HS50 pixels...

N

Neelix

Guest
I'll start off by saying that the the image is fantastic and I am very happy with it but would like to understand the technology better and convince myself that there is nothing wrong with my HS50. I have noticed that the pixels don't appear to overlap i.e. there is a green pixel and a pink/red pixel as seen below...

HS50_pixels.jpg


Is this normal or does this mean the LCD panels (RGB) are not aligned properly? I have noticed a slight disparity when looking at white writing e.g. film credits, the top part of a letter has a green hue and the bottom part a purple hue. This is only visible up close, beyond a couple of feet it can't be seen and at viewing distance the picture is fantastic.

I am also in the process of choosing a screen as it is projecting onto a freshly painted porcelain white wall. I tried an old 4:3 screen which needed to be up close i.e. only a 40" image and was shocked to see a bit of vertical banding which was not apparent on the wall at 70"+. It would appear for a small image up close VB is apparent in some scenes, it's not that bad but noticeable to me, but it does not show for a bigger image which is great! Anyway, what screen would peeps recommend for the HS50? I am guessing that a relatively neutral gain would be good at least no more than 1.2 :confused:
 
Panel alignment is rarely perfect on any LCD projector. A perfect specimen is a rare beast. Your unit is not faulty, in fact if it overlaps by less than 1 pixel you have a good'un.
Mine overlaps by about 1.5 pixels, but the picture quality is still sensational.
This overlap absolutely cannot be seen except when putting your nose up against the screen.

I think some units can be as much as 3 or 4 pixels out, at which point you might feel it warrants a swap. But even then, I doubt you'd notice at normal viewing distances.

As for the banding.... no banding on mine. Sony PJ's use a 12 bit panel driver (others use 10 bit) whichis sufficient to erradicate it.
Do you see it on all sources??
 
Thanks Jules, it's good to know it is at least normal. Looking at my pic I am guessing mine overlaps by about a 2/3s... should the pixels overlap or should each RGB pixel be separate as with CRT? I must say I cannot see anything at normal distance and the image is fantastic. Regarding the VB, I hadn't noticed at all until I projected a 40" image onto an old white screen. It became instantly viewable especially with blue sky but as soon as I increased the image size it vanished and it simply doesn't exist when projected onto my wall at 60"+ I only tried this old screen as I am currently looking to but an electric screen and wanted to see the difference that a white screen makes compared to the wall. What screen do you use?
 
Forgive me for butting in (as its a current gripe of mine)
But whilst we're on the (happy with the iffy quality) panel alighhnment issue.

You need red, green and blue pixels to overlap each other to produce white (or other colours come to that) so if they don't overlap, what are you going to get?
 
Well I was thinking along the same lines but if you look at a CRT tv or monitor it is very apparent that you have a Red, Green and Blue pixel side by side therefore they cannot physically overlap. Therefore it must be the eye that blends these colours together based on the illuminance etc in order to achieve the full spectrum of colours. However it works, I cannot fault the HS50 as the whites, colours, blacks etc are fantastic and it is only my inquisitive mind that thought to ask why they are arranged as shown in the above pic.
 
Neelix said:
Well I was thinking along the same lines but if you look at a CRT tv or monitor it is very apparent that you have a Red, Green and Blue pixel side by side therefore they cannot physically overlap. Therefore it must be the eye that blends these colours together based on the illuminance etc in order to achieve the full spectrum of colours. However it works, I cannot fault the HS50 as the whites, colours, blacks etc are fantastic and it is only my inquisitive mind that thought to ask why they are arranged as shown in the above pic.


Hmmmmm, perhaps that's a size issue!
We are talking massive pixels against the size of a monitor's pixels.

obviously the closer you are, the bigger the pixels and the easier it is to see the individual colours.

One could ever crazily argue that panel misalignment makes screen door appear better as it makes the black area between the dots appear smaller !

If the red, green and blue did not overlap I don't know how far you would have to be for your eye to blur them into 1 dot.
Obviously the higher the res the better as well.
 
I'm getting really bothered by discussions on LCD pixel misalignment (and I don't even own an LCD projector yet!). If you have misalignment of all three colours by 1 pixel (in both X and Y dimensions) then you will nearly halve your H & V resolution on white/black transitions. OK, a pure red colour transition to black will be at full resolution (G and B misaligned pixels are switched off and irrelevant), but stuff in the real world will be compromised to some degree.
Having thought about getting a high-ish res LCD machine, if they can't align its pixels I might as well buy a low-res PJ and save some money - it must be easier to get good alignment in 3 low-res panels. But if the low-res PJ is also out by a pixel then you have the problem across the board - a 1280 PJs only going to look like a display of ~640, and a 800 PJ is only going to show ~400. Or is there a point I'm missing here?
I guess this is one issue that does not apply to single DMD DLPs, but ironically could apply to the high-end jobs with 3 DMDs (unless that sort of silly money actually pays for near-perfect alignment!)
 
