Author Topic: Night shot with 5D3 + ML, how to avoid noise?  (Read 1092 times)

Danne

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #25 on: August 09, 2019, 01:11:29 PM »
What's wrong with posting the actual mlv_files? Much more effective.

adrjork

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #26 on: August 09, 2019, 01:43:42 PM »
Hi Danne, thanks for your reply.
What's wrong with posting the actual mlv_files? Much more effective.
Well, before annoying you too much it's better I repeat the test... Just to be sure.
Anyway, could you tell me that strange range 2047-16200? Is it an arbitrary assignment of the camera? Can I freely change it to 0-16838? Or 2047-16200 helps avoiding noise?

Danne

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #27 on: August 09, 2019, 01:48:13 PM »
Please, do your own testing or use search. White level handling has been discussed several times before.

adrjork

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #28 on: August 10, 2019, 10:29:55 AM »
About different exposure between MLV 2.0 and Lite 1.1, after several tests it never happened again. The first (and only) bad/strange result is really too heavy to upload it. My impression is that for some strange reason a gradual exposure transition function was activated (but I actually did nothing). Anyway, luckly all seems working normal now.

About white level discussions... I've found 151 topics (that I read...) here in the forum in which there is something about White/Black levels. Infos are too scattered. What would surely be useful (for me, but also for many newbies like me) will be a topic that sums up the discussion, or better a simple guide/tutorial/explanation about White/Black level. Perhaps this topic yet exist and I simply didn't find it, if so please someone link it here! (Thanks really a lot.)

What I've learnt is that 14-bit means 16384 values from black 0 to white 16383, in linear world. "Usable" range differs from camera to camera, and for 5D3 should be 2048-15000, where 2048 prevents color casting, and 15000 prevents purple fringing artifacts (and works well with highlight recovery in Davinci RAW tab).
Dmilligan says these values are not "adjustable"
but you could have to correct them when they are wrong (ExifTool, Switch, other ML tools) because "there is a correct (mathematically speaking) value for both of these". But this is math, because g3gg0 says you could try other values (1024, 1700, 1650 for black) "depending on what looks better".

The fact remains that my shots are not in 2048-15000 range: MLV App Info says 2046-16200 for 50% of my last tests and 2047-16200 for the other 50%. But I saw these values also HERE.
So here my questions:
1. Is 2047-16200 a correct range for 5D3 (or it's better to correct values to 2048-15000)? And if not, where does it come from?
2. Does it matter that some shots have 2046 instead?
3. In MLV 2.0 Rec module there si also the Fix Black Level to 2048 option. This makes me think that anything under 2048 is a wrong number. So, should I correct any shot of mine to 2048? (Via MLV App?)
4. Since black/white values are mathematically correct/incorrect, which is the method to calculate them for 5D3?
5. Switch let me change white to 15000/16383 only "if the tag is either 15000 or 16383 to begin with otherwise nothing will be changed to prevent other cameras to get these tags" (HERE), so does it mean that my 16200 is wrong? Perhaps because I'm using MLV Lite 1.1 instead of MLV 2.0?

(Guys, surely these questions are old stuff for you, but believe me it is not easy for me to navigate these waters.)

Thanks

Danne

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #29 on: August 10, 2019, 04:42:58 PM »
Safe margin I'd say 15000. 16200 probably no problem too. 16383, well if that extra information is needed, use it but look for strange highlight recovery depending on nle or light situation. Then add bitdepth changes and then white level is something else.
There is not one answer to this but you have so many tools to adjust, pixel peep and draw your own conclusion. Easy answer. If it looks good, stick to that. My personal take on this.

adrjork

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Re: Night shot with 5D3 + ML, how to avoid noise?
« Reply #30 on: August 11, 2019, 12:33:13 AM »
Thanks a lot Danne.