Ursa M4.6k Grain

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Johnny Harris

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Ursa M4.6k Grain

PostMon Apr 23, 2018 3:24 pm

I have a bit of an odd request but maybe you guys could help.

I need to extract UM4.6k grain to be used (layered) on stills so as to make them look filmed (w/same camera) not static. How would I go about doing it?

I seem to remember coming across one such video a while back but for the life of me I cannot find it. I think it was something like shoot at the desired settings (fstop, iso etc) and with the cap on the lens.... then do xyz and extract it.

So if anybody knows the process of extracting grain from footage please post instructions or a vid.

Much appreciated.
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Uli Plank

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Re: Ursa M4.6k Grain

PostTue Apr 24, 2018 2:43 am

There used to be a product called "Grain Surgery" doing just that. I think it was bought by Adobe and is the base of such features in AE now, so you might need to look into that.
No, an iGPU is not enough, and you can't use HEVC 10 bit 4:2:2 in the free version.

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robert Hart

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Re: Ursa M4.6k Grain

PostTue Apr 24, 2018 3:06 pm

Way back in the days of ground-glass based 35mm adaptors, there were techniques examined for countering the textural artifacts of stationary ground-glass adaptors. The same technique could be applied to images made with a moving ground-glass adaptor if the operator had forgotten to turn the motor on. It was only good for the P+S Technic Mini35-400 oscillating/orbital system and the better known alternative vibrating designs by Quyen and Hien Le, Dennis Woods, Wayne Kinney.

If you forgot to turn on the spinning ground-glass types, you were done.

With the fixed ground-glass and vibrating types, a inverse mask could be filmed of the stationary ground-glass texture later. If the taking camera had a zoom lens, it was near-impossible unless the zoom lens had to always be at full extension for the relay to work, which quite a few were. With the vibrating types it was complex because the mask had to be slipped under the original image with precision and sometimes a slight rotation as well. Some of the outer edge of the image would have to be cropped out. If you were lucky, the ground-glass would stop in near-to the same rest position when switched off.

To revisit the method it would require a very patient search of the old dvinfo.net thread on groundglass adaptors. It will be very daunting as the thread held the record for being the longest. Probably use the search function and look for keywords, "grain", "artifact", "fixed ground-glass", "stationary ground-glass","boss screen", "movietube".

The link is here :-

http://www.dvinfo.net/forum/alternative ... apter.html
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carlomacchiavello

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Re: Ursa M4.6k Grain

PostTue Apr 24, 2018 4:57 pm

In After effects is the plugin called “match grain”
It’s quite slow. For your work I think is better to shoot a grey card for different iso that you need and compose on top of photos like multiply blending mode, then adjust luminosity and opacity of grain level to obtain what you need.


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Savannah Miller

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Re: Ursa M4.6k Grain

PostTue Apr 24, 2018 7:37 pm

What you need is something called a "grain plate." They are occasionally used in VFX where you just capture a flat image with a lot of noise/grain and then extract it and add it back onto denoised images. If you shoot something black (for example) and use a subtract operation of a black solid and the moving grain image, you can add it back on using a "plus" or "add" operation. That's the fastest way to extract the grain you need and it's very simple.

That's about as simple as I can describe it, but it's not very hard. Usually in compositing though we just match the grain manually by going into the RGB channels individually and matching the size and density of the grain, making sure it changes density appropriately with the luminance too. Because 90% of major American TV shows are shot on Alexa, we usually have said grain matching plugins preset fairly close to where it needs to be already. There's a grain node in fusion that's quite good and Nuke has a few ones such as scanned grain and match grain too. If you want the most control the Luma Pictures grain gizmo is by far the best.
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Savannah Miller

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Re: Ursa M4.6k Grain

PostTue Apr 24, 2018 7:51 pm

This is actually a very common thing to do. In VFX that are fast turn arounds, especially big TV shows, it's sometimes common to denoise the entire shot using something like neat video and then do all of your work, and then just regrain the shot at the end to match how it was shot. I usually don't do that as it's a fairly lazy thing to do and degrades image quality a lot but in cases of Green Screen and other shots similar, sometimes it helps with keying and despill too. And then sometimes when shots are grained back. if the original images were really clean and well exposed then we'll sometimes sneak a little extra grain if it helps "integrate" something better or hides a touch of banding if some lower quality elements are used.

You'd be surprised with all of the new stock FX packs out there, sometimes there are old 2004 DV gems that really give you something you can't find anywhere else.
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Uli Plank

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Re: Ursa M4.6k Grain

PostWed Apr 25, 2018 6:29 am

Thanks, Carlo, for pointing to it. Yes, it's slow, but IMHO does a pretty good job of analyzing the original grain.

And let's make a clear difference between static 'grain' and dynamic 'grain' – even if it's not grain, which is a property of analog film. If the noise from any digital camera looks similar to cinematic grain or not at all is highly dependent on the compression (or absence of it).

Static noise is also called FPN and needs be avoided by giving cameras enough light. Dynamic noise with a pleasant structure can look very similar to analog grain, but like that, it should change structure from frame to frame. Thats what makes a locked-down shot, even without any motion, come alive and not look like a photograph.

