![](http://www.glaringnotebook.com/zimages/sig122.jpg)
Perhaps, it was indeed too soon to declare that I would only buy one A-mount lens in 2010. Here’s the second (the first being the rare Minolta 24-50mm F4.)
![](http://www.glaringnotebook.com/zimages/sig121.jpg)
This is the Sigma 12-24mm F4.5-5.6 EX DG, which sets the world record for widest, brightest rectilinear lens for 35mm full-frame format. 122 degrees diagonal coverage!
Of course, my Peleng 8mm F3.5 circular fisheye does 180 degrees from edge to edge, but de-fishing the image to make a rectilinear projection loses a lot of resolution!
![](http://www.glaringnotebook.com/zimages/sig128.jpg)
You can fit pretty much all you can see, in the frame!
![](http://www.glaringnotebook.com/zimages/sig127.jpg)
Perspective distortion makes closer objects much bigger.
![](http://www.glaringnotebook.com/zimages/sig1213.jpg)
A common misuse of ultra-wide angle lenses is when they are not pointing straight at the subject – you get parallel lines converging. In this case it is recommended to stand further away, aim forward, and crop the excess floor.
![](http://www.glaringnotebook.com/zimages/sig1212.jpg)
However, it is great when you are in a tight space! I could not stand any further back.
![](http://www.glaringnotebook.com/zimages/sig125.jpg)
It also gives plenty of leeway for group shots.
![](http://www.glaringnotebook.com/zimages/sig126.jpg)
Also, you may find you’d be cropping feet a lot less often in tight spaces!
![](http://www.glaringnotebook.com/zimages/sig129.jpg)
I used DxO Optics Pro Elite to process these pictures from the A900 – it applies a fair bit of barrel distortion correction, causing the corners to look more stretched out. Arguably, the barrel distortion of the original picture looks a bit more natural. Also, I shot this at a slower shutter speed, so don’t be confused between motion blur and stretched edges!
![](http://www.glaringnotebook.com/zimages/sig1210.jpg)
I was standing just in front of them.
![](http://www.glaringnotebook.com/zimages/sig1211.jpg)
So what about that other rectilinear lens for 35mm full-frame format? The Voigtlander 12mm F5.6 in Leica M mount? Here it is, with a Sony NEX-5 and Kipon M-mount to E-mount adapter.
It is, however, only for rangefinders with a shorter flange distance, or Sony NEX/Micro-Four-Thirds/Samsung NX cameras with an adapter. Though it won’t be so appealing on Micro-Four-Thirds due to the 2x crop factor, and the Samsung NX’s weaker ISO performance, especially since the lens is F5.6. It also does not zoom!
![](http://www.glaringnotebook.com/zimages/sig123.jpg)
However, its main plus point is its tiny size!
![](http://www.glaringnotebook.com/zimages/sig124.jpg)
I also stumbled upon the Sigma 8-16mm F4.5-5.6 EX DC HSM for APS-C cameras, which is slimmer, but has the same front-heavy balance. The Sigma 8-16mm focuses to 24cm close and has a front cap adapter (not to be confused with the lens hood) which takes 72mm filters. The Sigma 12-24mm meanwhile focuses to 28cm close and has a front cap adapter which takes 82mm filters.
While the 8-16mm does offer practical benefits in terms of size, there isn’t an APS-C camera that does 24 megapixels yet.