|
As this forum is rarely used anymore, we've locked it. Feel free to browse and read. Questions? Please reach out to us directly. Cheers! |
|
 |
|
|
| Author |
Message |
Diddern
Joined: 02 Jun 2013
Posts: 821
Location: Norway
|
| Posted: Wed Mar 18, 2015 10:13 pm Post subject: |
|
|
| stridsvognen wrote: | | Diddern wrote: | | stridsvognen wrote: | | Diddern wrote: | | Nashou66 wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Diddern wrote: | Stridsvognen!!!!!!
Dansken!!!! Har du gått i ydmykelsesdvale.
Answer my question.
And here some more. Why do you need red and green c-element on crt?
What happens with color red and green when using filters when messhuring primary colors up to HDTV D65 Rec709 on a CRT with pro equipments .?
What happens to the colors if you have to much punch in the picture on your crt.
What happens to the total black on a CRT if you adjust hundred percent correct after video level 16 to 235 with no black crush?
what is your reference gamma? |
Sorry Dildo im back..
Gamma is around 2.4
CRT had colored elements long before digital was able to show colors, so its not like a thing to keep up with digital, and the smart feature with a filter is that it wont go all waco at some area of the curve like a calculation error, or software error. So no C elements have ever had a firmware update.
perfect 16-235 coming out of black with a 2.4 gamma will leave a perfect out of black on my projector.
Now hope you can tell me if your CMS unit will be able to remap/ recalculate each pixel real time.?
So that the correction will happens perfect to each pixel with movie material with no shortcuts or loss.?.? |
Why do you have to call him names?? Why do you have to be so rude?
And how do you know you have a 2.4 gamma if you calibrate by eye?
What he is saying is that your CRT with a correctly setup video level 16-235 will not show black (0 IRE) as 0 because of the green tube will not shut completely down. To make this happen you need to set it up with some black crush.
And about you 2 last questions I have already answered them so it is no need for Diddern (not Dildo) to answer them. |
I agree with this statement. When I was talking to Tom Huffman of Chromapure about the auto calibration I asked if he could add a feature where you could select the amount of time before the next reading just because of what Andreas mentioned above.
You need at least 5-10 seconds before the green phosphor is dim enough on screen for it not to taint the next
lower % white reading. This does not matter if the software reads from 0-100% but there are occasions where the software first reads 100% white then reads 0% white. Also some read from 100-0 for auto calibration. Here is where the problem comes in. All auto cals read from 100-0 IIRC.
Green will always stay lit for some time, Crushing Green helps the CRT image stay black but you loose low detail in the 1-5% white range.
So What I end up doing is elevate the gamma for the low end and bring 0 to 0 via the lumagen luma adjustment.
It is just the inherent nature of the normal Green phosphor. P43 Green does not do this and this is why simulators for flight use it. You can not get a good greyscale with P43 phosphor but you gain better out of black performance than a standard Green tube.
Athanasios |
Stridsvognen and MP what do you have to say to this?? Nashou66 says the same as me and Andreas you ignore again? |
Im sure he is right, green tubes have all kind of problems.
Do you use the DI on your JVC.? |
What do you feel about the JVC iris? |
I have no feeling, thats why i ask you guys if your using it, or its better not to use it, My JVC just have a manual iris. |
I can tell you it works and more or less undetectable in movies, and increase on off contrast dramatically form 38000:1 to around 350000:1 so worth trying. And the iris Auto 2 gives a perfect fade to black just like a crt correct adjusted to video level.
|
|
| Back to top |
|
 |
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:15 pm Post subject: |
|
|
| Diddern wrote: |
I can tell you it works and more or less undetectable in movies, and increase on off contrast dramatically form 38000:1 to around 350000:1 so worth trying. And the iris Auto 2 gives a perfect fade to black just like a crt correct adjusted to video level. |
So you use it all the time when watching movies.?
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Wed Mar 18, 2015 10:16 pm Post subject: |
|
|
| stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Do any of your Norwegian JVC guys use the DI.? |
Why do you change the topic? |
Was there anything else you prefer to talk about.?
And im still curious if you find the DI worth using on the new JVC. |
Yes, why don´t you also tell me what a poor sh*t of an AV tech I was and no wonder why I changed career. |
Are you in a bad mood.?
