p.27 #1 · Sigma 14-24mm f/2.8 DG DN first impressions
Saying no need to use grads in 2019 is absurd. Grads can increase IQ in some cases. For example, ocean shots where you have a combo of moving action + graduated light (very common in ocean scenes) + flat horizons.
The digital alternative is to pull shadows and blending. The problem is pulling shadows damages IQ in every single camera at every ISO. Blending is simply not possible if action (waves) is moving over graduated light that isn’t a repeatable action. The only option without a Grad is to under exposure and therefore degrading IQ.
nhsonyshooter wrote:
Back when I had the 12-24 (great lens by the way) I used those style of filters and did have adapters for other lenses. That said I have since abandoned those style of filters all together because I can do a better job in LR/PS blending. I only use Polarizers and ND now , no need for graduated filters in 2019. And the simple fact is I was annoyed with the size of the adapters and filters. Plan out your kit right and you can save alot of space with regular circular with step down rings.
Any lens can flare if provoked. It did better than my FE 24/1.4 GM for many side by side backlit situations but I didn't test against any other lens yet. If you look at my sunstar series, one would struggle to find any ghosting there. I was not expecting it to have outstanding flare performance but so far it did much better than I thought. (Definitely better than Sony 12-24G)
The CV 21/3.5 E-mount has very strong flare resistance and I will test it against the zoom today.
p.27 #3 · Sigma 14-24mm f/2.8 DG DN first impressions
scalanc2 wrote:
Why do you need ND?
Multiple exposure are not Better?
I like to combine both for more natural motion and improved SNR.
If I start with a 4-stop ND and shoot 8-images + average them in post (mean stack), it's equiv. to using a 6-stop ND with very clean shadows.
p.27 #4 · Sigma 14-24mm f/2.8 DG DN first impressions
Surprisingly, flare resistance is not a weakness for the Sigma zoom. (like it is for the Sony 12-24) Here are some sunstars with it.
I also compared 6 scenes with the sun in the frame (or above and to the sides) and could not get much ghosting with either lens. (CV 21/3.5 and Sigma 14-24 @21mm). I consider the CV 21/3.5 to have outstanding flare performance just like CV 15 and Loxia 21.
Here are a couple side by sides...The Voigt did slightly better for the first scene.
Sigma (top), Voitlander 21/3.5 (bottom), sun at top left outside the frame
p.27 #5 · Sigma 14-24mm f/2.8 DG DN first impressions
I've tested the Lee Polarizer Gel today and it has great IQ and almost no color shift. It's more rigid than the ND gels.
There is almost 2 stops of light loss (which is normal for polarizers)
Here is a test at 14mm with maximum strength. (The sky will look very uneven at 14mm....just to show it works. )
It can be used in conjunction with the Lee 4-stop ND but aperture needs to be f/8 or smaller to mask the induced field curvature from the extra thickness. (total ~6 stops)
By itself, there is no change in field curvature.
Sky gets uneven at 14mm with a polarizer. My main usage is water reflection. Notice the extra saturation from the polarizer. (not from post-production)
Right (no polarizer filter), Left (with the Lee Polarizer gel)
p.27 #6 · Sigma 14-24mm f/2.8 DG DN first impressions
Here is just to show that field curvature remains unchanged with the Lee Polarizer (even though it's a bit thicker than the Lee NDs)
There is an improvement in contrast, color saturation and a slight warm cast.
extreme corners at ~14mm: (right: no filter | Left: Lee Polarizer gel)
p.27 #7 · Sigma 14-24mm f/2.8 DG DN first impressions
So, I recommend the Lee Gel filter solution for the Sigma 14-24/2.8 DN.
Both Lee 4-stop ND gel and Lee 2-stop polarizer gel are high IQ, maintain the lens contrast, and have subtle & reversible color shift. Both come in a big sheet and many rear filters can be made from it. (estimate about 50+)
A 4-stop filter can be pretty much left inside the lens and whenever higher ND strength is needed, image averaging can be used in conjunction with the filter. One can get ~6-stop with only 4 averaged images and ~8-stop with 16 images.
The polarizer can also be used together with image averaging. A ~4-stop ND effect by achiever by using the polarizer gel + 4 averaged shots.
PS: If you don't mind stopping down the lens to f/8 or smaller, two (2) gel filters can be used (ND+ND or ND+Pol). Wider apertures will show induced field curvature which is not that bad anyways but I consider it a negative.
f/8 masks it.
p.27 #8 · Sigma 14-24mm f/2.8 DG DN first impressions
I wonder if the field curvature with multiple filters is due to combined thickness or the extra air-resin surfaces. I guess one could try to join two sheets with optical adhesive and weight it between two glass plates during cure, it's a lot of extra effort and probably wouldn't work anyway.
p.27 #9 · Sigma 14-24mm f/2.8 DG DN first impressions
lora_to wrote:
I wonder if the field curvature with multiple filters is due to combined thickness or the extra air-resin surfaces. I guess one could try to join two sheets with optical adhesive and weight it between two glass plates during cure, it's a lot of extra effort and probably wouldn't work anyway.
Good thinking!
It's really an issue from f/2.8 until about f/5.6. By f/8, it's not detectable anymore.
I was surprised that the Lee Polarizer does not induce any curvature since it's slightly thicker.
p.27 #10 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
I've tested the Lee Polarizer Gel today and it has great IQ and almost no color shift. It's more rigid than the ND gels.
