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NEC MT1075 Anybody using?

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Derek Harkins:
We are looking at a NEC MT1075 for our church to run Song Show Plus is anyone using this model?  What are your thoughts?

Brian Kent Tennyson:
I've put in a quite a few NEC projectors and have always been happy with the results. Service isn't as good as Christie Digital but still a fine company.

Bob Payne:
We use an MT1075 projector for our main (FOH) projector and an MT1065 for our confidence screen (ROH). Both projectors are driven using SongShow Plus on a 3.0GHz custom-built desktop computer and sourced via the RGBHV inputs at the end of 75' and 30' (respective) runs over custom RG-6 Quad-shielded 75 ohm cabling.  The MT1075 projects onto a 6'x8' screen and the MT1065 lights up a 3.5'x5' screen.

So far the units have been rock-solid and provide crystal-clear, crisp images in this mode.  I've never had a problem with either projector and would gladly recommend them to anybody considering them for a church venue.

I'm not quite as pleased with the quality of the image presented while using the composite-video inputs (such as from a VCR or DVD player) but this may be a more a consequence of the lower resolution available from the NTSC standard than anything else.  Throw up a standard NTSC image onto a 6'x8' screen and you're bound to notice some problems.  Overall, however, a perfectly usable image.

My church seems quite satisfied with the pair.

Bob Payne



Derek Harkins:
Bob I apologize it took so long for me to get back.  It sound like you are doing the same thing I am attempting to do.  I will be running SSP on a custom build dual monitor PC as well to drive the MT1075 on a 5.5'x4.1' screen in a extremely bright environment.  I have a DVD player in the PC to use or do you think it is best that I run a 100' BNC cable for a direct feed from a separate DVD player?  My other thought was should I use a switcher scaler?  What do you do to play DVD 's?  If you like you can email me at derekharkins@excite.com or post the reply.  Thanks

Bob Payne:
Derek,

You mentioned that you are operating in an "extremely bright environment". Believe me, environments this bright can (and do) cause more problems than any other issue that you may encounter in your church.

A lot of people who are installing projection systems in churches do not realize how important contrast ratios are when it comes to getting acceptable images on their projection screens.  I've heard of horror stories of churches spending thousands of dollars to install a projection system just to find out that their ambient lighting situation is such that the screen appears all washed out (and therefore virtually unusable).  Getting control of your ambient lighting is CRITICAL to getting acceptable images.  In essence, the less light falling on your screen from ambient lighting the better.  Movie theaters understand very well this problem - they keep it dark in there for a very good reason!  

I mentioned that our MT1075 is used for FOH viewing on a 6'x8' screen (a motorized screen placed in front of the baptistry with a 1.1 gain).  Before we installed our system we played around with a portable white screen and overhead projector at the location where we intended to put the main screen and decided that, based on actual experimentation, we could do with no less than a 3:1 contrast ratio in order to project scripture and song lyrics in a manner minimally acceptable to the people in the sanctuary.  On Sunday mornings with the sunlight streaming through the windows the image is JUST BARELY acceptable, with a measured contrast ratio of about 3.1:1.  It's how we actually went about sizing the projector, by measuring the amount of light actually falling on the screen (in lumens) and then making sure that the projector could triple that in the areas that needed to be illuminated for text purposes.

You can do all of this yourself with a normal hand photoelectric exposure meter used by photographers to measure incident light levels on a subject.  These devices will tell you how much light is falling on a particular point (usually expressed in EV units) which is directly convertable to lumens (via a formula) per square foot of screen surface area.  Find somebody in your church who as a hand-held exposure meter that reports exposures in EV units and borrow it.  If you then know the total number of lumens falling on the entire screen, as well as your minimum required contrast ratio, then you can easily calculate the number of lumens that your projector will need to put out in order to satisfy your minimum contrast requirements.

For instance, in our worst-case scenario we had a total of about 28 lumens per square foot falling on our 6'x8' screen from ambient sources (mostly sunlight streaming through the windows during Sunday service on a cloudless day.)  This meant that there was rougly 28*6*8 (or about 1344 lumens) of ambient light falling on our screen.  Since we wanted a minimum of a 3:1 contrast ratio (worst case) this meant that we needed about 1344*3 (or about 4032) lumens to achieve our contrast goals.  Since the MT1075 is rated to put out 4200 (or 4400 lumens, depending upon what you read), it would barely meet our requirements.

Now a 3:1 contrast ratio is, perhaps, acceptable, but it's not great.  The image quality is usable, but not very good.  Since we don't have a lot of money to purchase a 10,000 lumen projector, we are tackling the ambient lighting problem via other avenues.  For one thing, we're in the process of adding reflective films to the windows which will cut down the ambient sunlight streaming into the sanctuary by 2 EV units (or from 28 lumens/ft^2 to about 7 lumens/ft^2, which should increase our contrast ratio (for sunlight) to somewhere around 12.5:1, a much, much better situation.  In addition, we are redirecting some of our stage lighting away from the the screen area by replacing or redirecting our stage lighting.  Some churches help the problem out with curtains over the windows.  Whatever it takes, try to decrease amount of ambient light hitting that screen!

With respect to the DVD issue, I tried playing DVD's on the computer and re-directing them through SongShow Plus, but the image quality was nowhere near as good as a direct feed from the DVD or VCR player through a separate RG-6 quad shielded cable straight to the projector.  I think that all of the image conversion processing going on inside the computer degrades the NTSC signal considerably, so I went ahead and mounted a DVD & VCR player in my equipment rack, routed the composite video signal and analog L/R channel sound through a Kramer 4x4 crosspoint vertical interval switcher, and then off to the projectors.  The composite video signal ends up at the projectors and the left/right audio ends up at one of my stereo inputs on my 32x8 channel mixer.  This setup seems to work best - all have to do to play DVD/VCR is to set the source via the 4x4 crosspoint switch and then select "Video" mode on the projector source select via the MT1075 remote control (which is hard-wired to the projector).  

I've achieved the best DVD/VCR image quality using this method.

Hope all this helps.

Bob Payne

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