I was just asking polite if you use your DI |
No, I´m not I just thought you would follow up the others.
And yes, I use the DI on my JVC. |
Ok.. Always or do it depend on anything.? |
I leave it on for the most part as it is almost undetectable and it gives an on/off boost that is very good.
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:26 pm Post subject: |
|
|
|
So both of you guys use the DI, and agree it makes the image better.?
|
|
| Back to top |
|
|
Diddern
Joined: 02 Jun 2013
Posts: 821
Location: Norway
|
| Posted: Wed Mar 18, 2015 10:27 pm Post subject: |
|
|
But now time to stop for to day, full shutdown to black. 
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:28 pm Post subject: |
|
|
| Diddern wrote: | | But now time to stop for to day, full shutdown to black. |
Closing the iris.? or leaving it to the auto iris.. lol
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Wed Mar 18, 2015 10:33 pm Post subject: |
|
|
| stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma.
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:34 pm Post subject: |
|
|
| Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.?
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Wed Mar 18, 2015 10:37 pm Post subject: |
|
|
| stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards.
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:39 pm Post subject: |
|
|
| Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.?
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Wed Mar 18, 2015 10:49 pm Post subject: |
|
|
| stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.? |
I don´t remember, but as it is almost undetectable the delta E is not very high, I can easy see small flaws in the grayscale if there is any and don´t see anything wrong with that with the DI engaged. Also it is easy to see gamma errors especially in the dark end, but with the DI it looks "correct" and with a much better blacklevel in the very low APL scenes. There is no special patterns to test the DI, just run the nomal patterns after calibration to see, just as you do after the calibration to see if everything tracks correct toghether with reference material to see if everything looks "correct".
But as you have seen Seegs108 X500, you must have an opinion of how the DI works, not everybody likes it and prefer to leave it off.
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 10:58 pm Post subject: |
|
|
| Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.? |
I don´t remember, but as it is almost undetectable the delta E is not very high, I can easy see small flaws in the grayscale if there is any and don´t see anything wrong with that with the DI engaged. Also it is easy to see gamma errors especially in the dark end, but with the DI it looks "correct" and with a much better blacklevel in the very low APL scenes. There is no special patterns to test the DI, just run the nomal patterns after calibration to see, just as you do after the calibration to see if everything tracks correct toghether with reference material to see if everything looks "correct".
But as you have seen Seegs108 X500, you must have an opinion of how the DI works, not everybody likes it and prefer to leave it off. |
Never seen his X500.
Sorry if this is a stupid question, but in the old days when i was calibrating gamma was a curve betwen 0 and 100%
How can gamma stay on target when changing the iris/ changing light output, and how do the z axis on the CIE chart work with that.? Is there somewhere its accepted acording to REC 709 to change the output after movie content, so lets say a the same green color has different values in 2 different scenes, depending on the overall light on that specific frame.?
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Wed Mar 18, 2015 11:14 pm Post subject: |
|
|
| stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.? |
I don´t remember, but as it is almost undetectable the delta E is not very high, I can easy see small flaws in the grayscale if there is any and don´t see anything wrong with that with the DI engaged. Also it is easy to see gamma errors especially in the dark end, but with the DI it looks "correct" and with a much better blacklevel in the very low APL scenes. There is no special patterns to test the DI, just run the nomal patterns after calibration to see, just as you do after the calibration to see if everything tracks correct toghether with reference material to see if everything looks "correct".
But as you have seen Seegs108 X500, you must have an opinion of how the DI works, not everybody likes it and prefer to leave it off. |
Never seen his X500.
Sorry if this is a stupid question, but in the old days when i was calibrating gamma was a curve betwen 0 and 100%
How can gamma stay on target when changing the iris/ changing light output, and how do the z axis on the CIE chart work with that.? Is there somewhere its accepted acording to REC 709 to change the output after movie content, so lets say a the same green color has different values in 2 different scenes, depending on the overall light on that specific frame.? |
Yes, you did on the blendzilla meet or what is was called. I think his name is Dylan.
