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Sigma 40mm A f1.4 - star test

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13 replies to this topic

#1 skanker

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Posted 22 May 2022 - 02:20 AM

Hi Guys!

 

I recently bought a 40mm Art and did a picture quality test.

 

Canon 6Da @ f1.4:

https://imgbb.com/3yjGBFy

 

 

Canon 6Da @ f2.8:

https://imgbb.com/VBvH7Tc

 

 

How do you rate the image quality? Should I keep the lens?

 

CS Gernot


Edited by skanker, 22 May 2022 - 02:23 AM.

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#2 erictheastrojunkie

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Posted 22 May 2022 - 01:09 PM

It's great even at f1.4, no LoCA, virtually no coma with only slight star elongation in the extreme corners. You aren't going to find many lenses as good as this, maybe the Tamron 35mm f1.4 if you get a great copy.
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#3 jesse 3

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Posted 22 May 2022 - 01:29 PM

It looks excellent at f1.4.

I got really good results with D850 & 35mm/f1.4 wide open for milky-way. 40mm f1.4 is obviously better, and there is also 35mm f1.2. I heard mirrorless systems are uniformly sharper across the frame. So quite confused about next upgrade path.
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#4 skanker

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Posted 22 May 2022 - 01:42 PM

It's great even at f1.4, no LoCA, virtually no coma with only slight star elongation in the extreme corners. You aren't going to find many lenses as good as this, maybe the Tamron 35mm f1.4 if you get a great copy.

Hi Eric!

 

The 40mm is definitely the best lens in this focal range. I could exchange the lens for a new one, so I'm asking because of its performance. Is it a "keeper"?

 

CS Gernot


Edited by skanker, 22 May 2022 - 01:42 PM.


#5 skanker

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Posted 22 May 2022 - 01:45 PM

It looks excellent at f1.4.

I got really good results with D850 & 35mm/f1.4 wide open for milky-way. 40mm f1.4 is obviously better, and there is also 35mm f1.2. I heard mirrorless systems are uniformly sharper across the frame. So quite confused about next upgrade path.

Hi Jesse!

 

I can only report from the Canon R series. Unfortunately, the required adpater adds additional coma to the images. That's too bad frown.gif

 

https://g2.img-dprev...B7D19B30AD8.jpg

 

CS Gernot 


Edited by skanker, 22 May 2022 - 01:45 PM.


#6 jesse 3

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Posted 22 May 2022 - 02:31 PM

Have you done brick wall testing for distortion and vignetting, and focus accuracy? Are you concerned about wide open extreme corners for stitching? I will be happy to have such a copy. If your retailer allows hassle free exchanges, perhaps a good idea to try another copy to compare and pick the best.
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#7 erictheastrojunkie

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Posted 22 May 2022 - 02:59 PM

Hi Eric!

The 40mm is definitely the best lens in this focal range. I could exchange the lens for a new one, so I'm asking because of its performance. Is it a "keeper"?

CS Gernot


Yes, I used this lens for a long time when it first came out and produced some excellent nightscapes with it, I was one of the first champions of this lens. The copy you have is superb, it doesn't need to be exchanged.
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#8 skanker

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Posted 23 May 2022 - 01:19 PM

Thx for the help Jesse & Eric!

 

I will keep the lens :)

 

CS Gernot



#9 vidrazor

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Posted 23 May 2022 - 10:29 PM

Definitely keep that sucker. I guess you don't trust your own eyes? grin.gif


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#10 skanker

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Posted 24 May 2022 - 02:11 AM

Definitely keep that sucker. I guess you don't trust your own eyes? grin.gif

I was a little worried about the comet shaped stars in the corners. Apparently that's normal with this lens.

I think it is a field curvature. I will try to focus away from the center of the image to optimize the corners.

 

CS Gernot


Edited by skanker, 24 May 2022 - 02:12 AM.


#11 vidrazor

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Posted 24 May 2022 - 06:47 AM

I was a little worried about the comet shaped stars in the corners. Apparently that's normal with this lens.

I think it is a field curvature. I will try to focus away from the center of the image to optimize the corners.

CS Gernot

Nah, concentrate on the center. If you want sharp to the edge go down to 2.8.
 



#12 erictheastrojunkie

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Posted 24 May 2022 - 08:53 AM

I was a little worried about the comet shaped stars in the corners. Apparently that's normal with this lens.

I think it is a field curvature. I will try to focus away from the center of the image to optimize the corners.

 

CS Gernot

Those aren't comet shaped stars, considering the focal length and speed of the lens those stars are amazing, compare this lens to something like the Sigma Art 28mm (which is one of the best lenses in the 20-30mm focal length range) or more average lenses like the various 24mm, 35mm, and even 50mm....ya, this 40mm (and your copy) is spectacular in its correction of aberrations. 



#13 skanker

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Posted 31 May 2022 - 08:56 AM

Those aren't comet shaped stars, considering the focal length and speed of the lens those stars are amazing, compare this lens to something like the Sigma Art 28mm (which is one of the best lenses in the 20-30mm focal length range) or more average lenses like the various 24mm, 35mm, and even 50mm....ya, this 40mm (and your copy) is spectacular in its correction of aberrations. 

Did you focus on the center of your images? You could also focus on the third of the picture to improve the edges (comets), am I wrong there?

 

CS Gernot 



#14 calypsob

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Posted 04 June 2022 - 03:17 PM

Wow that really is a great lens


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