p.2 #4 · DXOMark Review: Sigma 20mm f/1.4 high score
This is a VERY interesting and unique lens. Some amazing images will be made with it.
However, the inability to use standard filters is a show-stopper for me. That, plus the coma when shooting wide-open.
The Rokinon 24mm f/1.4 lens is probably the best available for wide-field astrophotography because it handles coma the best out of all lens tested at that focal length and maximum aperture.
In fact, I just bought the Rokinon (while on sale for $429 at B&H) for that dedicated purpose. And I also just bought the Sigma 24mm f/1.4 Art because it's an absolute peach of a lens (better overall than both Canon and Nikon equivalents). Especially while it was just briefly on sale for $699 at Adorama.
p.2 #6 · DXOMark Review: Sigma 20mm f/1.4 high score
Don't DxO shoot all their tests at MFD or 2m or something like that ? I'm not sure how relevant their tests are for Astro. I know one of the other testers (Lenstip maybe ?) shoot at far longer distances. That's the problem with Test Charts over reality I guess.
p.2 #7 · DXOMark Review: Sigma 20mm f/1.4 high score
chrisfphotog wrote:
I love the Sigma Art lenses but damn are they big and heavy. Plus no weather sealing. At their price points this has always been a bit of a bummer.
Actually I think their price points for the art series is a steal..
p.2 #8 · DXOMark Review: Sigma 20mm f/1.4 high score
hiepphotog wrote:
Not conclusive yet. The only test out there is from Lenstip and their laser coma test is not the most reliable one. They are inexperience in wide-field astrophotography as well so I don't put much stock in their first star shot either.
Good to know, I'd be very surprised if Sigma did not have astrophotography in mind when they designed this one.
p.2 #11 · DXOMark Review: Sigma 20mm f/1.4 high score
hiepphotog wrote:
Not conclusive yet. The only test out there is from Lenstip and their laser coma test is not the most reliable one. They are inexperience in wide-field astrophotography as well so I don't put much stock in their first star shot either.
Not true. The reviewer is an Astrophysicist. He did example star shots using a tracking mount. I don't know how you can get a better review than this one as he should know what he is doing. Few sites test coma, and Lenstip use diodes to check. The astigmatism will also contribute to problems on the edge of frame.
p.2 #12 · DXOMark Review: Sigma 20mm f/1.4 high score
Iwas joeking wrote:
Not true. The reviewer is an Astrophysicist. He did example star shots using a tracking mount. I don't know how you can get a better review than this one as he should know what he is doing. Few sites test coma, and Lenstip use diodes to check. The astigmatism will also contribute to problems on the edge of frame.
Thank you for the corrections. I'll eat my words then. . But the diode test they are using is not a good indicator of coma, as many have found out. For example, the Samyang 24/1.4 is very good in this respect, but their diode test looks pretty bad.
Since he tracked his star shot, I see mild astigmatism (short wings) and pronounced spherical aberration (fat star). Above average from what I see.
p.2 #13 · DXOMark Review: Sigma 20mm f/1.4 high score
hiepphotog wrote:
Thank you for the corrections. I'll eat my words then. . But the diode test they are using is not a good indicator of coma, as many have found out. For example, the Samyang 24/1.4 is very good in this respect, but their diode test looks pretty bad.
Since he tracked his star shot, I see mild astigmatism (short wings) and pronounced spherical aberration (fat star). Above average from what I see.
Yes, the Samyang does look poor, but I think it's the best of the bunch of 24f1.4 lenses as far as coma is concerned. It's too bad more review sites don't do coma tests. I don't know if it exists, but you would think a program to correct coma in post would be feasible, or at least reduce it.
p.2 #15 · DXOMark Review: Sigma 20mm f/1.4 high score
Iwas joeking wrote:
Yes, the Samyang does look poor, but I think it's the best of the bunch of 24f1.4 lenses as far as coma is concerned. It's too bad more review sites don't do coma tests. I don't know if it exists, but you would think a program to correct coma in post would be feasible, or at least reduce it.
That might help, but very tedious. Considering the various shapes and sizes of the wings, plus other element in the picture, it might be tough for an automated app.
That might help, but very tedious. Considering the various shapes and sizes of the wings, plus other element in the picture, it might be tough for an automated app.
It'd be the same as any other aberration- create a profile for the specific lens, aperture used, and possibly focal distance. It's never perfect, but it could certainly get close, and most certainly clean the image up for presentation purposes.
Dec 02, 2015 at 04:08 PM
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p.2 #17 · DXOMark Review: Sigma 20mm f/1.4 high score
Dj R wrote:
They should have made a 135 instead.
The nikkor 20 1.8 G is light, reasonably priced, and has ED glass with excellent optics. Really no need for a heavy siggy here.
I'm no sigma hater. I welcomed the sigma 35 into my bag.
Maybe (though the Lenstip test indicates that the Sigma is still better), but what would a Canon user do? The old Sigma 20/1.8 was *ahem* not universally loved. Nor was the 20/2.8 USM - it has a boatload of its own issues. So see the new Sigma as a unit aimed mostly at the Canon users.
I trust a 135 will follow in due time.
p.2 #18 · DXOMark Review: Sigma 20mm f/1.4 high score
Snopchenko wrote:
Maybe (though the Lenstip test indicates that the Sigma is still better), but what would a Canon user do? The old Sigma 20/1.8 was *ahem* not universally loved. Nor was the 20/2.8 USM - it has a boatload of its own issues. So see the new Sigma as a unit aimed mostly at the Canon users.
I trust a 135 will follow in due time.
Canon and Sony users- adapters that can actuate Nikon's mechanical lens apertures have *just* come online and aren't at all proven, whereas at the very least the aperture will be accurate on a Canon-mount Sigma adapted to E-mount.
p.2 #19 · DXOMark Review: Sigma 20mm f/1.4 high score
pizdets17 wrote:
Actually I think their price points for the art series is a steal..
I wasn't trying to imply they aren't a great value. I just think a lens at >$800 should, ideally, be weather sealed in 2015 is all. Maybe I'm nuts though.
Dec 02, 2015 at 11:02 PM
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p.2 #20 · DXOMark Review: Sigma 20mm f/1.4 high score
chrisfphotog wrote:
I wasn't trying to imply they aren't a great value. I just think a lens at >$800 should, ideally, be weather sealed in 2015 is all. Maybe I'm nuts though.
Certainly I'm thinking the same but it's not a deal breaker to me. YMMV.
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. But the diode test they are using is not a good indicator of coma, as many have found out. For example, the Samyang 24/1.4 is very good in this respect, but their diode test looks pretty bad.