Samyang 14mm full frame lenses

introduction

these are affordable super wide angle manual focus lenses for full frame cameras giving a field of view of 115.7° but also comes in cropped sensor mounts giving field of views 93.9° on DX, 89.9° on APS-C, and 76.24° on Micro Four Thirds system
fixed petal lens hood
NO ability to use filters!
the f/2.8 UMC lens is popular for astrophotographic landscapes of the Milky Way as photographers like its field of view on full frame, wide aperture, and don't need AF, and it gives nicer edge-to-edge star images with minimal coma/astigmatism, better than Canon or Nikon branded very expensive alternatives, BUT the original version has been criticised for not being as sharp and for having more distortion, and it only has 6 straight diaphragm blades
- original version released late 2009 Samyang 14 mm f/2.8 IF ED MC Aspherical
- it was soon released as an updated version Samyang 14 mm f/2.8 ED AS IF UMC which is similar design but has the UMC lens coatings, is sharper, better into the light, less coma and astigmatism (only 1% not 10%), a little more CA and distortion
- a newer AE version adds electronic contacts for EXIF, and AF confirm on dSLRs
the T3.1 VDSLR II lens is a a touch more expensive, with different optical design, much heavier, and is designed for Cine/video use but has 8 rounded blades for nicer out of focus image shapes stopped down, and presumably nicer star burst imagery stopped down.

	Samyang XP 14mm f/2.4	Samyang 14mm f/2.8 IF ED UMC Asph lens	Samyang 14mm T3.1 VDSLR II lens
price on Amazon.com	$US799	$US299/359	$US399
build		plastic/metal	aluminium alloy
aperture	f/2.4	f/2.8	T3.1
diaphragm blades	9 rounded	6 straight	8 rounded
stepless, quiet aperture ring	No ring	No	Yes
Cine gearing		No	Yes
close focus	0.28m	0.28m	0.28m
MF gearing		slow, more precise than needed
filter thread	None!	None!	None!
rear filter slot	None!	None!	None!
infrared marker	No	No	No
DOF scale	No	No	No
electronic contacts	Yes	No/Yes AE version	No
optical design	18 elements in 14 groups, 2ASPH, hybrid, 2ED, 3HR	14 elements in 12 groups, ASPH, UD, hybrid, 2UD, 3HR	14 elements in 10 groups, ASP, hybrid ASPH, HR ED
coating		UMC	UMC
resolution	sharp, best at f/4-5.6	sharp centres best at f/5.6 but soft edges improve marginally stopping down
distortion	3.8% simple barrel	severe, 7% weird barrel centrally, pincushion at edges
vignetting wide open		strong 2.3EV
lateral CA wide open	minimal	well corrected, better than the Canon 14mm II
coma wide open	low
weight	791g	424g	620g
length	109.4mm	94mm	96.1mm
weathersealed	No	No	No

http://www.northlight-images.co.uk/samyang-xp-14mm-f2-4-lens-review/
- minimal CA, some minor simple barrel distortion, good flare control, minimal coma, moderate vignetting
https://www.ephotozine.com/article/samyang-premium-mf-14mm-f-2-4-lens-review-30229
- sharpest at f/4-5.6
- minimal CA, excellent flare resistance, 3.8% barrel distortion, bokeh seems smooth
http://gippslandimages.com.au/samyang-xp-14mm-f2-4-vs-tamron-15-30-f2-8-vi-dc-coma-tests/
- less coma than the Tamron SP 15-30 f2.8 Di VC USD lens