HD picture grain problems.

[Skipjack]

Okay, I've had my 3100 box from TWC for a while now... 3 mos, I think.  I have it plugged into my Toshiba 50HDX82.

The HD picture looks great.  However, I've noticed a "grainy-ness" or a fine pixellation in dimly lit scenes.   Brightly lit scenes are amazing and jump right out at me.   But, shadowy scenes look like when you take a dimly lit photo with a really high-speed film; some detail is lost and the picture looks grainy... that's the best analogy I can come up with.

Is this a product of my TWC signal, cable box, TV, or just an inherent property of HDTV in general?

It's hard for me to troubleshoot the source of the problem as this is the only setup where I can achieve a true HD signal (I don't own a STB).

Anyone else see things like this?  Particularly you OTA users out there?

[Gregg Lengling]

It depends on the original recording....film vs HDVideo.  If you take a look at something originally mastered on HdVideo...the problem doesn't seem to exist.  However when transferring film to Digital, often times the film chain doesn't handle the dark scenes very well.

[Skipjack]

I should've been more descriptive... I do see it on the PBS HD loop (ch 510) on occasion which is filmed natively in 1080i.  Most recently on the "Classic Cars of Cuba" segment, there's a dim scene shot during dawn (or dusk, maybe) that looks grainy.  I also noticed that the majority of the HD loop stuff is shot during the day in brightly lit locations.  This makes me wonder if they are avoiding dim scenes intentionally to not display a shortcoming of HD broadcasting.  But, that's the conspiricy-theorist coming out in me.

If I stick a DVD in, dim scenes look fine (those do get upconverted to 1080, right?)... and I don't notice it on upconverted material from other non-HD cable channels (although I don't watch a lot of non-hd stuff through the colorstream input).  

This leads me to believe the problem lies with the TWC signal in my area or the source material itself.

[Gregg Lengling]

It will also depend on the camera and lenses used.  Some of the older HD cameras didn't have the light gathering capability that the better ones do.  A good example is comparing my Digital Camera (Fuji S-1 Pro) to a consumer camera with the same megapixel rating.  The use of CMOS devices vs. the CCD device in my camera makes a lot of difference on the amount of noise in low ambient light situations.

[Skipjack]

Interesting... thanks for the answer Greg.

So, perhaps they were avoiding dimly lit scenes on the PBS loop because the cameras used at the time didn't offer enough "light gathering" capability.  (I knew I should've stuck with the conspiricy theory angle! )  

Now that I think about it, my Sony Handycam has the same problem... so this is something similar only on an HD-scale.

The problem with becoming an HD/HT-geek is it takes away some of the fun of what your watching... I find myself over-scrutinizing the picture quality, sound.. etc.. instead of watching something just for the sake of its content.

Thanks again, Greg.