I can not tell you exactly how the iris works, but it does not only change the light, it works together with gamma and other parameters and is a very complecated algorythm I have no idea on how it works as I am sure this is a JVC secret. I have seen measurements with it off and on and it does nothing to the colorspace and very slight differences to the gamma/grayscale. The gamma differences with testpatterns can look quite bad on the calibration report but on screen it is almost undetectable and i prefer it on.
If it did visible things to degrade the image I would never leave it on. But since it is almost undetectable I leave it on for the most part. Bright movies you can leave it off as it makes no difference, but dark movies like sci-fi it gives you a totally different experience in the very low APL scenes.
Now it is bed time, good night!
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Wed Mar 18, 2015 11:19 pm Post subject: |
|
|
| Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.? |
I don´t remember, but as it is almost undetectable the delta E is not very high, I can easy see small flaws in the grayscale if there is any and don´t see anything wrong with that with the DI engaged. Also it is easy to see gamma errors especially in the dark end, but with the DI it looks "correct" and with a much better blacklevel in the very low APL scenes. There is no special patterns to test the DI, just run the nomal patterns after calibration to see, just as you do after the calibration to see if everything tracks correct toghether with reference material to see if everything looks "correct".
But as you have seen Seegs108 X500, you must have an opinion of how the DI works, not everybody likes it and prefer to leave it off. |
Never seen his X500.
Sorry if this is a stupid question, but in the old days when i was calibrating gamma was a curve betwen 0 and 100%
How can gamma stay on target when changing the iris/ changing light output, and how do the z axis on the CIE chart work with that.? Is there somewhere its accepted acording to REC 709 to change the output after movie content, so lets say a the same green color has different values in 2 different scenes, depending on the overall light on that specific frame.? |
Yes, you did on the blendzilla meet or what is was called. I think his name is Dylan.
I can not tell you exactly how the iris works, but it does not only change the light, it works together with gamma and other parameters and is a very complecated algorythm I have no idea on how it works as I am sure this is a JVC secret. I have seen measurements with it off and on and it does nothing to the colorspace and very slight differences to the gamma/grayscale. The gamma differences with testpatterns can look quite bad on the calibration report but on screen it is almost undetectable and i prefer it on.
If it did visible things to degrade the image I would never leave it on. But since it is almost undetectable I leave it on for the most part. Bright movies you can leave it off as it makes no difference, but dark movies like sci-fi it gives you a totally different experience in the very low APL scenes.
Now it is bed time, good night! |
Ahh ok, so you did a by eye evaluation, and preferred that one over the correct REC 709 calibration... Interesting..!!
|
|
| Back to top |
|
|
El Duderino
Joined: 23 Jan 2011
Posts: 4653
Location: Portland, OR
|
| Posted: Thu Mar 19, 2015 12:44 am Post subject: |
|
|
|
I believe even CRTs have a sort of 'dynamic iris' based on APL and area. I doubt your CRTs have the same brightness for a full-frame white as they do for a low area white. If you plot your gamma, you'll likely see a difference based on the APL area of the test patterns used.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
| Posted: Thu Mar 19, 2015 1:04 am Post subject: |
|
|
| El Duderino wrote: | | I believe even CRTs have a sort of 'dynamic iris' based on APL and area. I doubt your CRTs have the same brightness for a full-frame white as they do for a low area white. If you plot your gamma, you'll likely see a difference based on the APL area of the test patterns used. |
Right if you change the window size you are measuring
the luma Y will change and this will change Gamma.
So it is in essence the same thing. Also cranking contrast or lowering brightness changes Gamma
on a crt.
Lots going on and everything interacts with everything.
I remember Craig got my Marquee 8000 a super flat greyscale with no CMS
just the tricks of the trade. He still won't tell me how he does it
Nashou
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
|
|
| Back to top |
|
|
El Duderino
Joined: 23 Jan 2011
Posts: 4653
Location: Portland, OR
|
| Posted: Thu Mar 19, 2015 1:11 am Post subject: |
|
|
| Nashou66 wrote: | I remember Craig got my Marquee 8000 a super flat greyscale with no CMS
just the tricks of the trade. He still won't tell me how he does it |
Did it involve purposefully defocusing the blue channel?
