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11/05/15 New testing results from the Sigma 20mm 1.4 Art lens at lenstip.com

Posted on November 6, 2015 //
Sigma 20mm F 1.4 Art lens

Sigma 20mm F 1.4 Art Lens

As of this afternoon, the first full review of the new Sigma 20mm 1.4 has been published over on www.lenstip.com  You can read the full review here: Lenstip 20mm 1.4 Sigma review

From a quick read I have determined the following:

  1. The resolution of this lens can be expected to be superior to pretty much all other 20mm fast lenses out there, including the recent Nikon 20mm 1.8.  It seems that the center resolution even at F1.4 is excellent and by F3.5 to F4.0 the corners are very sharp also.
  2. There might be some issues with Chromatic aberrations, but hopefully the LR lens profile when available will correct for this. The build quality is as expected, excellent as with all the Sigma Art glass
  3. Coma, sadly it seems that this lens falls a bit short with coma corrections.  Per the testing at Lenstip, there are pretty harsh coma issues from F1.4 till F 2.0.  From their examples, it appears to me that these coma issues are as bad as with the 24mm 1.4 Sigma Art lens.  However the example shown at F2.0 looks pretty good to me as there     are butterfly wings showing, but nothing like what the Nikon 20mm F 1.8 shows at F 2.0 or even F 2.5.  I had hoped that this new lens, which Sigma states “is specifically designed to remove coma” would fare a bit better.  In daylight work, the coma aberrations may not show up, but anyone wanting to use this lens at night for astro-photography will be a bit disappointed as the quest has always been to get a wide that will work at F 1.4 without coma.
  4. Build quality appears to be as with all the Art line of lenses, excellent.

 

Sigma top view of 20mm F 1.4 Art lens

Sigma top view of 20mm F 1.4 Art lens

My main need for a fast wide, is night photography, where the difference between F 2.8 and F 1.4 is huge and can allow for a vastly different quality image as you can shoot short exposures of the Milky Way and other starscapes without having to be at a grossly high iso setting like ISO 12800.  There was no mention of the bokeh wide open, and again I am hoping to see something better than Sigma was able to provide for the 24mm F 1.4 which to my eyes has a very disruptive bokeh on landscapes, not as much on macro work.

The new Sigma Art 20mm 1.4 already has one strike against it with the fact that it has a fixed hood, and curved outer element which eliminates the ability to use standard filters.  Hopefully Lee or another company will come out with an adapter for this lens to use the SW-150 filter setup or something similar.

I have one of the new 20mm 1.4’s on order, hopefully it will ship sometime mid November, but I am not expecting it until December.

Sigma 20mm F1.4 Art Lens dual Views

Sigma 20mm F1.4 Art Lens dual Views

Filed Under: Photographic Equipment // Tagged: , , , , , , , , , , ,

07/01/12 The weather in Arkansas remains bleak–Heat and more Heat

Posted on July 1, 2012 //
The heat wave continues in Arkansas

The heat wave continues in Arkansas

Well as much as I would like to say “it’s all OK here in the State of Arkansas”, I really can’t.  This has to be the worst heat wave since the mid 1980’s when the state went almost 60 days with no measurable rainfall.  As you can see from the forecast page above, for the next ten days Arkansas temperatures will stay well over 95 degrees and on many days they will climb over 100 degrees.

If this continues for much longer, then you can safely assume a few things:

  1. Within 20 more days you will start to see large numbers of trees going into stress.  When this occurs the leaves will turn brown and stay on the tree until late fall.  However it also means that any hope of a good photographic fall will be ruined.
  2. Most if not all of the major trunk streams in the State are going to dry up totally, this includes the upper Buffalo River near Boxley, Piney Creek near Russellville, the Cossatot River in the Southwest corner of Arknasas, and the Mulberry River near Fort  Smith.  The smaller streams like Richland Creek have already dried up and unless the state gets some significant rainfall in July and August, I don’t think they will have anything in the fall either.
  3. The fire hazard in the state is at highest level.  On my last trip to the Buffalo River in early June, I was already seeing sights along the roads that let me know we were in for a long hot one.  The roadside wildflowers were gone and the grasses that grow along the road side were all brown.  Now almost a month later, all of these areas are going to be at a high risk if someone throws out a cigarette.
  4. Deer, Elk, and other large wildlife will stay in the deep glens and valleys of the state and not venture out in to the flats due to the excessive heat.  So wildlife photography will be much harder than stopping along the road side and taking out your camera.

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