There is almost 2 stops of light loss (which is normal for polarizers)
Here is a test at 14mm with maximum strength. (The sky will look very uneven at 14mm....just to show it works. )
It can be used in conjunction with the Lee 4-stop ND but aperture needs to be f/8 or smaller to mask the induced field curvature from the extra thickness. (total ~6 stops)
By itself, there is no change in field curvature.
Thanks Fred. I'm pretty sure by using a front polarizer instead of a fixed orientation rear gel you can get a much more even sky than that, even at 14mm. I don't think you'll get constant polarization strength either. From my tests with a rotating CPL you need to be able to rotate the filter to match the orientation of the camera relative to the sun to achieve that.
p.27 #11 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
Thanks Fred. I'm pretty sure by using a front polarizer instead of a fixed orientation rear gel you can get a much more even sky than that, even at 14mm. I don't think you'll get constant polarization strength either. From my tests with a rotating CPL you need to be able to rotate the filter to match the orientation of the camera relative to the sun to achieve that.
Can you try it out? It would be interesting to compare.
The filter was set to the strongest polarizing effect but the intensity depends on the location of the sun.
p.27 #13 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
Can you try it out? It would be interesting to compare.
The filter was set to the strongest polarizing effect but the intensity depends on the location of the sun.
I did try it out with the Nisi set-up on the Sigma, that's why I mentioned this. First I set up the polarization for max effect in the sky with a particular scene. Then I rotated the camera 90 degrees, and the sky lightened up, but I found I could get it back to the same darkness/saturation by rotating the CPL appropriately. You should be able to see the same effect if you have another lens for which you have a rotating CPL.
It's overcast at the moment, and the forecast for the next few days is not good, but if I get some clear skies I'll try to get a few shots to illustrate.
p.27 #14 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
I did try it out with the Nisi set-up on the Sigma, that's why I mentioned this. First I set up the polarization for max effect in the sky with a particular scene. Then I rotated the camera 90 degrees, and the sky lightened up, but I found I could get it back to the same darkness/saturation by rotating the CPL appropriately. You should be able to see the same effect if you have another lens for which you have a rotating CPL.
It's overcast at the moment, and the forecast for the next few days is not good, but if I get some clear skies I'll try to get a few shots to illustrate. ...Show more →
By rotating the filter, you lessen the intensity so it makes sense the sky would look more even.
The gel can't be rotated and that limits its usage. We can only choose one intensity (angle) before cutting it.
Today I just tested at the max intensity (for horizontal orientation) and that's why the sky looked so funky. Different filter cuts can be made with less intensity and for the other orientation...Like I said, it's not ideal.
p.27 #16 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
By rotating the filter, you lessen the intensity so it makes sense the sky would look more even.
The gel can't be rotated and that limits its usage. We can only choose one intensity (angle) before cutting it.
Today I just tested at the max intensity (for horizontal orientation) and that's why the sky looked so funky. Different filter cuts can be made with less intensity and for the other orientation...Like I said, it's not ideal.
I think it's not just reduced intensity that makes the sky more even when rotating the polarizer. If I set up the camera and CPL so one corner is dark, and the other is light, then I should only be able to lighten the dark corner if you are right. But I'm pretty sure I was able to also darken the light corner. I'll try it again when conditions allow.
If I understand this page correctly, the need to adjust the polarizer angle would agree with the idea that the light reflected from the sky has a different polarization angle as a function of its location relative to the sun (viewed from the camera).
p.27 #17 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
Can you try it out? It would be interesting to compare.
The filter was set to the strongest polarizing effect but the intensity depends on the location of the sun.
There was a break in the clouds late in the day, so I took two shots (with the lens at 14mm) to illustrate the effect of rotating the CPL when it's set near maximal polarization . If you look at the top image you can see its top left corner is darker than the top right. The region of strongest polarization runs clearly diagonal here.
The bottom image shows the same scene with the CPL rotated by 20 or 30 degrees so that the strongest polarization is more horizontal. You can see the corners are now more even, and the top right corner has actually become darker compared to the first image, which would not happen if the effect was due to overall reduced polarization strength.
p.27 #18 · Sigma 14-24mm f/2.8 DG DN first impressions
Here is another test I did to asses the benefit of having CPL rotation available, even for fixed camera orientation. This is a full-frame close up of an old leather chair with a strong highlight caused by overhead light coming through a window (somewhat similar to what might happen with a wet boulder in a forest setting).
Top left panel shows no CPL, the other three show various small CPL rotations near maximal effect. The terms "left emphasis" and "right emphasis" refer to which side of the large highlight area the CPL is best adjusted for. The CPL rotation allows you to select not only how strong the overall polarizer's effect is, but also where in the scene it is applied most.
p.27 #19 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
I've posted previously that I will be testing 6-stop and 10-stop ND gel filters soon.
They are the Kodak Wratten 96 ND gels.
Fred, any chance you've tested the 6 stop gel yet? I think if that works as well as the Lee 4 stop, I'm fully sold on using/keeping this lens. Just ordered the lens yesterday.
p.27 #20 · Sigma 14-24mm f/2.8 DG DN first impressions
Hello
I have just received my new Sigma 14-24 f2,8 DG DN. Please, would someone tell me how to check corner consistencies?
Do I have to focus on the same object on each extreme corner? Or should I focus at middle point and then recompose, without focusing again, to the same object on every extreme corner?
)
