Epson PowerLite Home Cinema 705HD

Color Temperature (5.62)

Our first color test looks at the consistency of the color temperature of whites as their intensity decreases. A perfect projector would keep the same color temperature as the intensity increased, but the 705HD was not perfect: we saw a number of distinct shifts in the color temperature, especially at the lower intensities. What this means is that some greys on the screen may have a slight orange look to them.

Color Temperature

RGB Curves (6.66)

In this test, we analyze the color response curve for the red, green and blue primary colors. On a perfect display, this curve would be completely smooth, meaning that the projector can accurately reproduce subtle color changes that are in the original image. The 705HD didn’t have a very smooth response: all of the curves have lots of stair-steps, which are where the projector didn’t accurately reproduce a subtle change in the color on the screen. Below the graph, you can see color gradients, with the top one being the ideal gradient, and the bottom being what the 705HD produced. Here, you can see what the sudden jumps on the graph mean: bands in the gradient that are not present in the original.

RGB Curves

Red Response Comparisons
Ideal Response
Epson Home Cinema 705HD
ViewSonic PJD6531w
Optoma HD66
Canon LV-8310

Green Response Comparisons
Ideal Response
Epson Home Cinema 705HD
ViewSonic PJD6531w
Optoma HD66
Canon LV-8310

Blue Response Comparisons
Ideal Response
Epson Home Cinema 705HD
ViewSonic PJD6531w
Optoma HD66
Canon LV-8310

Color Gamut (3.82)

We found that the 705HD didn’t quite stick to the color limits for HD broadcast colors. These limits (called the color gamut) are set in a standard called Rec.709, which defines what colors are present in an HD signal, so a perfect display would exactly match these. The 705HD did a rather lackluster job here: the red corner of the gamut is significantly off, and the other corners are somewhat shifted. What this means is that some colors (particular very deep ones) will look a little different to what the filmmaker intended.

Color Gamut

Below are the color co-ordinates of the rec.709 standard, and the measured co-ordinate that we found from this projector.

	u' (rec.709/measured)	v' (rec.709/measured)	Error
Red	0.4507 / 0.4174	0.5229 / 0.5287	0.0338
Green	0.125 / 0.1341	0.5625 / 0.5681	0.0168
Blue	0.1754 / 0.1782	0.1579 / 0.1393	0.0188
D65 (white point)	0.1978 / 0.1989	0.4683 / 0.4622	0.0021

Read Reviews of Comparison Products
ViewSonic PJD6531w	Optoma HD66	Canon LV-8310