|
|
| Back to top |
|
|
HogPilot
Joined: 21 Jan 2010
Posts: 2383
TV/Projector: Vizio P702ui-B3, Pioneer Elite Pro-151FD & 111FD
|
| Posted: Thu Mar 19, 2015 1:21 am Post subject: |
|
|
| mp20748 wrote: | | HogPilot wrote: |
Given that this discussion has centered on video fidelity, it's worthless for that purpose. Accurate calibration - i.e. not by memory/eye alone - is central to the whole debate of comparing displays in the first place (caveat: I still hold that screen shots are an almost worthless endeavor for that purpose, outside of a handful of very specific items). Despite it being completely irrelevant to this discussion, you continue to bring it up. It's proven to be nothing more than an obfuscatory subject. Let's move on to more relevant, productive topics |
Oh so you see it as me being the one to want to prove the video fidelity through the use of screenshots. I agree it would be worthless for that purpose and have been saying that over and over, yet it is I who copied a shot of mine from the Screenshots thread and posted it here for comparison..lol |
I'm simply using your words. You have stated within the last several pages - to include this post I'm quoting - that things such as "black," "deep black," (care to explain how the former differentiates from the latter, or even just provide a definition of both?), and "flesh tones" can all be assessed using screen shots. This is wholly incorrect. None of these things can be assessed via screen shots, for reasons already explained here time and time again.
| mp20748 wrote: | | I as you also mention, based my part on only one ("handful of very specific items") object for discussion, that was agreed on. Did I also comment on anything other than that? |
Not one item that you claim to be assessable via screen shot can be done, outside of calibrating every single display and capture unit in the chain to incredibly tight tolerances. Even then, it's highly likely that the end result will be someone looking at these things on an LCD computer monitor with no better than 1000:1 real world on/off CR and abhorrent black levels. To say that one can judge "blacks" and "deep blacks" (again, a differentiation/definition of both might help everyone else's confusion on what these terms mean within the context of this conversation) on such a low contrast display directly opposes the idea that high CR is critical to attaining high image fidelity.
| mp20748 wrote: | | And how many times would I have to say "you cannot use screenshots for comparison purposes" and "we are using cheap point and shoot cameras" and "screenshots cannot be used as a quantitative means of evaluation" |
You keep saying that, and then you go and talk about judging things that can't be judged via screenshots, so I highly doubt you're doing more than repeating a mantra. See my previous paragraph for how contradictory your statements have been.
| mp20748 wrote: | | So having fun with the guys result in me saying something I've never said other than "black' "deep black "and "Flesh tones" you think maybe I've been doing them long enough to know about these three things? |
This is a classic "appeal to authority" logical fallacy. You're attempting to dodge legitimate criticisms by simply citing that you've been doing this for a while. One can just as easily do things wrong for a long time as they can do them correctly. The length of time for which you've been doing things incorrectly, misapplying knowledge, or utilizing falsities doesn't magically make them less wrong.
| mp20748 wrote: | | And any discussions on calibration and equipment, I'll not get into and think it's an entirely useless discussion, when even you yourself talked about the merits of screenshots. Why even bother to bring up proper calibration on on the subject, when we're talking about the use of cheap point and shoot cameras. Plus, I made it clear, my PJ was NOT calibrated!! |
You dove into the calibration conversation several pages back - by attempting to correct another forum member with your ideas about what does and does not qualify as calibration, nonetheless. Now you're bailing on the discussion when your knowledge of it and how it applies to the topic are being questioned? There would be no need to bail if you had a sufficient working knowledge on the subject.
And exactly how does one compare "flesh tones" between two different projectors in person - let alone via screen shots - when one of the two projectors isn't even calibrated? This is so nonsensical that it boggles the mind.
| mp20748 wrote: | | It's not my field of expertise, and has never been. |
On that, everyone here can agree. Of course, "field of expertise" is a bridge or two too far - I think most would agree that your knowledge of video calibration on any level is tenuous, at best.
_________________
| ecrabb wrote: | | Curt Palme wrote: | | Interesting, Mac isn't returning my emails. Go figure. |
He's mad at us for making Hog a moderator. He took his ball and went home.
