Projector Lens sound?

CAvolleyballguy

Hey all,

Noticed my projector makes a noise that sounds like a lens focusing. Like on my digital slr camera when it auto focuses you can hear it moving.

well when I fast forward video it really makes a lot of "movement" sound... sometimes if the scenes change brightness like changing camera angles I can hear the projector "re focusing"

1. is this normal
2. is fast forwading video and making these really rapid changes bad for the projector
3. what is actually causing this... what is the mechanism in the projector doing this, since the focus is manually set?

ps. i have the sanyo z2000

kuntasensei

You're not hearing re-focusing. What you're hearing is the auto-iris mechanism. The Auto-iris function attempts to extend contrast by lowering light output for dark scenes and opening the iris for bright scenes. Essentially, there's a gate in the light path that opens and closes to limit light output... but with fast changes, that gate makes noise. Fast-forwarding can make the most noise... but shouldn't particularly be bad for the projector because the Z2000's iris is a fairly simple design. You can set the auto-iris to SLOW to prevent the noise from fast changes, but it makes the scene changes slowly fade in and out of brightness, which was too distracting to me.

Personally, I find iris trickery like that gimmicky, so I set my iris to FIXED and tweak around the native contrast of the Z2000's panels. I'm running my Z2000 with custom settings based on Brilliant Cinema. If you have a copy of Avia or DVE, go here to read my quick guide to calibrating your Z2000. This should not only get you a great picture, it should get grayscale closer to 6500k than the out of the box settings. I've been pretty happy with these settings even after my bulb hit 200 hours, so I think you'll be pleased. Keep in mind that contrast and brightness will vary by screen type, etc. so don't just plug in my numbers. Follow the directions to find the best settings for your setup.

CAvolleyballguy

I knew I wasnt hearing "re-focusing" was just using that as an example, but thank you very much for the detailed answer. I will do as you suggest, and I need to get that dvd. I may try the fixed iris setting, but mostly I was just concerned that I wasnt damaging the projector or lens in some way. when the movies playing, i have it plenty loud enough that I dont hear either the iris mech or the fan.

thanks again..

kuntasensei

Well, until you get a calibration disc, try just plugging in the numbers in steps 1-4 of my method and see how you like it (though I actually think I'm using +4 for contrast now). The only part you won't be able to do without a calibration disc is the color correction (steps 5-12).