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Profiling Colorimeter To Spectro

post #1 of 23
9/9/12 at 8:23pm
Thread Starter 
Hi,

I have a D3 (i1 Display Pro) here which I will profile to the i1 Pro (Rev D) I just purchased.

It appears that this spectro / colorimeter combo is a good consumer level solution, I wonder would the Discus / i1 Pro combo give me better results ? I'm assuming the only improvement would be the better repeatability accuracy of the Discus over the D3... Anything else that the Discus brings to the table as an improvement to the D3 in a combo solution ?

Regarding the profiling process and workflow:

1) For my previous calibrations (using just the D3) I have placed the D3 directly on the screen - do I place it directly on the screen for the profiling process as well ?

2) what is the placement of the i1 Pro when profiling ? on screen ? on a tri-pod a few inches away ?

3) use the (profiled) colorimeter for grayscale & gamma and the spectro for gamut work ?


Thanks for any help, input and general info on this process.

- M
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post #2 of 23
9/11/12 at 12:14pm
Quote:
Originally Posted by Iron Mike View Post

Hi,
I have a D3 (i1 Display Pro) here which I will profile to the i1 Pro (Rev D) I just purchased.
It appears that this spectro / colorimeter combo is a good consumer level solution, I wonder would the Discus / i1 Pro combo give me better results ? I'm assuming the only improvement would be the better repeatability accuracy of the Discus over the D3... Anything else that the Discus brings to the table as an improvement to the D3 in a combo solution ?
Regarding the profiling process and workflow:
1) For my previous calibrations (using just the D3) I have placed the D3 directly on the screen - do I place it directly on the screen for the profiling process as well ?
2) what is the placement of the i1 Pro when profiling ? on screen ? on a tri-pod a few inches away ?
3) use the (profiled) colorimeter for grayscale & gamma and the spectro for gamut work ?
Thanks for any help, input and general info on this process.
- M

Hi ironlike,

In answer to your questions;

1). directly
2). On screen using the adaptor
3). Upto you, D3 better at low light, pro more accurate at everything else.
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post #3 of 23
9/11/12 at 2:58pm
Thread Starter 
@ndaa75: thank you for your response.

just to make sure I'm not misunderstanding calibration fundamentals here: when we talk about "low light" (where the colorimeter is more accurate), we talk about usage in grayscale & gamma, correct ?

Also, I just chatted with another AVS member regarding WARM UP TIME, and we are both a little bit confused as there are so many posts that say different things:

> obviously the display needs to warm up properly (1-2 hours)

4) Is there a warm up time for colorimeters, for example the i1 Display Pro ?

5) can I leave the colorimeter on screen for the duration of the calibration or will the heat of the display throw off the colorimeter over time ?

6) Is there a warm up time for spectros, for example the i1 Pro ?

7) can I leave the spectro on screen for the duration of the calibration (e.g. gamut work) or will the heat of the display throw off the spectro over time ?


Thanks again.

- M
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post #4 of 23
9/11/12 at 6:46pm
Quote:
Originally Posted by ndaa75 View Post

3). Upto you, D3 better at low light, pro more accurate at everything else.

How low is 'low light'? ie, are we talking about 10, 20%? or slightly higher? How accurate is the Pro at those brightness settings. Obviously it may not be as accurate as the D3, but how much error are we talking about?

Thanks.
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post #5 of 23
9/11/12 at 10:58pm
Quote:
Originally Posted by wildgoose View Post

How low is 'low light'? ie, are we talking about 10, 20%? or slightly higher?.

It's not really a function of %stimulus, "low light accuracy" of the i1pro is a function of absolute luminance. In my (limited) experience with the i1pro, it starts getting a bit wonky below ~1.0 to 1.5 nits (or ~15% stim on my display.) Of course, I never got around to profiling my colorimeter for comparison as I originally planned. YMMV ...
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post #6 of 23
9/11/12 at 11:31pm
Quote:
Originally Posted by HDTVChallenged View Post

It's not really a function of %stimulus, "low light accuracy" of the i1pro is a function of absolute luminance. In my (limited) experience with the i1pro, it starts getting a bit wonky below ~1.0 to 1.5 nits (or ~15% stim on my display.) Of course, I never got around to profiling my colorimeter for comparison as I originally planned. YMMV ...

That's about dead on.

Also to note, is that it's not like it hits a point and falls off a cliff, it just starts getting off at maybe even 2-3 cd/m and just continues to be further and further off as the light levels drop.

So If you have a bright flat panel that point is pretty low, but if you have a dim projector, then that threshold is much more significant.
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post #7 of 23
9/12/12 at 12:57pm
Scotti

So, what you're saying is that the readings start becoming inaccurate? I thought you just started getting readings that bounce around alot..
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post #8 of 23
9/12/12 at 1:38pm
Quote:
Originally Posted by JimP View Post

Scotti
So, what you're saying is that the readings start becoming inaccurate? I thought you just started getting readings that bounce around alot..

Repeatability is closely tied to accuracy.

Whenever you lose repeatability accuracy drops. CalMAN has some advanced handler code to take multiple readings and do intelligent averaging, but even then your accuracy is going to decline as luminance levels drop.
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post #9 of 23
9/12/12 at 3:26pm
Thread Starter 
can anybody comment on the warm up periods, points 4) 5) 6) 7) ?

Thanks !

