1080p RAW??

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James McDonagh

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1080p RAW??

PostSat Jan 06, 2018 1:02 pm

My Ursa mini pro is currently being shipped so I am not too familiar with the recording options/camera interface so forgive me if this sounds silly but Im currently deciding whether or not to purchase the SSD recorder in order to have the option of shooting 4k Raw or just stick with fast SD cards and be happy with the ability to shoot 1080p raw.

Is there much of a difference between 4k RAW and 1080p RAW? Also, I don't understand how Lossless, 3:1 and 4:1 RAW recording options come into play regarding 2160p and 1080p recording options.


PS: There is a spectacular video on YouTube that use Rokinon lenses on an Ursa Mini (same as my set-up). I know that I can't link videos here but the video is called "A Day in the Highlands with URSA MINI" if you want to have a look at it. The video info says that it was shot in uncompressed raw. How much of a difference would 1080p RAW look to that? Especially considering that I (and 99% of people) will only be able to watch the video in 1080 and even if I did click the 4K option my screen would not be able to render 4k and even if it did render 4k it would need to be over 55 inches to see a difference.

So to sum up: why bother with 4k RAW over 1080 RAW?
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Xtreemtec

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Re: 1080p RAW??

PostSat Jan 06, 2018 1:33 pm

James McDonagh wrote:So to sum up: why bother with 4k RAW over 1080 RAW?

About 4 times more pixels.. They both look stunning. But if your client wants 4K video. You want 4K raw.. Otherwise you could have gone with a BMCC which you can pick up for $800 online and have 1080 raw. ;)
Daniel Wittenaar .:: Xtreemtec Media Productions ::. -= www.xtreemtec.nl =-
4K OBV, ATEM TVS HD, 1M/E 4K, 2M/E Broadcast Studio 4K, Hyperdeck Studio Mini, SONY FS7 4K, Ursa Broadcast 4K
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James McDonagh

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Re: 1080p RAW??

PostSat Jan 06, 2018 1:42 pm

Xtreemtec wrote:
James McDonagh wrote:So to sum up: why bother with 4k RAW over 1080 RAW?

About 4 times more pixels.. They both look stunning. But if your client wants 4K video. You want 4K raw.. Otherwise you could have gone with a BMCC which you can pick up for $800 online and have 1080 raw. ;)


About 4 times more pixels... which no one will see ;)
Haha. There's big big difference between the URSA Mini's sensor and the BMCC. If all I was looking for in a camera was 4K video than I would've stuck with my iPhone 7
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rick.lang

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Re: 1080p RAW??

PostSat Jan 06, 2018 5:28 pm

James, Xtreemtec addressed the difference in terms of the recording resolution shooting any flavor of raw. If you’re using the 4.6K sensor, you can record any flavor of raw in any of nine resolutions including 4608x2592 at the highest resolution and 1920x1080 at the lowest resolution. So the number of pixels involved in recording the frame in raw is of course a major difference where the angle of view with the 4.6K frame will be much larger than when you shoot with the HD resolution. Remember when you record raw from the sensor HD is a window of the sensor. So the detail in a given area is exactly the same for 4.6K raw as HD raw, but your view of the scene is much greater at 4.6K.

The other part of your question relates to the flavor of raw selected: uncompressed ‘raw’ or raw 3:1 or raw 4:1. Any flavor can be recorded in any resolution. Raw is compressed as well but is still sometimes referred to as uncompressed because it is a lossless compression, bit for bit completely identical to the original camera data when it is uncompressed in Resolve for example. This mathematical compression reduces the storage space between 20% to 30% depending upon the scene complexity. Raw 3:1 and raw 4:1 are lossy compressions that throw away some information that you may not notice is missing. That’s why they’re referred to as visually lossless. Under normal viewing the 3:1 or 4:1 image may seem just fine when expanded. But if you had a highly detailed scene shot in raw and raw 3:1 and raw 4:1 that you are pixel peeping to carefully compare each DNG frame, you can see there are differences, typically where some detail loss while colour information still looks very good. When you view in motion video, it’s possible there may be some differences in some situations but generally they’ll normally be indistinguishable to most viewers. John Brawley, among others, often shoots in raw 3:1, so you know that it’s an excellent choice. However, when you can manage the storage requirements of your shoot, you may wish to use raw; when your shoot requires you to conserve your storage space, then raw 3:1 and 4:1 will save you a lot of storage allowing you to extend your shoot easily two or three times longer.

So why record in 4.6K raw when your deliverables are HD video? Three reasons come to mind. These reasons are also why I never record in HD, always using at least 2K instead to give me greater flexibility in post.

First, I mentioned the increased angle of view letting you see a lot more of your scene without having to rely on wider angle lenses that you need to capture the same view in HD raw. In post your HD deliverable can be downscaled from 4.6K retaining the wider field of view.

Secondly, having a higher resolution recording may allow you to reframe a clip or stabilize a clip in post processing without any loss of detail. If you stabilize or reframe material recorded in HD, you’re upscaling your material and it may appear to be softer or less detailed.

Third, the more information you record, the better your result likely will look in post as you create those smaller deliverables. Both the colour information and the detail shown in your deliverable can be improved over an HD recording. That’s due to the oversampling of information recording at higher resolution as Resolve then downscales your deliverables.

Hope this answers your original questions.


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Rick Lang

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