Alex Leith
Well-known member
So, for anyone who can't be bothered to read the entire threads on noise/banding/macroblocking, I've pulled-together what (I think) we've learned about how to get the best image out of the HVX...
The HVX displays three types of noise: grain; banding in gradients; and macroblocking.
The "grain" noise is a function of the way any camera samples and amplifies the signal from the CCDs. Each camera displays noise slightly differently depending on how they're engineered, and preference is down to individual taste. The noise is different in nature to the DVX100, HD100 or XL-H1, and to some eyes seems "less noisy" and to others "more noisy".
The banding seen in flat surfaces (such as a plain wall) is a limitation of an 8bit codec. The reason that the DVX100 didn't show banding is because it was inherently more noisy (which breaks up the bands)... although that doesn't totally explain why other less noisy 8bit camcorders (SD or HD) don't display banding.
Macroblocking in shadows is mostly seen during colour correction. 8bit codecs throw away shadow detail to make the image prettier further up the range. If you pull this detail out in colour correction, it looks pretty ropey.
So, to reduce image anomalies...
1. Avoid plain flat surfaces, as detail does a good job of hiding the noise and will also reduce the chance of banding and macroblocking.
2. Only colour correct "down". If you raise levels you risk stretching the shadow areas too much which reveals (sometimes severe) macroblocking and banding.
3. The "CineLike-D" gamma curve is inherently slightly more noisy than the other gamma curves. This has the positive side-effect of breaking up macroblocking and banding. This combined with the "Normal" matrix produces macroblock free images.
4. Reduce the Master Ped down to -4 or -6. This crushes the blacks which further hides any macroblocking in the shadows.
5. Reducing the Detail level reduces the "grain" noise, but has the unfortunate side effect of increasing the banding. Increasing the Coring also has a similar effect.
6. To get the best image out of the HVX you need to overexpose while you shoot... but not too much or you lose the highlights - You can set Zebra to 105% to make sure you're not losing anything. When colour correcting, you need to be careful not to bring the white levels down too far, as it creates a rather strange detail-less grey area wherever the levels blew out.
7. Lastly, the noise levels may be more or less apparent depending on what you are watching the footage on. Many LCD monitors are not "noise-friendly", and make footage look worse than it really is.
All-in-all, expose sensibly and don't try to do anything too radical in post and you should be okay.
The HVX displays three types of noise: grain; banding in gradients; and macroblocking.
The "grain" noise is a function of the way any camera samples and amplifies the signal from the CCDs. Each camera displays noise slightly differently depending on how they're engineered, and preference is down to individual taste. The noise is different in nature to the DVX100, HD100 or XL-H1, and to some eyes seems "less noisy" and to others "more noisy".
The banding seen in flat surfaces (such as a plain wall) is a limitation of an 8bit codec. The reason that the DVX100 didn't show banding is because it was inherently more noisy (which breaks up the bands)... although that doesn't totally explain why other less noisy 8bit camcorders (SD or HD) don't display banding.
Macroblocking in shadows is mostly seen during colour correction. 8bit codecs throw away shadow detail to make the image prettier further up the range. If you pull this detail out in colour correction, it looks pretty ropey.
So, to reduce image anomalies...
1. Avoid plain flat surfaces, as detail does a good job of hiding the noise and will also reduce the chance of banding and macroblocking.
2. Only colour correct "down". If you raise levels you risk stretching the shadow areas too much which reveals (sometimes severe) macroblocking and banding.
3. The "CineLike-D" gamma curve is inherently slightly more noisy than the other gamma curves. This has the positive side-effect of breaking up macroblocking and banding. This combined with the "Normal" matrix produces macroblock free images.
4. Reduce the Master Ped down to -4 or -6. This crushes the blacks which further hides any macroblocking in the shadows.
5. Reducing the Detail level reduces the "grain" noise, but has the unfortunate side effect of increasing the banding. Increasing the Coring also has a similar effect.
6. To get the best image out of the HVX you need to overexpose while you shoot... but not too much or you lose the highlights - You can set Zebra to 105% to make sure you're not losing anything. When colour correcting, you need to be careful not to bring the white levels down too far, as it creates a rather strange detail-less grey area wherever the levels blew out.
7. Lastly, the noise levels may be more or less apparent depending on what you are watching the footage on. Many LCD monitors are not "noise-friendly", and make footage look worse than it really is.
All-in-all, expose sensibly and don't try to do anything too radical in post and you should be okay.
Last edited:
rogar-BigGrin(DBG)