I don't understand how the pixel alignment works but I honestly cannot fault the picture from my HS50. Using a PC via VGA with TheaterTek the results are absolutely stunning, far better than my DVD player with component. The WMV HD samples take this to another level and I have watched Star Trek Enterprise and Star Wars II in HD and it is truly stunning! There is no doubt that however the pixels are aligned the image is superb with the high resolution :)
 
I wouldnt accept anything but perfect to be honest. Ive had two Sony 10HTs and they were both perfectly aligned. The 10HT is higher res but the panels are bigger so maybe that makes them easier to align.
 
So are you saying you should see just the one pixel not two (or three) as shown in my pic?
 
One pixel not three? Well, in theory, yes, if the full stated resolution of the PJ is to be realised. It's not like a shadow-mask CRT, where the colours have to be placed side by site. Wth a PJ, all three colours are (or should be!) projected into the same pixel space, if the panel alignment is perfect.
Having said that, there is of course the chromatic aberration of the lens, which will throw these three colours onto different parts of the screen. The effect is that the different colours will throw *slightly* different sizes if images, depending on how wll the CA has been corrected in the lens. But this is easy to check - if this is the only problem, you should have perfect alignment in the centre of the image, and it would be progressively worse towards the edges. And the problen would be symmetrical, so if, say the reds are to the left of the blues at one side, they should be to the right of the blues on the other side. Any consistent left or right displacement across the whole image has to be down to panel alignment.
Happy to be contradicted, but that's my understanding.
 
3 chip DLPs like the Sim2 HT500+ have overlapping pixels, and the spec says that the alignment should be less than half a pixel. If the HT500 had panel alignment like your seeing, it would be classed as defective. To be fair, there's a huge price difference, but I would still expect to see white where the pixels line up.

Are other LCDs like the HS50?

Gary.
 
The http://www.cine4home.de/ comparison does show close-up pixel pics of the main LCDs. According to this comparative review, the HS50 did particularly poorly in this aspect.
...PJ
 
Ignoring the technical aspects of manufactures tolerance levels on panel alignment. I guess what matters is whether the user sees the lack of alignment in normal viewing. If the answer is no the so what if the dots are either side of each other. In your case however you noticed it under normal viewing conditions so it shouldnt be accepted.

As a matter of interest are you using keystone\image shift on the HS50 and if so by how much? Does centering the proj to the screen help?
 
Hmmm, must admit to being a little confused about what to do. Looking at the pics on the cine4home.de website it would seem my pixels are way off!! :eek: Yet I can't say that the picture is anything less than fantastic but could it be better?! :confused: I am not using any keystone correction as the lens shift is very forgiving. I have noticed that pixels on the left side of the projected image appear to be much tighter to the point where they appear as a single pixel. It is only on the middle to right part that you can clearly see the two pixels as shown in my pic. I am minded to send it back as it will have to have a firmware upgrade at some point to correct the HDMI cropping. Can the LCD panels be aligned by myself, is there a mechanism inside which can adjust? It would be very useful if some other owners could take a look at their pixels and a photo would be even better to compare.
 
Neelix said:
Hmmm, must admit to being a little confused about what to do. Looking at the pics on the cine4home.de website it would seem my pixels are way off!! :eek: Yet I can't say that the picture is anything less than fantastic but could it be better?! :confused:

I'm sure every PJ could be better, that's why some people pay for calibration. Close up, as the pics on the web site show, the TX looks like a massive scrabble game. Yet at normal viewing it's great. I wouldn't worry, if you are happy with the pics then that's what matters. And I'm sure most if not all the HS50's are exactly like yours - it's just that no-one has taken such an excellent pic of the pixels!

Just out of curiousity, and at the risk of prolonging this thread, what *was* the colour of the image at the point at which you took the close-up? :D
...PJ
 
Hi Neelix,

I purchased my HS50 over a week a ago, and like you am delighted with the picture, but like you I'm concerned about the pixel alignment(see pic). The red panel is misaligned which also produces a cyan colour when there is light colour against dark.

I have contacted the retailer about this plus the 720p cropping issue, but am reluctant to get it replaced as everthing else about the projector is spot on. I could end up with something a lot worse.

Chever.
 

