CurtPalme.com Home Theater Forum

[kal]

[kal]

[MikeEby]

[timf]

So Kal how far off is the guide you mentioned earlier on?

[kal]

I've taken a few screenshots but haven't started writing anything yet. Been futzing around with my own greyscale too much to do any writing. (Why is it that getting 90% of the way there only takes 10% of the effort? This last 10% is a real time waster).

Kal

[kal]

I've taken a few screenshots but haven't started writing anything yet. Been futzing around with my own greyscale too much to do any writing. (Why is it that getting 90% of the way there only takes 10% of the effort? This last 10% is a real time waster).

Kal

[WTS]

Hi Kal,

Well it was worth a shot, I just thought maybe it might have been problem. Not sure when I;ll be doing mine next but I'll record my numbers etc and pass them on to you. I know when I was doing it last time my bottom end fell in line just like the rest. I used the continuos mode and then just went through the IREs(full window).

[kal]

Full window? That's not the way to do it Walter unfortunately. You'll only get about 6-7 ft/L at 100IRE instead of 11-15. Makes a huge difference on how the tubes react/behave. You need to use the 10% windowed pattern. It won't make much of a difference in the low end but your high end will react completely differently.

If you use full screen patterns you're really only calibrating for about the 0 to 40/50 IRE range. The reason/logic: I get 5.1 ft/L at 40IRE and 8.5 ft/L at 50IRE while using a 10% window pattern which is similar in light output to my 100% window pattern at 100IRE which only gets around 6-7IRE! If I do a 10% window 100IRE pattern I get 11.8 IRE (I was targeting 12 ft/L output). Our Zenith 1200 projectors can do more than 12 ft/L (I can get 16 ft/L easily) but my rooms very dark (all black for 6 feet around the screen and ceiling) so I find 16 ft/L just too bright when watching average movie content.

Kal

[kal]

Full window? That's not the way to do it Walter unfortunately. You'll only get about 6-7 ft/L at 100IRE instead of 11-15. Makes a huge difference on how the tubes react/behave. You need to use the 10% windowed pattern. It won't make much of a difference in the low end but your high end will react completely differently.

If you use full screen patterns you're really only calibrating for about the 0 to 40/50 IRE range. The reason/logic: I get 5.1 ft/L at 40IRE and 8.5 ft/L at 50IRE while using a 10% window pattern which is similar in light output to my 100% window pattern at 100IRE which only gets around 6-7IRE! If I do a 10% window 100IRE pattern I get 11.8 IRE (I was targeting 12 ft/L output). Our Zenith 1200 projectors can do more than 12 ft/L (I can get 16 ft/L easily) but my rooms very dark (all black for 6 feet around the screen and ceiling) so I find 16 ft/L just too bright when watching average movie content.

Kal

[studio]

[kal]

My signal path:

PS3 -> HDMI to DVI cable -> HDfury plugged directly into -> RTC2200 (gamma boost & cable driver) -> 25' good RGBHV cable -> Zenith 1200

Kal

[kal]

My signal path:

PS3 -> HDMI to DVI cable -> HDfury plugged directly into -> RTC2200 (gamma boost & cable driver) -> 25' good RGBHV cable -> Zenith 1200

Kal

[WTS]

Well my logic says if I was watching a 10% window then I would do it that way, but I'm not so why do it that way. Calibrate it the way you're going to be using it.

I do it that way and my results(pic) are excellent.

[Person99]

[WTS]

I'll try it both ways and see which way looks better or if they produce difference results on the HCFR software.

Just seems to me that stressing or driving the tubes that hard by using a 10% window is not how the tube is going to be under normal viewing/operating conditions. Yes of course you'll rarely see a 100IRE full window from any movie or program but you normally watch the full screen not a small window going from 0 to 100 IRE or 0 to peak current draw in this case for the whole pattern.

I think maybe the proper way to do it then is to have a 100 or 80 or whatever IRE level in a 10% window located in the middle(surrounded by) of a mix of other various level IRE boxes to simulate a more typical condition for current draw over a full screen.

Walter

[kal]

Well I've been back and forth trying different things and I pretty much always end up in the exact same spot as I try and get the blue tube to not drop off in the very low IRE's.

