Canon 24mm 1.4 L mk I for astro?

[YellowJersey]

Hey guys,

So I got a second hand Canon 24mm f/1.4 L mk I for Christmas. It wasn't so much a gift as it was a relative giving me a good chunk of his old gear since he now shoots mirrorless.

Canon glass seems notorious for not being great for astro work, but I figured I'd ask: am I wasting my time thinking I can use this for astro? Canon never seems to have good coma, but I've heard you can stop it down to to 2.8 help correct this. All my other lenses are f/4.

Any ideas? And before you say, "sell it," that's currently not an option due to the terms of this "gift" being unclear. I'm not sure whether it's an outright gift or a long-term loan. My relative who gave this to me is a little funny in that regard and asking whether I can sell it is not an really on the cards as asking would most likely result in him wanting it back (my family is weird, trust me).

At least I got an EX420 flash out of it, which I definitely can use and don't need to consider selling.

 

[rfdesigner]

The best reccomendation I can give is just try it. You have nothing to lose. Everyone has different standards so one persons horrible coma is anothers slightly fuzzy in the corners.

Do an experiemental run, from F1.4 to F4 in 1/2 stops.

Take a look here: http://petapixel.com/2014/01/29/picking-great-lens-milky-way-photography/

Note: the effective focal ratio in the corners will never be much better than 3 on any lens, but may not get much worse at lower fstops so stopping down a little doesn't carry as much penalty as you might at first imagine.

i.e.

• aperture vignetting corners
  f1.4 2.4stops f3.8
  f2.0 2.0stops f4.0
  f2.8 1.4stops f4.2
  

Have some ziplock bags handy to put your camera and lenses in before bringing them indoors to prevent condensation problems.

Once you can take one exposure that you're happy with you can then play with stacking images.. but I would do it in a propper astro program like deepskystacker, not photoshop, transfer to photoshop et al after you've got a single image to work with.

 

[JMZawodny]

I concur with the "just go do it" recommendation. It is the digital age and if you don't like it delete it. You should be able to to shoot 10 pics at various apertures in about 5 minutes. That will be more than enough to learn whether the performance will be acceptable to you.