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Discussion Starter · #1 ·
Hi all,


I just bought a Davis DL450 (new) to connect to my HTPC. There seems to be a lot of information on here about certain tweaks but a lot of them are above me. If anyone can offer me some advice on any tweaks that I should do to get the most out of it please let me know.


Thanks,

Chris.
 

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1.) Color wheel mod; installing rubber grommetts on both sides of

the screws reduces noise significantly.

2.) Use of an EVC to VGA cable without a buffer box as with the

Davis cable, improves picture (brightens, with a clearer picture)

3.) Have it Thumperized. Or if your brave, at the very least

darken the DMD chamber.

4.) Put a hood over the PJ lens inside. This further improves black

level and further reduces light spillage. NOTE: This will limit

zoom functionality depending on the dimensions of the hood

and how far the hood extends out from the lens. I suggest

setting your zoom properly first, and then install the hood.

You'll need to experiment to get proper results, the idea

behind the hood is to limit the light entering the lens to just

the DMD chip as much as possible. Another way to look at

it is, the hood restricts what the lens sees inside the chamber.

Make sure the hood is black, this again can only help in further

reducing light reflections inside.

5.) There are other areas that require blockage of light spill. If

you wont be using a hush box, you can block some of the

light spill exitting the vents, at the color wheel area inside the

PJ.

6.) Don't know the specifics, but something about software and

gamma.

7.) Do a search on this forum for details. Aside from getting

specifics on the tweaks enumerated here, this might also turn

up some hidden gems that have not been discussed or

given much attention! You never know what else you might

find. Cheers!


Gerald
 

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Quote:
Originally posted by cutman0122
6.) Don't know the specifics, but something about software and

gamma.
Yes, I've put together something for changing the gamma curves of Davis projectors. This is very useful for DLX650 projectors, which have a screwed up color table (too green).


I'm thinking about working with Thumper, so that he mods the projector (which may change the grayscale tracking somewhat) and then he uses my stuff to put on a new gamma curve. Of course, you really need a light sensor to do that - can you say ColorFacts? :)


I'd *highly* recommed the Thumper mods, with or without any gamma table changes.


Mike
 

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I have a question regarding this projector, also. I bought a Thumperized projector from a fellow forum member and am noticing something that I can't get rid of.


When viewing anything against a dark background, I have vertical light "streaks". For instance, in the beginning of The Fifth Element, when it is showing text on a black background, there is very noticable "streaking" both above and below the text. I have calibrated the projector using Avia, so I know that the contrast and brightness are set correctly.


What could the problem be? Here is my setup:
  • HTPC using WinDVD and ATI Radeon 64MB DDR VIVO video card
  • 80"w x 46"h DIY Screen (made from Blackout Material from Joann's)
  • Thumperized Davis DL450 clone (Viewsonic)
  • Full light control (pitch black when lights are off)
  • Projector is ceiling mounted, with dark ceiling
  • Using EVC to VGA convertor instead of supplied box
  • VGA cable length >20' (actually two VGA cables - one 10' and one 6')

I have my Playstation hooked directly into the S-Video of the projector and don't notice it. Could it be in the VGA cables? The 10' cable is a male-male and the 6' is a female-male. I am not using a gender changer. I have yet to try building my own cable using Cat5.


Any ideas?
 

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When you say "streaking", could you mean ghosting?


This is typically an artifact of using a suboptimal cable setup (ie multiple VGA cables end-to-end).
 

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I would venture a guess that ghosting is what I am seeing. It's as though you took the smudge tool inside Photoshop and smudged the color both above and below the text. The colors are outstanding.


Would it be worth my effort to make up a Cat5 Shielded VGA cable? It doesn't seem to be difficult to do and the cost factor is well within the WAF.


Thanks for the quick reply.
 

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Well, someone actually made one of those Cat5/VGA cables for me, (and am also using an EVC-VGA converter) and I actually see lots of ghosting! It's not exactly as you describe it, as it's to the right of the image, and it's not a smudge, it's like an echo of the character.


FYI, here's a link for an EVC-VGA cable, $73 for 25'. Haven't tried it yet, but I might.


Also, have you tried going through the buffer box instead of the EVC-VGA converter? I wonder how that would affect your image.


Mike
 

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Discussion Starter · #8 ·
Should have also added, I am in Sydney, Australia. If anybody in Australia has any experience with the unit please contact me. Sending the unit to the US for whatever reason is pretty much out of the question due to the monstrous costs involved.


Chris.
 

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Well, I have yet to come across some Cat5 Shielded cable to use. One other thing to note related to my problem is that this smearing even occurs when I pull up the built-in menus. The menus have a definite "shadow" below them. I wouldn't think that this would be caused by the VGA cable, as the menus are built into the projectors memory.


I'm at somewhat of a loss as to what I need to do next. The picture quality seems to be quite nice, regardless of my problems. Granted, if I fix the problem, chances are pretty great that the overall picture quality will improve also.


Anyone else have any ideas?
 

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I just thought to add that the VGA cables that I have do NOT have the ferrite cores at both ends of the cable. They were purchased at a computer parts store, but I have a feeling that the quality could be under question.


I may try and get a 15'-20' VGA cable with the ferrite ends to see if that makes a difference, since Cat5 Shielded seems to be close to nonexistant around here.
 
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