Film-Tech Forum ARCHIVE: aperture kits for nec1200c

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Posted by Drew King (Member # 6349) on 07-06-2011, 02:54 PM:

I'm getting flicker from lamp at 58amps, but reading 5FL on screen and we need to hit 4.5 without any flickering. This is reading through the real D system and glasses. We experience no flicker with lamp at 79amps but reading 9FL on screen.

Looking in to aperture plate kits and I dont see anything for the nec1200c.

Any suggestions?

Posted by Mark Gulbrandsen (Member # 72) on 07-06-2011, 03:23 PM:

Actually all the new NEC projectors include an extra aperature plate in the accessories box. Why there is even an NC-1200 is beyond me because it is way too limiting at strictly being a 2kw capacity projector except for 2-D on a 20 foot wide screen.. The smallest NEC I will ever spec in is the NC-2000. Now I am doing 3-D at a couple of sites with 35 foot wide screens and Real-D XL with 2kw Ushio lamps in NC 2000's and have plenty of headroom on the lamp as it ages. The Ushio is also a 2400 hour lamp. Osram is releasing an equivelent 2kw that will sell for less than half the price of the Ushio and has the same warranty hours. As to your flicker, brightness and so on I need to know what lamp you're running and what screen surface and so on.... Are you running an XL or Z screen?
As to aperature plates... The one in the kit is to increase contrast and it will reduce your light output by about 5%. The aperature that is already in the projector can not be increased over what the input size is on the integrator rod and you'll probably find it as such.

Posted by Steve Guttag (Member # 268) on 07-06-2011, 04:18 PM:

Try targeting 7.7fL in the center, if you have a flat screen and see if you have flicker problems. If you set your light that high, you will find that your "average" light will be about 4.8fL. You won't get complaints about it being too dark or too bright either.

-Steve

Posted by Daniel Morez (Member # 5787) on 07-06-2011, 04:46 PM:

I unpacked a new NC1200C a few months ago and noticed it didnt include an option ap-plate. Ill have to look for the pack list and see if it was supposed to come with one. I do recall seeing them included with new NC800s years ago.

To the original post, can you play with the lamp focus, aka lamp Z axis adjustment? In the post environment (shorter throws and smaller screens) we often counter excessive luminance defocusing the lamp. Probably not ideal for everyone but its a handy adjustment if you have the training, time and resources to play with.

Posted by Drew King (Member # 6349) on 07-14-2011, 03:30 PM:

interestingly the lamp does not flicker at a lower amperage like 53.3

can someone explain how the arc stabilizes. I was thinking in a world where I believed 58 was just not enough power, but now I see that lower amperage actually stabilizes the arc and I do not have to go higher.

thanks

Posted by Mark Gulbrandsen (Member # 72) on 07-14-2011, 05:40 PM:

Drew... I tried filming how to enter lamp settings but my phone does not focus that close. You can't actually read anything on the chart. As for aperatures... I have a bunch that I won'tbe using and could send you one. The NC1200 is identical in all aspect to the NC2000 as far as I know except the rectifier and of course the firmware. The aperature will also increase the stock contrast ratio a bit as well...
On the lamp settings... be sure you save them on the lamp page as "flat" or "Scope" or what ever you need to call them and so on then on the title page click on advanced and select the lamp setting BE SURE TO HIT THE UPDATE BUTTON after making changes!!! If you don't update changes you make in the macro you will loose your settings.

Mark

Posted by Carsten Kurz (Member # 5396) on 07-18-2011, 05:27 PM:

Why would one waste money and light just to reach a ficitious 4.5fL? What's so bad about delivering more than the bare minimum fpr 3D? I would do personal testing on ghosting at higher brightness levels and choose the bulb amperage according to these tests. I know RealD is more sensitive to ghosting at higher levels, but screen, seating and other aspects come into play there, too.

- Carsten

Posted by Steve Guttag (Member # 268) on 07-18-2011, 05:41 PM:

4.5 is NOT the minimum....3.5fL is...it may not sound like a lot but it is nearly 25% less/more light...depending on how you look at it.

Why one should target the desired light has to due with color saturation as well as black levels.

The movies are timed for 4.5fL...going substantially above that will indeed get your whites whiter but your blacks will become grayer because it was presumed that the light level was low. Furthermore, the colors will over saturate.

-Steve