- Messages
- 803
- Edit My Images
- No
A few days ago I received an early present from Santa. I had pondered long and hard which fast low light lens I needed to mate with my EF-S 17-55mm. The 17-55mm is a good lens, but it simply cannot stop motion at acceptable ISO speeds on my Canon 7D.
For a long time the choice was between the Canon EF 50mm F/1.4 and the Sigma 50mm F/1.4. Ultimately, I decided 50mm was just a little too long for a crop lens, bit the bullet and ordered the Sigma 30mm instead. Here are my observations.
What's Included?
For around £300 you get the lens, a quality lens hood and a protective pouch. I think these "free" extras are one of the main reasons for purchasing my first 3rd party lens. I felt a little short changed after spending £700 on the Canon 17-55 and then having to buy a £30 lens hood. Wake up Canon!
Build Quality & Handling
This is not an L lens. However, it feels much closer to L quality than my EF-S 17-55mm which cost 3 times as much money does. The Sigma 30mm is very solid, weighty and I like the feel and weight of the focus ring. The AF/MF switch is also reassuringly solid compared to my 17-55mm. In many ways the 30mm is almost L quality. As for handling, the rather heavy (for a ~30mm prime) Sigma balances really well on a 7D. Being a prime there is only one ring to grip and it is perfectly positioned and sized for the task.
Focus
Focus is one area where this lens (and it's bigger 50mm brother) has come in for some criticism. Many users report that it front focuses on Canon bodies and I confirm this is true with my sample. Fortunately this is easily corrected on my 7D by setting Micro Focus Adjustment to +9. The percentage of sharp shots wide open went from ~5% prior to adjustment to ~80%. after. At F/1.4 you do need to be really accurate and steady with focus because the slightest movement backwards or forwards will catapult you out of the wafer thin DOF. If you do not own a body with Multi Focus Adjustment I would strongly suggest trying the lens before you buy.
Focus speed is fast and pretty quiet (although not as quiet as most Canon USM lenses). It can struggle to focus in low light, but it is certainly no worse than my Canon F/2.8 & F/4 lenses. Rolling of shots in AI Servo mode whilst following a moving target is no problem for this lens.
Image Quality
I did not expect much from the Sigma at it widest aperture (F/1.4) when fixed to an 18MP crop sensor. I need not have worried because even wide open it is possible to get sharp images, although you do have to be really careful with focusing. Stop down to F/2 and you see a noticeable improvement but results are really good at F/2.8. The weak point is at the edges where the lens is consistently soft, even when stopped down to F/5.6 and beyond. Fortunately centre sharpness is generally superb, and this more than makes up for edge quality. Bokeh is very nice and smooth thanks to the 8 blade design.
One problem I have noticed is purple fringing at wide apertures. Areas of white/dark contast can show up high ammounts of fringing. This can be corrected quite easily by software but I would rather not have to do it. By f/2 fringing has greatly reduced and at f/2.8 it has all but disappeared.
Sample 100% centre crops converted straight to jpegs using DPP and without further processing. Click on images for full size jpegs. Focus point is on the bugs eyes.
For a long time the choice was between the Canon EF 50mm F/1.4 and the Sigma 50mm F/1.4. Ultimately, I decided 50mm was just a little too long for a crop lens, bit the bullet and ordered the Sigma 30mm instead. Here are my observations.
What's Included?
For around £300 you get the lens, a quality lens hood and a protective pouch. I think these "free" extras are one of the main reasons for purchasing my first 3rd party lens. I felt a little short changed after spending £700 on the Canon 17-55 and then having to buy a £30 lens hood. Wake up Canon!
Build Quality & Handling
This is not an L lens. However, it feels much closer to L quality than my EF-S 17-55mm which cost 3 times as much money does. The Sigma 30mm is very solid, weighty and I like the feel and weight of the focus ring. The AF/MF switch is also reassuringly solid compared to my 17-55mm. In many ways the 30mm is almost L quality. As for handling, the rather heavy (for a ~30mm prime) Sigma balances really well on a 7D. Being a prime there is only one ring to grip and it is perfectly positioned and sized for the task.
Focus
Focus is one area where this lens (and it's bigger 50mm brother) has come in for some criticism. Many users report that it front focuses on Canon bodies and I confirm this is true with my sample. Fortunately this is easily corrected on my 7D by setting Micro Focus Adjustment to +9. The percentage of sharp shots wide open went from ~5% prior to adjustment to ~80%. after. At F/1.4 you do need to be really accurate and steady with focus because the slightest movement backwards or forwards will catapult you out of the wafer thin DOF. If you do not own a body with Multi Focus Adjustment I would strongly suggest trying the lens before you buy.
Focus speed is fast and pretty quiet (although not as quiet as most Canon USM lenses). It can struggle to focus in low light, but it is certainly no worse than my Canon F/2.8 & F/4 lenses. Rolling of shots in AI Servo mode whilst following a moving target is no problem for this lens.
Image Quality
I did not expect much from the Sigma at it widest aperture (F/1.4) when fixed to an 18MP crop sensor. I need not have worried because even wide open it is possible to get sharp images, although you do have to be really careful with focusing. Stop down to F/2 and you see a noticeable improvement but results are really good at F/2.8. The weak point is at the edges where the lens is consistently soft, even when stopped down to F/5.6 and beyond. Fortunately centre sharpness is generally superb, and this more than makes up for edge quality. Bokeh is very nice and smooth thanks to the 8 blade design.
One problem I have noticed is purple fringing at wide apertures. Areas of white/dark contast can show up high ammounts of fringing. This can be corrected quite easily by software but I would rather not have to do it. By f/2 fringing has greatly reduced and at f/2.8 it has all but disappeared.
Sample 100% centre crops converted straight to jpegs using DPP and without further processing. Click on images for full size jpegs. Focus point is on the bugs eyes.
