Ursa Mini 4.6K + Sigma Cine 18-35 T2 + Ultracon

Quick edit of our practice/test shoot with the Sigma Cines and Tiffen's Ultra Contrast (1). Practicing/prepping for my friend's short film he asked me to help him with later.

Review/Comparison of Non-Cine and Cine 18-35mm coming this week.
I shot all of this in slow motion since I did not profile the helix. There are a few shots not in slow motion and they worked well but didn't quite fit the style.

All the morning scenes were recorded in 1080p on the Video Assist (5") with rec709 at T16. I rented the Video Assist since I'm waiting on a new monitor and left the cfast cards/ND filters at home. All the later shots are 4.6K 4:1 raw.

Thanks for sharing Note! This footage looks great.

I'll add the Sigma Cine Zooms to my wish list. Considering you could get the 18-35 T2 and the 50-100 T2 for $8,000 I'd say it's a great deal. Just have to rob a bank... be right back... hehe.

Thanks for sharing Note! This footage looks great.

I'll add the Sigma Cine Zooms to my wish list. Considering you could get the 18-35 T2 and the 50-100 T2 for $8,000 I'd say it's a great deal. Just have to rob a bank... be right back... hehe.

Very similar to the non-cine. I'll create that video about the comparisons really soon. One of the biggest benefits has to be build and focus rotation.

And thanks for watching!

I kinda liked the Ultracons on the BMCC but they made the image really milky and green. Are you not seeing that? I wouldn't go above a 1 from what I've seen.

What's your opinion on those on the 4.6k? I havent tested them. Kinda forgot about them, but interested in LowCons instead of UltraCons.

Hey did you notice any vignetting?

In theory, the Sigma zooms have an image circle of 28.4 while the 4.6K sensor is 30mm. It is kinda putting me off buying these zooms but I guess that in the real world it doesn't affect much, right?

Note, this is the first footage I think I've seen with the Sigma Cine 18-35 T2. If these are raw 4.6K, where is the vignetting that Sigma points out on their webpage? When Sigma says the image circle at 18mm is 28.4mm, that should vignette. Were you using 18mm in your short here?


Sent from my iPad using Tapatalk

I kinda liked the Ultracons on the BMCC but they made the image really milky and green. Are you not seeing that? I wouldn't go above a 1 from what I've seen.

What's your opinion on those on the 4.6k? I havent tested them. Kinda forgot about them, but interested in LowCons instead of UltraCons.

I believe I read that the Lowcons have some halation or that the ultracons really just lifted the blacks somewhere. And I think the ultracons are more refined? (could be bad source of info haha). No, the blacks definitely get lifted on the Sigma—and it's noticeable when you put the filter up to your eye—but since the Sigma Arts have quite a bit of contrast, it works out fairly well. I only have the 1 currently but may get a 1/2 soon. I'm going to write a review and put some cDNGs out soon but I'm generally not a fan of filters yet these are awesome to have. I didn't like the HBM but am loving these.

Hey did you notice any vignetting?

In theory, the Sigma zooms have an image circle of 28.4 while the 4.6K sensor is 30mm. It is kinda putting me off buying these zooms but I guess that in the real world it doesn't affect much, right?

Yep, there's vignetting. I'll either put an example or will put in the review/comparison. I shot the gimbal scenes at 35mm since I needed to test out how well the dji focus works haha. Normally it's always 18-20mm for focus.

Note, this is the first footage I think I've seen with the Sigma Cine 18-35 T2. If these are raw 4.6K, where is the vignetting that Sigma points out on their webpage? When Sigma says the image circle at 18mm is 28.4mm, that should vignette. Were you using 18mm in your short here?

Sent from my iPad using Tapatalk

I wasn't but I did play around with it and have some screens. At 18mm, it's a hard cut and very noticeable.

Thanks, Note. Love your work and looking forward to the comparison video.


Sent from my iPad using Tapatalk

I found another video of the URSA Mini Pro w/ Sigma Cine 18-35 T2 and Sigma Cine 50-100 T2. This footage also looks really good.

Very cool Tim!

I kinda liked the Ultracons on the BMCC but they made the image really milky and green. Are you not seeing that? I wouldn't go above a 1 from what I've seen.

What's your opinion on those on the 4.6k? I havent tested them. Kinda forgot about them, but interested in LowCons instead of UltraCons.

I'll make a better comparison with dngs soon so you can play with it.

No filters of any kind:


Ultracon 1

Note, this is the first footage I think I've seen with the Sigma Cine 18-35 T2. If these are raw 4.6K, where is the vignetting that Sigma points out on their webpage? When Sigma says the image circle at 18mm is 28.4mm, that should vignette. Were you using 18mm in your short here?


Sent from my iPad using Tapatalk

This is 18mm (very cool to have lens data haha)

Excellent illustration of the Ultracon helping define the edges in a shot.

