Instant HVX Noise Reduction
 

As most of us know (and for those that don't) the HVX has noticeably more noise than other the other sub-$10k HD cameras and we've all been looking for the best ways to deal with it.

I previously had posted results from my extensive color test, but for some reason glossed over dealing with noise.

Today, I've stumbled across an exquisitly simple method for cleaing up HVX noise. The best part? Anyone can do it!! (laughs)

The Trick: in SCENE FILE menu under GAMMA settings, use the B PRESS gamma and, voila! About 50% to 60% instant reduction in overall image noise. And that gamma setting does not adversely affect color space or other chroma settings.

I think someone had mentioned that they felt the CINELIKE V gamma had better noise characterisitcs, but after todays testing the clear winner by a huge margin is in fact the B PRESS gamma.

For an analogous comparison, the improvement is likened to that of a Nikon DSLR going from ISO 400 to 100 or, a Canon DSLR going from ISO 800 to 100. The difference is completely obvious.

Note that the HVX does not become noise-less at the B PRESS gamma setting but the improvement is just... amazing.

Try it!

And set the detail coring up...

Cheers

Gunleik

It should be pointed out that while turning up DETAIL CORING will help noise artifacts, the benefit of B PRESS gamma is just a strong without DC being changed.

Right on Robert! How does this compare to the "lonoise" setting from Barry's HVX book CD file setting? Just curious.

Hi Vince,

I've not made any direct comparisons to Barry's settings, but using the B PRESS gamma reduces noise regardless what other settings are used. It's one of those "easter egg" surprises.

Robert,
Are you sure you have actually less noise at this setting , or do you have less apparent noise because you are crushing the dark parts of the scene.

Its always been true in video that if you get rid of the darker areas, you will see less noise, but this is at the expense of a gentle grey scale.
Likewise if you crush the blacks there will be less apparent noise.

Leonard,

I'm sure it's the latter but the overall appearance of blacks are near the same when compared to the HD NORM gamma, just that the visual noise is much less. It's so easy to test, just try the setting in your camera and see what you think.

It should be noted that you cannot see the noise reduction in the flip-out LCD; if you really want to see how much better B PRESS looks you need a good external monitor or even an HDTV hooked up.

I guess what I'm saying is that I believe you when you say that the noise is lower on black press. It should be, but at the expense of engaging black press and what that does do to the grey scale.

I'm not sure what you mean about the appearance of blacks being the same as at HD Norm. The black level itself should stay the same or could adjusted to the same setting with a minor black level adjustment, but black press should lower the areas surround 20 IRE or so ( that's just a guess based on typical black press circuits).

From what I remember when I looked at these on a scope the Gamma setting on black press is based on the SD Norm setting which is higher than that on HD Norm. The main difference between HD & SD Norm seemed to be a lower gamma on HD Norm.

So I would think the difference between Black press & HD Norm is that the former has a higher gamma (midtone) but a lower shadow area.
That would tend to give a more contrasty look without actually losing any detail like crushing blacks would.

Indeed you are be right that this a quieter setting, but I generally prefer a lower gamma with a little more extended shadow area.

Many people I know generally set up D30/D500 type Sony cameras this way ( -6 Gamma & + 5 black stretch) as I find it a more pleasing and "filmlike" look.

Ultimately I'm saying there is no free lunch.
More contrasty look, darker, shadow area, darker blacks = less noise.
More shadow area , gentler grey scale = more noise.

Take your pick - The noise is there either way, either you disguise or you don't. I go for the grey scale I want & just accept the noise as the price of a 1/3" chip.

If you prefer a snappier grey scale you are in luck with noise and the Blackpress may be a great solution.

Crushing the blacks will generally reduce noise but, as noted by others, this is at the expense of losing most the details in dark areas. You can do the same thing by turning down the master pedestal as well.


ash =o)

Where is that setting ASH?
The master pedestal? Also how you been? What are you shooting these days?

I shoot a lot of everything. Always have a couple big projects, couple pet projects and the freelance stuff. The master pedestal adjusment is in the setup menu of the HVX. I generally shoot with it at -5 on the HVX. When you shoot a bigger format like Varicam, you can adjust the pedestal for the various colors as well. I learned to combat noise from using the SDX and Vari so much. The SDX rarely has noise but the Vari can get pretty nasty if you push it too hard. Like with anything, there are ways to minimize it. The HVX is no different.



ash =o)