Product Review
 

Optoma HD73 Single-Panel 16:9 720p DLP Digital Projector

Part III

May, 2007

Sandy Bird

 

Calibration and Measurements

Out of the box, I can't say this projector came very well calibrated. I understand why Optoma does this (basically, to get even close to the specs, they need to increase the color temperature and a few other things), but I worry that most average users will never adjust them, leaving them with a picture that is "just ok" instead of the exceptional image this unit is capable of.

The HD73 also uses a 7-segment color wheel with two RGB sections and a white segment. Darin already explained how this works in the HD72 review, so I won't spend too much time on this. Basically, the white segment is used to gain lumens when light control in the room is an issue.  However, it changes the gamma curve in doing so. Depending on the calibration settings, the white segment may or may not be used, which is a great compromise for a projector to be used by the average individual in the average room.

If you have proper light control in your theater (or at night), you can use the Cinema mode of the HD73 and calibrate it such that the white segment will not be used to obtain the desired 2.5 gamma. If you do need a brighter image, say for having the guys over to watch sports on the weekend and need the room lights up a bit so you can find the beer and chips, you can change to a slightly different setting and gain the added lumens so you can keep a small light on in the room.

Color Temperature Measurements

We start the measurements with the HD73 in bright mode un-calibrated, giving a color temperature of 9276. That is pretty high and the image looks very blue (which is not optimal for watching movies).

Even after changing to the cinema mode the color temperature only fell to just over 8K which is still very blue looking.

With a quick calibration using just the user adjustable settings we were able to get the unit to almost a perfect 6500K.

The Gamma of the projector is also in poor shape using the standard bright mode. If you are in a room with poor light control (and you weren't going to calibrate the rest of the projector) this might not be a bad thing but it not how the projector should be setup even with just reasonable light control.

Cinema mode on the other hand tracks very closely to the optimal gamma of 2.5. So if you are going to calibrate the projector to have decent brightness and contrast in your room, but aren't going to mess with the color settings this is probably the best mode.

After color calibration the gamma remained the optimal 2.5.

Go to Part IV.

© Copyright 2007 Secrets of Home Theater & High Fidelity

Go to Table of Contents for this Issue.

Go to Home Page.

 

About Secrets

Register

Terms and Conditions of Use

 

PAGEFEEDBACK
Our Vault pages may have some display quirks. Let us know if we need to take a look at this page or fix a bug.
SUBMIT FEEDBACK
Connect with us
  • Instagram
  • Google+
  • YouTube
  • LinkedIn
  • Pinterest
Secrets "Cave"
Facebook
Close