And as you mentioned, that Sigma 18-35mm Cine Zoom has hard vignettes on the full 4.6K. Looking at that example, I'm not sure it would look good on the 2.4:1 widescreen crop 4608x1920. It might pass, but I think there will be loss of quality and light in the corners of that crop too. Fine for all the other windows.


Sent from my iPad using Tapatalk

Excellent illustration of the Ultracon helping define the edges in a shot.

And as you mentioned, that Sigma 18-35mm Cine Zoom has hard vignettes on the full 4.6K. Looking at that example, I'm not sure it would look good on the 2.4:1 widescreen crop 4608x1920. It might pass, but I think there will be loss of quality and light in the corners of that crop too. Fine for all the other windows.


Sent from my iPad using Tapatalk

Do you mean cropped in camera?

And yes, I find it works in tandem very well with the Sigmas. Lowers contrast makes the grading process slightly more "flexible".

Note, yes, I should have said the 2.4:1 widescreen window of the 4.6K sensor.


Sent from my iPad using Tapatalk

Note, yes, I should have said the 2.4:1 widescreen window of the 4.6K sensor.


Sent from my iPad using Tapatalk

I'll test that and put it up for you.


Also did a quick comparison between Cine and non cine. Interesting find though I may technically be wrong.

Hey, all. I don't mean to call into question Note's findings, but I'm absolutely certain that the Sigma 18-35 Cine Zoom does not vignette on the URSA Mini Pro at 18mm. There's no reason this shouldn't be true of the Mini as well. Sorry to speculate here, but perhaps the vignetting seen in the above image was caused by a matte box or the Ultracon?

I've used the lens quite a bit over the last few weeks without any issues, so I've attached a simple shot (18mm, wide open, ProRes HQ, 4.6K) of the roof tiles in my office as some hard evidence.

Hopefully, this clears things up. It's an amazing lens and there shouldn't be any reservations in pairing it with the URSA Mini. Can't say the same for the 50-100mm, which has terrible breathing at close focus distances.

Brian, you may be right about Note's filter. I'm sure he'll respond on that. But your sample shot does have a pronounced decrease in luminosity a bit in each corner. With the published image circle of 28.4mm and the sensor diagonal of 29.08mm, that little bit of darkening at the corners may be why Sigma doesn't recommend that lens on the 4.6K sensor. Your overall image is extremely good, but those corners don't look like a normal slight fall off of light from a lens; it might be because those corners are close to the edge of the image circle. The 28.4mm image circle must be the dimension that Sigma knows will have an even illumination. Thoughts?


Sent from my iPad using Tapatalk

Brian, you may be right about Note's filter. I'm sure he'll respond on that. But your sample shot does have a pronounced decrease in luminosity a bit in each corner. With the published image circle of 28.4mm and the sensor diagonal of 29.08mm, that little bit of darkening at the corners may be why Sigma doesn't recommend that lens on the 4.6K sensor. Your overall image is extremely good, but those corners don't look like a normal slight fall off of light from a lens; it might be because those corners are close to the edge of the image circle. The 28.4mm image circle must be the dimension that Sigma knows will have an even illumination. Thoughts?


Sent from my iPad using Tapatalk

I will do a test with the ultracon later today.

Brian, you may be right about Note's filter. I'm sure he'll respond on that. But your sample shot does have a pronounced decrease in luminosity a bit in each corner. With the published image circle of 28.4mm and the sensor diagonal of 29.08mm, that little bit of darkening at the corners may be why Sigma doesn't recommend that lens on the 4.6K sensor. Your overall image is extremely good, but those corners don't look like a normal slight fall off of light from a lens; it might be because those corners are close to the edge of the image circle. The 28.4mm image circle must be the dimension that Sigma knows will have an even illumination. Thoughts?


Sent from my iPad using Tapatalk

You're absolutely right, Rick. I meant only that there shouldn't be pronounced, full black vignetting like you'd find when shooting a Super 35 lens on a full frame camera. That being said, the image circle as listed by Sigma clearly does not fully cover the sensor. And I think you see the true result of that borne out in the very far corners of my image (see below). The wider luminosity drop, however, especially on the left hand side, is mostly the ambient lighting.

Agreed, Brian. Let's see what Note brings to show and tell shortly. Gentlemen, place your bets!


Sent from my iPad using Tapatalk

Agreed, Brian. Let's see what Note brings to show and tell shortly. Gentlemen, place your bets!


Sent from my iPad using Tapatalk

Ben is right!
It's the ring.

We still love you, Note. It happens to all of us...

I'm starting to feel better about my shameful out-of-focus infrared contamination video from last September knowing at least one other person's work on this planet is less than perfect.


Sent from my iPad using Tapatalk