URSA Mini 4.6k The Original™ Magenta Cast Issue

That is interesting! Looks like in ProRes there is much less of the obvious blue tint you get in the RAW example? Looks like ProRes is making a better job at keeps the really dark parts black. But at the moment I have no idea why this is the case.

Best regards,
Florian

That is interesting! ... Looks like ProRes is making a better job at keeps the really dark parts black. But at the moment I have no idea why this is the case.

Best regards,
Florian

Florian, that surprised me too. Nothing like running tests to knock down some assumptions. At ISO 800, with no light, raw is respectable, but at ISO 1600, you can see the tendency towards the blue channel. In both ISO settings, ProRes is giving a truer representation of 'no light.'

I think I'm going to throw some of my preconceptions out the window, and start doing more in ProRes at ISO 200.

Although the little video only illustrated 'no light' for ISO 1600 and 800, I also have the clips for ISO 400 and 200 in my media pool.

I understand I may lose some dynamic range but many shooting situations don't require 15 stops of dynamic range and having richer colour has its appeal as was pointed out by CaptainHook and others years ago. Let's face it, it's good to be proficient shooting raw and ProRes and knowing when one codec may be preferred over the other in a given situation. I just aspire to be proficient, I have a long way to go!


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Florian, that surprised me too. Nothing like running tests to knock down some assumptions. At ISO 800, with no light, raw is respectable, but at ISO 1600, you can see the tendency towards the blue channel. In both ISO settings, ProRes is giving a truer representation of 'no light.'

I think I'm going to throw some of my preconceptions out the window, and start doing more in ProRes at ISO 200.
k

Thank you for sharing the tests Rick! Very interesting. Before you decide to take the dynamic range hit, you might try shooting ProRes at 800 but overexposing by a stop or so, then pulling it back down a stop or so in Resolve. Doing it that way might be able to preserve more dynamic range, but still achieve the lower noise and deep blacks you get at 200. At least that how it worked in my experience with the original BMCC and Pocket. I'll need to run a comparison on the 4.6K to see if it holds true there as well.

Hook or JB might be able to better describe this... Or just tell me I'm wrong, but the way log works is it gives more bits to highlights than shadows. So you may be loosing a bit of your shadows that you have in raw, but those shadows may be all noise ( the blue maybe? ). The log curve is holding on to all it can in prores, but throwing away the lowest end that would most likely be noise. That all being said I've still been able to record about 14.5 stops of dynamic range in prores (444 as well as 422hq) when we did a lot of dynamic range testing. 14.5 stops is a ton of range. Most vision 3 stocks are rated at 13 stops... As a reference.

My next video is for you, Jamie. I have it rendering now. And should be able to post later today. Again comparing raw and ProRes 444 for all ISO values but varying the exposure from something close to ETTR down to levels that look too dark but only occasionally clipping blacks. Wait for it?

I’ll post it in "High ISO = more highlight detail" thread though as this isn’t appropriate for the magenta thread. Apologies.

Edit:
I finished this video that illustrates noise and image quality at all ISO for raw and ProRes 444, but it was too big for me to upload to Vimeo. I cut it back as much as possible but will need to wait until next week to upload since I'm not yet a paying member of Vimeo. I think I need Vimeo Plus.

Some more tests.
4.6K open gate, Sigma 18-35 at f16, Shutter 75 degrees.
f8

f8-35mm.jpg (155.91 KiB) Viewed 19227 times

f16

f16-35mm.jpg (102.06 KiB) Viewed 19227 times

Pretty clean.
Some magenta at f16 but not extreme.

What I can see is similar to my sensor, but I think it's less pronounced with your sensor and that is a falling off in luminosity on the right side that is not present on the left side. I've referred to that as a trace of the problem. The strip is about 7% of the width of the sensor. Maybe some specialized routine in the camera could just give that strip a slight boost and we would no longer see any problem. Or it could be addressed in post.

Edit:
My comments seem to me to be too critical, the shots of the sky look good to me and I suspect will only get better. How do you feel about the results? What are you seeing on the scopes?

