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Discussion Starter · #1 ·
OK - this is a new thread for the HS10 but it seems a lot of the hype has died down and this is for a specific topic. Plus there have been few new posts in the official threads in the last few days.


I measured the effect of the cinema filter with Colorfacts to determine what changes (if any) should be done to the RGB bias and gain settings to remove the "pink" colours when you use the filter. As you can see on the attached measurement file (on the "CIE Zoomed Chart" page), the filter clearly shifts all colours linearly almost directly away from the Green primary and somewhat away from the Blue primary (which means towards the "pinky magenta").


This shift appears to occur from dark grays to light whites in the same amount. Using the filter is a good idea though as it darkens blacks and allows for a more efficient use of the red colour.


To approximately correct for the colour shift, I found that the best way is to increase the Green and Blue Gains only. DO NOT reduce the Red Gain! Red is the limiting colour of the three primaries and will run out of juice in very bright scenes making them shift towards a bluey cyan. Adjusting the Biases makes only a subtle difference to the filtered greyscale so don't change these.


Here's my suggested changes to the Gains to correct for the cinema filter:

Increase G-Gain by 28%

Increase B-Gain by 19%

[edit]

I realized that a subtle change to the Biases at the same time will give an even better result:

Decrease G-Bias by 3%

Decrease B-Bias by 4%


Dave

 

sony hs-10 1203a no filter to filter.zip 22.0478515625k . file
 

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Dave, thanks for posting your findings on correcting for the "pink" colors when using the filter. Your posts have been a valuable source of information for those who wish to maxamize the potential or their HS10's. What are your thoughts on the picture now that you've had more time to tweak the settings? Keep the flow of info coming!


Regards,

Anthony :cool:
 

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Hi Dave,


If I look at your measurements, the first set you posted with the calibration using the filter, it looks like the color temps are more correct over there (compared to the one you have posted above). The one thing I see different between the 2 sheets is that the contrast is set to 79 in the "no filter to filter" where in the "filter calibration" is set to 63 initially and 50 afterwards.

Are you saying that as an afterthought, people should NOT change the contrast (from 79 to 50 in your measurements) and just increase the G and B gain? And that would fix the color shift?
 

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Discussion Starter · #4 ·
Costa,


The colour shift from the addition of the filter and the colour shift from having a Contrast setting that is too high are two different things:


- adding the filter shifts all colours of the greyscale slightly towards the magenta, this can be "fixed" by making the changes to GB gains and bias I suggested above


- having a too high a Contrast setting shifts only the brightest colours towards the cyan - it has no effect on the dark scenes, only the bright scenes. Out of the box, with no changes to the RGB gains and biases, around 85 or 90 Contrast will be OK and not cause a major colour shift.


Note that the settings to RGB gains and biases I posted earlier are with the filter on, so you don't need to "fix" them with the changes I show above.


Changing the Contrast setting from 79 to 50 was required in my case to tame the bright whites because I cranked up all the RGB Gain values in the service menu (which is analagous to cranking up the contrast past 100!) at the same time.


This is probably a little confusing :) It's quite difficult to explain but I hope it helps.


Dave
 

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Oh ok. So if I understand correctly, as a pointer, you suggest people who use the filter may want to change the gain and bias by the values you mentioned above and leave the contrast as is (or as directed by Avia or video essentials) ?

Also, I just noticed, that your luminance (after calibration) was at 114 (down from 925). Is that a typo or did it really go that low?
 

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Discussion Starter · #6 ·
Costa,


That is correct - the HS10 factory settings are clearly set to be used without the filter (at least on my projector). Contrast can be set anywhere the user likes, but you should be aware that it is possible to set it so high (even using Avia) that there will be significant colour shifting in the brightest scenes.


Maybe the best way to check it by eye is to put up the horizontal gray scale steps on Avia and increase Contrast until the bright white starts to turn slightly blue-green relative to the other grays. Then bring it back a few notches.


Re the luminance measurements, I must have moved the sensor location from one test to the next. The closer to the projector, the higher the luminance values. The contrast ratio calculation is valid as long as the sensor is not moved between measurements.


Dave
 

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711 without, 728 with. It's in the spreadsheet.
 

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ok - I'm confused. Are the settings in the spreadsheet above before you recalibrated for the filter? What final settings did you end up with? Because I don't see a change in the gain values in the measurements in the spreadsheet. How dramatic is the resulting change in picture quality after dong these calibrations? Just getting the image in the wal; will be dramatic for me since I don't have my HS10 yet.
 

