Tamron 28-75 f2.8 for night sky shooting? anyone?https://www.dpreview.com/forums/post/55074813
Sigma 20mm 1.4 art vs nikon 14-24https://www.dpreview.com/forums/post/58493310
Best Lenses for Milky Way Photography: Canon Astrophotographers .http://www.lonelyspeck.com/best-lenses-for-milky-way-photography-canon/
Best Lenses for Milky Way Photography: Nikon Astrophotographers http://www.lonelyspeck.com/best-lenses-for-milky-way-photography-nikon/
SIGMA 17-70mm f/2.8-4.5 - AstroBinhttp://www.astrobin.com/gear/3264/sigma-17-70mm-f28-45/https://www.dpreview.com/forums/thread/3655471
Nikon 16-35mm, 17-35mm, or 28mm
Nikon D600 Astrophotography - Tamron 24-70mm F2.8 - YouTubehttps://www.youtube.com/watch?v=GnOYk44zJ4k
How-To: Picking a Great Lens for Milky Way Photographyhttp://petapixel.com/2014/01/29/picking-great-lens-milky-way-photography/
24-70mm f2.8 for astrophotography?https://www.reddit.com/r/photography/comments/43yxvd/anyone_use_2470mm_f28_for_astrophotography/
Astrophotography Without a Telescope - Randombiohttp://www.astropix.com/HTML/I_ASTROP/LENSES.HTM
Canon Lenses for Astrophotography
The following lenses and astrophotographic performance descriptions apply to APS-sized 1.3x, 1.5x and 1.6x crop-factor sensors. In general, lens performance in the corners degrades as the sensor size gets larger.
Canon EF-S 10-22mm f/3.5 - 4.5 USM ($820) - ok wide open, better stopped down 1 stop
Canon EF 15mm f/2.8 ($650) - good at f/4
Canon EF 16mm-35mm f/2.8 L II USM Zoom ($1,580) - ok at f/2.8, better at f/4.5
Canon EF-S 18mm-55mm f/3.5 - 5.6 IS Zoom ($175) - ok wide open at all focal lengths, better when stopped down one stop
Canon EF 17mm-40mm f/4 L USM Zoom ($800) - ok at f/4, very good at f/5.6
Canon EF 24-105mm f/4 L USM IS Zoom ($1,100) - ok at f/4, very good at f/5.6
Canon EF 24mm f/1.4 II L USM ($1,700) - ok at f/3.5, good at f/4.5
Canon EF 28mm f/1.8 USM ($485) - ok at f/3.5, good at f/4.5
Canon EF 35mm f/2 ($310) - ok at f/3.5, good at f/4.5
Canon EF 50mm f/1.4 USM ($400) - ok at f/3.5 good at f/4.5
Canon EF 50mm f/1.8 II ($125) - ok at f/3.5, good at f/4.5
Canon EF 85mm f/1.8 USM ($400) - ok at f/2.8, good at f/4
Canon EF 85mm f/1.2 L II USM ($2,100) - good at f/2.8, very good at f/4
Canon EF 100mm f/2 USM ($475) - good at f/2.8, very good at f/4
Canon EF 100mm f/2.8 USM Macro ($570) - good at f/2.8, very good at f/4
Canon EF 135mm f/2 L USM ($1,035) - good at f/2.8, very good at f/4
Canon EF 200mm f/2.8 L II USM ($780) - good at f/2.8, very good at f/4
Canon EF 300mm f/4 L USM non-IS - ok at f/4, good at f/5.6
Canon EF 400mm f/5.6 L USM non-IS $1,275 - ok at f/5.6, better at f/6
Older Canon Lenses
Canon made some fine manual-focus lenses, such as the R, FL, and FD series, for their film cameras before they came out with the EOS system and auto-focus. Unfortunately, these lenses can't really be used on the new auto-focus EF camera bodies for astrophotography.
When Canon redesigned their cameras and lenses for autofocus, they changed the distance from the lens flange to the sensor. Older FD lenses have a register (flange to sensor distance) of 42 mm. Modern EOS lenses have a register of 44 mm. That means that for infinity focus, older lenses come to a focus 2mm in front of the sensor. This is not a good thing for astrophotography!
The older FD lenses can not be used at infinity on an EOS body unless an adapter with an optical transfer lens is used. This usually degrades the performance of the lens enough to be undesirable for astrophotography. So basically, you don't want to use older Canon FD lenses on EOS EF bodies for astrophotography. But if you have one of these rare Canon optical adapters, you can certainly try it! There are also some third party optical adapters to use older FD lenses on new auto-focus bodies, but they are of poor optical quality.
Nikon Lenses for astrophotography
Nikon is proud that they have not changed their lens mount, and have maintained backwards compatibility with older Nikon lenses with the newest Nikon camera bodies.
You can also use Nikon lenses on Canon EOS EF lens-mount bodies. This is because the register distance on a Nikon is 46.5 mm, so there is room for a simple mechanical adapter between a Nikon lens and a Canon EOS body. An excellent quality, inexpensive adapter is available from Fotodiox.com for $28 on the internet. They also offer many other adapters to use different lenses on different camera bodies. Nikon lenses used on Canon bodies require manual focus and must be stopped down for metering, but these two drawbacks are not important for astrophotography.
Nikon AF-S 14-24mm f/2.8G ED AF Lens ($1,785) ok at f/2.8, very good at f/4
Nikon AF Nikkor 16mm f/2.8 D ($900) - soft corners and coma at f/2.8, OK at f/4.5
Nikon AF Nikkor 35mm f/2.0 D ($360) - coma at f/3.5, good at f/4.5
Nikon AF Nikkor 50mm f/1.8 D ($125) - ok at f/3.5, good at f/4.5
Nikon AF Nikkor 50mm f/1.4 D ($330) - ok at f/3.5, good at f/4.5
Nikon AF Nikkor 85mm f/1.4 D IF ($1,175) - bad coma at f/1.4, good at f/4
Nikon AF Nikkor 85mm f/1.8 D ($430) - ok at f/2.8, good at f/4
Nikon AF DC Nikkor 135mm f/2.0 D ($1,350) - ok at f/2.8, good at f/4
Nikkor AF 180mm f/2.8 D ED-IF ($850) - good at f/2.8, very good at f/4
Third-party manufacturers, such as Sigma and Tokina, also make lenses in the Nikon F and Canon EF lens mounts. These lenses are less expensive, but usually not quite as good. Quality control seems to be the major problem with third party manufacturers so individual samples of lenses can vary. Test them if you can before you buy them.
Sigma, in particular, has a decent reputation for making some lenses that are good for astrophotography on a budget. In particular these specific lenses are recommended for astrophotography:
Sigma Fisheye 8mm f/3.5 EX DG Circular Fisheye $900 - for Canon, for Nikon
Sigma 20 f/1.8 EX DG $630 - for Canon, for Nikon
Sigma 28mm f/1.8 EX DG $450 - for Canon, for Nikon
Sigma 105/2.8 EX DG $479 - for Canon, for Nikon
Sigma Apo 150mm F2.8 EX DG HSM Macro $729 - for Canon, for Nikon