[samalmoe]

so my sharp z9000 has a gamma correction disc with it. can anyone tell me if its worth dinking around with it. the 4 built in gamma settings seem to cover a pretty wide range already. I am projecting onto a vutec graydove screen and the detail in the darks looks pretty good already. can i expect a big improvement gammaizing?

 

[ghibliss]

Having measured the Sharp 9000 projector recently you will only be able to improve the performance at the extreme ends of trhe scale. The projector tracks very well (within 300 degrees Kelvin) between 10-90 ire. The only area for improvement lies between 0-10 and 90-100 ire where the color temperature is approximately 900 degrees to Blue. The software should allow for the correction by increasing the Red. This is done in the custom Gamma selection and the software.

 

[noah katz]

Cliff,


Did you measure contrast on the 9000? What was it?


Thanks

 

[samalmoe]

cliff..thanks for the reply. can you also tell me if that range of adjustment on the gamma would show a very noticible improvement in appearance or a neglible one. is it worth it for a computerbonehead to fuss with it? thanks

 

[ghibliss]

I measured a contrast ratio of the Sharp 9000 to be just under 800:1 with a lamp that had about 200 hours of use on it. This was after we had calibrated the projector to track very well (within 300 degrees Kelvin) through out most of its range. Wm Phelps has measured the same model at close to 900:1 out of the box. I believe that there is a significant drop off in light output from a new lamp on any projector in the first 50 hours of use and this accounts for a great deal of the discrepancy in our findings.


I have not tried the gamma adjustment software in the Sharp projector but beleive that you should be able to correct for virtually all of the Blue error found at the top and bottom end of the scale with a little work and proper instrumentation to guide you (spectroradiometer) to the target coordinates of D65).


The picture quality of this projector is very good out of the box. Aside from the gamma issue outlined above the only shortcoming I find is that the Green of this projector is not accurate. This is common to most all single chip DLP projectors and done to increase trhe light output but at the expense of color fidelity/accuracy.


Here is the data which I collected on the Sharp 9000 recently:




Red Green Blue White

x 0.6615 0.3040 0.1502 0.2963

y 0.3250 0.6480 0.0480 0.3441



Cliff