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Sigma 30mm f/1.4 DC HSM vs. Sigma 30mm f/1.4 EX DC

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There is a bit of confusion regarding the names of the old versus new version of Sigma’s 30mm DX (crop sensor) lens. The original version is officially the Sigma 30mm f/1.4 EX DC HSM, while the new one is the Sigma 30mm f/1.4 DC HSM A1. I think. I do want to thank them for not calling it the 30mm f/1.4 X, though.

Since we got a nice bunch of the A1 version lenses in yesterday, we thought it would be worthwhile to do a bit of comparison with the older version. For those who haven’t had the pleasure used the original Sigma 30mm f/1.4 lens, it was something of a love-hate relationship. The original 30mm was small, sharp, and inexpensive; a perfect combination for those shooting a crop sensor camera. Unfortunately, it had the somewhat dubious combination of being rather inaccurate to autofocus, yet extremely difficult to manually focus because of its inaccurate MF ring. There was, perhaps, a bit more copy-to-copy variation than many of us found acceptable.

Sigma’s new version of the 30mm APS-C only lens, would, we hoped, eliminate those negatives. It might even be dramatically better than the original version optically. The original wasn’t a bad lens at all, but the recent Sigma 35mm f/1.4 lens had most of us anticipating something impressive with the new 30mm, too. But before we get to the optics, lets take a look at the two versions.

 

The new 30mm DC HSM (left) and the original 30mm EX DC (right). Copyright Roger Cicala, 2013

 

Tale of the Tape

 

30mm EX DC 30mm DC HSM
Elements / Groups7 / 79 / 8
Aperture blades89
Min. Foc. Dist. (ft)1.30.9
Filter size6262
weight (oz.)1515
Price$289$499

 

So the new lens gives us a new optical formula, an extra aperture blade, and closer minimum focusing distance to go along with a higher, although still reasonable, price tag. It also comes with the much improved outer coating that doesn’t peel off like the one on the original lens and a HSM (hypersonic) motor that should improve AF speed and perhaps accuracy.

After putting the lens on a camera the build difference is immediately apparent. The lens feels more solidly built, particularly the hood. Most immediately apparent, though, is that the manual focus ring turns smoothly and accurately, which is not at all the case with the gritty, jumpy, inaccurate MF ring on the original version. Did I mention I didn’t like the original MF ring? To paraphrase Shakespeare, “I would beat thee, but that would only infect my hand.” The new one, though, is a pleasure to manually focus; smooth and accurate.

Optical Evaluation

I don’t usually put optical formulas and MTF charts in these posts, but I’m going to make an exception today. Because the lenses look so similar on the outside and have such similar names, I think it important to demonstrate how different they are inside. Here are the optical formulas for the two lenses.

 

Optical formula for the origina (left) and new (right) Sigma 30mm f/1.4 lenses. Sigma, USA

 

The MTF charts from Sigma’s calculations would suggest the new lens is much better than the old along the edges and corners.

 

Sigma’s computed MTF charts for the old (left) and new (right) 30mm f/1.4 lenses. Sigma USA

 

I need to mention that we tested these lenses on a Canon 7D. Results would be slightly different on other cameras so please try not to make comparisons to, say, the Sigma 35mm f/1.4 tested on a Canon 5D Mk III. Yes, I know you’re going to anyway, but at least now I can say, “I told you so.”

Anyway, we compared the 8 copies of the 30mm A1 that came in today with 6 copies of the 30mm f/1.4 DC that were on the shelf. As usual, average MTF 50 across the entire lens is plotted on the vertical axis, center MTF 50 on the horizontal, both in Line Pairs / Image Height.

As you can see on the vertical axis, the new version (blue dots) has slightly higher overall (average) resolution, while the older version (red dots) has, perhaps, slightly higher center resolution. (The center difference is pretty minimal and I doubt you could pick it up even pixel-peeping.) The difference away from the center is a bit clearer when presented as a table with corner values included.

Center MTF 50 Avg MTF 50 Corner MTF 50
Sigma 30mm f/1.4 HSM A1600490340
Sigma 30mm f/1.4 EX DC605450260

The lenses, at f/1.4, are about identical in the center, but the new version is significantly better in the corners.

Let’s look at how that changes as we stop down.

The new version starts of sharper in the corners and the corners steadily improve to f/5.6. The old version starts off softer in the corners and improves less as we stop it down. Its corners peak at f/8, but never get nearly as sharp as the new version does.

