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Author Topic: Choosing a new desk lamp for digital processing.  (Read 88202 times)

Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #60 on: August 10, 2015, 03:08:11 pm »

This stuff is tricky.  I've been trying to improve my understanding of color science by reading books on color science.  Color science books are generally treated as college textbooks and are priced accordingly (usually more then $100 (US)).  However, I've been able to find earlier editions of these books a lot cheaper.

Wayne, I'm at a loss on what you're trying to derive from color science literature that will help you make a choice on print viewing lighting. I can't make heads or tails from it that provides more information than what my eyes tell me which is what I use to make final judgements on how to make better pictures. Subjectivity and visual adaptation will always be a part of the process which makes all this a moving target. All color science appears to do is to constantly adjust their aim to a standard reference that appears to be needing updating. Where's the consistency in that?

I have to remind myself that R=G=B neutrality on a 6500K calibrated display is an emulation of a reference that is impossible to see and that D50 is suppose to be a comparatively warmer looking reference, another standard that is impossible to see. It's made impossible because daylight changes constantly and so does human visual perception. How close is close enough visually or do we want some scientific instrument to tell us and what if that doesn't give us what we want?

Reproduction work of fine art paintings might benefit from this knowledge, but I find practical application and trial and error processes in this area works a lot quicker, is more informative and more accurate.
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Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #61 on: August 10, 2015, 03:45:38 pm »

And then there's the online marketing bullshit you have to sift through like this page I found discussing Philips Lumileds Crisp White...

http://www.ledinside.com/showreport/2015/5/led_chip_and_package_trends_at_led_expo_thailand_2015

Scroll down to the photo of the statues. OH?! A camera malfunction? No one on this Earth can find a decent shot of what these lights are suppose to look like? No one has a better camera at a convention in Thailand?!

Are you freakin' kidding me?!
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Ernst Dinkla

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Re: Choosing a new desk lamp for digital processing.
« Reply #62 on: August 11, 2015, 08:22:06 am »

Still waiting for the commercialization of this invention:
http://news.vanderbilt.edu/2012/05/quantum-dots/
10 years now since the accidental discovery.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2014 update, 700+ inkjet media white spectral plots
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #63 on: August 11, 2015, 09:56:14 am »

Quote
Wayne, I'm at a loss on what you're trying to derive from color science literature that will help you make a choice on print viewing lighting.


You recommended the Soraa bulbs.  I got one based on your recommendation and am trying to evaluate it.  When I compared it visually with my Solux bulb I could see that the Soraa bulb was way different.  So I did some investigating to try to determine what was going on.

Color management is based on color science.  It is impossible to avoid color science if you are using color management.   You don't need to go whole hog and read the classic color science reference books.  But reading articles about the Soraa lamps that you recommended doesn't seem unreasonable.

Wayne
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #64 on: August 11, 2015, 10:05:24 am »

Quote
http://www.ledinside.com/showreport/2015/5/led_chip_and_package_trends_at_led_expo_thailand_2015

Scroll down to the photo of the statues. OH?! A camera malfunction? No one on this Earth can find a decent shot of what these lights are suppose to look like? No one has a better camera at a convention in Thailand?!

You are referring to



The caption is

The camera was malfunctioning during this photo shoot, but at the booth it could clearly observed with the naked eye the statue on the right featuring Lumileds Crisp White LED technology was much whiter than the statue on the left. (LEDinside)

I think that "malfunctioning" means that cameras respond differently than eyes do.    This is no surprise, but complicates the "color rendering index" problem.  We need different methods to measure color rendering for cameras than we need to measure for humans.  

Color science is still a work in progress.

Wayne
« Last Edit: August 11, 2015, 10:07:27 am by WayneLarmon »
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digitaldog

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Re: Choosing a new desk lamp for digital processing.
« Reply #65 on: August 11, 2015, 10:23:44 am »

Color science is still a work in progress.
Indeed! And a photo of what two bulbs are supposed to look like (and we've seen examples) is rather pointless and not based on color science. You're right to use your eyes as well as measurement devices but the reason why LOOKING at something is more valid than measuring it is because measurement is about comparing solid colors. Color appearance is about evaluating images and color in context which measurement devices can not do.
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http://www.digitaldog.net/
Author "Color Management for Photographers".

Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #66 on: August 11, 2015, 03:48:14 pm »

You are referring to...

The caption is

The camera was malfunctioning during this photo shoot, but at the booth it could clearly observed with the naked eye the statue on the right featuring Lumileds Crisp White LED technology was much whiter than the statue on the left. (LEDinside)

I think that "malfunctioning" means that cameras respond differently than eyes do.    This is no surprise, but complicates the "color rendering index" problem.  We need different methods to measure color rendering for cameras than we need to measure for humans.  

Color science is still a work in progress.

A bunch of smart technologists on lighting can't figure out how to switch their camera's AWB to Daylight preset on their camera? Ten years ago I bought a Fuji F10 P&S at Walmart and could set it to Daylight preset which clearly showed WB distinctions in its jpeg rendering between even invisible (pinkish) UV spectrum biases in lighting I photographed.

In case you missed my point calling a WB error as a malfunction of the camera peaked my BS radar off the charts. You've got all these smart scientists and technologists and they just can't seem to produce accurate looking photos of their lights. I couldn't find in a Google image search one image showing the look of Philips Lumileds Crisp White LED lighting except the white fabrics compared to off white from regular LEDs. I can't even find a home use bulb for retail sale that has this technology except car headlights. And if it's as blue as I'm seeing in my rearview mirror at night I'm not interested.

There's too much marketing BS hidden by a vale of respectability provided by all this "techy talk" that thinly qualifies as "color science".

Ernst, thanks for that very interesting link on quantum dots. I too wonder why no actual product has come to market after all that research. So they used an acid ants produce to mark their trail to improve luminance efficiency. A story perfect for CBS's 60 Minutes.
« Last Edit: August 11, 2015, 04:10:07 pm by Tim Lookingbill »
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Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #67 on: August 11, 2015, 04:06:48 pm »

You recommended the Soraa bulbs.  I got one based on your recommendation and am trying to evaluate it.  When I compared it visually with my Solux bulb I could see that the Soraa bulb was way different.  So I did some investigating to try to determine what was going on.

Wayne


Just curious, Wayne, but how different did the Soraa look compared to the Solux? Color of white? Did yellows look greener or reddish?

My issue I had reading those linked LED magazine articles you provided is they don't ask the questions I want answers to and that magazine seems VERY dedicated to this new technology. They write in a way that peaks expectation and interest but deliver very little useable information.

Today I don't have any information that makes me want to buy any of the products they review or analyze. I found out more by just buying and examining the product like the Soraa which is what I've had to do with all the "daylight" lights I've bought for the past 8 or so years researching this.

We're in an information age explosion free to those with an internet connection and I'm having to make the above statement. That makes no sense.
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #68 on: August 11, 2015, 09:56:11 pm »

Quote
A bunch of smart technologists on lighting can't figure out how to switch their camera's AWB to Daylight preset on their camera?

I don't think that it is a white balance issue.  A global white balance adjustment can't correct part of an image.  The author said that the statue on the right looked much whiter than the statue on the left with her eyes.  How can you do a global white balance adjustment that would make the statue on the right be white while leaving the statue on the left looking warm?

I think that it is what I said: that cameras work differently than how humans see.  Most of the time they are similar enough that it doesn't cause a problem.  But sometimes the difference is caught out.  I think that these two particular light sources triggered this kind of failure.

I know that my own cameras see differing white balances as being more extreme than how my eyes see them.  I use warm "soft white" 2700Kish CFLs and LEDs through most of my house.  But use daylight balanced (5000K, I think) bulbs in our kitchen.  I can tell the difference when looking at both rooms, but it isn't extreme.  But if I, for example, shoot a picture in our living room (2700Kish), any portion of the kitchen that shows will be glaring blue.  It doesn't look like this in real life.

Wayne
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #69 on: August 11, 2015, 10:29:01 pm »

Quote
We're in an information age explosion free to those with an internet connection and I'm having to make the above statement. That makes no sense.

Color science hasn't caught up with our needs.  We need ways to measure color rendering in a way that correlates with how our eyes (and cameras) see.  We don't have any such test (yet.)

I just did a test switching between the Soraa lamp, my 4700K Solux bulb, a 120v 90 W 3500 K Solux bulb, and my Home Depot "full spectrum" 5500K CFLs.  I was looking at one of Andrew's test prints and the Digital Outback Printer Evaluation Image. All the bulbs looked different.  It seems to me that the Soraa lamp exaggerates chroma.  Andrew's test image has lots of very saturated colors.  Whenever I switched to the Soraa lamp, the saturated colors looked too extreme (similar to looking at an sRGB image on a wide gamut monitor in a non-color managed environment (like the Windows desktop.))  The colors in the Digital Outback image are more restrained so the effect isn't as pronounced.  The 4700K Solux bulb seemed the most accurate, followed by the 3500 K Solux bulb.   Colors under the CFLs look more muted than any of the other sources.

The Soraa bulb made the whites I saw look whiter than any of the other bulbs did.  But I haven't tested whites (OBAs, etc.) as exhaustively as you have, so I can't really make a judgement on whites.   

If I was judging prints in earnest, I think that I'd want several of the 12V 4700K lamps with the Plano Convex Diffusers  (The diffusers are really needed but they reduce the light level such that it is difficult to use a single Solux lamp.)  One of the three fixture track lighting fixtures with Solux bulbs that were described on the Imatest site clamped to something would probably work.   

The Imatest site doesn't say, but I think that it would be prudent to get the more expensive Solux lamps that have a Black Back.  The Solux bulbs radiate unwanted light out the back of the bulb.  It isn't good to have the unwanted light reflect off the back of the light fixture.    I currently use a Solux black bulb shield on the back of my (non black back) Solux bulb, but it doesn't mount to anything.  It just bobbles loose on the back of the bulb.   I'm afraid that if the bulb works slightly loose in the socket, that the bulb shield would short across the pins.  This would be bad.  In the future, I'd go for the Solux bulbs that have the back permanently black.

Yeah, the only way to really judge them is get copies of the bulbs so you can test them with your own eyes.  Maybe try one of the 120V PAR Solux bulbs.   

Wayne
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Lundberg02

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Re: Choosing a new desk lamp for digital processing.
« Reply #70 on: August 12, 2015, 01:56:03 am »

Wayne, I received my Lavish Desk Lamp, and it is by far the whitest yet pleasing I have around my work area. It is noticeably whiter than the Phillips CFL and Blue Max CFL. I'll be getting some Phillips 100w equiv LEDS in a day or two, so will see how hey match up. Reds look especially good under the Lavish. I wish I had that Argyll color meter to check it. It has that little four tube bulb marked 27 watt.
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Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #71 on: August 12, 2015, 02:38:27 pm »

The Lavish Desk Lamp competitors on that Amazon page Wayne linked to has reviewers using them to grow plants indoors. And then Lights Of America's version... http://www.amazon.com/dp/B00LG6YVLQ/ref=psdc_1063292_t3_B008E6BQXW

has this claim...

Quote
Benefits of full spectrum Lighting: 1) Increases contrast in Reading. 2) Increase release of seratonin a hormone linked to an improved feeling of well being. 3) Increases vitamin D production in skin, which helps the body efficiently use calcium. 4) Render color much more accurately. 5) Reduce levels of melatonin, a harmone that promotes fatigue.

As I recall and I may be wrong but isn't long term exposure to plant growing light dangerous to humans?

I didn't realize there was this many full spectrum desk lamp competitors. Some have over 1000 Amazon reviews.
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #72 on: August 12, 2015, 07:15:28 pm »

Quote
I didn't realize there was this many full spectrum desk lamp competitors. Some have over 1000 Amazon reviews.

It's a SAD, SAD, world. 

Wayne
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Lundberg02

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Re: Choosing a new desk lamp for digital processing.
« Reply #73 on: August 13, 2015, 02:44:30 am »

 <As I recall and I may be wrong but isn't long term exposure to plant growing light dangerous to humans?>
Turns you into a vegetable, yes.
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Rand47

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Re: Choosing a new desk lamp for digital processing.
« Reply #74 on: August 13, 2015, 10:13:43 am »

We've got a person at work who likes this:
http://fiilex.com/products/V70.php

I'm by no means an expert, but would be interested in thoughts.



I checked out their web site and ended up ordering one.  Must say I'm very impressed.  Perfect for prints up to 13x19" and fun and useful to see them under different color temperatures.  The dimmer is sticky, so easy to match monitor for good screen to print match that comports well with my larger inspection station.  This item is great for "sitting next to the monitor" evaluation of proof prints/smaller prints.

