Optoma HD8600 Projector Calibration and Settings
We calibrate each home theater that is reviewed. We perform contrast, brightness, saturation and other image adjustments, as well as a grayscale balance. A complete professional calibration can go even further, but the settings we provide, generally offer a anywhere from a slight to dramatic improvement, compared to the out of the box settings.
12/6/2009 - Art Feierman
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Optoma HD8600 Color Temperature
These are the measurements, taken "right out of the box." Mike chose Cinema 2 as our starting point for a "best" mode. To start, the HD8600 looked pretty good, though not exceptional. For example, it doesn't look as good as, say the THX modes on the JVC or Epson projectors. (Apparently Epson and JVC are getting their money's worth with the THX deal, in terms of out of the box color, if nothing else).
Color Temp over IRE Range, Best Mode (Pre calibration):
Cinema 2:
30 IRE – 6282K (dark gray)
50 IRE – 6344K (medium gray)
80 IRE – 6369K (light gray)
100 IRE – 6529 (white
For those interested, here are the color temperature measurements (and lumens) for white (100 IRE), for each of the preset modes
Lumen Output and Color Temp at 100 IRE:
Cinema 1= 579 @ 6451K
Cinema 2= 787 @ 6529K
Reference= 785 @ 6513K
Photo= 801 @ 7548K
Bright= 1132 @ 9021K
Graphics= 1127 @ 8987K
User= 785 @ 6499K
As you can see, the Cinema modes, Reference and User all have starting color temperatures near the 6500K ideal.
The other three modes, are cooler, with Bright and Graphics "way cool" around 9000K. (If green is in balance even 9K can be watchable, but reds are way down, and therefore still not good color.
Mike also came up with another way of looking at the data. Here he measured the Bright mode, but for each of the different available color temps including what they call D93 (9300K). You can see that the native lamp temp is very cool, and as you lower the color temp, to achieve colors in the proper 6500K range, lumens drop off.
Optoma HD8600 Basic Settings
In addition to calibrating Red Green and Blue for a correct grayscale balance (6500K), there are a number of other settings that come into play. Typically Contrast and Brightness (white balance and black balance), need to be done first. Color saturation and gamma also need adjustment.
Settings for measurements (default values are in parenthesis):
| Cinema1 | Cinema2 | Reference | Photo | Bright | Graphics | User | |
Contrast (-9)= |
–1 |
–1 |
–2 |
–1 |
-1 |
-2 |
-2 |
Brightness= |
(1) 2 |
(1) 2 |
(1) 4 |
(2) 3 |
(-1) 1 |
(1) 4 |
(1) 3 |
Color= |
(0) |
(0) |
(0) |
(2) |
(5) |
(0) |
(0) |
Tint= |
(1) |
(1) |
0 |
0 |
0 |
0 |
0 |
Color Temp= |
(D65) |
(D65) |
(D65) |
(D75) |
(D93) |
(D93) |
(D65) |
Dynamic Black= |
(Cinema2) |
(Cinema1) |
(Off) |
(C1) |
(C1) |
(C1) |
(Off) |
Iris= |
3 |
6 |
5 |
5 |
9 |
9 |
5 |
Gamma= |
(Film) |
(Film) |
(Std.) |
(Std.) |
(Video) |
(Graphics) |
(Std.) |
Color Gamut= |
(Native) |
(Native) |
(HDTV) |
(HDTV) |
(Native) |
(Native) |
(HDTV) |
Lamp mode set on Bright for all
All other settings at default (untouched)
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
Color Temp over IRE Range (Post calibration):
Calibrated color temps, 20 – 100 IRE: User Mode
20 IRE = 6424K
30 IRE = 6538K
40 IRE = 6528K
50 IRE = 6573K
60 IRE = 6566K
70 IRE = 6498K
80 IRE = 6549K
90 IRE = 6555K
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
Calibration settings:
User 1 Bright (Quick Cal)
Gain R = 2 R= -1
G = 0 G= 0 B = 3 B= -5
Bias R = 0 R= -10 G = 0 G= 0 B = 4 B= 0
Color Saturation: -4 0 Tint: 1 0
Lumens at 100 IRE: 696 @ 6529K 1166 @ 7040K