Conclusion

Like a lot of people, I was hoping for a crop-sensor version of the Sigma 35mm f/1.4 full-frame lens; an amazingly high-resolution optic. This lens isn’t that good optically. It’s a very nice lens with good resolution and excellent corner performance. If corner performance is important to you this lens is a significant upgrade. If you are more interested in center resolution, than optically it’s not better than the original.

However, I’d still consider this a worthwhile upgrade for a number of reasons. Build quality is far better. The new lens can be accurately focused manually, something that live-view shooters like myself found was difficult to do with the original. I can’t speak for autofocus accuracy yet, but the Sigma USB dock,which now has a release date of early May, will allow us a degree of microfocus adjustment not available with other lenses. The dock is fully compatible with the A1 lens. To me, that’s worth the price of the upgrade right there.

Roger Cicala and Aaron Closz

Lensrentals.com

April, 2013

16 Responses to “Sigma 30mm f/1.4 DC HSM vs. Sigma 30mm f/1.4 EX DC”

asad said:

Any chance we could see a comparison with the Canon 28mm f/1.8 on a crop sensor?

David said:

A great summary, thanks. It’s a good time to be a crop shooter.

Berzemus said:

I still use the old 30mm f/1.4 as my throw-around/can’t-decide-what-to-take/it’s-gonna-be-dark/gimme-bokeh lens. Used it as a burning glass once, while drunk, worked like a charm. Did leave some permanent but negligible traces on the optics though.

Would be interesting to see if the new version offers better rendition: I often found the contrast & colours on the old one a bit dull.

Salty said:

Any chance of comparison between the new Sigma and Nikon 35/1.8g?

Stephen Froehlich said:

Roger, how do you feel about this lens’s longitudinal CA compared to its predecessor and the Canon 28mm f/1.8?

Pavel Suprun said:

Resolution was not the strength of this lens, but its beautiful and pleasant bokeh. Did Sigma spoiled this feature or made it even better – that is the question. Autofocus is also an interesting question. But not resolution.

eric said:

This lens is used mostly at large aperatures, so unless you’re shooting a wall, the corners won’t be in focus anyhow. Otherwise (if I do not need large aperature), I’ll use the kit lens for the flexibility of a zoom. So I won’t be upgrading unless AF is much improved. I find AF to be very good except in low light. Also, live view contrast AF takes a LOT longer than my canon lenses.

eric said:

This lens is used mostly at large aperatures, so unless you’re shooting a wall, the corners won’t be in focus anyhow. Otherwise (if I do not need large aperature), I’ll use the kit lens for the flexibility of a zoom. So I won’t be upgrading unless AF is much improved. I find AF to be very good except in low light. Also, live view contrast AF takes a LOT longer than my canon lenses.

This lens was clearly better (sharper with less chromatic aberations) than the 28mm Canon lens in most reviews I read at the time.

Stephen Froehlich said:

My thinking is that the lateral CA of the Canon 28mm f/1.8 is pretty easily correctable in software, but the longitudinal CA of this lens is harder to correct in software.

Other reviews have shown the bokeh to be of a very nice quality with pretty evenly-lit discs, by the way.

Satya said:

Hi, I am interested in difference of a lens performance on D7100 compared to D7000. The D7100 clearly has 50% more resolution packed into it in a similarly sized sensor. While the camera can do a better job, how does that increase the demands on a lens?

I want to know if the lower performance of a lens will limit the new hi-res camera. If so, what are some of the highest performing lenses under $1000 that will work well on D7100?

Thanks.
Satya

Ian said:

The older 30mm autofocus issues are resolved when you send in your lens and body to Sigma for calibration. I live in NY so I drove to the service center and had itresolved in 30 minutes

Jean-Marie said:

INACCURACIES IN YOUR FIGURES AND COMMENTS

Hi Roger,
Thank you for you job : I consult your blog very often and get a lot of precious information.
This post would also be very useful to me… if inaccuracies didn’t confuse my mind. Sorry, I may “cut the hair in fourth” (as we say in France), and resolution isn’t everything, but since it is the main subject of this post… Here they are.

YOUR FIRST GRAPH
I guess your first graph relates measurements made at full aperture, i.e. f/1.4 ?