Beautifully made as well.

Rand
« Last Edit: August 13, 2015, 10:15:46 am by Rand47 »
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Rand Scott Adams

Tim Lookingbill

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Re: Choosing a new desk lamp for digital processing.
« Reply #75 on: August 13, 2015, 03:46:15 pm »

I checked out their web site and ended up ordering one.  Must say I'm very impressed.  Perfect for prints up to 13x19" and fun and useful to see them under different color temperatures.  The dimmer is sticky, so easy to match monitor for good screen to print match that comports well with my larger inspection station.  This item is great for "sitting next to the monitor" evaluation of proof prints/smaller prints.

Beautifully made as well.

Rand

Does the Fiilex desk lamp render cadmium yellow with a slight green or cyan tint at any color temperature? I noticed Fiilex site's CRI for yellow requires a quite bluish 6500K to render yellow at CRI 96.

What I've noted about overall CRI claims on a wide range of daylight CFL & LED bulbs/tubes' is that it doesn't indicate hue differences which is more noticeable than saturation. Most of the colors viewed under these lights look acceptable except for yellow and WB looking a bit too cyan blue or slightly greenish pastel beige but I've never come across a CRI table that measures and rates each individual color patch as noted on the Fiilex site. For me if cadmium yellow looks as it should under any light that's all I need to know.

$200 for a lamp? Understandable for professionals but not sure it's enticing for hobbyists, but then they're known to spend over $3000 for a lens & camera system. Hope its AC to DC converter holds up better than my discontinued Eiko Solux task lamp.

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Lundberg02

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Re: Choosing a new desk lamp for digital processing.
« Reply #76 on: August 13, 2015, 09:55:50 pm »

Apparently the Argyll PRO ColorMeter will run on Android v4 and later . I already have an i1 Display Pro, so it looks like I could get n RCA 7" tablet running Android 4 something for 45 bucks at Walmart and be able to measure all my lights. This cheap tablet has the microUSB needed. Its resolution is 1080x640 but who cares. I could also get a Nexus 7 for 149 from Newegg that is quite a nice tablet. I'm not happy with my 1st gen iPad anyway. Any thoughts?
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Lundberg02

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Re: Choosing a new desk lamp for digital processing.
« Reply #77 on: August 14, 2015, 06:51:55 pm »

So I am seeing now my Phillips A19 100w equivalent, 5000K bulb side by side with the Lavish desk lamp 6500K fluorescent. The Phillips claims 1500 lumens and the Lavish 1300. i have moderate north light coming in thru  a basement window well. Both lamps compare fairly well with the north light. The Lavish is bluer, the Phillips is brighter. I also have a CFL in another desk lamp that is not on but is 3000k and is considerably warmer when I want it. I'm quite pleased with this setup. So pleased that I think I'll go ahead and get something Android to use the Argyll with so that I'll know exactly what I'm seeing.
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #78 on: August 14, 2015, 07:34:52 pm »

Quote
Apparently the Argyll PRO ColorMeter will run on Android v4 and later.

Yes. I have ColorMeter and it works great.  This is what I used to get the spectro plots I put in my posts here.

I use an 8" Samsung Galaxy Tab Pro tablet, but it also works on my wife's discarded Samsung Galaxy III smartphone.  The UI is designed to run on a 7" tablet.   You can download it and try it on your own device in demo mode (everything works, except that it won't takes any real measurements--it substitutes dummy sample measurements.)   You need an OTG adapter to connect your spectrometer (I use ColorMunki Design).

Highly recommended.

Wayne
« Last Edit: August 15, 2015, 09:09:22 am by WayneLarmon »
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WayneLarmon

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Re: Choosing a new desk lamp for digital processing.
« Reply #79 on: August 14, 2015, 09:59:55 pm »

Quote
...So pleased that I think I'll go ahead and get something Android to use the Argyll with so that I'll know exactly what I'm seeing.

I missed this line.  If you are already using Argyll with a spectrometer, you can get some of what ColorMeter does with Argyll spotread.  Both ColorMeter and spotread will display the spectral plot of whatever you are measuring.  Both will give CRI (Color Rendering Index) and CCT (Correlated Color Temperature).   

But ColorMeter on a tablet is easier to use and does a lot more than spotread does.

Wayne
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