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Hello,

I just came home from a shoot on Alexa and captured some dark frames at ISO 1600 and 3200 to compare it to the Ursa Mini 4.6K. I have uploaded short segments of the Alexa ProRes footage here: https://we.tl/DWo0p13H6W

As you can see, there are no lines/fpn or other uneven noise levels visible, but you will be surprised by lots of hot pixels visible if you push the contrast with a low pivot point

Maybe this is interesting for someone out there

Best regards,
Florian

Hey Paul, may I ask, what are the first four digits of your serial number?

And is that firmware 3.3?

Thanks!

Hey Paul, may I ask, what are the first four digits of your serial number?

And is that firmware 3.3?

Thanks!

Serial is 3169***
Firmware 4.0

Edit:
My comments seem to me to be too critical, the shots of the sky look good to me and I suspect will only get better. How do you feel about the results? What are you seeing on the scopes?

Hi Rick. I deleted those shots but will try again next week and check out the images on scopes.
Sometimes it seems green and others magenta.
I guess it depends on the white balance and tint.
In my test shots at home I am thinking there is not a problem unless pushed to extremes but I want to see if it interferes with real life shooting.
I'm doing a shoot over the weekend so will have some real world shots to test.

Wanted to get ppls opinion on my sensor:

magentasmall.jpg (517.01 KiB) Viewed 18916 times

https://www.dropbox.com/s/d8zj7bx7yrt7e ... 0.dng?dl=0

this is a pentax-k 28mm f2 @f8 iso 800, raw open gate, 4.0, tint @ -20. Firecrest ND 1.2 + .6

Just to test further, I decided to try removing any ND even though the firecrest are supposed to be neutral... iso 200, shutter: 75, all at f11

pentax.jpg (801.13 KiB) Viewed 18876 times

I also tried another lens at same mm:

sigma28.jpg (972.12 KiB) Viewed 18876 times

magenta seems to go at 18mm: like others have reported:

sigma18mm.jpg (940.83 KiB) Viewed 18876 times

Good tests Ben.
One should be able to shoot at f8 without getting artifacts.
I'm going to do some more controlled tests to compare to yours.
I will have to wait till next week though.

Hello,

I just came home from a shoot on Alexa and captured some dark frames at ISO 1600 and 3200 to compare it to the Ursa Mini 4.6K. I have uploaded short segments of the Alexa ProRes footage here: https://we.tl/DWo0p13H6W

As you can see, there are no lines/fpn or other uneven noise levels visible, but you will be surprised by lots of hot pixels visible if you push the contrast with a low pivot point

Maybe this is interesting for someone out there

Best regards,
Florian

Thank you very for sharing those clips Florian! Looking forward to pushing them around in Resolve.

here is a shot taken on my new 4.6k. sigma 18-35 @35mm f11 need to test on some blue skes really but alas I live in England. there seems to me the slightest hint of magenta but nothing i see an issue with.

here is my "white wall" test.sadly all my walls are magnolia and i couldnt get it very bright. but you can clearly see there is still some magenta colouration in the bottom left corner and the right hand side.

In direct comparison to a Red Epic Dragon I can't see any magenta corners issue. The Ursa Mini's serial is starting with 3200, still running firmware 3.

With a good lens, a Red Pro Prime 50mm, they look so close to each other in shading that you couldn't tell them apart without naming the files.

With a pretty old Arri/Zeiss Planar 40mm I see obvious shading on both. The rear lens of this one is considerably closer to the sensor. Both are PL mount.

BTW, there are some lenses, like Illuma, which even change their color when you adjust the aperture.

My examples have only been neutralized in color and brought to the same level, no secondary corrections.

Red Pro Prime 50mm:



This is from the old Zeiss (a nice lens nevertheless):

I'm really enjoying the incredible colour and latitude of the 4.6K.
This is my first project with it, on the work of a Maori wood carver.

Wood-Carver_1.1.1.jpg (587.29 KiB) Viewed 18666 times

Lens was an SLR Magic 50 Apo at f2.1, ISO 800, DCI 4K raw.
Shot in an large exhibition hall, where there was only just enough light to use these settings.
The lights were some kind of sodium lamps.

