I've been using my Eyeone display lt sensor for calibration purpose only at night, on my plasma screen to avoid light interference.

Wishing to calibrate in daylight conditions, I'm wondering if there is any risk of light interference on sensor's measurements.

I mean the sensor is attached to the screen and wondering if there is any need to put some black tape around the sensor to avoid light interference.

Any suggestion?

I've been using my Eyeone display lt sensor for calibration purpose only at night, on my plasma screen to avoid light interference.

Wishing to calibrate in daylight conditions, I'm wondering if there is any risk of light interference on sensor's measurements.

I mean the sensor is attached to the screen and wondering if there is any need to put some black tape around the sensor to avoid light interference.

Any suggestion?

Why not try to get a reading with the TV off? If you get any reading,
you know you have light leakage.

good idea!

Do you want to laugh? :D

This morning with the TV room flooded by sun, I've attached the sensor to the plasma screen (power OFF), WITHOUT any lightshied,and performed a free measurement:

x=0.320
y=0.195
Y=0.000

I'm wondering how can it be possible! Maybe the rubber "ring" on the base of the sensor is preventing light leakage?

Could someone confirm?

Confirmed, well, perhaps not with the room flooded in sunlight, but in daylight conditions I get no different readings for the black level compared to what I get with the room in complete darkness so that foam seal seems to be doing a good job, at least as long as you are able to put pressure on the Display 2/LT sensor to make a tight seal, i.e. when using on a TV with a glass panel. I don't think it would work so well with a LCD for example where you can't push the sensor against the screen in the same way.

That's a good news! No more "all night long" calibrations! Can start in the afternoon!
Consider that the 8Gs are reported not to have a glass, but the surface "accepts" small pressures (at least it looks like)... I use my daughter's small chair to "push" gently the sensor on screen...

Moreover we don't need that clumky shoebox, that sure doesn't help with temp drifts.

Well, a better scenario! Don't need to darken room and TV when recal and can be used in daylight!

Good! :)

Yes, well said, I certainly didn't mean anything other than very slight pressure applied on the sensor against the glass surface to keep the seal tight.

The only thing to consider is setting of black level and white level which will differ when viewing in a lighted as opposed to a darkened room, which in turn means a different gamma target, i.e. I still think you will need to calibrate in a darkened room (or only lit by a bias light) for a dark room result ;)

Yeah, well I'm still in the "learner" phase, trying to tame measurements and settings!!! Thos fine adjustments between day and night are in a not-so-near future!!!!
At the moment I'm trying to achieve good measurements and good looking images!
BTW did you get the cable? If so you could post some results in the other thread.....

Hehe, certainly no professional myself, also learning as I go along.

Yes, I finally got my hands on a cable and I will post results eventually. Still learning the slightly different approach using an interface to the TV :)

Ok share your thoughts (workflow, patterns, sensor usage...) :)

Will do, as soon as I have something to share that I feel works well for me ;)

I've also done daytime and nighttime readings with my Samsung LCD and an Eye-One Display colorimeter and the results were within normal variance (i.e. the same differences I might get between two nighttime readings). I was simply gently pressing the sensor up against the display so the suction cups just make contact. While the room was not flooded within sunlight, it was definitely much brighter than at night with the lights off.

cheers,


--tom

Having just completed about seven calibration runs (first time using instruments!) on my 50" plasma; I ran some tests between normal daytime light and a darkened room and the readings seem to be affected at 10% gray and below. That 10% area and below is not considered highly accurate anyway.
One thing that did help to diminish the low level errors of external light was to place a black matt finish, 8 x 10 inch paper over the sensor, to eliminate light hitting the surrounding sensor glass.

I think it depends a lot on how do you place the sensor.

I use a small chair to press very gently the sensor on the screen, in a way that the pressure is distributed evenly on the sensor so the rubber ring adheres perfectly on the screen, avoiding light leakage.

It's a bit tricky because the sensor's shell is rounded so you have to experiment and find the right point to apply the pressure (if you ideally cut in half horizontally the sensor, it looks like the ideal point is slightly below the "cut")

Light leakage around the seal is very important as you point out, however I suspect that the light will bounce off the screen (plasma unit) and return through the one or two layers of glass to the sensor, depending on the angle of the incident light.
I'm sure these issues only affect the very low (<10%) values in normal room light.

As I've wrote, I've measured in sunlight conditions (no direct sun on screen, just sun beams in the room, on the floor for eaxample) and got an Y=0. Did so for a few minutes to be sure.