measuring 0.001 cd/m2 - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 17 Old 01-21-2013, 01:12 AM - Thread Starter
Senior Member
 
freebits's Avatar
 
Join Date: Jan 2004
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Which meter would you recommend to measure lowest black level like 0.001 cd/m2?

Minolta LS-100, or Klein K-10, Jeti 1211?
freebits is online now  
Sponsored Links
Advertisement
 
post #2 of 17 Old 01-21-2013, 01:42 AM
Senior Member
 
<^..^>Smokey Joe's Avatar
 
Join Date: Aug 2006
Location: Christchurch, New Zealand
Posts: 362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 38
A caution about measurement, Just because a device can detect something doesn't actually mean that the measurement has any meaningful result.

Klien K-10A

Most consumer displays will deviate each reading at this level greater than the measurement accuracy, or repeatability of the device.
Secondly, most displays are far to crude in adjustment steps to take absolute advantage of such low level readings.

The advantage of the Klien is speed, relative to the likes of the Jeti, but if time isnt the problem, the jeti can read(describe) colour better overall. Horses for courses.

Masterpiece Calibration Ltd
Christchurch NZ
<^..^>Smokey Joe is offline  
post #3 of 17 Old 01-21-2013, 02:21 AM
AVS Special Member
 
ConnecTEDDD's Avatar
 
Join Date: Sep 2010
Location: Athens, Greece
Posts: 2,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked: 406
Tom has upload a video of Measuring a KURO using Klein K-10A

His Full Review is here

Ted's LightSpace CMS Calibration Disk Free Version for Free Calibration Software: LightSpace DPS + CalMAN ColorChecker
S/W: LightSpace CMS, SpaceMan ICC, SpaceMatch DCM, CalMAN 5, CalMAN RGB, ChromaPure, CalPC, ControlCAL
Meters: JETI Specbos 1211, Klein K-10A, i1PRO2, i1PRO, SpectraCAL C6, i1D3, C5
ConnecTEDDD is offline  
post #4 of 17 Old 01-21-2013, 02:30 AM
Advanced Member
 
Light Illusion's Avatar
 
Join Date: Aug 2010
Posts: 518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 211
The Jeti 1211 cannot measure low light levels - it's limit is quoted as being 0.1 Nits.
(This because it has no in-built sensor cooling)

The k10-A (not the K10) can read down to 0.01 Nits.
The PR-670 can do 0.035 Nits.
The CS-200 can do 0.01 Nits...

But, just because a probe can read to low-light levels doesn't mean it will be accurate - especially with colour readings.

Steve

Steve Shaw
LIGHT ILLUSION

Light Illusion is offline  
post #5 of 17 Old 01-21-2013, 04:10 AM - Thread Starter
Senior Member
 
freebits's Avatar
 
Join Date: Jan 2004
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Nobody has commented on Minolta LS-100? Isn't it a reference luminance meter cheaper than K10 or 1211?
freebits is online now  
post #6 of 17 Old 01-21-2013, 04:11 AM - Thread Starter
Senior Member
 
freebits's Avatar
 
Join Date: Jan 2004
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14

I've seen it before. Thanks.
freebits is online now  
post #7 of 17 Old 01-21-2013, 07:48 AM
AVS Special Member
 
derekjsmith's Avatar
 
Join Date: Oct 2003
Location: Mukilteo, WA
Posts: 1,890
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 98
Quote:
Originally Posted by Light Illusion View Post

The Jeti 1211 cannot measure low light levels - it's limit is quoted as being 0.1 Nits.
(This because it has no in-built sensor cooling)

The k10-A (not the K10) can read down to 0.01 Nits.
The PR-670 can do 0.035 Nits.
The CS-200 can do 0.001 Nits...

But, just because a probe can read to low-light levels doesn't mean it will be accurate - especially with colour readings.

Steve

So Steve how did you arrive at these numbers? Do you know how the K10 is tested by Luhr at Klein? The K10A can accurately measure lower than 0.01 so I'm not sure why you say it can't.