I shot some performers on a stage at this exhibition too, under mixed lighting.
It was a request at very short notice and I had no input into lighting and was a long way from the stage.
Lens was a Sigma 18-35 PL. I was able to crop out unwanted areas of the shot because it was in 4K.
In the footage the highlights looked blown and some of the performers faces were in the dark.
With some quick processing in Resolve I got a lot of the highlight detail back and raised the shadows.
Though it is far from perfect, under the circumstances it looks incredible, like it did when I was there.

Expo.jpg (762.9 KiB) Viewed 18666 times

I just wanted to say, I'm still unsure how much the magenta cast, however slight, is going affect shooting but I'm loving the DR, colour and detail.

Uli and Richard, although not quite perfect, with a quality lens providing even illumination, these cameras should be very good in actual shooting situations.


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Paul, just love that shot of the carver. In terms of this thread which is focussed on a theoretically perfectly illuminated neutral field of view, it's important to remember how beautiful the images can be in a real shoot.

Even a still image can tell a story and your shot is a great example of that as our eyes and mind are immediately engaged in the scene and unfettered by anything that isn't part of the story you're telling us.


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So true, Rick!

For me the magenta thingy is a non-issue from now on, since any PL lens I tested had more influence on shading than the sensor itself. Apart from Red Pro Primes, a Red zoom and old 35mm Arri/Zeiss I also tried Zeiss Superspeeds in 2K mode (which would not challenge the sensor anyway). On flat illumination I could see some shading with any classic cine lens.

If the sensor doesn't have more of an issue (in this respect) than the Dragon in an Epic, I really don't care.

So true, Rick!
For me the magenta thingy is a non-issue from now on, since any PL lens I tested had more influence on shading than the sensor itself. ...On flat illumination I could see some shading with any classic cine lens.
If the sensor doesn't have more of an issue (in this respect) than the Dragon in an Epic, I really don't care.

This is it.
The tint issue seems dependent on the lens's characteristic vignette behaviour, which can be an issue on any camera, if not tint related, then illumination based.
I've noticed a green tint on the BMPCC footage when using a Tokina 11-16 and an IR cut filter.

That's to be expected. Some lenses can show quite different behavior in the IR range from the visible spectrum. Plus, no IR filter cuts like a knife, it will eat in some of the reds too.

In a big shootout with top of the line cameras they even found that different IR filters are best for each of them.

Uli, I meant to say, it hard a green vignette, like the UM4.6K can have a magenta vignette.

Rick, thanks. The carver is a great subject and so is his work. He's very very charismatic and photogenic as well.

Hi Joshua,

I'm really digging this new policy of being very responsive! I think we can all see the positive effect it has had on the tone here (and on BMCUser). It's also great that this new firmware has been released so quickly.

I had mistakenly thought that this update would attempt to solve the issue entirely, and my concern now is not knowing how long this will take to fully work out. I know you've been sharing what you can, but can you tell us what the few different issues were and maybe share what the engineers are planning to do about them? Even if they don't have a fully formed plan yet, just a rough timeline would be amazingly reassuring.

This is the most expensive camera purchase I've made (with my own money), and I'm sure you can understand it makes me nervous if I don't have any reassurances that this will be all worked out in a reasonable amount of time (I use f/8 and f/11 for daytime establishing shots and landscapes pretty often).

Thanks!

You're right. I've tried to keep the details a little light until we had a better idea of what we were going to need to do on our side in order to get this completely addressed.

Today's release, is meant to address the vignetting magenta. Or what what we're calling the symmetrical magenta. Obviously this update had many other improvements as well but those aren't really the focus.

Another issue is the asymmetrical magenta cast. This is where certain sides or areas will have more of a magenta cast than the others. This is what we're looking at right now. I can't really talk about what the plan is right now as we're still working on it.

As for rough timeline. That's tougher. It's going to be sooner than you'd probably expect, but it won't be tomorrow. But again, we're still working out the details which of course I will share with you the second my leash is off.

So yeah, this update was definitely not the "drop the mic" update, where champagne and rose petals fall from the ceiling, all issues fixed. But it is a really solid first step. We'll keep making it better.

