Issue with Grainy/Noisy Footage X5 DLOG

[AJW]

found this this may be helpful ---

 

[OneEyeOpen]

Shot this very noisy clip yesterday in D-Log and LOW ISO. Absolutely frustrating result.

• Olympus ED 12mm 2.0
• 1/50s
• f2.0
• ISO 100

Dropbox - X5 d log Noise.mov

My questions are as follows:

• Is the camera not working properly?
• Can it be avoided by overexposing D-Log by 1-2 stops like mentioned in the above tutorial?
• Do I have to get used to it cause this is the X5 style?

Thanks,
Marc

 

[AJW]

yeah that was trash for sure...but go back out to the field and over expose 2-3 stops until you start to see the zebra pattern start appearing on the highlights. I did this earlier today. the noise will go away and then you can adjust exposure first (knock it down 1 to 1.5 stops), then adjust shadows and highlights and then resaturate until the image starts to pop.

 

[Kilrah]

Shot this very noisy clip yesterday in D-Log and LOW ISO.

The whole principle behind log is basically to use different equivalent ISOs for different parts of the image, i.e. the darker parts get recorded at a higher ISO equivalence than brighter parts.
So while you might be shooting ISO 100 the dark parts (that would normally be clipped to black) are boosted say to ISO800 equivalent, and thus will be as noisy as if you had shot them at ISO800.

Log is not magic, it's a way of storing data that allows for keeping something you otherwise would lose completely, but it doesn't come without limitations. You need to work with the compromise and apply it appropriately to your situation.

You can liken it to single-shot HDR processing from RAW in still photography.

 

[OneEyeOpen]

@Kilrah: Thanks for the explainer. The comparison helps me getting my head around the log concept.

@AJW: Thanks. I'm glad you got it right by overexposing the shoot. Keen to try it myself asap.