SC |
|
|
| Back to top |
|
|
Andreas21
Joined: 02 Oct 2013
Posts: 582
|
| Posted: Thu Mar 19, 2015 5:56 am Post subject: |
|
|
| stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | Andreas21 wrote: | | stridsvognen wrote: | | So both of you guys use the DI, and agree it makes the image better.? |
We know the limitations with using irises and what it does with gamma, but it is a choise you have to make sometimes and here the positives outweigh the negatives. And JVC has done a good job on their first try and is up there with Sony and other DLP PJ´s with really good irises. The JVC DI is actually quite stable when it comes to gamma. |
Nice.
So you have the DI on when calibrating.? |
Of corse not, but we have done measurements with it on afterwards. |
How was Delta E with the DI on, and what kind of patterns do you use to test that with, is there special patterns to test DI.? |
I don´t remember, but as it is almost undetectable the delta E is not very high, I can easy see small flaws in the grayscale if there is any and don´t see anything wrong with that with the DI engaged. Also it is easy to see gamma errors especially in the dark end, but with the DI it looks "correct" and with a much better blacklevel in the very low APL scenes. There is no special patterns to test the DI, just run the nomal patterns after calibration to see, just as you do after the calibration to see if everything tracks correct toghether with reference material to see if everything looks "correct".
But as you have seen Seegs108 X500, you must have an opinion of how the DI works, not everybody likes it and prefer to leave it off. |
Never seen his X500.
Sorry if this is a stupid question, but in the old days when i was calibrating gamma was a curve betwen 0 and 100%
How can gamma stay on target when changing the iris/ changing light output, and how do the z axis on the CIE chart work with that.? Is there somewhere its accepted acording to REC 709 to change the output after movie content, so lets say a the same green color has different values in 2 different scenes, depending on the overall light on that specific frame.? |
Yes, you did on the blendzilla meet or what is was called. I think his name is Dylan.
I can not tell you exactly how the iris works, but it does not only change the light, it works together with gamma and other parameters and is a very complecated algorythm I have no idea on how it works as I am sure this is a JVC secret. I have seen measurements with it off and on and it does nothing to the colorspace and very slight differences to the gamma/grayscale. The gamma differences with testpatterns can look quite bad on the calibration report but on screen it is almost undetectable and i prefer it on.
If it did visible things to degrade the image I would never leave it on. But since it is almost undetectable I leave it on for the most part. Bright movies you can leave it off as it makes no difference, but dark movies like sci-fi it gives you a totally different experience in the very low APL scenes.
Now it is bed time, good night! |
Ahh ok, so you did a by eye evaluation, and preferred that one over the correct REC 709 calibration... Interesting..!! |
I see where you are going, but if you read my post we measured everything to check first and the DI does nothing to rec 709 colorspace, it does very little to D65 grayscale and some to the gamma as it works with gamma (dynamic gamma). We did no calibration by eye, just the evaluation after and this is always done with post calibration measurement and by eye with reference material. This also goes when testing the DI.
_________________
http://www.minhembio.com/21Andreas
|
|
| Back to top |
|
|
mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
|
| Posted: Thu Mar 19, 2015 11:30 am Post subject: |
|
|
| HogPilot wrote: | | mp20748 wrote: | | HogPilot wrote: |
Given that this discussion has centered on video fidelity, it's worthless for that purpose. Accurate calibration - i.e. not by memory/eye alone - is central to the whole debate of comparing displays in the first place (caveat: I still hold that screen shots are an almost worthless endeavor for that purpose, outside of a handful of very specific items). Despite it being completely irrelevant to this discussion, you continue to bring it up. It's proven to be nothing more than an obfuscatory subject. Let's move on to more relevant, productive topics |
Oh so you see it as me being the one to want to prove the video fidelity through the use of screenshots. I agree it would be worthless for that purpose and have been saying that over and over, yet it is I who copied a shot of mine from the Screenshots thread and posted it here for comparison..lol |
I'm simply using your words. You have stated within the last several pages - to include this post I'm quoting - that things such as "black," "deep black," (care to explain how the former differentiates from the latter, or even just provide a definition of both?), and "flesh tones" can all be assessed using screen shots. This is wholly incorrect. None of these things can be assessed via screen shots, for reasons already explained here time and time again.