I believe this was the last official word from BMD about the magenta issue. I thought we'd turned a corner about transparency and communication, but on numerous threads when asked directly those questions have gone unanswered. I have my theories as to why, but I'd rather stick to the facts; and right now, we have none beyond what I'm quoting here. To BMD: with respect, we don't actually know that this is still being worked on unless you tell us. I don't think it's ok to end communications on the magenta problem on the note above.

If someone has additional information, I'd love to be wrong about this.

Now I've had the Mini 4.6K for 5 months, I've noticed quite an improvement. The source of the improvement may be in part due to firmware changes. I suspect there's some truth to the rumour about the temporary solution that was improperly formulated or improperly applied to the sensor assembly. It is taking a long time to evaporate, but I think the gradual improvement I have seen lends credence to that rumour. Now I no longer have a significant falloff on the right border of the sensor and only a very slight abnormality in some corners.



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Now I've had the Mini 4.6K for 5 months, I've noticed quite an improvement. The source of the improvement may be in part due to firmware changes. I suspect there's some truth to the rumour about the temporary solution that was improperly formulated or improperly applied to the sensor assembly. It is taking a long time to evaporate, but I think the gradual improvement I have seen lends credence to that rumour. Now I no longer have a significant falloff on the right border of the sensor and only a very slight abnormality in some corners.

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Great, I should be waiting for five more months then to get all problems ironed out. I'll have a warranty of one year, while you'll have two months left.

Krishna, are you teasing me? I should think if part of the problem was this chemical wash, it's been improved on most of the more recent cameras as we have seen examples from newer cameras that look much better.


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Krishna, are you teasing me? I should think if part of the problem was this chemical wash, it's been corrected on the more recent cameras as we have seen examples from the newer cameras that look much better.

There was a recent thread on here of someone who just got their camera and it exhibits the magenta issue on the right side. I don't feel like searching for it right now, but I bet if you do a search you'll find it. He posted a still of some clouds in the sky and it was pretty apparent. So I don't think it's been fixed completely. I think it's just that a lot of people have stopped talking about it and posting about their tests for it. It makes it feel like that's what BMD was hoping for... eventually everyone stops talking about it and just moves up, allowing them to sort of sweep it under the rug. I hope not, but with no recent news regarding the fix and no willingness to answer questions about it, that's exactly what it looks like.

You're right, Mike. Thanks for reminding me of that. I edited my post to be less black and white about it.


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Mike, what are the first four digits of your serial number?

So I don't think it's been fixed completely.

Anyone care to guess when BM will release an updated version of the 4.6k (new features, real fixes of all of its problems)? I'm really interested in this camera and I have seen some amazing footage shot on it online, but reliability is a very important feature to a lot of pros. I don't like the look of the FS7 (looks like pure video compared to the minis), but I would choose the Sony for work because I know it would be less likely to give me problems. I know some on here would debate this, but even if this is just a perception then this perception itself is a problem for BM.

So I don't think it's been fixed completely.

Anyone care to guess when BM will release an updated version of the 4.6k (new features, real fixes of all of its problems)? I'm really interested in this camera and I have seen some amazing footage shot on it online, but reliability is a very important feature to a lot of pros. I don't like the look of the FS7 (looks like pure video compared to the minis), but I would choose the Sony for work because I know it would be less likely to give me problems. I know some on here would debate this, but even if this is just a perception then this perception itself is a problem for BM.

Simmilar debate i have,
need to get married again soon.
Girl.that i am seeing is beatiful and stunning but she comes with lots of quirks.
She flirts a lot,always on the phone and has bit of attitude.
Another girl i ve known for long time and have been friends comes.from good family,she is.hard working and responsible,loves house work and very caring but average looks...
Which one of these 2 will be right...potentially both could.leave me.and take my house and children it is hard to tell.
But if they do then why not be with prettier one and have better looking kids.
At the same time less attractive seems better choice becouse she is more stable and grounded more likely to settle down....
Beautiful things usually come with problems... but you pay the price for it or you get settled.with average...this is been my debate,getting old and will have to make choice soon again.
Last.time i went for.average also i payed the same price,house went as they did the kids.
As for 5K camera,that was easy choice for.me,just got UM mini!

