The Wide-Angle Winter Sky

By: Alan Dyer

Mar 02 2013

Tags: , , , , , , , , , ,

Category: Constellations, Milky Way, Nightscape, Tips and Techniques

1 Comment

Focal Length:50mm
ISO:800
Shutter:301 sec
Camera:Canon EOS 5D Mark II

Orion and his friends are beginning their descent into the evening sky, signalling the welcome end of winter and the coming of spring. 

I shot this last night from home, in a scene similar to some earlier posts, such as Winter Stars Rising. But the difference here is that I’m using a new lens, testing it for the first time. I wasn’t really after a “keeper” shot, but I think this one turned out pretty well!

The lens is the Samyang (aka Rokinon) 14mm f/2.8, an ultra-wide angle lens that sells for a bargain price, a fraction of the cost of name brand 14mm lenses. The reason is that this lens dispenses with all the automatic features and electronic communication and is a classic manual lens, just like we used to recommend people buy for astrophotography in the old film days. For shooting stars you don’t need autofocus or having the aperture stay wide-open until you take the photo. So we’re not missing much employing a no-frills manual lens like the Korean-made Samyang series – they make well-respected 24mm and 35mm lenses as well.

Star images are quite sharp across the very wide field, with very good control over coma at the corners. Stopping the lens down to f/4 does sharpen them up but the lens is perfectly usable at f/2.8, as it is here. The big issue is the extreme amount of vignetting — darkening of the corners of the frame. In star shots, we often have to boost the contrast a lot to make the shot presentable, and that increases the visibility of any vignetting, making the photo look like it was taken through a porthole. For this shot I “flattened” the image by applying very generous levels (almost maximum) anti-vignetting both in Adobe Camera Raw (at the start of processing) and again in Photoshop (at the end of processing) with its Lens Correction routine. The final result looks very good and natural I think.

Another drawback to the Samyang manual lenses is that they feed no information to the camera about what lens is attached. The “EXIF” data that the camera records lacks any info on aperture and focal length. So in the photo info at left (which is picked off the image automatically by WordPress), you’ll see the lens listed as a 50mm and with no aperture specified.

So the verdict? The Samyang/Rokinon 14mm is a very nice lens for wide-angle piggyback shooting (like this stack of five 5-minute tracked exposures), and for nightscapes and time-lapse work. A bargain at ~ $360. Recommended!

– Alan, March 2, 2013 / © 2013 Alan Dyer

 

One comment on “The Wide-Angle Winter Sky”


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