I'm going to be heading into some mountains later this month with some decent dark areas, so I figured I'd give a shot at getting some Milky Way shots (the moon is going to make that a challenge). The research I did shows an overwhelming amount of support for the Rokinon 24mm 1.4. It seems to be very sharp, but the main point that seems to be made is that it is relatively inexpensive (especially compared with other 24mm 1.4 lenses). The Canon 24mm f/1.4 L II never gets a mention. For my general shooting, even spending $519 for a manual focus 24mm lens isn't practical; it would likely live in my bag unless I am in a situation to try astro again (I live in NJ, so no dark anywhere at night without driving hours). Therefore, I'm considering renting the Canon lens, since I prefer to avoid off-brand lenses.
Long story short, I'm wondering if cost is the only reason sites aren't mentioning the Canon lens, or are there IQ issues, as well? I'm struggling to believe that a $500 off-brand lens is sharper than a $1500 L lens. The rental cost isn't sufficiently different for me to consider cost, so my primary concern is IQ.
Moonshae wrote:
Thanks! AF isn't important. I'll rent the Rokinon. I'm surprised none of the reviews mentioned the coma issue with the Canon lens as one to avoid.
Lenstip.com includes coma performance in their reviews.
Many lens designers don't even consider coma in their designs, because for almost anything other than astrophotography, it doesn't really matter much. Rokinon (Samyang) lenses tend to perform well with respect to coma, which makes me think they design for it.
I believe the Canon L is sharper than the Rokinon wide open, but the Canon's poor coma performance renders it useless for star fields. I bought the Rokinon for both astrophotography and for infrared work, where it also shines (and where many Canon options don't.*) I have also used the Rokinon 24 for regular landscapes, where it performs quite well stopped down.
* I love my 16-35/4L IS - it performs extremely well with visible light. But in infrared and near-infrared wavelengths it appears unable to deliver sharp/in focus images in both the center and edges of the frame at the same time.
As surely you're catching on, the Canon 24mm f/1.4L is ill-suited for astrophotography.
In astro, everything comes after coma, then field curvature (the latter is actually what most people observe as off-center softness). Conventual measures of acuity is almost a non-consideration.
There's not as much reason to get a Samyang 14mm f/2.8 anymore (aside from its piddling cost and marginal extra width... marginal, since you consume a lot of the edge if you try to correct its complex mustache distortion), now that we have the EF 16-35mm f/2.8L III USM and the Tamron SP15-30mm f/2.8 VC (but I'd wait for the refreshed G2 version just for the programming dock compatibility). These lenses do the full general duty as UWA zooms, but also works well for astro. They're obviously much more versatile.
For faster than f/2.8... yes, the Samyang 24mm f/1.4 is still the hot ticket for astro (portrait orientation). I kept that *just* for astro. I had been hoping that the wide-fast Sigma Art primes were going to usurp that crown... but nothing I've seen so far seems to suggest that's the case.
Wide open the Canon is sharper than the Samyang in the center, and the Sigma is sharper than the Canon. https://www.lenstip.com/upload3/4239_roz2.png
The Samyang is better for coma, true, but it has a number of other issues - like being very soft at f/1.4 and f/2.0 if Lenstip's tests are to be believed. The Canon is a known coma machine (it's so bad it can be seen clearly in the APS-C frame wide open). The Sigma is better but not by much (again, per Lenstip's results). At least the Sigma has less vignetting (though still a lot in absolute terms).
I have used my Canon 24/1.4 II for astro, but not on full frame and with quite some reservations. It is serviceable but those looking for outstanding quality might need to look elsewhere.
You should note that a couple of Rokinon/Samyang lenses have been mentioned thus far, and you may be unaware of the distinction.
They currently sell the following, which have almost all been variously aluded to in this thread:
Rokinon 14mm f/2.8
*the old, cheap, all manual one
*available in both photo and cine varieties, both optically identical
*good astro performer from a sharpness/coma standpoint
*terrible moustache distortion that is hard to correct for https://www.the-digital-picture.com/Reviews/Samyang-14mm-f-2.8-Lens.aspx
Rokinon 14mm f/2.4 SP
*more expensive, but still comparably affordable
*better resolving power, better performance overall, still good coma performance
*still manual focus, but has auto-aperture
*finally corrected moustache distortion, but still a slight barrel distortion (easy to correct) https://www.the-digital-picture.com/Reviews/Rokinon-SP-14mm-f-2.4-Lens.aspx
Rokinon 14mm f/2.8 AF
*more expensive yet, but still comparably affordable
*similar optical performance to SP, with slight differences
*still good coma performance
*auto focus, auto aperture
*no moustache distortion, very little distortion overall https://www.the-digital-picture.com/Reviews/Rokinon-AF-14mm-f-2.8-Lens.aspx
DtEW wrote:
As surely you're catching on, the Canon 24mm f/1.4L is ill-suited for astrophotography.
In astro, everything comes after coma, then field curvature (the latter is actually what most people observe as off-center softness). Conventual measures of acuity is almost a non-consideration.
There's not as much reason to get a Samyang 14mm f/2.8 anymore (aside from its piddling cost and marginal extra width... marginal, since you consume a lot of the edge if you try to correct its complex mustache distortion), now that we have the EF 16-35mm f/2.8L III USM and the Tamron SP15-30mm f/2.8 VC (but I'd wait for the refreshed G2 version just for the programming dock compatibility). These lenses do the full general duty as UWA zooms, but also works well for astro. They're obviously much more versatile.
For faster than f/2.8... yes, the Samyang 24mm f/1.4 is still the hot ticket for astro (portrait orientation). I kept that *just* for astro. I had been hoping that the wide-fast Sigma Art primes were going to usurp that crown... but nothing I've seen so far seems to suggest that's the case....Show more →
in terms of coma/astigmatism the samyang hands down is still king, but the sigma 14mm art is actually not bad, very acceptable performance (to me anyway), compared to even the new samyang 14mm 2.4 XP which i've also used the sigma is sharper across the frame, has less vignetting and distortion and is a stop faster, but you're paying for it of course (in coma/astigmatism performance and actual $)
It's far from perfect, but the Rokinon/Samyang 24mm f/1.4 is probably still the "gold standard" for UWA astro work.
The lack of coma sets it apart from the others. Especially once you start stopping down a little bit from wide-open. And especially when considering price.
I've been looking at this closely for a while and finally "settled" on the 15-30 tamron and the 14mm 1.8 sigma art lens. The 16-35 III has too much vignetting for my taste. The rokinon 14mm sp was a close second.
Flowernut wrote:
I've been looking at this closely for a while and finally "settled" on the 15-30 tamron and the 14mm 1.8 sigma art lens. The 16-35 III has too much vignetting for my taste. The rokinon 14mm sp was a close second.
Given the amount of money that you spent, you hardly "settled" for anything. Good choices.
