# Teardown: Sigma 35mm f/1.4 DG HSM Art by LensRentals.com



## Canon Rumors Guy (Dec 22, 2015)

```
On the heals of the <a href="http://www.canonrumors.com/teardown-canon-ef-35mm-f1-4l-ii-by-lensrentals-com/">Canon EF 35mm f/1.4L II teardown</a> by LensRentals.com, they now bring us a teardown of its main competitor, the Sigma 35mm f/1.4 DG HSM Art.</p>
<p>While the Sigma isn’t as well built as the EF 35mm f/1.4L II, it also costs half as much and by the looks of things, should hold up rather well.</p>
<blockquote><p>Many people are going to compare this lens to the Canon 35mm f/1.4 teardown we did and say that’s why they chose the Canon. That’s legitimate reasoning. The Canon is weather resistant, twice the price, and twice the weight, roughly. If I was going to subject my lens to harsh conditions and use, the Canon looks like the way to go if you can afford it. But if I want to carry several primes in a convenient size and at a convenient expense, the Sigma is a superb choice and I expect it will hold up very well. As always, horses for courses. <a href="http://www.lensrentals.com/blog/2015/12/sigma-35mm-f1-4-dg-hsm-art-lens-teardown" target="_blank">Read the full article…</a></p></blockquote>
<p>One noticeable issue with the Sigma 35mm f/1.4 Art is there is nowhere to optically adjust the lens, so that may be a reason there can be such a copy performance variation. The Canon EF 35mm f/1.4L II has 2 spots, and copy variation is the best of the 35mm options for your DSLR.</p>
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## Chaitanya (Dec 22, 2015)

thanks Roger for the teardown.


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## raptor3x (Dec 22, 2015)

dilbert said:


> Do Sigma expect that use of the USB dock will replace needing to tweak the lens internally as they do at Lens Rentals?
> 
> Also, I didn't read if Lens Rentals did USB dock tuning on all of the lenses that they tested?
> 
> ...



The optical adjustments they're talking about have nothing to do with the focusing system but with the positioning (i.e. tilt, centering, etc.) of the internal lens groups.


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## HighLowISO (Dec 22, 2015)

*Re: Teardown: Sigma 35mm f/1.4 DG HSM Art by LensRental*

i think canon may automate AF tuning for their dSLR camera bodies. makes sense and seems easy now. they just need to use a sensor with a few phase detect pixels as is common now with mirrorless and then they can have the camera automatically calibrate the AF sensor and the image sensor. With this level of tollerance and the current lens calibrations at the factory we could see the AF discrepencies really take a nose dive. Canon can do it at the factory so the need for the consumer to do it would be very minimal, but they could leave it as an option. 

I wouldn't be surprised if this is released in 2016.


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## Luds34 (Dec 22, 2015)

Did he say twice the weight? That can't be right can it?

The Sigma is already a beast in size and weight. I couldn't imagine a normal/wide prime weighing in at like 3 lbs. That's 70-200 f/2.8 territory. Mis-spoken, or just a really bad exaggeration?


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## tianxiaozhang (Dec 22, 2015)

Luds34 said:


> Did he say twice the weight? That can't be right can it?
> 
> The Sigma is already a beast in size and weight. I couldn't imagine a normal/wide prime weighing in at like 3 lbs. That's 70-200 f/2.8 territory. Mis-spoken, or just a really bad exaggeration?



Sigma 35mm is 665 g,
Canon 35mm II is 760 g,
Canon 35mm I is 580 g,

"The Canon is weather resistant, twice the price, and twice the weight, roughly."

That's a bit too exaggerated.


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## ballyscanlon (Dec 22, 2015)

canon: 26.8 oz
sigma: 23.5oz

so about twice the weight.


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## RGF (Dec 22, 2015)

Interesting to see the inside of lens and learn what makes a good lens (vs a poor lens) and what make a great lens.

Thanks for the review.


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## 9VIII (Dec 22, 2015)

The "Lensrentals.com" link beside the "Source" image is broken.
It doesn't go to the Sigma teardown, or Lensrentals, it goes to the Canon 35mm article on this website instead.


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## IglooEater (Dec 23, 2015)

I'm sure if I bought one of these options it would be the sigma-because of the price, but dang does that canon's build quality makes me want it!


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## infared (Dec 23, 2015)

I love the work that Roger does. It's always so vital to the craft!
I think that it's fantastic that the Canon 35mm f/1.4LII is so incredible optically and physically. Actually stunning....part of the asking price is justified just by the consistency of each lens to "hit the mark".
I picked up my Sigma for under $800 overseas. I can't justify the $1800 for a 35mm prime..(wish that I could), but clearly that lens is worth its price...and it would seem that my lens is worth its price. 
