I’m looking for some advice on choosing a lens for astrophotography with my Canon R7.
I currently own the TTArtisan 7.5mm f/2 fisheye, which I’ve used for some night-sky shots. I’m considering adding the Sigma 10-18mm f/2.8 DC DN, mainly because it seems like a good combination of a wide field of view, f/2.8 aperture, and relatively compact size.
I also own the Canon RF 24-105mm f/4L, but on the R7’s 1.6x crop sensor it isn’t really wide enough for the type of astrophotography I have in mind.
For EF lenses, I also have the Sigma 17-70mm f/2.8-4 DC Macro OS HSM, which I use on the R7 with an EF-RF adapter. However, at 17mm it’s still relatively narrow for Milky Way landscapes.
So I’d appreciate recommendations from R7 users:
Is the Sigma 10-18mm f/2.8 a good choice for astrophotography on the R7?
How does it perform in terms of coma, corner sharpness, and overall image quality at f/2.8?
Are there other lenses I should consider instead, either EF or RF?
Would you keep the TTArtisan 7.5mm and add the Sigma, or would you replace the TTArtisan with something else?
My main interests are Milky Way landscapes and star trails rather than deep-sky astrophotography.
Thanks in advance for any recommendations or real-world experience!
