CMV1515 vs BenQ 581s

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I think they both have about equal CR (~350:1), at least the A150X1 datasheets I've seen list this CR (but there may be new revisions that actually have bettered the CR). However, CMV1515 should have the full 24-bit color support whereas BenQ uses dithering to get 16.2M colors from 18 bits. I use BenQ (FP567s) LCD but might prefer the CMV (not available in my country).

Btw. The contrast ratio (CR) list in specs may be the maximum value measured at optimum viewing angle (see my posts and links in DIY projector part II thread).
 
Just thought I'd share some thoughts seeing these forums have given me so much in return..

I just got my CMV1515 yesterday. I paid $495AUD for it. :bawling: hassler, where did you get your $429AUD price?

Originally I had ordered a FP567S but I changed it to a CMV1515 instead after reading posts here on the forums. Now that I have the thing apart, I'm not so not sure I shouldn't have gone for the FP567S instead. Reason being that the 1515 is not so suited for the OHP kind of a setup without the flat cable extension. Its also bit more delicate to handle because of the extra connectors along the sides of the LCD.

I knew about this before hand but I figured that the faster 24bit display was more important. :xeye: I'm only really interested in it to play games on so fast response and colors is better. Movies are just a bonus.

I've photos of most of the dissassembly which I'll post up here sometime when I get around to it. This is the first time, I've ever disassembled something so delicate. Nothing like ripping apart a PC which I do regularily. Its quite easy to screw it up.

Anyway, here's what I mean..

An externally hosted image should be here but it was not working when we last tested it.


I had envisioned that I could lay the LCD flat like this. After I took the picture, I realised what a incredibly stupid idiot I was doing this. I almost had a heart attack when I noticed that all the connectors along the top of the LCD were being stretched and stressed. It only takes one to tear slighty to ruin the whole panel. I then flattened the thing out as best as I could and plugged it in and luckily it still works. whew..

Also, notice the top left brown flat cable that needs to be extended so the top board can go flat or it must be at 90 degrees or less.

I'm now going to do what Brainchild suggest and glue the panel to the metal frame.

http://diyaudio.com/forums/showthread.php?threadid=13798&perpage=15&pagenumber=3

Check out the difference in FP567S here, its seems the breeze
..
http://cfeuillet.free.fr/KolimaVP.html

Though.. on the plus side, I think its an excellent LCD desktop monitor. I spent about about an hour playing with the panel before I pulled it apart. I played HaloPC and a few videos on it and didnt notice any blurring at all, even on the most intense action scenes. Colors are clear and really nothing to complain about though I very much doubt that it has a 450:1 contrast ratio as the manufacturer claims. If fact, the instructions say only 300:1. My old Toshiba SatellitePro notebook LCD has more vibrant colours when I did a side by side comparison.

An interesting note (I'm not sure if this the same with other CMV1515s people got here) but mine was a true OEM product, i.e. there is absolutely NO BRANDING ANYWHERE on the boxes it came in or instructions or on the case itself. It's only identified as a generic "15"TFT LCD Monitor". No Polyview,CMV, etc. In fact, the only indentification I found are just the letters 1515 on the back sticker.

I'm still waiting for my OHP next week so I'll post some more info when I have it.
 
thanks hassler, i think dead pixels are pretty rare nowadays anyway. Mine had zero dead pixels. Unless you count the 2mm scratch I put on the front of the LCD while dissassembling :(

Anyway, I'd like to know about the contrast as well. Hopefully someone more knowledgeable here can enlighten us.

Maybe these will help..

The back sticker, its reflective and hard to photograph. Notice no branding.
An externally hosted image should be here but it was not working when we last tested it.


Panel model number(?) on the board above the LCD.
An externally hosted image should be here but it was not working when we last tested it.


And if someone can let me know where I could get other bit of this flat flex cable and/or extend it without actually cutting it or soldering, I would be very grateful. It goes into one of those tiny FFC sockets.
An externally hosted image should be here but it was not working when we last tested it.
 
Hi Looie,

Have you removed any polarising sheets from the screen??

I've got my monitor disassembled and can't bring myself to pry what MAY be a polarising sheet from the back of the LCD for fear of breaking the LCD.

I'll be playing around with LCD and fresnel placement later this week to see if I can maximise the CR.
 
Am I missing something here? I thought that the nature of LCD requires polarising sheets for it to work properly?? I didnt even know you could pull it off.

Anyway, I dont plan on doing it. I dont I think I could stand the trauma of destroying a brand new LCD. I can live with a dimmer picture, otherwise. Please, feel free to try it and let me know how it goes.. :)

I'm expecting my OHP in a few days so I work on it a bit more then. I'm planning some sort of split fresnel lens LCD sandwich OHP hybrid monster.

brainchild, did you pull the sheet off? you got such excellent results in your pics.
 
god no

LOOie said:


brainchild, did you pull the sheet off? you got such excellent results in your pics.

If you pull the actual polarizers off you will have trashed your lcd! They are the dark films that are permanently adhered to each side of the lcd. If you're talking about a CMV1515 here, there is absolutely NOTHING that needs to be 'peeled' off of anything.
 
that sheet isn't actually a polarising sheet, it is a refractive layer, that splits the light into 3 directoins, stright ahead and to + and - 45 degrees, so that the backlight makes the lcd visible to people standing next to you, although i may well be talking about different designs that the cmv
 
dude..

VvvvvV said:
that sheet isn't actually a polarising sheet, it is a refractive layer, that splits the light into 3 directoins, stright ahead and to + and - 45 degrees, so that the backlight makes the lcd visible to people standing next to you, although i may well be talking about different designs that the cmv


I don't know wtf you're talking about but every TFT LCD that I know of has permanent polarizers, one on each side of the LCD panel. You could in theory peel them off but that would be very stupid..:)
 
I don't know wtf you're talking about but every TFT LCD that I know of has permanent polarizers, one on each side of the LCD panel. You could in theory peel them off but that would be very stupid..

I'm glad that nothing has to be removed.

In other threads I have seen it mentioned that some polarizing sheets were removed from other LCD's.
 
i was confused about this for some time also because i have a laptop LCD that has not only the fixed polaroids that you tell me about on both sides but also two cling film like transparent layers that split the light in a ' Y ' shape from as it comes in the backlighting. the result is two images of the backlight projected on the roof. it is cool plasic, you look through it straight and you can see things beside you. quite shagadelic.
 
errrr

In other threads I have seen it mentioned that some polarizing sheets were removed from other LCD's.

Ummm, often there are diffusers or collimators, usually as thin semi transparent sheets that you would want to remove, but I haven't heard of them being glued to the lcd, altough there may be cases in which they are. If someone removed the polarizers I would like to know how they could get the lcd to work after that, they are necessary for the lcd to function.

"Polarizing filters being a set of very fine parallel lines act to block all light waves apart from those parallel to the lines of the polarizing filter. If you use another polarizing filter at 90 degrees to the first filter you would block all light getting through. So if you now put the twisted liquid crystals between these two polarizing filters the light passing through the first polarizing filter is twisted the 90 degrees necessary to allow it to pass through the second polarizing filter. Apply a voltage to the liquid crystals to align them vertically and the untwisted the light is now blocked by the second polarizing filter. No light gets through."
 

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