Sigma 30mm DC HSM f/1.4 Art lens

Sigma has been enjoying consistently universal acclaim for its Art series of fast prime lenses and zooms and continues to add exciting new models like the recent 105mm f/1.4 prime!    Somehow they are able to offer high optical performance and reasonable pricing while continuing to manufacture in their Aizu factory  in Fukushima, Japan.   It is refreshing to see a company that is not solely driven by the quest for every increasing profits.    One of the first Art lenses that they introduced in 2012 is the 30mm f/1.4 DC HSM and it is currently available brand new for $499 USD.

Even though I’m the proud owner of a Sigma 85mm f/1.4 , I’m finding the focal length a little too strong and wanted something shorter for a couple of photography gigs I have this summer.   And because I’m notoriously cheap, I looked around for a good used deal and found that once again, the previous generation of this 30mm lens could be had for only $200.    This is the very similar looking 30mm f/1.4 EX DC HSM that was introduced in 2005 with the optical prescription of 7 elements in 7 groups featuring one aspherical element, one extra low dispersion element and one special low dispersion element.  The current lens has 9 elements in 8 groups with the same aspherical element located closest to the camera body but no special dispersion elements at all!  Both of these lenses were designed to work with the APS sized sensor so I was a little concerned that I might have issues when using the lens with one of my Metabones or Viltrox focal reducers.  And of course I wanted to test its optical performance relative to some native lenses of similar focal length.

From left to right:     Sigma 30mm f/1.4 EX DC HSM (EOS mount),   Leica  D Summilux 25mm f/1.4 (43rds),  Lumix 20mm f/1.7 (m43)

 

MTF curves (MTF10 in red, MTF30 in green) from left to right:    Sigma 30mm @ f/1.4 – f/2.8 – f/4,    Sigma 30mm with Viltrox EF-M2 @ f/1 – f/1.4 – f/2.8,    Sigma 30mm with Metabones Speedbooster T Ultra @ f/1.4 – f/2.8 – f/4, Leica 25mm @ f/1.4 – f/2.8,   Lumix 20mm @ f/1.7 – f/2.8

Some interesting conclusions can be drawn from this small study.

1.  The four element Viltrox focal reducer has performance similar to the much more expensive five element Metabones focal reducer (note:  the Metabones is not able to deliver an aperture of f/1 despite lowering the focal length to 21 mm, perhaps this will be corrected in the next firmware update)
2.  For once, the focal reducers do not appear to improve the image quality.  Perhaps because the lens was designed not for full frame sensor but the significantly smaller APS sensor.
3.  The native Leica and Lumix lenses are optically superior to the Sigma in all applications.

Although vignetting is increased because the image circle of the lens was designed to be used with APS sensors, it’s not too severe and likely not noticeable in real life applications.

Sigma 30mm f/1.4                                                                Sigma 30mm f/1.4 with Viltrox focal reducer

 

 

And finally a quick use of the Sigma 30mm with our 17 year old geriatric rabbit, at 21 mm f/1.

So in conclusion, I’m not sure I can endorse this purchase although it hardly broke the bank.   It is a means to obtain extreme bokeh but likely not visibly different from the Leica 25mm which also happens to be a much sharper lens.

If this is your first time here, click the HOME button in the upper right hand corner to review the complete list of topics.