p.43 #2 · Sigma 14-24mm f/2.8 DG DN first impressions
lkunl wrote:
I just found Kase rear ND filter for Sigma 14-24 DG DN on ebay. It has exact same shape as gel filter as Sigma guide. It must be thin as gel filter to put it on slot. Even Haida also change filter shape to fit it easy. https://www.kasecn.com/en/newsshow.aspx?ID=1643
It looks too thick from the images. (same as Haida) which means it could be 0.5mm+ and that would alter field curvature behavior. (sharp center and OOF corners at the wide range)
As a comparison gel filters are ~0.1mm and have no effect on FC. So far from what's available only the Aurora will be glass and thin enough.
p.43 #6 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
It looks too thick from the images. (same as Haida) which means it could be 0.5mm+ and that would alter field curvature behavior. (sharp center and OOF corners at the wide range)
As a comparison gel filters are ~0.1mm and have no effect on FC. So far from what's available only the Aurora will be glass and thin enough.
Just got this email from Kase. How thick is Aurora?
p.43 #9 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
I just contacted Kase filters. Hopefully I can get their new rear filters for testing.
Fred
Nice!!
If/when you get a reply and/or test them, keep me posted.
I havent used rear filters for landscapes. As I understand, they are more fragile, can cause field curvature and I presume a bit inconvenient to change by removing lens but having much smaller filters to carry is a big plus.
Am I missing something more here with rears that I should be aware of?
p.43 #10 · Sigma 14-24mm f/2.8 DG DN first impressions
docsmiles17 wrote:
Nice!!
If/when you get a reply and/or test them, keep me posted.
I havent used rear filters for landscapes. As I understand, they are more fragile, can cause field curvature and I presume a bit inconvenient to change by removing lens but having much smaller filters to carry is a big plus.
Am I missing something more here with rears that I should be aware of?
Kase does also offer this. Interesting but 170mm
As long as the thickness is around 0.1-0.2mm (gel or film filters), field curvature remains unaffected even at the wide range wide open.
0.3mm is pushing the limits but works quite well when I tested the Aurora 0.3mm rear NDs. Anything thicker than that will cause adverse effects on field curvature.
So far we have the following rear ND filter options for the Sigma 14-24 E-mount:
p.43 #15 · Sigma 14-24mm f/2.8 DG DN first impressions
Bobu wrote:
I've measured the Haida filters with a caliper. They are exactly 0.5mm. Therefore I can confirm the value above.
I've tested the earlier 0.5mm Aurora prototype and induced FC was pronounced at 14mm. The Haida having the same thickness is out of the question for me.
It looks like the current contenders will be: Kase and Aurora. (the former's thickness to be confirmed)
p.43 #18 · Sigma 14-24mm f/2.8 DG DN first impressions
Hi guys
Just posted at Lenstip (Optyczne.pl). The awaited Sigma 14-24 f2,8 DG DN review. It is in polish, still not translated to english at Lenstip. Use Google translate.
p.43 #19 · Sigma 14-24mm f/2.8 DG DN first impressions
Curiously this is the second unit they test. The fisrt one was badly misaligned (too often for this 14-24 model). In this occasion the 24 mm FL is the strongest, contrary to what was commented in this FM post.
p.43 #20 · Sigma 14-24mm f/2.8 DG DN first impressions
JeyB wrote:
Curiously this is the second unit they test. The fisrt one was badly misaligned (too often for this 14-24 model). In this occasion the 24 mm FL is the strongest, contrary to what was commented in this FM post.
It seems possible that the FM post with 14 as the strongest is only at infinity and that 24mm is better at closer distances, since chart testing doesn't measure resolution at infinity.