What's cool about this situation is that if a great image was shot with both lenses simultaneously ....the image quality difference in reality is moot. Academic. The image would come through in both instances. That is pretty cool.
I wonder how the build on the Sigma holds up to the Canon 35mm f/1.4L I? I'm curious now...since even that lens is still commanding $1100, currently.....


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## tron (Dec 23, 2015)

ballyscanlon said:


> canon: 26.8 oz
> sigma: 23.5oz
> 
> so about twice the weight.


what kind of math is that?


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## Intel478 (Dec 23, 2015)

tron said:


> ballyscanlon said:
> 
> 
> > canon: 26.8 oz
> ...


Sarcasm math; it's between the lines.


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## Sporgon (Dec 23, 2015)

I'm not surprised that the Sigma doesn't have any lens element adjustment. These third party manufacturers have to save cost in order to offer the lens at a relatively attractive price. Being able to assemble the lens 'as is' must be a decent saving in production but from the lens rentals variability graphs it looks like Sigma haven't mastered the consistent assembly that Canon have achieved with say the new 50mm STM. 

I bet if Lens Rentals disassembled one of the new Tamron primes they would find the same thing - decent enough construction but straightforward.


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## 9VIII (Dec 23, 2015)

I really have to wonder if Sigma doesn't have a tuning option at the factory. My thought is that if they have a pre-assembly check then they could estimate which individual elements work together well and then group them up.

Unless that's still overthinking it and they're actually confident enough to assemble lenses with nothing but a final "pass/fail" QC check.
In interviews the Sigma CEO did mention higher failure rates with the Glbal Vision line.

The funny thing is the variation doesn't seem to affect reviews. In a way they're right not to bother if the worst copies are still very sharp.


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## Luds34 (Dec 23, 2015)

Sporgon said:


> I'm not surprised that the Sigma doesn't have any lens element adjustment. These third party manufacturers have to save cost in order to offer the lens at a relatively attractive price. Being able to assemble the lens 'as is' must be a decent saving in production but from the lens rentals variability graphs it looks like Sigma haven't mastered the consistent assembly that Canon have achieved with say the new 50mm STM.
> 
> I bet if Lens Rentals disassembled one of the new Tamron primes they would find the same thing - decent enough construction but straightforward.



Not really a valid comparison. The 50mm STM is probably as simple of a design as Canon has in their current lineup.


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## Luds34 (Dec 23, 2015)

9VIII said:


> I really have to wonder if Sigma doesn't have a tuning option at the factory. My thought is that if they have a pre-assembly check then they could estimate which individual elements work together well and then group them up.
> 
> Unless that's still overthinking it and they're actually confident enough to assemble lenses with nothing but a final "pass/fail" QC check.
> In interviews the Sigma CEO did mention higher failure rates with the Glbal Vision line.
> ...



These are mass produced, consumer level products. I tend to think that there would be no find tuning done after manufactering. Just simple pass/fail quality checks as you said. The adjusting comes in handy for when a lens is sent in for repair, etc.

I think Roger eluded to it with his, "liking to make a good lens better". Meaning his team, while working with the lenses that are going in and out probably can take the time to make the adjustments.


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## Sporgon (Dec 23, 2015)

Luds34 said:


> Sporgon said:
> 
> 
> > I'm not surprised that the Sigma doesn't have any lens element adjustment. These third party manufacturers have to save cost in order to offer the lens at a relatively attractive price. Being able to assemble the lens 'as is' must be a decent saving in production but from the lens rentals variability graphs it looks like Sigma haven't mastered the consistent assembly that Canon have achieved with say the new 50mm STM.
> ...



Fair enough but Lens Rentals have shown that the other latest lenses from Canon such as the 35/1.4II and the 100-400/II are very consistent.