- M
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post #10 of 23
9/12/12 at 4:08pm
Quote:
Originally Posted by Iron Mike View Post

can anybody comment on the warm up periods, points 4) 5) 6) 7) ?
Thanks !
- M

From everything I have read, both meters have temperature compensation built in and should not be effected.
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post #11 of 23
9/12/12 at 6:39pm
Thread Starter 
Quote:
Originally Posted by airscapes View Post

From everything I have read, both meters have temperature compensation built in and should not be effected.

is there a necessary warm up period for either colorimeter or spectro ?
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post #12 of 23
9/12/12 at 6:45pm
Quote:
Originally Posted by airscapes View Post

From everything I have read, both meters have temperature compensation built in and should not be effected.

the D3/C6 has built-in temp comp? I find I need about 30 mins of warm up on the display to get stable, accurate readings (and the display needs to be warmed up for a hour or more)

I assume the i1Pro uses the dark readings for temp comp? am I right?
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post #13 of 23
9/12/12 at 7:51pm
Quote:
Originally Posted by PlasmaPZ80U View Post

the D3/C6 has built-in temp comp? I find I need about 30 mins of warm up on the display to get stable, accurate readings (and the display needs to be warmed up for a hour or more)
I assume the i1Pro uses the dark readings for temp comp? am I right?

I could swear I recall Derek or someone from specracal saying the C6 has thermal compensation built in. BUT, I have been wrong before.. just ask my wife! biggrin.gif
I think most folks that use a meter in contact mode hang as soon as they start the display so it warms up with the display but if you are using a tripod in non contact mode it really wouldn't need that.. so your readings become stable would seem to be more of a display stabilization issue than meter wouldn't you think?
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post #14 of 23
9/12/12 at 8:48pm
Any temperature compensation for the i1Display3 pro?
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post #15 of 23
9/12/12 at 9:21pm
Quote:
Originally Posted by JimP View Post

Any temperature compensation for the i1Display3 pro?

According to this review, the i1 Display Pro (a.k.a. D3) does have some temperature compensation.
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post #16 of 23
9/12/12 at 9:35pm
Quote:
Originally Posted by sotti View Post


Also to note, is that it's not like it hits a point and falls off a cliff, it just starts getting off at maybe even 2-3 cd/m and just continues to be further and further off as the light levels drop.
So If you have a bright flat panel that point is pretty low, but if you have a dim projector, then that threshold is much more significant.

Exactly ... It (the i1Pro) was good enough on my LCD to do the traditional power law (+BLC) curve without dragging out the colorimeter to get the 10% point.

I originally planned to profile my D2 (which for the record was reading ~4 dE "off" from the i1pro) and redo my BT1886 curve, but I haven't gotten around to that yet.

From all the horror stories, I expected the D2 to be much worse than it was. wink.gif

Edit: I should clarify that the i1pro said the previous D2 run was off by ~4 dE (not enough green.) For those that care about such things. smile.gif
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post #17 of 23
9/13/12 at 6:07am
Quote:
Originally Posted by slb View Post

According to this review, the i1 Display Pro (a.k.a. D3) does have some temperature compensation.

What it doesn't address is whether or not its software based similar to the i1pro2. I think it's more likely that they'd use the same logic on both.
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post #18 of 23
10/5/12 at 5:17pm
Thread Starter 
I can definitely confirm that my i1D3 needs a warm up time on screen (about 30 min)... I did a full 125 point calibration with the Lumagen on my RPTV yday and the initial readings by the i1D3 were bogus (4-5 dE off), it stabilized later...
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post #19 of 23
10/5/12 at 5:27pm
That's surprising. I've not known an RPTV screen to get warm. Was the meter colder than room temperature at the beginning?
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post #20 of 23
10/5/12 at 5:47pm
Thread Starter 
Quote:
Originally Posted by Chad B View Post

That's surprising. I've not known an RPTV screen to get warm. Was the meter colder than room temperature at the beginning?

hmmm, hard for me to say but I don't think so - i mean I didn't have the i1D3 in the freezer... ;-) btw Chad, the RPTV I'm referring to is the model you used to own as well: Sony KDS-R60XBR1... ;-)

in my scenario yday, the display was warmed up (3-4 hours), I put on the i1D3 and ran a verification report again in Calman 5 on a calibration I did a day earlier... numbers were completely off (4-5 dE) from what I wrote down a day earlier... I thought I had an issue with the Lumagen... after checking everything and coming back to it 20 min later or so, I ran the verification again and numbers now matched from a day earlier (+- 0.2 dE for the usual inaccuracy in repeatability with colorimeters)...

I will definitely from now on make test readings with the i1D3 before starting to calibrate to make sure it returns consistent, stable, accurate readings...
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post #21 of 23
10/6/12 at 6:15pm
Iron Mike,

Could it be that just having the i1D3 connected to your laptop with it on runs enough power through it, that in 20-30 minutes it stabilizes? That's what I'm finding using Chromapure and didn't know if Calman performed the same way.
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post #22 of 23
10/6/12 at 8:19pm
Thread Starter 
I don't think that the power stabilizes over a while on a USB connection - it should be consistent from the moment you plug it in... will make more tests later tonight when I do another calibration...
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post #23 of 23
10/7/12 at 2:01pm
Light is radiation energy, transform it by sensor absorbing the energy and you have heat.
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