Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Sigma 40mm 1.4: new benchmark

  • Please log in to reply
5 replies to this topic

#1 garret

garret

    Apollo

  • ****-
  • topic starter
  • Posts: 1321
  • Joined: 26 Jul 2009
  • Loc: Netherlands

Posted 14 December 2018 - 03:18 PM

It is very difficult to design a wide field, superfast, super sharp and coma free photo lens, no such lens has been ever designed...until now: the new Sigma Art 40mm 1.4... this lens has it all.

The size of a 135mm lens, 16 elements, super sharp even wide open with FF sensors, very low coma in the corner even with FF sensors, close to zero chromatic aberrations... this is a dreamlens  for wide field astrophotography, should be amazing with Ha and other filters.

Price tag of this dream: $1400.=/ Euro 1250.=

 

Bench test: https://www.lenstip....resolution.html

 

Garrett

Attached Thumbnails

  • sigma 40mm.jpg

Edited by garret, 14 December 2018 - 03:34 PM.


#2 whwang

whwang

    Vanguard

  • *****
  • Posts: 2494
  • Joined: 20 Mar 2013

Posted 14 December 2018 - 06:21 PM

Right. Sigma does it again, to an even higher level. Its Art 35/1.4 and 50/1.4 are already the best and rival the Zeiss Otus. Now this 40/1.4 can offer an F1.4 corner sharpness that’s even higher than the other Art lenses at F5.6. This must be some alien technology.

I am thinking about selling my Art 35 and 50 and replace them with this lens. But I will need to worry about how to support its weight. Just the lens mount of the camera is not likely to be enough.

ps,
There are already some astronomical pictures taken by this lens on the internet. They do look good.
  • Michael Covington, tkottary and twomonger like this

#3 garret

garret

    Apollo

  • ****-
  • topic starter
  • Posts: 1321
  • Joined: 26 Jul 2009
  • Loc: Netherlands

Posted 15 December 2018 - 06:41 AM

I hope this Sigma lens will have very good alignment of all these 16 elements...

 

Canon has this very well under control and their latest lenses show very low sample to sample variation, at Lensrentals.com there should be a recent review to show it clearly but I can't find it, maybe removed? 

No I found it: https://www.lensrent...200mm-f4-is-ii/

Excerpt from the review: "We hear Canon is doing a lot more automation and robotic assembly than other manufacturers. This lens suggests that stuff is working"

 

Garrett van der Veen


Edited by garret, 15 December 2018 - 06:51 AM.


#4 james7ca

james7ca

    Fly Me to the Moon

  • *****
  • Posts: 6461
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 15 December 2018 - 08:10 AM

It's all kind of relative and it depends upon the reproduction size, but the first full-frame, star-field image that I found that was taken with this lens isn't what I'd call an unqualified "dream." At full scale many of the stars are triangular shaped and the corners definitely show both chromatic aberration and other distortions. Here is a link to the image in question:

 

  https://www.dpreview...s/post/62035633

 

That said, for a full-frame image taken at f/1.4 it's not bad even though the pixels on the test camera (Canon 6D MkII) are a little on the large size (5.8 microns). What I mean by the latter is that with smaller pixels results are going to look even less impressive. Of course, you can't judge from just a single image as there may be sample-to-sample variability.



#5 whwang

whwang

    Vanguard

  • *****
  • Posts: 2494
  • Joined: 20 Mar 2013

Posted 15 December 2018 - 10:14 AM

The judgement of absolute size of the stars will be affected by the pixel size, but the judgement on the elongation of stars won't.  I own the 35/1.4 and 50/1.4.  If the 40mm picture was taken at F1.4, then I would say that it's better than my 35mm and 50mm at F4. I will happily take it, and probably use it routinely at F2 or F2.8 (while I usually use my 35mm and 50mm at F4).

 

(To be fair, it's not only the pixel size. The removal (or not) of the anti-aliasing filter will also change the size of stars.  When the AA filters are not removed, it is possible that a camera with a larger pixel show larger stars, larger in the absolute sense, i.e., xx microns on the focal plane rather than yy pixels.)

 

Sample variance is an interesting topic, especially regarding products made in Japan.  Japanese are notorious for keeping the best batch from their QC in the Japanese market, and sell the next tier oversea.  None of my Sigma lenses purchased in Japan has any problems, but many of my friends who purchase Sigma lenses in Taiwan complain about the lens alignment.  This is something to keep an eye on.


  • tkottary likes this

#6 garret

garret

    Apollo

  • ****-
  • topic starter
  • Posts: 1321
  • Joined: 26 Jul 2009
  • Loc: Netherlands

Posted 15 December 2018 - 12:17 PM

Understand that exact focusing with such fast lenses is exceptional important and difficult, Critical Focus Zone is only 4.3 Microns wide... that is less then 9 waves of green light!!

I did own the Canon 135mm F2.0 at that speed focusing was already a challenge (external motorized focusing) 

But I already see the very good performance of this lens in the image.

 

Garrett


Edited by garret, 15 December 2018 - 12:41 PM.

  • whwang likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics