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Author Topic: Light for print viewing  (Read 2413 times)

digitaldog

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Re: Light for print viewing
« Reply #60 on: December 06, 2017, 10:16:54 AM »

I purchased a SoLux proofing kit with 4 5000K bulbs. After assembling it and plugging it in here’s something burning/vaporizing off the bulbs. I never touched the bulbs or fixtures with bare hands, only my paper handling gloves. Is this normal? Also their web site says the 5000K bulbs are rated for 100 hours while the 4700K bulbs are rated for 4000 hours. That 40x difference can’t be right, can it?
Yes, it's somewhat normal. But you should really gone CCT 4700K as it is the same bulb, running LESS wattage and lasts longer.
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Andrew Rodney
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Mackman

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Re: Light for print viewing
« Reply #61 on: December 06, 2017, 10:42:34 AM »

Ok, guess I’ll swap to 4700K when these burn out.
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Rand47

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Re: Light for print viewing
« Reply #62 on: December 06, 2017, 11:19:12 AM »

I purchased a SoLux proofing kit with 4 5000K bulbs. After assembling it and plugging it in here’s something burning/vaporizing off the bulbs. I never touched the bulbs or fixtures with bare hands, only my paper handling gloves. Is this normal? Also their web site says the 5000K bulbs are rated for 100 hours while the 4700K bulbs are rated for 4000 hours. That 40x difference can’t be right, can it?

Yes... the first time I fired up my Solux track lights (after being careful not to get fingers on bulbs, etc.) it sent my electrician scrambling up into the overhead to make sure all was well with the wiring!  I think it was a combination of “some” residual people-oil on the glass discs, and/or bulbs, but mostly the paint on the fixtures themselves “curing” under the heat generated by the bulbs.   It went away after a bit.  So, as long as you’re sure you’re “good” wiring-wise, I’d not be alarmed.

And I concur re the 4700k temp bulbs.  While my GTI booth (5000) is great for accurate comparisons, the Solux 4700k is what I used to “enjoy” prints and to show clients how their prints look! While my GTI booth (5000) is great for accurate comparisons, the Solux 4700k is what I used to “enjoy” prints and to show clients how their prints look!

I also have a Fiilex V70 desktop viewing lamp (LED) w/ variable temps.  Specs say CRI is greater than 90.  It’s actually quite nice, for what it is, and is often useful for showing clients the impact of different color temps on the apearance of their prints.

Rand
« Last Edit: December 06, 2017, 11:29:56 AM by Rand47 »
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Rand Scott Adams

Tim Lookingbill

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Re: Light for print viewing
« Reply #63 on: December 06, 2017, 02:23:02 PM »

I've been having issues with the Hyperikon 5000K LED BR40 floods in that the second one I bought has a noticeable color temp difference (see CCchart image below that I also sent by email to Hyperikon's support).

It appears these daylight balanced CFL/LED high CRI rated bulb companies vary in their manufacturing tolerances and quality of customer service because Hyperikon jumped on my problem immediately and shipped me free of charge a replacement only to find it too had the white balance hue (greenish buttermilk) I didn't want. I just got off the phone with Hyperikon CSR and they narrowed it down to the bulb I want has an FCC number which they are going to hunt down in their inventory and ship it to me for free. Now that's customer service.

I wish I could say that about the LED Soraa folks. It was impossible to even find a contact number when I had issues with a cracked front Fresnel glass element.

For print viewing both Hyperikons are adequate at 94 CRI but the one that is on the slightly reddish side (the one the left) has more accurate CCchart Lab numbers by clicking for R=G=B on the mid gray patch. None look perfectly neutral but they do put out a lot of ambient light for a 12x14ft. white walled room.

My Solux lamp's power converter block quit after about 40 hours of off and on use spread out across several years. I paid around $80 that included the 50watt 4700K bulb. I still have the bulb but never bothered to buy another lamp after Tailored Lighting wouldn't replace the lamp since it was out of warranty.

My Hyperikons have a 5 year unlimited warranty and put out far more light than the 50 watt Solux.

I wonder how PIXAR became a client of Hyperikon's after seeing their logo on their website.
« Last Edit: December 06, 2017, 02:26:19 PM by Tim Lookingbill »
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digitaldog

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Re: Light for print viewing
« Reply #64 on: December 06, 2017, 03:22:26 PM »

For print viewing both Hyperikons are adequate at 94 CRI but the one that is on the slightly reddish side (the one the left) has more accurate CCchart Lab numbers by clicking for R=G=B on the mid gray patch. None look perfectly neutral but they do put out a lot of ambient light for a 12x14ft. white walled room.
Adequate at 94 CRI? You still seriously believe that CRI has any useful metric outside the massive marketing speak from those who designed CRI and use it to sell bulbs?

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My Hyperikons have a 5 year unlimited warranty and put out far more light than the 50 watt Solux.
Now please compare a spectral plot of each and post. 5 years of spikes vs. smooth and less light? I know which I'd buy.
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Andrew Rodney
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Tim Lookingbill

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Re: Light for print viewing
« Reply #65 on: December 06, 2017, 04:06:41 PM »

Adequate at 94 CRI? You still seriously believe that CRI has any useful metric outside the massive marketing speak from those who designed CRI and use it to sell bulbs?
 Now please compare a spectral plot of each and post. 5 years of spikes vs. smooth and less light? I know which I'd buy.

