DR & ISO Test

[j_szczygiel]

We translated really interesting test of KineMINI dynamic range and ISO writen by Tomasz Wolski from FilmCyfrowy.net

http://studyjne.com/newsy/13/test-kinemini-4k-rozpietosc-tonalna-i-iso

Feel free if you have any questions 🙂

Jacob Szczygiel

[SaxRix]

Thanks for posting this j_szczygiel. I haven’t got my camera yet and I know some people have struggled to understand the more advanced options to begin with. I think I get the basic idea that you are practically able to shift the dynamic range of the camera higher (towards the highlights) or lower (towards the shadows) to accommodate the current lighting of the scene. Where as BMCC can not do such a thing. Is that right?

[filmcyfrowy]

Not exactly. It looks like you move the gamma but you loose some stops. Take a look at the screenshot with DR stops we prepared (on the left you have shadows, and white on the right)

[img]http://filmcyfrowy.net/wp-content/uploads/2014/08/Screen-Shot-2014-08-19-at-19.23.24.png%5B/img%5D

These are 13 stops you can deal with. Not more.

When you move gamma by setting HIGHLIGHTS (in ISO MODE or ADVANCED Mode, or even in EI Mode -these settings are changing but automatically) to the left (to the shadows) you loose some information in the whites. Take a look:

[img]http://filmcyfrowy.net/wp-content/uploads/2014/08/Screen-Shot-2014-08-19-at-19.58.50.png%5B/img%5D

[img]http://filmcyfrowy.net/wp-content/uploads/2014/08/Screen-Shot-2014-08-19-at-19.58.52.png%5B/img%5D

You will never gain more information in whites. You have maximum approx. 13 stops to deal with. EI Mode is like in the film cameras – without any gain. You choose your film stock f.e. 400ASA and then you use chemicals to develop film. You can develop in 5 minutes or 10 minutes and you will receive different results. ISO Mode looks like move gamma left or right (it looks like it is the same as “gain” in digital cameras like Sony FS700 or Canon C300). In ADVANCED Mode you move gamma left/right and up/down.

I received information from Kinefinity that you will get max dynamic range at:

<=2560 @EI mode,

<= 640@ISO mode.

For 4K recording dynamic range is around 12 f-stops;

For 2K recording is over 13 f-stops.

This is officially information.

For me it looks like KineMini has 11-12 stops and you can gain to 13 stops by settings in ISO or Advanced Mode.

I wrote that Blackmagic looks like can achieve more information in whites. Bu this is not exactly true. In Blackmagic you see information by the LUT so your white is approx. at 70%. Then in postproduction you can make it 100% and you have information there. But you cannot shift gamma in BM.

In KineMini you can set Zebra by RAW or POST. So when you set Zebra by POST your camera will behave the same as BM.

All these is thought about KineMini took my and my friend about 5 days of examining. There is no English manual so we are not sure if we are right. It’s not easy 🙂

[j_szczygiel]

Yes, we had the same problem about advanced functions when started with KineMINI 😉 Basically you are able to make an fine adjustement if camera records more informations in highlights or in shadows by moving gamma. Moreover, it has an influence on the noise.

BM used a tricky way how to avoid overexposure on their cameras 🙂 The reason is located in the way how zebra and histogram interpret overexposure. Zebra use RAW signal, but histogram is basing on RGB (post LUT). That’s the reason why zebra in BM shows overexposure before you can see it on the histogram 🙂 Finally, footage is underexposured if you work with zebra and there is a lot of room to recover details in highlights. In KineMINI you can set in the menu which signal is used for zebra – RAW or RGB (post LUT). To sum up – you can’t recover (nearly) any data if zebra blinks on RAW signal because these informations are captured directly from the sensor.

Update:

I see Tomasz joined our discussionand explained with much more details 🙂

[George A.]

Thank you so much for sharing this was a very good read.

[RobBannister]

Yes this is a great read, I may have some questions, but the settings you mention are a great start.

What setting are you finding the most pleasing or least amount of noise?

[filmcyfrowy]

Generally I find ISO Mode less noisy than EI Mode.

[Author]

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