| mp20748 wrote: | | I as you also mention, based my part on only one ("handful of very specific items") object for discussion, that was agreed on. Did I also comment on anything other than that? |
Not one item that you claim to be assessable via screen shot can be done, outside of calibrating every single display and capture unit in the chain to incredibly tight tolerances. Even then, it's highly likely that the end result will be someone looking at these things on an LCD computer monitor with no better than 1000:1 real world on/off CR and abhorrent black levels. To say that one can judge "blacks" and "deep blacks" (again, a differentiation/definition of both might help everyone else's confusion on what these terms mean within the context of this conversation) on such a low contrast display directly opposes the idea that high CR is critical to attaining high image fidelity.
| mp20748 wrote: | | And how many times would I have to say "you cannot use screenshots for comparison purposes" and "we are using cheap point and shoot cameras" and "screenshots cannot be used as a quantitative means of evaluation" |
You keep saying that, and then you go and talk about judging things that can't be judged via screenshots, so I highly doubt you're doing more than repeating a mantra. See my previous paragraph for how contradictory your statements have been.
| mp20748 wrote: | | So having fun with the guys result in me saying something I've never said other than "black' "deep black "and "Flesh tones" you think maybe I've been doing them long enough to know about these three things? |
This is a classic "appeal to authority" logical fallacy. You're attempting to dodge legitimate criticisms by simply citing that you've been doing this for a while. One can just as easily do things wrong for a long time as they can do them correctly. The length of time for which you've been doing things incorrectly, misapplying knowledge, or utilizing falsities doesn't magically make them less wrong.
| mp20748 wrote: | | And any discussions on calibration and equipment, I'll not get into and think it's an entirely useless discussion, when even you yourself talked about the merits of screenshots. Why even bother to bring up proper calibration on on the subject, when we're talking about the use of cheap point and shoot cameras. Plus, I made it clear, my PJ was NOT calibrated!! |
You dove into the calibration conversation several pages back - by attempting to correct another forum member with your ideas about what does and does not qualify as calibration, nonetheless. Now you're bailing on the discussion when your knowledge of it and how it applies to the topic are being questioned? There would be no need to bail if you had a sufficient working knowledge on the subject.
And exactly how does one compare "flesh tones" between two different projectors in person - let alone via screen shots - when one of the two projectors isn't even calibrated? This is so nonsensical that it boggles the mind.
| mp20748 wrote: | | It's not my field of expertise, and has never been. |
On that, everyone here can agree. Of course, "field of expertise" is a bridge or two too far - I think most would agree that your knowledge of video calibration on any level is tenuous, at best. |
Hey Hog, here's my answer to all of this:
It ain't worth my time. Make of it what you want, because this whole thread is a joke if you ask me and anyone taking anything in it seriously needs to step away from it. Why start majoring in the minors, when the original point in the beginning of the thread is dumb (CRT vs Digital). However, Batman and Robin keeps showing up with the latest and greatest in a present digital technology, when we've been trying to let them know they are not in Gotham, and we go on to let them know we have no interest whatsoever. And to prove my point, how many people here have inquired about the latest X500? First it was an 4K Sony that was so great, but when they found out there was little to no 4K material and had black level issues they got rid of them. Now we must know about how great their new JVC X500 is..
These guys have come in this forum (once more) and have been very rude and disrespectful, they have most arrogantly told us our CRT projectors are too old and worthless, to even posting a picture of a grave. Yet, you want to pick out one from the CRT community to reprimand and/or point out the possible inaccuracies in their post. Why don't you kindly direct them away from this forum instead to keep down the confusion. Or help us to remind them that we're not interested.
And I would say, if they come back the next time, at least let it be an entirely different technology, because that's what we're really waiting on. We already know that anything present is just going through an ongoing upgrade path, and being sold much like how Windows have been ripping us off since the 90's with Windows this that and the other, when none of them were really finished products.
And also, in their pursuit to show us the greatness of the X500, they once again failed. Regardless of all of it's new bells and whistles, it's still just a glorified version of Windows 98 to us....please, when some new technology comes out let us know.
The X500 - No
|
|
| Back to top |
|
|
|
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Forum powered by phpBB © phpBB Group
|
|
