you’ve reasonably strong hands this combination won’t be a problem. However, the zoom ring is a little narrow for a man’s fingers, so a tight grip is essential. I like the weight of the lens on the camera – it’s manageable and very stable.
The included lens hood (Canon claims lens hoods are "optional"!) will help to prevent flare, and so far I've had no serious problems. However, some have complained about flare with this lens. It’s interesting to note that the camera’s 1.6x cropping means the lens hood could be a little longer without appearing in the shots.
Conclusion: I got what I expected for the money I paid. To put it another way: 6 out of 10, but 8 out of 10 with the help of subtle software techniques. Please don’t let the limitations of less expensive independent zooms stop you from taking truly impressive shots!
Hope this text is useful to someone out there.
Sam