That being said, the results are still very good from 20-100IRE and very flat from 30-80/90 which is what you're supposed to aim for. The lack of blue at 10 IRE isn't really noticed as 10 IRE is pretty darn dark.

The general rule to try and aim for a delta E at any given more that is below 10. Changes in deltaE of 3 or less are said to be unoticeable by the human eye, so anything at 3 or is considered 'perfect'.

I may try increasing the red and blue gains by one notch to try and pull them up a bit at the high end to get the 90/100IRE reading slightly better and more in line with the other reading I posted earlier, but frankly, I doubt it would even be noticeable. Tweaking this stuff's never ending if you try and get it absolutely "perfect". Even waiting an hour will result in very slightly different readings so you have to just look at the bigger picture sometimes and consider the the margin of error that's involved in taking these readings.

I may have to reduce the contrast slighty too - I'm getting 13.8 ft/L at 100IRE (10% window pattern) and it's a little too bright I think. 12 ft/L may be a little more confortable on the eyes considering that my HT's dark (black on the wall all around the screen and for the first 6 feet into the room on the walls and ceiling).

RGB readings: From 30-90 all readings are very close to within 3 deltaE from perfect which is x=313, y=329. 10IRE is off but such is life


Primaries & secondaries: All RGB readings (except for 10 IRE) are within 10 deltaE from perfect. Primaries (the corners) are pretty close to the actual perfect values. Red's a bit off to the left but there's nothing I can do about that.


The one graph I don't know what to make of is Luminance (gamma):


White=Reference
Green=Average
Yellow=Luminance

The numbers in the first picture (very top) tell me that my average gamma is is 2.27. I'm told you want to be between 2.2 and 2.5 where 2.2 gives you more black (dark) details.

From 40-90 the luminance aboite is slightly under the reference. Not sure it matters. I use an RTC2200 with about 11 turns of gamma boost to get out of black faster so that details are not lost. The results look fantasic. I just really know what to make of this graph or how to use it. Oddly enough, if I set the greyscale settings back to defaults everything is out of whack but the luminance graph is very nice (?).

Kal

[kal]

Well I've been back and forth trying different things and I pretty much always end up in the exact same spot as I try and get the blue tube to not drop off in the very low IRE's.

That being said, the results are still very good from 20-100IRE and very flat from 30-80/90 which is what you're supposed to aim for. The lack of blue at 10 IRE isn't really noticed as 10 IRE is pretty darn dark.

The general rule to try and aim for a delta E at any given more that is below 10. Changes in deltaE of 3 or less are said to be unoticeable by the human eye, so anything at 3 or is considered 'perfect'.

I may try increasing the red and blue gains by one notch to try and pull them up a bit at the high end to get the 90/100IRE reading slightly better and more in line with the other reading I posted earlier, but frankly, I doubt it would even be noticeable. Tweaking this stuff's never ending if you try and get it absolutely "perfect". Even waiting an hour will result in very slightly different readings so you have to just look at the bigger picture sometimes and consider the the margin of error that's involved in taking these readings.

I may have to reduce the contrast slighty too - I'm getting 13.8 ft/L at 100IRE (10% window pattern) and it's a little too bright I think. 12 ft/L may be a little more confortable on the eyes considering that my HT's dark (black on the wall all around the screen and for the first 6 feet into the room on the walls and ceiling).

RGB readings: From 30-90 all readings are very close to within 3 deltaE from perfect which is x=313, y=329. 10IRE is off but such is life


Primaries & secondaries: All RGB readings (except for 10 IRE) are within 10 deltaE from perfect. Primaries (the corners) are pretty close to the actual perfect values. Red's a bit off to the left but there's nothing I can do about that.


The one graph I don't know what to make of is Luminance (gamma):


White=Reference
Green=Average
Yellow=Luminance

The numbers in the first picture (very top) tell me that my average gamma is is 2.27. I'm told you want to be between 2.2 and 2.5 where 2.2 gives you more black (dark) details.

From 40-90 the luminance aboite is slightly under the reference. Not sure it matters. I use an RTC2200 with about 11 turns of gamma boost to get out of black faster so that details are not lost. The results look fantasic. I just really know what to make of this graph or how to use it. Oddly enough, if I set the greyscale settings back to defaults everything is out of whack but the luminance graph is very nice (?).

Kal

[kal]

[kal]