Is the ultimate astro lens coming? Another RF 14-21mm f/1.4L USM mention [CR2]

RobbieHat

EOS 90D
Feb 4, 2015
115
98
56
Rocklin, CA/The Sea Ranch, CA
I guess we always want what we do not have. Can I ask you your impression on Sigma. As I have already written I have seen flare from moon (not 100% of course but I do not remember details) while that not being on frame. But when I shot lights at my house I didn't see any! Strange! Maybe it had to do with the angle of the light and that big bulbous element...
I like mine for astro (basically the only thing I use it for). Pretty good control of comma and not too bad vignetting for a 14mm f1.8. Easily corrected in post. I have gotten bad flare on the few occasions I have used it with the sun out if the sun is anywhere near frame. As you said the bulbous lens is a major attractant of flare. My MW shots are all done without any moon out as it tends to significantly wash out the MW. I haven't tried it at night with the moon in frame but will have to see if that causes flare next time I am out when the moon is out.

Otherwise I love the lens. I use it with my 5DSR and shoot it stopped down a bit to f2.4 or so. That allows me to shoot 30 seconds at ISO 3200 or lower and stack bright and dark images to get pretty good pinpoint stars in Starry Tracker. My most used astro lens by far and I will be adapting it to the R5 until Canon comes up with something better (if ever). I also have the Sigma 24 f1.4 and love that lens for tighter shots. I stop it down to f1.8 and shoot it at 20 seconds at ISO 3200 and it works like a charm. Both are quite good lenses from Sigma. I wish Canon would take this UWA, very fast lens market serious. Nikon and Sony both have great offerings in this space natively and Canon has nothing to compare.

Bob
 
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TominNJ

EOS M6 Mark II
Mar 14, 2015
73
62
Interesting discussion. I’ve been shooting with a Rokinon 14/2.8.

one facet of astro work that I haven’t seen mentioned is that larger apertures make it easier to manual focus. Trying to use live view on my 5D4 and magnifying to get the best focus isn’t easy. I’m going to have to look at that Sigma.

i really hope Canon makes a great astro lens whether it’s this zoom or a wide fast prime
 

RobbieHat

EOS 90D
Feb 4, 2015
115
98
56
Rocklin, CA/The Sea Ranch, CA
Interesting discussion. I’ve been shooting with a Rokinon 14/2.8.

one facet of astro work that I haven’t seen mentioned is that larger apertures make it easier to manual focus. Trying to use live view on my 5D4 and magnifying to get the best focus isn’t easy. I’m going to have to look at that Sigma.

i really hope Canon makes a great astro lens whether it’s this zoom or a wide fast prime

The Sigma isn't any easier to focus in live view per se. I typically can focus on Jupiter so know I am getting infinity and the MW in focus but if I am using a foreground or light painting then I will use my flashlight to focus on a foreground object or if there is any stationary object that is partially lit I will use that to focus nearer than infinity. My friend shoots Nikon (D850 and Z7) and it is able to focus check/confirm with the Z7 EVF if we light paint and we have a flashlight on for focusing. That is pretty nice.

Bob
 

Baron_Karza

EOS RP
Feb 17, 2019
343
412
The Sigma isn't any easier to focus in live view per se. I typically can focus on Jupiter so know I am getting infinity and the MW in focus but if I am using a foreground or light painting then I will use my flashlight to focus on a foreground object or if there is any stationary object that is partially lit I will use that to focus nearer than infinity. My friend shoots Nikon (D850 and Z7) and it is able to focus check/confirm with the Z7 EVF if we light paint and we have a flashlight on for focusing. That is pretty nice.

Bob

If I want to photograph (or even just view objects with my telescope) that are dim or maybe not even visible to the human eye, I first focus manually on the moon fist, or the most biggest brightest object in the sky, such as Jupiter. Those objects are easier to focus on. Then lock focus and move on to my main target.

garfieldinspace.png
 
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RobbieHat

EOS 90D
Feb 4, 2015
115
98
56
Rocklin, CA/The Sea Ranch, CA
If I want to photograph (or even just view objects with my telescope) that are dim or maybe not even visible to the human eye, I first focus manually on the moon fist, or the most biggest brightest object in the sky, such as Jupiter. Those objects are easier to focus on. The lock focus and move on to my main target.

View attachment 192765

Agreed. I typically am shooting MW with no moon present so as not to wash out the MW, but Jupiter tends to be a bright enough focusing target to see and use.
 

Johnw

EOS R5, Ra
Oct 10, 2020
8
2
This is my dream lens, it could replace 3 Sigma lenses I already have.

Sigma 14 1.8
Sigma 20 1.4
Sigma 14-24 2.8