p.16 #2 · Sigma 14-24mm f/2.8 DG DN first impressions
I really like how Sigma designed the real filter slot.
Basically the little notch from the Gel shape goes first (look for the 2 arrows) and the rest of the gel filter can be dropped inside and locked in place.
To remove it, it’s even easier: just unlock and tilt the lens. It will fall but still be on the lens for you to grab it from the edges.
The only issue is that it looks like 4-stop is the strongest ND available but additional image averaging can increase the ND effect even further.
rvh23 wrote:
Thanks Fred. Can you comment on your thoughts regarding the practicality of using the gel filter in the field.Looks like it might be a bit like putting in contact lenses - not good in outdoor environments.
p.16 #3 · Sigma 14-24mm f/2.8 DG DN first impressions
I will try two 4-stop gel filters (sandwiched) for a 8-stop ND effect and see what happens...I'm only worry about induced field curvature and now understand why gel filters are the best option. (they are super thin)
p.16 #4 · Sigma 14-24mm f/2.8 DG DN first impressions
Here are some crops with and without the Lee 4-stop Gel filter at 14mm f/2.8.
Atmosphere was hazy.
PS: I fixed the ND color cast as much as possible to match the original without the filter. There is also a slight hit in contrast which I compensated adding +15 in post.
The good news is that adding the ND gel is very inexpensive and it does not change field curvature behavior.
Center at 1:1: Left (with 4-stop) | Right (Lens bare)
Mid-field at 1:1: Left (with 4-stop) | Right (Lens bare)
Extreme corner at 1:1: Left (with 4-stop) | Right (Lens bare)
p.16 #8 · Sigma 14-24mm f/2.8 DG DN first impressions
vdo1 wrote:
So what do you do below 14, stitch?
12mm and 14mm are not that different IMO. I am waiting for a high IQ 10mm designed for mirrorless though. The CV options just don't perform well on the A7R4 off-axis.
p.16 #9 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
Here are some crops with and without the Lee 4-stop Gel filter at 14mm f/2.8.
Atmosphere was hazy.
PS: I fixed the ND color cast as much as possible to match the original without the filter. There is also a slight hit in contrast which I compensated adding +15 in post.
The good news is that adding the ND gel is very inexpensive and it does not change field curvature behavior.
Looking good. I might have to try this for occasions where an absolute minimal amount of gear is prerequisite. Is it easy enough to avoid getting finger prints on these small filters when handling them?
p.16 #10 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
Looking good. I might have to try this for occasions where an absolute minimal amount of gear is prerequisite. Is it easy enough to avoid getting finger prints on these small filters when handling them?
It's very easy to get fingerprints on the gel sheet. However, it's possible to remove them with a microfiber cloth. (I used a microfiber glove to cut them using the template)
It may be a good idea to keep the gel filters in separate bags (small zip locks for example) and handle them from their edges.
p.16 #11 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
It's very easy to get fingerprints on the gel sheet. However, it's possible to remove them with a microfiber cloth. (I used a microfiber glove to cut them using the template)
It may be a good idea to keep the gel filters in separate bags (small zip locks for example) and handle them from their edges.
What is your favorite / most used ND? 3, 6, 10 stops? what kind of use?
p.16 #12 · Sigma 14-24mm f/2.8 DG DN first impressions
vdo1 wrote:
What is your favorite / most used ND? 3, 6, 10 stops? what kind of use?
I like carrying only 4 and 10-stop. (Would not mind only bringing a 6-stop ND though)
It's possible to use two gel sheets for a 8-stop but color shift is more severe. Still fixable though. I will post some crops later.
BTW: Once the filter is cut and ready to go on the lens, my advice is to handle it with 2 fingers using the area below (blue). Finger prints are ok on the blue area because it won't be 'seen' by the lens.
p.16 #13 · Sigma 14-24mm f/2.8 DG DN first impressions
Is there an estimate on the amount of vignetting wide open near 14-18mm, compared to other fast wides? Most seem to be around 2-3 stops, but if it extends deeper into the frame it makes a big difference on shutter speed for astro.
p.16 #14 · Sigma 14-24mm f/2.8 DG DN first impressions
juicer wrote:
Is there an estimate on the amount of vignetting wide open near 14-18mm, compared to other fast wides? Most seem to be around 2-3 stops, but if it extends deeper into the frame it makes a big difference on shutter speed for astro.
Below is a link for a full resolution jpeg taken at 14mm @ f/2.8 with absolutely nothing done to it. The short answer is that the vignetting is minimal for an ultrawide.
p.16 #15 · Sigma 14-24mm f/2.8 DG DN first impressions
juicer wrote:
Is there an estimate on the amount of vignetting wide open near 14-18mm, compared to other fast wides? Most seem to be around 2-3 stops, but if it extends deeper into the frame it makes a big difference on shutter speed for astro.
Vignetting is excellent. At 14mm F2.8, by my estimates it's only about 1.5 stops in the corner, and about half that midway towards the corner.
Here is a set of 3 crops comparing brightness of the same portion of the sky (to ensure equal illumination) placed in the extreme corner (left), midway towards the corner, and center of the frame (right crop).
14mm f2.8 vignetting comparison: from L to R, corner, midway, and center
p.16 #16 · Sigma 14-24mm f/2.8 DG DN first impressions
Has anyone used the Tamron 17-28mm to compare? Beginner hobby photographer here I have the 28-75 and was mostly impressed by it. Mainly will be using for landscapes, trying my hand at astro etc. The filter thing with the Sigma is a bit of an issue, dont want to pay heaps really for the NiSi set up. Not that I really use filters that much but I do enjoy a long exposure of waterfalls, skies etc
p.16 #18 · Sigma 14-24mm f/2.8 DG DN first impressions
Petegh wrote:
Fred, what tipped the balance in favor of keeping the Loxia 21 for you, vs the Voigtlander 21 f1.4?
I will be mainly using the Sigma zoom for now but need an ultra wide option for shooting against the light, especially with the sun in the frame (sunstars). There is nothing as good as the Loxia 21 and CV 21/1.4 lenses for that but I decided on the former just because it's lighter. They are both equivalent in IQ on the A7R4.
