|Canon 24mm f/1.4L II lens|
The Canon 24mm f/1.4L II lens seemed like the perfect answer for my star photography. All the reviews I read said that it performed well, even wide open, with only moderate vignetting (which is important when you want to stitch several images together into a panorama). By being able to shoot at f/1.4, I could lower my ISO and greatly reduce the noise I had been getting in my starry night skies.
None of the reviews mentioned the problem of coma. To my horror, I noticed stars in my photographs that were shaped more like white doves in flight! Returning to the Canon dealer in distress, I was told the only solution was to stop down my new 24mm lens. (Note: Not all aspherical lens designs are created equal. This expensive Canon lens has two high-precision aspherical elements, and 2-UD elements, but exhibits much more coma than another prime lens costing about one-third the price!)
|Canon 24mm @ f/1.4: enlarged area near the edge shows stars with severe coma distortion.|
|Aspherical elements in Samyang Optics 24mm f/1.4|
The 24mm lens also includes ED elements that are usually reserved for more expensive lenses. (ED means extra-low dispersion, referring to a type of glass that disperses light less than ordinary glass. Dispersion is the breaking up light into its original colors. Because dispersion can cause chromatic aberration, ED glass elements help reduce purple fringing and other chromatic aberrations.)
|Aspherical lenses by Samyang Opics: 14mm f/2.8 - 24mm f/1.4 - 35mm f/1.4|
Recommendations and Reviews: Several of my night photography friends have purchased these lenses and recommend them. For example, Masahiro Miyasaka (Astrononomy Photographer of the Year 2012) uses the 14mm; Mike Berenson uses the 24mm; and David Kingham uses the 35mm for awesome panoramas. I have purchased the 24mm, and plan to purchase the other two lenses. The 14mm (116º angle view) will be my next purchase, to compliment the 15mm Canon Fisheye (180º angle coverage) that I have now.
The Samyang / Rokinon / Bower 14mm has a little more barrel distortion than than the $1700 Nikon 14mm f/2.8D ED, and more barrel distortion than the $2400 Canon EF 14mm f/2.8 L II USM. Both the Canon and the Nikon are excellent choices for architectural photography, where it is important to maintain straight lines, but you're probably not going to notice this too much on landscapes and starscapes. Here is a Digital-Picture review on the Samyang 14mm.
The Samyang / Rokinon / Bower 24mm is my favorite lens because of its 84º angle of view, its fast, f/1.4 aperture, and its excellent correction for coma and fringe color. For starscapes, I would actually prefer the wider coverage of the 14mm, but its slower f/2.8 aperture gives overall preference to the 24mm. A Flickr contact of mine, Rick Whitacre, did this coma comparison between the Canon 24mm f/1.4 and the Rokinon 24mm f/1.4 (here's a 260% larger view). Rick did other tests on sharpness, brightness, and vignetting starting here (click image to view all sizes). Nikon users will want to see this LensTip coma comparison between the Nikon Nikkor AF-S 24 mm f/1.4G ED and the Samyang 24mm. Here's a Digital-Picture review on the Samyang 24mm.
The Samyang / Rokinon / Bower 35mm is my least desirable starscape lens because of its 63º angle of view. However, because it has a less distorted view (closer to that of a normal lens) than most wider angle lenses, it is preferred by many photographers for panoramas, where several vertical images are stitched together (like this one by David Kingham). Here's a Digital-Picture review on the Samyang 35mm.
NOTE: All of these lenses are designed for full-frame camera sensors (i.e. a Nikon FX). They can be used on a Nikon DX camera or a Canon camera with an APS-C size sensor, but the angles of view are less. The angle of view with the 14mm becomes 94º using the Nikon APS-C sensor, and 90º using the Canon APS-C sensor. The angle of view with the 24mm becomes 62º using the Nikon APS-C sensor, and 58º using the Canon APS-C sensor. The angle of view with the 35mm becomes 43º using the Nikon APS-C sensor, and 41º using the Canon APS-C sensor.
Pricing and ordering: (the links are to B&H, which often has lower than list pricing)
Rokinon 14mm f/2.8 Nikon mount - Canon mount - Sony mount ~ List: $399.00
Rokinon 24mm f/1.4 Nikon mount - Canon mount - Sony mount ~ List: $699.00
Rokinon 35mm f/1.4 Nikon mount - Canon mount - Sony mount ~ List: $499.00
(Disclosure: using these links will give me a 2% referral commission. Thanks for your support!)
SALE on Bower 24mm f/1.4 (ends on March 5, 2013): B&H is giving a $200 discount on the Bower branding of this Samyang lens (only in the Nikon and Canon mounts):
Bower* 24mm f/1.4 Nikon mount - Canon mount ~ SALE price: $499.00 (instead of normal $699)
*Remember, this is the same Samyang Optics lens as the Rokinon, just with the "Bower" branding name. I was a little concerned though when I read the descriptions on the B&H website and could not find mention of "Aspherical Lenses" for the Bower brand, even though all the other specifications were the same. To be sure, I went to the Bower website and confirmed that the lens design was the same 12 group/13 element construction, with aspherical elements. The specifications are exactly the same as the Rokinon lens brand, except that with the Bower branding, you also get a carry case.
Royce Bair is the editor of this blog and the photographer of the above images. Here is my gallery of NightScape images. My schedule of workshops, tutorials, and other events is available here.
Here is my first article on Overcoming Coma.
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