Finally, test your grain with the whole chain all the way to the viewer, since later compression (like for internet or satellite chains) can make it look ugly. Noise is like a strong medicine: a small amount can cure problems, even banding, but overdosing just a bit can kill your image. I had a case where a director insisted on adding quite a lot of grain, she wanted that '16mm' look. I warned her, since she intended a DVD version too (it was a while ago). I finally asked her to sign her decision off before getting it into distribution. A wise move: they had to throw the first version into the plastic melt…
No, an iGPU is not enough, and you can't use HEVC 10 bit 4:2:2 in the free version.

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carlomacchiavello

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Re: Ursa M4.6k Grain

PostWed Apr 25, 2018 7:59 pm

Hi Uly, when you can master the file (no stream, on line, etc), but dvd and Blu-ray you can use ffmpeg which can have internal profile to keep and compress correctly grainy movie. For h264 you can download free interface handbrake for every is, win Mac Linux, under setup you can find a slow profile but good to keep grain, I’m out of work but there is a specific option called grain or film grain support to keep it. Often used for ripping Blu-ray grainy but is excellent for some difficult movie to produce right Blu-ray source for authoring


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Uli Plank

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Re: Ursa M4.6k Grain

PostThu Apr 26, 2018 4:35 am

Yes, Carlo,
I really like ffmpeg too.

But the OP was asking about 'copying' grain from one source to another. And now that BM is offering a complete postproduction solution, many would like to stick with it from input to delivery, I suppose.
No, an iGPU is not enough, and you can't use HEVC 10 bit 4:2:2 in the free version.

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Robert Niessner

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Re: Ursa M4.6k Grain

PostThu Apr 26, 2018 10:42 am

Johnny Harris wrote:I have a bit of an odd request but maybe you guys could help.

I need to extract UM4.6k grain to be used (layered) on stills so as to make them look filmed (w/same camera) not static. How would I go about doing it?

I seem to remember coming across one such video a while back but for the life of me I cannot find it. I think it was something like shoot at the desired settings (fstop, iso etc) and with the cap on the lens.... then do xyz and extract it.

So if anybody knows the process of extracting grain from footage please post instructions or a vid.

Much appreciated.


I've created you four pieces of 5 sec grain plates from my URSA Mini 4.6k ready to overlay on any footage.

I've shot an out-of-focus colorchecker graycard on the outside on an overcast day in ISO200 - ISO1600 in ProRes XQ 444, then did a little processing in After Effects to flatten out any vignetting and exported that as 3840x2160 16-bit TIFF sequences.

It is a 23 GB download, which will be online in 1.5 hours - then I'll post you the link. Upload will be online for 7 days.

Just use Overlay as your blend mode. Of course it is film log, so you would have to add the same color treatment as for the footage you are overlaying it to.

If you want to make the grain more visible, you could sharpen it a bit.
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Robert Niessner

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Re: Ursa M4.6k Grain

PostThu Apr 26, 2018 12:07 pm

Saying "Thx for help!" is not a crime.
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Robert Niessner
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Robert Niessner

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 10:06 am

Well, I guess I did that for nothing...
Saying "Thx for help!" is not a crime.
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Robert Niessner
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Sean van Berlo

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 11:00 am

I saw you went the extra mile and think it's really awesome you did that!
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Robert Niessner

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 11:21 am

Thanks Sean. If anybody needs the files, I can upload them again.
Saying "Thx for help!" is not a crime.
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Robert Niessner
LAUFBILDkommission
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Read the blog in English via Google Translate:
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rick.lang

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 5:49 pm

Robert Niessner wrote:Well, I guess I did that for nothing...


You’re reward for performance above and beyond awaits you in heaven!


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Robert Niessner

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 6:18 pm

rick.lang wrote:You’re reward for performance above and beyond awaits you in heaven!


Rick, I do not believe in heaven, so my reward will be a warm fuzzy feeling in my stomach for helping other ;)
Saying "Thx for help!" is not a crime.
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Robert Niessner
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Read the blog in English via Google Translate:
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Ivon Visalli

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Re: Ursa M4.6k Grain

PostWed May 09, 2018 11:24 pm

Robert Niessner wrote:
rick.lang wrote:You’re reward for performance above and beyond awaits you in heaven!


Rick, I do not believe in heaven, so my reward will be a warm fuzzy feeling in my stomach for helping other ;)

Okay, to the god of warm fuzzy feelings then. That was very nice of you Robert.
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Denny Smith

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Re: Ursa M4.6k Grain

PostFri May 11, 2018 5:28 am

Yes, yes it was Robert.
Cheers
Last edited by Denny Smith on Sat May 12, 2018 1:53 am, edited 1 time in total.
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Ivon Visalli

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Re: Ursa M4.6k Grain

PostFri May 11, 2018 9:31 pm

Denny Smith wrote:Yes, yes it was a Robert.
Cheers

As in "that was a Robert thing to do"?
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Denny Smith

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Re: Ursa M4.6k Grain

PostSat May 12, 2018 1:54 am

OK Ivon, you caught me, a typo, it should just “ Robert”
Cheers
Denny Smith
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