CurtPalme.com Home Theater Forum

jrodefeld · Joined: 19 Mar 2012 Posts: 18

Hello everyone,

I was reading the "GREYSCALE & COLOUR CALIBRATION FOR DUMMIES" thread and noticed that part where the author recommended a Gamma Booster of some kind to get the correct gamma and restore shadow detail in a display.

Could someone elaborate and expand on how useful and important is would be to add an external gamma booster to a home theater setup?

I have a 50" plasma tv. It is a Pioneer Kuro. The blacks are fantastic but I sometimes feel like I am losing shadow detail. So I wonder if adding a gamma booster could really make a difference.

Of course I haven't calibrated the display yet either, so I'm sure the shadow detail can and will get significantly better when I adjust the settings correctly.

One thing I find confusing was that all the devices the author recommended in the calibration guide where for RGB signals through a computer VGA port.

Now, all my devices in my home theater are connected through HDMI. Wouldn't I want a gamma booster device that has HDMI inputs and outputs?

So, please help me out here. Do you thing I could benefit from a Gamma Booster like those mentioned in the guide?

And is there an inexpensive (relatively speaking) gamma corrector device that has HDMI inputs?

I would love to buy something like the GammaX except with HDMI inputs.

Please help me out. I would really appreciate it.

**kal** · Posted: Tue Mar 27, 2012 3:23 pm Post subject:

Hi,

Kal here, author of the guide you're reading.

See here: Gamma Correction: What is it? Why is it needed?

Re-read the guide too as there's a ton of information on gamma and why it's used in there. Search for "gamma" in the guide and you'll come up with a ton of info. The Gamma Correction: What is it? Why is it needed? link is from the guide.

You would indeed want something with HDMI input/output. I've never heard of a standalone HDMI box with gamma adjustment but most video processors have gamma adjustment built in. Something like the high end Radiance provide multi-point (parametric) gamma boost too. See: http://www.curtpalme.com/Radiance.shtm

It's not something that is used to only do gamma however. Nobody would spend that much money only for that.

If you haven't calibrated yet I'd suggest you calibrate to see how off your gamma is. If you're missing black detail it could be as simply as boosting the brightness to the right level.

You say you think you are losing shadow detail but without calibrating and looking at your gamma curve you'll have no way of knowing where the problem is. You need to measure first, see what the problem is, and then apply the right solution to fix it. Anything else is just guessing.

Kal

jrodefeld · Joined: 19 Mar 2012 Posts: 18

**kal** · Posted: Tue Mar 27, 2012 3:47 pm Post subject:

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

CRTs have a known standard response curve that benefits from gamma boost. Plasmas I'm not sure about. Kal, do you happen to know what the normal response curve is on plasmas?

jrodefeld, Kal is right (of course Smile

). Measure and calibrate, then measure the calibrated results. Find out if your display, when properly calibrated, has an issue or not.

**kal** · Posted: Tue Mar 27, 2012 5:31 pm Post subject:

From what I understand, most digitals do pretty well without a gamma boost. With CRT is almost a requirement. I don't think I've ever seen one CRT that couldn't benefit from it. Always best to measure like you said however.

Kal