Derek

CTO / Founder - SpectraCal Inc.
derekjsmith is offline  
post #8 of 17 Old 01-21-2013, 08:21 AM
AVS Special Member
 
turbe's Avatar
 
Join Date: Feb 2001
Location: Lake Tahoe, NV
Posts: 4,422
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 84
I actually shot Luhr an email this morning about this.. What's a little confusing about the K10-A's posted spec is "displayed value > 0.01 nits" (Chroma "displayed value > .33 nits").

I know the head unit's can actually process 256 measurements per second, but only 8 per second are displayed / reported (for "readability"). I asked Luhr to expand further on whether there is a cap during this reported / displayed process in regards to the above..

At first thought, I thought there was a cap in Klein's own software, there may be one in the instrument's reporting.. My K10 has not been upgraded by Luhr to a K10-A yet.

Also, that spec for the CS-200 is not correct from what I am seeing..

Need to find a Professional Calibrator? Click Here to PM me with your Display & City

Calibrator List - Pioneer ISFccc Interface

Calibration Reports - Pioneer

 

ControlCAL™
Designed by Calibrators for Calibrators™

No need to fumble through the Display's Menu with its Remote Control™

turbe is offline  
post #9 of 17 Old 01-21-2013, 11:05 AM
AVS Special Member
 
Doug Blackburn's Avatar
 
Join Date: May 2008
Location: San Francisco - East Bay area
Posts: 3,440
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 196
The CS-200 has a pretty low light measurement spec, but the tolerance is quite large at the lowest levels, and it really can't deal with color at those low levels, color readings jump all over the place when the light levels are very low, even though the luminance reading may be consistent.

The LS-100 Konica Minolta meter is quite good for luminance, but it's not a meter can use for calibration since it doesn't measure color. So while it may be less expensive than "better" colorimeters, it can't tell if what it is measuring is red or lavender or lime green and it can't tell your software what the color coordinates for the measured point are. Luminance... yes, color... no.

"Movies is magic..." Van Dyke Parks
THX Certified Professional Video Calibration
ISF -- HAA -- www.dBtheatrical.com
Widescreen Review -- Home Theater & Sound
Doug Blackburn is offline  
post #10 of 17 Old 01-21-2013, 11:16 AM
Advanced Member
 
Light Illusion's Avatar
 
Join Date: Aug 2010
Posts: 518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 211
Quote:
So Steve how did you arrive at these numbers? Do you know how the K10 is tested by Luhr at Klein? The K10A can accurately measure lower than 0.01 so I'm not sure why you say it can't.
Yep, I talk with Luhr a lot - we are the European 'hub' for sales of the Klein probes biggrin.gif

All the value are what the manufacturers have told us they are 'happy' to quote as viable operational limits.

Often the probes 'may' read lower, but that is not guaranteed...

Also. probes often show inaccurate 'colour' when measuring low-light values due to 'strange' colour spectrum radiation from back-lights, etc.
This means that even though the probe may technically be reading accurately, the results are not viable for calibration.

All good fun!

Steve

Steve Shaw
LIGHT ILLUSION

Light Illusion is offline  
post #11 of 17 Old 01-21-2013, 11:19 AM
Advanced Member
 
Light Illusion's Avatar
 
Join Date: Aug 2010
Posts: 518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 211
Quote:
Also, that spec for the CS-200 is not correct from what I am seeing..
Ooops! Added an extra '0' in there!

Thanks for pointing that out!

biggrin.gif

Steve Shaw
LIGHT ILLUSION

Light Illusion is offline  
post #12 of 17 Old 01-21-2013, 04:33 PM
Senior Member
 
<^..^>Smokey Joe's Avatar
 
Join Date: Aug 2006
Location: Christchurch, New Zealand
Posts: 362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 38
What you talk about here is dominant wavelength, when the light is weak only that peak is detected.


I'd also point out my first comment(earlier post), about measuring nonsense. These are Toms sequence readings for one point, according to his settings 0 white.
Dominant wavelength effect, maybe, but appears to blue region, but then look at the scatter and eractic readings seen as linear lines. This is noise. Which is correct??? Hard to tell. The noise is possibly also the display, also hard to tell.