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i keep asking this noob question again and again (unanswered in that other god-awful thread):


in my SM, i cant find anything that having to do w/ BIAS..only GAIN and OFFSET...where are the BIAS settings? :rolleyes:


thanks alot DB for all your helpful info :D
 

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Quote:
Originally posted by WatchThis
i keep asking this noob question again and again (unanswered in that other god-awful thread):


in my SM, i cant find anything that having to do w/ BIAS..only GAIN and OFFSET...where are the BIAS settings? :rolleyes:


thanks alot DB for all your helpful info :D
Here's the answer from one of those other unusable threads:


"WatchThis


Yup - you are in the wrong menu - the RGB bias and gain settings are accessed by selecting the third icon up from the bottom when in Factory mode (F in upper left) or the second up when in Service mode (S in upper left). Not the icon in the bottom left corner (not sure what these are called - I'm at work right now).


To get from the bias to the gains when you see the RGB values, just use the up or down arrow a few times to change to the next page in the menu.


I'm not sure how those offset settings work in the factory menu (by selecting the icon in the bottom left). Anybody feel like doing some serious experimenting?


....


Dave"


Again, thanks Dave for the settings--what are your current settings for filter on, are they still the same as your original spread sheet?
 

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Quote:
Originally posted by costa
711 without, 728 with. It's in the spreadsheet.
That is an absolutely incredible contrast ratio for an LCD projector. Wow, this is even better than my Piano DLP which I measured at 685 with the filter on. The Sharp 9000u only managed to achieve 1:750 after calibration.



Is the Sony VPW12 suppose to be a better in contrast than the HS10 because if it is then it would not make any sense. All the demos of the 12s I saw had pretty grey blacks...that is no where near the black levels achieved by the Piano or the Sharp 9000u.


The HS10 must be a better machine in some ways compared to the 12 then ???
 

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Would a gray screen improve the CR even more? If so, by how much? What screen are you using?


Thanks, and great report!
 

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If I was going to buy a LCD, a grey screen and an FLD filter would be mandatory and should help perceived contrast levels significantly. Although, just like any DLPs or LCDs under a 900:1 contrast ratio, after sometime you'll begin to notice the greys. You'll be impressed by the incremental improvement first then the grey problem will come back.


I don't believe that these will happen with higher contrast machines above 1000:1 like the HD2 chips or the NEC HT1000. You'll only notice a lack of black if you have a reference point or a point of comparison.
 

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the contrast ratio on the HS10 bugged me ALLOT :( mainly because I had sat in front of a decent CRT projector for years before hand. But I found simply masking the screen with a 2 inch border didn't do allot for me, but after masking about 3 feet around the whole screen the perceived black levels increased dramatically!


I think its a case of stop fussing about the niggles and enjoy the movie. Think of the first time you saw colour television and thought how on earth did we put up with black and white?


I'm going to keep my CRT for special uses (the tubes are almost knackered) as SOME movies look lots better, blade 2 is a perfect example!


But apart from that I would have to say the HS10 is about the best LCD I have seen for less than a year's wages ;) Although I could be wrong but I though I read somewhere the 12ht can attain 950:1 with cinema filter and adjustments. Then again I have only seen one 12ht running and it had a bad pixel so it drove me nuts with a bright green dot to the side :(


In terms of the gain settings on the panels, I turned mine up using Video Essentials to try and set it up and I cranked the blue up 47 points and the green up 49 points and left the red where it was, I didn't touch the bias settings as when I had a fiddle with them it and increased them it seemed to decrease black levels, and when I decreased the bias settings it seemed to wash out the picture.


I'm hanging out for laser CRT projectors ;)
 

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Dave-

I had downloaded another one of your files earlier, where you had actually made the adjustments to gain and bias. It looks like the file at the beginning of this post is a before and after comparison of the filter, where the earlier file was a filter w/o adjustments to a filter w/ adjustments. Is this correct?
 

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Discussion Starter · #17 ·
Eric,


This is correct - the first file I uploaded was for before and after corrections with the filter on. The second one (the one in this post) is really just to see what happens to the colour balance and contrast ratios with and without the cinema filter.


The answer another query, the filter does not appear to significantly affect the contrast ratio. What it does is lower the overall luminance to make both blacks and whites darker, and shifts the colours towards the magenta-red to make better use of the three primary colours.


Dave
 

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srgfx-

I don't think that SMART will result in anything better than what Dave has done with Colorfacts. SMART is just a "poor man's" version of the same type of calibration.


Dave, another question-

We can see that the filter reduces a large amount of the green component, and a little of the blue as well. By re-calibrating and increasing these components in the projector, do we end up cancelling the effect of the filter? In other words, what effect does the filter have if the color balance is the same after calibration? Couldn't we achieve the same effect by adjusting the color balance without the filter?
 

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Discussion Starter · #19 ·
Eric,


Because the filter adds strength to the Red colour, it allows you to increase the contrast setting to a higher level before the red hits its upper limit relative to the blue and green than you could without the filter.


Hmmm, makes me think that the before and after contrast ratios on my sheet are not quite correct because I did not take into account the upper limit of the contrast setting. I'll have to redo it.


The callibrated contrast ratio with the filter should not change - only the calibrated without the filter contrast ratio should decrease.


Dave
 
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