I think an important distinction is whether by astrophotography you mean deep-sky targets such as individual nebulas and galaxies, or wide-angle nightscapes with Milky Way and stars?
There are a lot of options for wide field. Samyang / Rokinon / Bower have some manual focus lenses that are popular but copy variation seems to be an issue. Check out the Astrophotography forum, lots of good advice there. This was my 1st try at astro with a Sigma 18-35 on a crop body, a little long but it works well.
Milky Way and stars is what I am wanting to try.
Thanks I will check out the forum.There are a lot of options for wide field. Samyang / Rokinon / Bower have some manual focus lenses that are popular but copy variation seems to be an issue. Check out the Astrophotography forum, lots of good advice there. This was my 1st try at astro with a Sigma 18-35 on a crop body, a little long but it works well.
24mm is about the size of constellations (Orion, Scorpio,...) on a cropped camera.
That Sigma 18-35 is looking like a nice lens. B&H has it on sell right now too. Very tempting
It's f1.8 not f2.8. 18mm on crop is, IMO workable. I've seen some excellent shots in the Astro forum with the Samyang 20mm on crop. See my shot above, be kind, it was my 1st try at this.
I don't do much Astro and bought this lens so I could use it for Astro if I wanted to. It's an excellent lens for general shooting; very sharp at all apertures and focal legnths. Mine underexposed by 2 stops through the viewfinder on my 90d (it was fine in live view). The firmware update fixed it.That Sigma 18-35 is looking like a nice lens. B&H has it on sell right now too. Very tempting
I don't disagree with you that wider can be better but there are plenty of excellent shots out there done with 18 and 20mm lenses on crop. As I said, I do very little Astro so having a lens that can do Astro but is also excellent for other work was more important than having a dedicated Astro lens. Plus I didn't have to go through the buy and return process I hear so many Samyang / Rokinon buyers talking about.I would also sway you to get something wider than 18mm. Most of the Milky way shots you see online are taken with a very wide angled lens.
This was taken at 17mm on FF, so close to 10mm on Apsc
. if the lens is usable wide open it should be okay. the 1.3 stop difference from f2.8 is a help with the noisy crop sensor.Its not really about the price, it is about aperture, primarily. I made excellent MilkyWay shots with a Canon EF 50 1.4 which sells for just around 200. Certainly not the typical MW lens, but I made panels to cover a bigger section.
As I get older, the number of things I knew before I didn't gets larger. ;-)I actually knew that before I didn't
At least now they get a chance to understand.i'm sure everyone understands that, Mitch
I too held off buying the 18-35 because of the viewfinder focus issues. Canon released a firmware update that fixed it so I bought it. The 18-35 works great on the 90d. 14mm on your Tokina would be better than 18mm on the Sigma for Astro. But the Sigma is a fabulous lens for other work and works for me for the minimal Astro shooting I do.