TABLE AND COMMENTS UNDER THE FIRST GRAPH
The comment under this first graph, abaout center/average resolution, doesn’t sound balanced to me, and the tables doesn’t help :
- Figures in the table are from single copies of the lenses, and the comparison is unfair (one of your best Sigma Art vs. one of your worst Sigma EX)
- It would be more significant to average the numbers in your table over the entire sets of tested lenses.
Then I retrieved the data from your graph, and did the math :
—————————-
| Center MTF | Average MTF |
————————————–
Sigma | 623 | 448 |
EX | | |
————————————–
Sigma | 572 | 482 |
Art | | |
————————————–
ABSOLUTE | -51 | +34 |
VARIATION | | |
————————————–
ABSOLUTE | -8% | +8% |
VARIATION | | |
————————————–
So, to be more balanced, the difference in center resolution is the same as in average resolution. Actually this is what the graph shows more clearly than the table.

MTF vs. APERTURE GRAPHS
I feel very uncomfortable with those two graphs:
- Either you unintentionally mixed or switched the data. (No lens in your Sigma Art set of your first graph has the (center MTF,average MTF) couple of your second graph. And no lens in your Sigma EX set of your first graph has the (center MTF,average MTF) couple of your third graph)
- Or you switced the titles of those two graphs.
In both cases, your following conclusions should be revised…
(Actually, it seems to me that you put the average & center data of the Sigma EX lens with the corner data of the Sigma Art lens on your second graph, and put the average & center data of the Sigma Art lens with the corner data of the Sigma EX lens on your third graph)

Am I wrong somewhere?

Sincerly,
Jean-Marie

LensRentals Employee

Roger Cicala said:

Hi Jean-Marie,

YOUR FIRST GRAPH
I guess your first graph relates measurements made at full aperture, i.e. f/1.4 ?
That’s correct, at f/1.4

TABLE AND COMMENTS UNDER THE FIRST GRAPH

—————————-
| Center MTF | Average MTF |
————————————–
Sigma | 623 | 448 |
EX | | |
————————————–
Sigma | 572 | 482 |
Art | | |
————————————–
ABSOLUTE | -51 | +34 |
VARIATION | | |
————————————–
ABSOLUTE | -8% | +8% |
VARIATION | | |
————————————–
So, to be more balanced, the difference in center resolution is the same as in average resolution. Actually this is what the graph shows more clearly than the table.

I totally agree with your end statement here and tried to make that clear when I said “perhaps slightly higher center resolution”. It’s close. Our numbers are a bit different, probably partly from your reading them on a compressed graph and because i record them in the spreadsheet rounded to the nearest 10. So if I have 644 and 649 as actual numbers, my table would have give the result as 645, etc. It looks like we both agree that Imatest numbers have the potential to be over read in accuracy so I don’t worry too much about whether the result in the table would be 645 (my way) or 648 (actual average).

Your point about the aperture corrected graphs is something I should probably mention in the article, but people are always complaining that my blog posts are overlong so I tend to leave out things I’d put in a scientific paper like methods. Doing the aperture curves is very time consuming. I use 3 lenses (throwing out highest and lowest, then taking 3 of the remaining) so the numbers are a bit different than the earlier charts.

Again, I think Imatest results are shotguns: if I repeated the tests tomorrow I’d expect at least a 5% (and perhaps even a bit more) difference in results. I really wish we did meta analysis in photography so we could present a broader set of various tester’s results lumped together.

Hope this answered some questions,

Roger

Bart said:

A dissapointment. Time to get a cheap second hand lens?

Does a soft lens (like this) affect your footage if you shoot mainly video in 2MP (1080p)?

JS said:

I have this lens for a week now. I spend a lot of hours with it so far, learning to know the lens. I had to do some small adjustments with fine tuning the AF on my Nikon D7000. So far I simply love the lens and I think I will leave on my D7000 a long time. It is solid as a rock, auto focus motor is so silent I can hardly hear anything and images are real sharp. It is a little wider on a DX as the 35mm and all the corners are sharp. So far so good!

Jaideep said:

Thank you for the comparison. Althought it is true that the new 30mm from Sigma is superior than the older 30mm which had 7elements in 7 groups. However, I believe the older 30mm F1.4 EX DC also has a HSM motor. The packaging doesn’t say that anywhere but if you look at the older lens itself (image above) it says DC HDM under 30mm F1.4. Please let me know if that’s correct and if the older one had HSM. Thanks!

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