p.70 #1 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
Very strange indeed. Does the difference remain visible as you stop down?
No, at f/4 they are pretty much the same (extreme corners) Filter and no-filter (And when I say filter, this goes for both Aurora and Kase).
Only wide open, the extreme corners look a bit worse with the lens bare when focusing at center. What's puzzling to me is that I've tested this before and the results were the opposite!
Could be some other setting? I am out of ideas.
p.70 #2 · Sigma 14-24mm f/2.8 DG DN first impressions
Thanks Fred. Here's my take on these:
The best of the lot to me looks to be the corner-focused shot without filter. Both shots with the filter (with and without refocus) seem a little softer.
For the center focused shots, the one without filter shows the effect of the lens' FC. And I agree the corner with(edit) the filter does look a little sharper, suggesting the filter fortuitously modifies the FC such that the corner is more like the center.
Combined this to me suggests the filter slighlty reduces FC, at least for your copy of the lens at 14mm, but it also reduces overal sharpness across the frame slighlty.
Good to hear there is minimal difference in corners by F4 though. Does the center catch up there too?
The ease of mounting makes this a much more viable option.
p.70 #3 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
What's puzzling to me is that I've tested this before and the results were the opposite!
Could be some other setting? I am out of ideas.
I assume you previously tested the exact same focal length/aperture. If the camera settings were also the same, that leaves only test-retest error.
p.70 #4 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
I assume you previously tested the exact same focal length/aperture. If the camera settings were also the same, that leaves only test-retest error.
The camera is different. Previously tested on A7R IV and now A7R II. Should not make any difference but it's another variable.
p.70 #5 · Sigma 14-24mm f/2.8 DG DN first impressions
Is the lens designed to always have a filter installed? This implies a clear filter if no ND, colour or pola effect is desired. Remember how super tele lenses with a filter drawer always have a clear filter installed. I think that Sigma should or may even have (?) designed the lens to have a filter installed. If not you will see effects on FC due to the different optical path length in glass vs air. This is even more important in floating element designs, which includes internal focus designs with one focus group , i.e. the Sigma 14-24/2.8 DN Art. This explains why you see effects on sharpness and FC by installing vs not installing a filter.
The optical path length in glass is shorter than in air, so removing a glass filter makes the lens slightly near sighted. Think of an incorrectly adjusted flange to sensor distance.
p.70 #8 · Sigma 14-24mm f/2.8 DG DN first impressions
bjornthun wrote:
Is the lens designed to always have a filter installed? This implies a clear filter if no ND, colour or pola effect is desired. Remember how super tele lenses with a filter drawer always have a clear filter installed. I think that Sigma should or may even have (?) designed the lens to have a filter installed. If not you will see effects on FC due to the different optical path length in glass vs air. This is even more important in floating element designs, which includes internal focus designs with one focus group , i.e. the Sigma 14-24/2.8 DN Art. This explains why you see effects on sharpness and FC by installing vs not installing a filter.
The optical path length in glass is shorter than in air, so removing a glass filter makes the lens slightly near sighted. Think of an incorrectly adjusted flange to sensor distance.
p.70 #9 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
If the lens were desigmed to always have a filter, I would have expected/hoped a clear filter would have been included with the lens at this price.
I checked the instructions for the lens, and they specify sheet filters, that are thinner than even the very thin Schott glass filters. I perfectly understand the desire for glass filters, as I too find gel filters to be a nuisance. Since Sigma states sheet filters they are on safe ground by not providing a clear glass filter, but that makes for a clumsy filter solution, I think. Kase and Aurora have just gone a bit closer to the bleeding edge.
Now at least the challenges with very thin Schott glass filters are clear to us, as Fred’s tests have demonstrated. So, then the mystery is solved and appropriate meassures can be taken, when using glass filters. These same considerations will apply to other wide angles, for which Kase and Aurora provide rear filter solutions.
The Laowa 10-18/4.5 comes with a glass filter installed, so Laowa took the other approach, to always require a real glass filter to be installed. Their lens formula even requires that.
p.70 #10 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
It must be the camera.
Is this R2 also a different camera to the one that you initially used to review the CV 3.5/21 some time ago?
One thing I noticed when you posted the CV vs. Sigma shots a few pages back in this thread, which may have been done with this same R2, was that the corners were surprisingly soft compared to your earlier assessments. If I remember correctly in those earlier tests you found the CV's corners at infinity were actually very good stopped down and that only the midzone showed some more pronounced softness.
I have a CV 3.5/21 coming within a few weeks, so I'll run an f7.1 corner comparison of the Sigma zoom against the CV (and also Loxia 21) on my R4 to see if I get the same result you did.
** edit ** I found your original review comparison between CV 3.5/21 and the Loxia 21 here and they were apprently on a different camera (R3 rather than R2). But I note also that comparison is labelled 'extreme edge', which perhaps is not be the same as extreme corners?
p.70 #16 · Sigma 14-24mm f/2.8 DG DN first impressions
Some recent Astro and Landscape efforts. The difference in color from the two astro shots was pretty dramatic after processing. To the naked eye it didn't look different, but the vertical was taken one hour prior to the start of Astronomical twilight and the horizontal one was taken a while later after Astronomical morning twilight had started.
p.70 #17 · Sigma 14-24mm f/2.8 DG DN first impressions
NatDeroxL7 wrote:
Some recent Astro and Landscape efforts. The difference in color from the two astro shots was pretty dramatic after processing. To the naked eye it didn't look different, but the vertical was taken one hour prior to the start of Astronomical twilight and the horizontal one was taken a while later after Astronomical morning twilight had started.
I need some help with recommendation for Aurora Aperture filters. For landscape / seascape photography, how many should I get and which ones? ND16, ND64 and maybe LPR if I try astro at some point?
PowerDusk™, a light pollution reduction filter for astrophotography and for cityscape photography in blue hours by reducing artificial light pollution.
p.70 #19 · Sigma 14-24mm f/2.8 DG DN first impressions
Well there are a handful of shots better than anything I've ever taken! Fantastic work.
NatDeroxL7 wrote:
Some recent Astro and Landscape efforts. The difference in color from the two astro shots was pretty dramatic after processing. To the naked eye it didn't look different, but the vertical was taken one hour prior to the start of Astronomical twilight and the horizontal one was taken a while later after Astronomical morning twilight had started.
p.70 #20 · Sigma 14-24mm f/2.8 DG DN first impressions
I need to invest in some of the filters. I have the Nisi S5 holder + ND6, but a CPL might help sometimes, but out here in the SW, i think a CPL may not work that well? I had the Nikon 14-24 for years when I lived in the PNW, and never had the CPL for it.
Here is a few shot blend from a few weeks ago at Zebra slot canyon. I find that F/7.1 is superbly sharp and less blending is needed.
Enchantment Range-1126-HDR
untitled-1-2-Edit-Edit
Dragontail Milky Way-Edit
Enchantment Range-142-HDR
Enchantment Range-216-HDR