Optoma HD8600 Projector Calibration and Settings-2

Posted on December 6, 2009 by Art Feierman

To get the very most out of the HD8600, a calibration is necessary. It will definitely improve color accuracy and therefore overall picture, although not by a huge amount. Primarily it will bring up the blues slightly. Dynamic mode improves dramatically, and is much more watchable with Mike's settings.

Optoma HD8600 Post Calibration Grayscale

When done with the calibration, the HD8600 achieves color accuracy about as good as any other projector recently reviewed, including the JVC DLA-RS25

Calibrated color temps, 20 – 100 IRE


20 IRE	6424K
30 IRE	6538K
40 IRE	6528K
50 IRE	6573K
60 IRE	6566K
70 IRE	6498K
80 IRE	6549K
90 IRE	6555K
100 IRE	6529K

On paper, those are spectacular numbers, with the entire range from 20 to 100 IRE only varying by 151 degres total.

Viewing the projector supports the numbers. Skin tones, and for that matter, everything looks very right on. I don't know if the HD8600 right now, with our settings, is quite as good as my all time favorite reviewed projector (in regards to skin tones), the InFocus IN83. I'd say it's as close as anything else has come, and that's me talking having just reviewed the JVC RS25 a couple of weeks ago. The JVC RS25 is most certainly, the HD8600's most direct competitor, when it comes to picture.

Gamma settings

Optoma offers up four customizable gamma settings - Film, Video Graphics and Standard. Mike chose Standard for our setup of the User memory. Measuring it, he came up with an average gamma of 2.27. Not bad, just a little darker in the mid-ranges than the ideal 2.2.

For almost all of my movie viewing filling my 128" Stewart Firehawk G3, however, I favored the Film setting which has a lower gamma (Mike didn't provide a measurement). I'd put it somewhere between 2.1 and 2.2, and, since Mike preferred Standard, Film is probably closer to 2.1. Sure worked for me, as my screen is of the high contrast gray variety.

For our "quick-calibrate" of the "brightest" mode (Bright mode), Mike recommends Video mode, which from my viewing has an even lower gamma number, almost certainly below 2, and really lights up (lightens) those mid bright and mid-dark areas, as well as the middle of the range.

As I noted above, each gamma is customizable, although the controls are just a little coarse. For example, the Gamma for Standard has two adjustable controls: Curve type and offset. For example, Film gamma is -2,+1, and Video gamma is -3,+2.

Regarding the HD8600 Manual Iris

The HD8600 also has a manual iris. Each of the modes has it set down, to different levels, with only the Graphics mode defaulting to wide open. Stopping down the iris will increase contrast somewhat and with it a small increase in black levels. That said, I spent all my time watching the HD8600 in our User mode, with the iris wide open 9 (90% of the time), or, at most, stopped down to 7. (I like bright!).

Optoma HD8600 RGB Settings

These are the adjustments we made to Red, Green and Blue for the grayscale balance of THX mode. This is accomplished by placing these adjustments into one of the three Custom settings (1, 2, or 3). We placed all of these into User 1 (which starts out as a copy of THX).

Calibration settings for User 1:
Gamma on Normal, Color on -2