Film-Tech Forum ARCHIVE: How do you determine when it is time to change a digital projector filter?

This is topic How do you determine when it is time to change a digital projector filter? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Eric Robinson (Member # 2966) on 04-05-2011, 01:27 PM:

I know there are guidelines in the manuals of digital projection equipment which provide a filter changing period; however, after perusing the forums here it seems evident that different locations require different intervals for filter changes. So to have the most effective filter changing process it would seem that inspecting the filters would be the best indicator of the filter changing frequency. What I'm wondering though specifically is what criteria indicates that a filter is due for change? Is there some way to quantify it other than common sense?

Posted by Paul Mayer (Member # 355) on 04-05-2011, 01:29 PM:

On the Sony 320, the interval is set at 2500 hours. You'll get a yellow tail light indication when it is time to change the filters.

Posted by Steve Guttag (Member # 268) on 04-05-2011, 03:51 PM:

Most of the others use an "at every lamp change" as the criteria however the booth and how long the lamp/fans are operating greatly weigh into this.

I just changed out a lamp in an NEC at 1500 hours and the filters were definitely ready for a change. In fact, I've yet to see a machine with 1500 hours + of projection time where the filters didn't look bad enough to warrant cleaning/changing.

-Steve

Posted by Mark Gulbrandsen (Member # 72) on 04-05-2011, 04:58 PM:

The lamphouse air filters on the NEC's are HEPA type filters and are supposed to be changed out with every lamp change, however that is NOT necessarily the case with all lamps. The electronics filters which are seperate are supposed to be checked at 2K hours and changed IF NEEDED. Of course the lamp house has far more volume of air moving through it than the electronics section does so the filters will clog much quicker. What I have found is that the filters will last the life of a longer life... say 1500 (warranty) hour digital lamp so if you are running a high output lamp that goes ~650 (warranty) hours you should get 2 lamp changes from a single pair of lamphouse filters. On the NEC there is a nice feature where if the lamphouse over heats due to insufficient air flow the lamp will simply shut off and you'll get an error on the side panel LCD display so you know... Strong is now selling the filters seperately as one will need more lamphouse filters than electronics filters. The fact that NEC filters the lamphouse air I feel is a big advantage as the lamphouse parts and rectifier will always stay clean as new... neither of the other manufacturers do it.

Posted by Eric Robinson (Member # 2966) on 04-06-2011, 10:34 AM:

Thanks for the contributions. Good info so far, [thumbsup]