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## TWI by Dustin Abbott (Dec 23, 2015)

Canon Rumors said:


> On the heals of the <a href="http://www.canonrumors.com/teardown-canon-ef-35mm-f1-4l-ii-by-lensrentals-com/">Canon EF 35mm f/1.4L II teardown</a> by LensRentals.com, they now bring us a teardown of its main competitor, the Sigma 35mm f/1.4 DG HSM Art.</p>
> <p>While the Sigma isn’t as well built as the EF 35mm f/1.4L II, it also costs half as much and by the looks of things, should hold up rather well.</p>
> <blockquote><p>Many people are going to compare this lens to the Canon 35mm f/1.4 teardown we did and say that’s why they chose the Canon. That’s legitimate reasoning. The Canon is weather resistant, twice the price, and twice the weight, roughly. If I was going to subject my lens to harsh conditions and use, the Canon looks like the way to go if you can afford it. But if I want to carry several primes in a convenient size and at a convenient expense, the Sigma is a superb choice and I expect it will hold up very well. As always, horses for courses. <a href="http://www.lensrentals.com/blog/2015/12/sigma-35mm-f1-4-dg-hsm-art-lens-teardown" target="_blank">Read the full article…</a></p></blockquote>
> <p>One noticeable issue with the Sigma 35mm f/1.4 Art is there is nowhere to optically adjust the lens, so that may be a reason there can be such a copy performance variation. The Canon EF 35mm f/1.4L II has 2 spots, and copy variation is the best of the 35mm options for your DSLR.</p>



One major question: "Twice the weight, roughly". Umm, the lenses are less than 100g apart - 665 vs. 760g. I'm holding both lenses at the moment, and the physical differences are pretty minimal. The Canon is 10.5mm longer and 95g heavier. I don't really see this as a selling feature for Sigma. Price, yes, but the size difference is too minimal to meaningfully impact any photographer. That is a selling feature for the 35mm f/2 IS (less than half the weight and almost half the length), and even marginally for the Tamron SP 35mm f/1.8, but not really for the Sigma.


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## TWI by Dustin Abbott (Dec 23, 2015)

infared said:


> I love the work that Roger does. It's always so vital to the craft!
> I think that it's fantastic that the Canon 35mm f/1.4LII is so incredible optically and physically. Actually stunning....part of the asking price is justified just by the consistency of each lens to "hit the mark".
> I picked up my Sigma for under $800 overseas. I can't justify the $1800 for a 35mm prime..(wish that I could), but clearly that lens is worth its price...and it would seem that my lens is worth its price.
> What's cool about this situation is that if a great image was shot with both lenses simultaneously ....the image quality difference in reality is moot. Academic. The image would come through in both instances. That is pretty cool.
> I wonder how the build on the Sigma holds up to the Canon 35mm f/1.4L I? I'm curious now...since even that lens is still commanding $1100, currently.....



That is somewhat true (re image quality), but the new Canon is definitely in another league. Think Canon L to Otus. The 35L II has better contrast, color, and overall resolution, and I find that images just look more "special". The drawing is better with the L lens, though that probably won't show up on any chart testing. I've been using the lenses side by side in my review process, and for critical moments I find myself reaching for the Canon every time.


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## TWI by Dustin Abbott (Dec 23, 2015)

Sporgon said:


> I'm not surprised that the Sigma doesn't have any lens element adjustment. These third party manufacturers have to save cost in order to offer the lens at a relatively attractive price. Being able to assemble the lens 'as is' must be a decent saving in production but from the lens rentals variability graphs it looks like Sigma haven't mastered the consistent assembly that Canon have achieved with say the new 50mm STM.
> 
> I bet if Lens Rentals disassembled one of the new Tamron primes they would find the same thing - decent enough construction but straightforward.



I would be very interested in that teardown. The weather sealing is supposed to extend to seals at all the proper points, and I'd like to see a third party confirmation of that.


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## Bdube (Dec 23, 2015)

9VIII said:


> I really have to wonder if Sigma doesn't have a tuning option at the factory. My thought is that if they have a pre-assembly check then they could estimate which individual elements work together well and then group them up.
> 
> Unless that's still overthinking it and they're actually confident enough to assemble lenses with nothing but a final "pass/fail" QC check.
> In interviews the Sigma CEO did mention higher failure rates with the Glbal Vision line.
> ...



It's possible to match fabrication errors in elements to each other, but it is difficult and requires expensive sorting. Each element gets measured anyway, but for example if the front element's radius of curvature is too small, the focal length becomes shorter but the aberrations also change. It requires a thorough study of the lens system to match errors in a way that is constructive. The errors of alignment, at least in the art series lenses produced thus far, are quite a bit larger than the errors of the elements.


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## infared (Dec 24, 2015)

TWI by Dustin Abbott said:


> infared said:
> 
> 
> > I love the work that Roger does. It's always so vital to the craft!
> ...



I think if I had both lenses size-by-side that I would be reaching for the Canon EVERY time. ... But I am happy to know that a lens that is less than half the price holds up so well optically to the Golden Fleece. I look forward to your review. I am interested to see the comparison of the bokeh of the two lenses especially in the transition zone...I bet the Canon is impressive.


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## Larsskv (Dec 24, 2015)

TWI by Dustin Abbott said:


> infared said:
> 
> 
> > I love the work that Roger does. It's always so vital to the craft!
> ...



I am happy you point this out. I don't think MTF charts is a proper tool to evaluate the quality of a lens. It tells quite a bit, of course, but your real world testing are way more important to me. Looking forward to your review of the 35 L II!


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