# Sigma 135mm f/1.8 ART vs Zeiss Milvus 135mm f/2: Round 2 | Dustin



## TWI by Dustin Abbott (Jul 11, 2017)

After I did my review of the Sigma 135mm f/1.8 ART (http://bit.ly/ART135DA) I got feedback from a number of end users who felt that the copy I tested wasn't representative of the potential performance of the lens. I brought in a second copy of the 135 ART and put it back up against the Zeiss Milvus 135mm f/2 (which I own). This video shows what I discovered:

http://bit.ly/ARTvMILVUS2


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## SecureGSM (Jul 11, 2017)

Dustin,
Thank you for the exellent follow up to the initial review. I am glad that you liked the second copy of the lens better than the first one.
I noticed that the "skewed AWB" issue was likely resolved as well? at least looking at OOC JPGs in the video, I was unable to detect any meaningful difference in the colour temperatures between the Milvus and Sigma lens. Unless you have used custom WB settings for each lens individually.


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## TWI by Dustin Abbott (Jul 11, 2017)

SecureGSM said:


> Dustin,
> Thank you for the exellent follow up to the initial review. I am glad that you liked the second copy of the lens better than the first one.
> I noticed that the "skewed AWB" issue was likely resolved as well? at least looking at OOC JPGs in the video, I was unable to detect any meaningful difference in the colour temperatures between the Milvus and Sigma lens. Unless you have used custom WB settings for each lens individually.



That's right. There was something wonky in that first copy that played havoc with the metering on my 5D Mark IV. I found saturation levels more on parity, too, though the Zeiss still exhibits superior color performance.


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## SecureGSM (Jul 12, 2017)

good news then. Just thinking: should you, perhaps, consider conducting your reviews with at least couple of copies of the lens on hand in future? that would certainly help in drawing more accurate conclusions and avoid false positives? I do not for a second question creadibilty of your reviews! It is that for the last 2 months I keep hearing noise on internet that Sigma 135 Art glass has an akward AWB skew problem and is not as sharp as people think it is (with reference to your review page). 

Now that your reviews are extremely popular and became an authoritative source of information for the great many photo enthusiasts globaly, perhaps, it is a good time now to start offering reviews based on multiple copies? I am sure that your vendors will accomodate.




TWI by Dustin Abbott said:


> SecureGSM said:
> 
> 
> > Dustin,
> ...


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## AlanF (Jul 12, 2017)

This is not to run down your reviews, which usually contain many valuable points about how well a lens handles and performs and is constructed, but I would like to emphasize the change in your opinion on looking at a second copy of the Sigma.

Comparison of the optical performance of just one copy of one make of lens with just one copy of another make and then drawing general conclusions is not satisfactory. As lensrentals has pointed out in their comparisons of many copies of lenses, the variation between copy to copy of one make of lens can be greater than the difference between two makes.

You should now look at a second copy of the Zeiss!


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## BeenThere (Jul 12, 2017)

Better performance from a second copy isn't exactly good news. If there are significant copy to copy variations then buying the lens could be a crap shoot. What happens to all the lenses sent back to seller for exchange and a possibly better copy?


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## SecureGSM (Jul 12, 2017)

you cannot really claim copy to copy variation being "significant" if only 2 copies in total were sampled. you need a greater number to make a sense of the this. wait until LensRentals published their review based on multiple copies of the lens. They do study copy to copy variation quite religiously. until then, there is no reason to be concern.

p.s. actually, they already have:

https://www.lensrentals.com/blog/2017/04/sigma-135mm-f1-8-art-mtf-charts-and-a-look-behind-the-curtain/

"... You may be interested to know that I gave all 10 of these lenses to one of our more experienced techs and asked him to test them on a high resolution test chart. He said they all passed. When I told him one was bad and to check again, he did identify this one, but described it as ‘just a bit softer, but still fine’. I mention this because part of what you’re seeing here is that this lens is really, really good. Even the worst copy looked OK optically to a very experienced tech. It’s just not quite as good as the others. This is a bit unusual, since a true bad copy usually has some signs of side-to-side variation or decentering, and this lens really didn’t. You could make an argument that this lens is actually OK and I’m just overly picky, and you might be right...."

so there you have it: 1 out of 10 was an outlier. very good copy to copy variation that is.



BeenThere said:


> Better performance from a second copy isn't exactly good new. If there are significant copy to copy variations then buying the lens could be a crap shoot. What happens to all the lenses sent back to seller for exchange and a possibly better copy?


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## chrysoberyl (Jul 12, 2017)

BeenThere said:


> Better performance from a second copy isn't exactly good new. If there are significant copy to copy variations then buying the lens could be a crap shoot. What happens to all the lenses sent back to seller for exchange and a possibly better copy?



I agree on the crap shoot comment. This lens intrigued me, though, so I rolled the dice. If there is significant copy to copy variation, I lucked out this time, at least for the first two weeks.

I checked decentering, AF performance and resolution and found them all acceptable. I compared the resolution to that of my 100mm Milvus and found it noticeably higher - which surprised me! And I see no AWB skew problem.


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## TWI by Dustin Abbott (Jul 12, 2017)

SecureGSM said:


> good news then. Just thinking: should you, perhaps, consider conducting your reviews with at least couple of copies of the lens on hand in future? that would certainly help in drawing more accurate conclusions and avoid false positives? I do not for a second question creadibilty of your reviews! It is that for the last 2 months I keep hearing noise on internet that Sigma 135 Art glass has an akward AWB skew problem and is not as sharp as people think it is (with reference to your review page).
> 
> Now that your reviews are extremely popular and became an authoritative source of information for the great many photo enthusiasts globaly, perhaps, it is a good time now to start offering reviews based on multiple copies? I am sure that your vendors will accomodate.
> 
> ...



I often get early access to lenses when having multiple copies may not even be an option due to scarcity. Beyond that, however, this isn't actually my real job! I only have so much time to give, and frankly I don't really make much money from the time investment already. Testing multiple lenses means more time and effort...which I don't really have time to give.


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## Cory (Jul 12, 2017)

TWI by Dustin Abbott said:


> I only have so much time to give, and frankly I don't really make much money from the time investment already. Testing multiple lenses means more time and effort...which I don't really have time to give.


Well, it's appreciated by many which is why I need to start buying stuff through your links.


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## TWI by Dustin Abbott (Jul 12, 2017)

Cory said:


> TWI by Dustin Abbott said:
> 
> 
> > I only have so much time to give, and frankly I don't really make much money from the time investment already. Testing multiple lenses means more time and effort...which I don't really have time to give.
> ...



That's a nice start


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