Some people solve this problem by renting. It might seem more expensive in the short run, but probably cheaper in the long run.

Gene,

sorry,you refer to woman or camera?

I don't think it matters. There is this bumper sticker out there that says it all, "Don't get married, find a woman you hate and buy her a house."

So much wisdom from you guys. Nothing says loving like the song, "Never make a pretty woman your wife!" Good advice there, but a pretty lens on a pretty camera? Of course we get weak in the knees and buy them!


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So much wisdom from you guys. Nothing says loving like the song, "Never make a pretty woman your wife!" Good advice there, but a pretty lens on a pretty camera? Of course we get weak in the knees and buy them!


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"pretty lens with pretty camera..."
Its something only James Packer can afford unfortunately

I'm all for humour but it seems in poor taste when we start comparing renting cameras to women.

The ACS here in Australia currently has a less than 3% female membership rate. I bet the participation rate here is even less.

I would love to encourage the engagement and participation of women in our industry. I don't believe this kind of language is becoming, respectful or welcoming to those we should be treating as equals.

JB.

So John, are you saying that modern professional women would rather own than rent?

Lets not discuss anything other than what's relevant to the thread folks. Any discussion going forward other than that will be removed and warnings/bans be issued.

Maybe time to get back to the topic of this thread. We only intended some light humour, but good to remember this is a public forum, not the men's room in a beer parlour.


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Lets not discuss anything other than what's relevant to the thread folks. Any discussion going forward other than that will be removed and warnings/bans be issued.

Good! So BMD's moderators are alive and read this forum.
Can someone reply to the UK UM4.6 thread?
We are stuck in an horrible limbo...


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I'm all for humour but it seems in poor taste when we start comparing renting cameras to women.

The ACS here in Australia currently has a less than 3% female membership rate. I bet the participation rate here is even less.

I would love to encourage the engagement and participation of women in our industry. I don't believe this kind of language is becoming, respectful or welcoming to those we should be treating as equals.

JB.

JB,

I was being slightly sarcastic about people who are overexamining options when discussing UM mini,mostly at my own expense.

No female DP in Australias have been harm during this process i can reassure you,if anything we made them have a laugh and feel included.
Yes reply was in context with quality of UM mini.
I am well educated to know fine line between humor and distastful comments...
Otherwise, we continue to be boring and be politicaly correct at all times

No offence meant.

Oh my god... New products: "sense of humor" and "sarcasm".

Shipping in July.

Some quick and dirty tests of my new Ursa mini 4.6k Pl received today. These shots are a wall white or at least i think is... under a dim tungsten bulb in my room., No IR or ND filters used. Sorry didn't have time to light the wall evenly and all that jazz I shot at 4.6k 3:1 raw
Also i shot outside my house at the sky it was raining here in brooklyn, so its very overcast. I DIDNT TOUCH ANYTHING IN RESOLVE. i just screenshot the frames after bringing them in. This is firmware 3.3 I haven't updated to 4.0 beta 2 yet. The lens i used are Schniedar Xenar 3 35mm at T8 and T16

wall @T8

wall.png (296.62 KiB) Viewed 17535 times

sky T16

no correction.png (189.44 KiB) Viewed 17535 times

4.6K PL

4.6k.JPG (244.92 KiB) Viewed 17535 times

Here is my first grade from the 4.6k


The last screenshot is the shot of the sky pic i posted above, corrected..i'm practicing my teal and orange blockbuster look

4.6K GRADE

4.6k grade.png (555.11 KiB) Viewed 17516 times

I definitely do not see any magenta in those sky shots or the corners of the frames on the wall on the tests above

That's one boring camera you got there, Donnell. No character or personality at all. Just perfect!

Of course it might have a lot to do with your telecentric lenses. So the combination of camera and lenses is perfect.


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ha! Rick, yes this camera is so Boring, I Stayed up all night playing with it.. My wife said why don't you marry it? I said send me the paperwork. Both myself and the mini had to stay out in the living room last night. It was well worth it. I think i'll have to shoot a video of some roses with the mini and give it to her later.

I'm happy to join the club ..thanks rick

YESSSSS those telecentric lenses... what a combo