[yubyub]

I'm heading over to my friend's house this weekend to help calibrate his Sharp 10k to D65.


I've read a good deal about, but never used, a Sharp 10k. I understand that using their CMS, you can actually change the CIE coordinates of the primaries.


Any tips and tricks from people who have done this before? I'll be using my Colorfacts Eye-One and tristimulus meters for the calibration.


Also, I'd love to setup one scheme for him which has the HDTV colorspace, and one for NTSC colorspace. Is there a way to do this easily given that the projector will always be fed via the DVI input? I understand that the 10k has one scheme per input, but perhaps there's a way to change the CMS profile?


TIA,


-Jon

 

[lovingdvd]

Regarding CIE see the details of this thread: http://www.avsforum.com/avs-vb/showt...hreadid=250694


I don't the EyeOne is going to give you the CIE readings you are looking for unfortunately. Please report back here and let me know if you encountered the same issues measuring this as I and others discussed there.


Regarding calibration of the 10K see my notes here:
http://www.avsforum.com/avs-vb/showt...hreadid=244635

In particular please report back on whether you find that your run out of red and have to back down contrast several notches below where the clipping point occurs as a result.

 

[yubyub]

lovingdvd,


Interresting threads - thanks for the references. I'll definitely post my experiences back here.


I'm also looking forward to using the tristimulus device, as it is supposed to be much more sensitive in the lower IREs.


-Jon

 

[BobL]

Hi Jon,


I'm not sure which tristimulus you have. But, tristimulus devices are usually designed to work with SMPTE phoshors on a CRT. Some of the devices have offset files that are made by the manufacturer to allow it to be used with various other technologies. You might have to get the offset file for your Sharp 10K for it to be accurate. BTW, it does read lower IRE's better than the eye one.


Hope this helps


Bob

 

[yubyub]

It's the tristim which can be purchased with CF-6500:

http://www.milori.com/products/cf6500/specs.asp


As I understand it, Milori claims their tristim will work with any technology except LCD panels (as in large screen TVs, not projectors). I'm not quite clear why LCD panels are different, but a tech on the Milori site explained that the use of "light pipes" would be required to use their tristim on an LCD panel.


I've been digging around for info on this ever since... I love the eye-one, it just drives me crazy in the lower IREs. I'm now in the market for a good optical comparator.


Jeez, so much calibration info to learn. "Will buy beers for advanced info on calibration technology."


-Jon

 

[lovingdvd]

Yes from what I hear the tristim can read well below 20 IRE. I find the EyeOne struggles with 25 IRE and anything below - forget about it.


This has made it difficult to get reliable on/off contrast readings since those readings are so dependant on an excellent black level reading.


yub - please post back here the following when you have a chance:


1) did you run out of available red prior to hitting the clipping point - as I encountered and discussed in the Official Sharp 10K calibration thread?


2) how well did you like the new tristim meter? How low were you able to get reliable readings from - 10 IRE perhaps? How good of a job does this meter do with color temps and helping you dial in D65 in particular?


3) Were you able to get reliable on/off contrast ratio readings with the tristim (without each reading giving you dramatically different results)? What was the CR when you were finished?


Oh a couple other tips - calibrate with high contrast mode and Power Save mode OFF. Also I find that my results were better using the Sharp's white enhance mode (can't recall what they call it).


Let us know how it goes.

 

[BobL]

Hi Jon,


The 6500 is a trichromatic sensor not a traditional tristimulus. Although in appearance they look similar. The LCD's have too big of pixels that is why they need a light pipe to work.


Bob

 

[yubyub]

Bob,


My goodness, I've just blindly been referring to it as a tristimulus. Thanks for the wakeup.


Care to elaborate on the differences? Inquiring minds want to know

 

[yubyub]

lovingdvd,


Will do. I'm gonna recalibrate my lowly NEC vt540k tonight, and will try to grab some comparisons between the trichromatic and the eye-one.


-Jon

 

[Guy Kuo]

The LCD's are a problem because the color of light emission varies tremendously with emergence angle. A normal tristimulus meter placed close to the panel sees a mix of on angle and off angle light. The off angle light confuses the sensor. This can be mitigated somewhat by backing the sensor from the LCD surface, but that drops the amount of light available to sense. Light pipes would be a method for making the light acceptance angle smaller and thus make the sensor more suitable for LCD. I know the Spyder now has a honeycomb attachment for the front of the sensor which helps control the acceptance cone.

 

[smithb]

Since we are discussing Sharp calibration, I have a somewhat related question. I realize calibration is dictated by the source player and screen, but are there also differences between the format of the source material?


In other words, once calibrated for color is it also at its best for b/w movies? I've gotten into some of the old classics as they have come out on DVD and I am just wondering if there are tweaks to make b/w movies look their best that may not be the best settings for movies in color.

 

[lovingdvd]

Quote:

Originally posted by smithb Since we are discussing Sharp calibration, I have a somewhat related question. I realize calibration is dictated by the source player and screen, but are there also differences between the format of the source material? In other words, once calibrated for color is it also at its best for b/w movies? I've gotten into some of the old classics as they have come out on DVD and I am just wondering if there are tweaks to make b/w movies look their best that may not be the best settings for movies in color.

Yes, there can be measurable differences from the source depending on your equipment. For example its possible that inputting 720p into your pj requires different calibration adjustments than even 1080i from the same equipment.


In the case of the 10K it is consistent for the most part between 720p and 1080i except sharpness needs to come down in any of the stretch modes to about -10, 720p dot-by-dot mode can stay at 0 (credit Greg Rogers).


As for color vs. black and white - no need to worry about those differences. By definition when you are calibrating the grayscale to D65 you are calibrating black and white - that is the basis of the picture. In other words if black and white is not dialed in correctly than there's no way the colors will be accurate. So a calibration to D65 will take care of both black and white movies as well as color. In fact folks often remark about how surprised they are when they see black and white movies after their calibration because they black and white looks so pure - that is the beauty of D65 at work.

 

[yubyub]

Guy Kuo,


Thanks for the explanation. Again, you've provided us with a little golden nugget of info.


smithb,
Quote:

Since we are discussing Sharp calibration, I have a somewhat related question. I realize calibration is dictated by the source player and screen, but are there also differences between the format of the source material?

On a slightly different note, there also exist differences between sources i.e. a DVD player which has slightly "hot" electrical outputs, or a scaler which has out of spec electrical outputs. If you're really getting down into calibration, it's good to scope the electrical outputs to make sure you're not crushing blacks or whites electrically.


For instance, on my system at home (Panny rv31, via component into a Faroudja NRS, then via RGB to my projector), I calibrate the NRS's output with my scope to make sure the levels are correct (I can't tweak the Panny's output at all besides black level setup), then calibrate my projector's values after that.


-Jon


-Jon