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Not wanting to fire this up again :)

But I would be happy (enough!) if the pixels of my projector were no more than 1/2 a pixel out in any direction.
At least then 1/2 a (what is supposed to be) white pixel, would indeed be a white pixel and not a trio of 3 different colours that you have to stand far enough back from to not notice.
Do you think the HS50 is being built, a little say (cheaper) than the previous (more expensive initially) models it replaces?
As was said above, it should def be adjusted in the factory to be dead on (alignment) in the center of the screen (like a CRT is) with lenses ect making it drift a bit equally towards the edges.
Hopefully returns count, and if people don't accept badly aligned units, then Sony (or anyone else) will address the issue.
I did read about some better panel mounting in later revisions, so perhaps this is already an issue they are dealing with.
 
Tempest,

Not wanting to fire this up again

But I would be happy (enough!) if the pixels of my projector were no more than 1/2 a pixel out in any direction.

Having participated in your thread on this issue, I'm somewhat reluctant to step in here, but...... Do you you think you could tell whether your projector had misalignment by half a pixel vs misalignment by 0.75 of a pixel when viewing a movie from your normal seating distance ?? Unless you can honestly answer "yes", then your statement above has more to do with you wanting to know that the projector is "perfect" from a technical standpoint, as opposed to any visible difference in the image being displayed. If someone is looking for "perfection" I doubt that any display technology is going to suffice.

As to questioning whether the HS50 is being built to a price, you're joking, aren't you ? Of course it's built to a price, comparisons in terms of build values or QC don't stand comparison with the HT series, which were produced by Sony's broadcast division in what is now a different era in terms of the market for accessible front projection. The quality of image offered by the current 1280x720 projectors is substantially advanced in comparison to the models available 2 years ago, and in the vast majority of cases at prices that are far cheaper in real terms.

This thread now has a prospective projector buyer saying

I'm getting really bothered by discussions on LCD pixel misalignment (and I don't even own an LCD projector yet!).

....when, in reality, it is not an issue which causes any effect when viewing at normal distances. Gross misalignment of LCD panels is pretty rare - the panels are pretty securely constructed into the optical block inside a projector, and on the rare occasion when the get dislodged the effect is so pronounced that no-one could mistake the fact that there is something wildly amiss.

I have to say that I can't understand what the fuss is - this is a non-issue unless it actually affects the quality of an image you're viewing. Seeing as most people (!) don't view a movie from 1 foot away from the screen, the distance required to assess whether there is any mis-alignment, why get worked up about it ?


Sean G.
 
Chever, your image looks very similar to mine! There is a slight colour shift of green at the top and purple at the bottom but you simply cannot see this beyond a foot or so. Sean, I must admit that this thread started purely from the fact that I honestly didn't know whether my pixel alignment was normal or what! I agree that as long as the picture looks great from a normal viewing distance then in reality there is no problem. It's not the same a demoing a system, when you own the stupid thing you look at EVERYTHING to see how it all works which then inevitably poses questions! Anyway, I'm going to wait a while until it I get my new Vutec screen, have it ceiling mounted and setup perfectly! If I feel I am missing out on something then I'll take it further but at the moment I'm as happy as larry as I'm about to sit down with a vindaloo and enjoy The Chronicles of Riddick on a painted wall with a 6ft image.... bliss :D
 
I agree with Sean. This discussion is focussing on technical rather than visual perfection. To the end user, that's rediculous.

Do you think the HS50 is being built, a little say (cheaper) than the previous (more expensive initially) models it replaces?

Well, my previous HS20 (originally £2800) had panels nearly 3 pixels out, and it was never even remotely a problem unless I looked for it with my nose at the screen.

When I got my HS50, the first thing I looked for was dead pixels. None were found. Then I looked for colour staining (the HS50 suffered here).... All ok here too!
Then I looked for tiny variations in focus accross the screen, and then I checked for panel alignment. Then, I had a word with myself and just settled down to watch a film!

Seriously, I've been as guilty as anybody for fault finding in the past, but it's a pretty pointless excercise and can drive you up the wall!
I'm practicing a more laid back approach to my hobby just recently, and its far more enjoyable.
 
hear hear Jules. Last sentence says it all. Nothing ever comes 100% perfect that includes the Wifey lol, oops hope she dont read these forums lol.

Ive resisted the temptation to be critical with me HS50 im very happy infact over the mooon, once you start lookin for faults the dreaded paranoia sets in.

Bad road to go down and thats not just for PJ's ;)
 
Yep get help ,advice read up choose..then don,t come back here!! :eek:
 

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