The fact is, in the field without lab grade equipment or lab environment you ain't going to measure 0.001 cd/m^2 accurately or easily. Detection and accuracy are two completely different things.

Masterpiece Calibration Ltd
Christchurch NZ
<^..^>Smokey Joe is offline  
post #13 of 17 Old 01-21-2013, 07:50 PM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,353
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked: 203
Guys, at the light levels we are talking about--0.001 cd/m2--the accuracy of COLOR measurements is pretty much irrelevant since humans must rely on scotopic vision that low and are all but color blind. The only concern at very low levels of stimulus that is relevant to display calibration is luminance, to which the human eye remains very sensitive even at these very low levels. The Klein K-10A cannot measure color down to 0.001 cd/m2, and even if it could it wouldn't matter because we couldn't see it. However, it can measure luminance that low with good repeatability.

Tom Huffman
ChromaPure Software/AccuPel Video Signal Generators
ISF/THX Calibrations
Springfield, MO

TomHuffman is offline  
post #14 of 17 Old 01-21-2013, 08:34 PM
AVS Special Member
 
turbe's Avatar
 
Join Date: Feb 2001
Location: Lake Tahoe, NV
Posts: 4,422
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 84
Quote:
However, it can measure luminance that low with good repeatability.

yes, I was posting about that (Chroma "displayed value > .33 nits") and (Luminance displayed value > 0.01 nits), however, I still don't understand the spec Luhr has up now for displayed value> 0.01 nits... I ask for clarification!

Need to find a Professional Calibrator? Click Here to PM me with your Display & City

Calibrator List - Pioneer ISFccc Interface

Calibration Reports - Pioneer

 

ControlCAL™
Designed by Calibrators for Calibrators™

No need to fumble through the Display's Menu with its Remote Control™

turbe is offline  
post #15 of 17 Old 01-21-2013, 09:07 PM - Thread Starter
Senior Member
 
freebits's Avatar
 
Join Date: Jan 2004
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by Doug Blackburn View Post

The CS-200 has a pretty low light measurement spec, but the tolerance is quite large at the lowest levels, and it really can't deal with color at those low levels, color readings jump all over the place when the light levels are very low, even though the luminance reading may be consistent.

The LS-100 Konica Minolta meter is quite good for luminance, but it's not a meter can use for calibration since it doesn't measure color. So while it may be less expensive than "better" colorimeters, it can't tell if what it is measuring is red or lavender or lime green and it can't tell your software what the color coordinates for the measured point are. Luminance... yes, color... no.

Thanks. The only concern I have is luminance not color. It seems it's a hand held device easy to measure contrast w/o PC.
freebits is online now  
post #16 of 17 Old 01-21-2013, 09:27 PM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,353
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked: 203
Quote:
Originally Posted by turbe View Post

yes, I was posting about that (Chroma "displayed value > .33 nits") and (Luminance displayed value > 0.01 nits), however, I still don't understand the spec Luhr has up now for displayed value> 0.01 nits... I ask for clarification!
I suspect that they are just being conservative.

Tom Huffman
ChromaPure Software/AccuPel Video Signal Generators
ISF/THX Calibrations
Springfield, MO

TomHuffman is offline  
post #17 of 17 Old 01-22-2013, 01:53 AM
Senior Member
 
<^..^>Smokey Joe's Avatar
 
Join Date: Aug 2006
Location: Christchurch, New Zealand
Posts: 362
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 38
Tom I agree with ya about colour and levels, depending on the source of information and testing method, Photopic detection cuts off about 3~1.0 cd/m^2, where human chroma detection is greatly effected.

Freebits, you don't really describe your purpose of the low level readings and what value you place upon the knowledge (How much you want to spend to know the answer).
The i1Display (oem) is rated to 0.1 cd/m^2 and arguably the best hit power for buck for detection levels.
The Klien costs considerably more for the 0.01 cd/m^2 ,actually like the decimal factor of ten, likewise the cost difference.

2.1c worth

Masterpiece Calibration Ltd
Christchurch NZ
<^..^>Smokey Joe is offline  
Reply Display Calibration

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off