Astrophotography Lens?

[LTCSZ]

Hello: I am just getting into astrophotography and am looking for a good, entry level wide angle  lens for my SL2...It needs to be f1.4 or f2.0...I am willing to consider used if in good shape...Any advice will beappreciated! Thanks...

[Waddizzle]

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@jrhoffman75 wrote:

The 14mm f/2.8 Rokinon is a very popular lens for star trail and Milky Way photography. It has very strong moustache distortion, which is not a problem for astro. It also has poor factory QC. Not uncommon to have to go through several copies to get a good one. But once you get a good one it performs well. 

Very fast lenses generally don't work out well for astro. Wide open they have edge problems - coma and sharpness issues. Need to stop down to address, which defeats the benefit of wide aperture. The fast and expensive Canon 14mm f/1.4 is an example of this. 

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I have bought three copies of the Rokinon 14mm T3.1 Cinema Lena, one for me and two for my sones.  All three copies have been really sharp, without any of the issues often assigned to the photo versions of the lenses, as you have described.

The photo and cinema versions of the lenses are identical, except for the aperture ring and model number.  I am going to guess that depending upon how many QC checks the lenses pass, they wind up as either cinema or photo lenses, which the cinema lenses seemingly getter better passing grades than the photo lenses.

[ebiggs1]

"The fast and expensive Canon 14mm f/1.4 is an example of this."

I am well aware of the poor performance of this lens. What I was saying is, all, or at the very least most, lenses benefit from stopping down one stop or even more.  The fact  you recommend stopping down the 14mm f1.4 isn't surprising. I would actually say it is normal and accepted practice.

I have been around guys with Rokinons that work very well wide open even though they, too, get better stopped down one

stop.

"Very fast lenses generally don't work out well for astro."

Although I am no longer an active member of our astronomy club, I think you would get some serious negative feed back with that statement. f2.8 and faster is the norm, IMHO, of course.

[KayeP]

Hi. I’ve purchased this lens and having trouble getting to work. I own an Eos M3 and having trouble finding the function to shoot without lens. Does anyone have a suggestion for me please. Can’t find it in custom settings. 
Thanks 
Kaye 

[jrhoffman75]

See if Custom Function III Others will do it. See page 88.