I don't make nor am I interested in viewing photos according to whether they follow a spectral plot. I indicated the Hyperikons are adequate for me as print viewing lights. They're even better than the Philips Natural Light 5000K T8's flotubes.

And I only use CRI as a guide on whether I should consider their color rendering capabilities. I'm not looking for perfection because my eye's adaptive nature to changing lights from different devices takes care of the rest. The CC chart results I posted are adequate enough for me.
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digitaldog

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Re: Light for print viewing
« Reply #66 on: December 06, 2017, 04:58:35 PM »

I don't make nor am I interested in viewing photos according to whether they follow a spectral plot.
Don't have the hardware, software or know how? But a bogus CRI number impresses you.
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I indicated the Hyperikons are adequate for me as print viewing lights. They're even better than the Philips Natural Light 5000K T8's flotubes.
Yes adequate for you. And no comparisons with Solux who's spectral plots are damn telling.
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And I only use CRI as a guide on whether I should consider their color rendering capabilities
Indeed, you believe despite the facts, this marketing designed metric from the lighting manufacturers actually tells you about color rendering capabilities: it really doesn't. 
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I'm not looking for perfection because my eye's adaptive nature to changing lights from different devices takes care of the rest.
Yes, do tell us about how your eyes adapt when the spike in the spectrum of lights you are ignoring affects OBAs in papers among the other issues with such lighting.   
Quote
The CC chart results I posted are adequate enough for me
A rendered JPEG. Terrific. 
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Andrew Rodney
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Doug Gray

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Re: Light for print viewing
« Reply #67 on: December 06, 2017, 11:54:57 PM »

Yes, do tell us about how your eyes adapt when the spike in the spectrum of lights you are ignoring affects OBAs in papers among the other issues with such lighting.

CRI numbers are and indication, higher is better, but only a rough one. LEDs are spikey and the key question that determines how well they work with a specific printer is the way the spikes interact with the inks and color matching functions. While that is a non-trivial thing to evaluate it's pretty easy if you have an I1Pro spectro and I1Profiler. You can capture the LED spectrum with the spectro. Load it into I1Profiler, and make a special profile using that illuminant as well as a standard one using the default D50.

To visually compare the effect of the LED v D50 in Photoshop, take an image and convert it to one printer profile. Make a copy. Now assign the other printer profile to the copy. Now just click back and forth between the two image tabs. The places the image changes colors will show the effects of the LED v D50. (D50 is VERY close to Solux profiles). If you want to see just how bad industrial fluorescent lighting is do the same with T2 illuminant.

Having measured the spectrums from various supposed high color rendering LEDs, including Hyperikons, they all have negligible uV. Which means they should be used with OBA free paper or M2 based profiles with any paper containing OBAs. Fluorescent lights, OTOH, typically have uV to various degrees so you may also need to consider a M0 ro M1 profile for those.
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Ernst Dinkla

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Re: Light for print viewing
« Reply #68 on: December 07, 2017, 06:16:17 AM »

CRI numbers are and indication, higher is better, but only a rough one. LEDs are spikey and the key question that determines how well they work with a specific printer is the way the spikes interact with the inks and color matching functions. While that is a non-trivial thing to evaluate it's pretty easy if you have an I1Pro spectro and I1Profiler. You can capture the LED spectrum with the spectro. Load it into I1Profiler, and make a special profile using that illuminant as well as a standard one using the default D50.

To visually compare the effect of the LED v D50 in Photoshop, take an image and convert it to one printer profile. Make a copy. Now assign the other printer profile to the copy. Now just click back and forth between the two image tabs. The places the image changes colors will show the effects of the LED v D50. (D50 is VERY close to Solux profiles). If you want to see just how bad industrial fluorescent lighting is do the same with T2 illuminant.

Having measured the spectrums from various supposed high color rendering LEDs, including Hyperikons, they all have negligible uV. Which means they should be used with OBA free paper or M2 based profiles with any paper containing OBAs. Fluorescent lights, OTOH, typically have uV to various degrees so you may also need to consider a M0 ro M1 profile for those.

Few institutes test lamps as good as Olino.org
For example:
http://www.olino.org/us/articles/2017/11/17/dmlux-medi-art-led-panel
http://www.olino.org/us/articles/2016/03/14/pharox-pharox-400-ledlamp-dimmable-8w-40w-e27

What does a Solux say 4000K on UV output and what is the choice then for the profile to convert to?

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots
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digitaldog

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Re: Light for print viewing
« Reply #69 on: December 07, 2017, 11:03:55 AM »

While that is a non-trivial thing to evaluate it's pretty easy if you have an I1Pro spectro and I1Profiler.
Tim you got that?
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Andrew Rodney
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Tim Lookingbill

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Re: Light for print viewing
« Reply #70 on: December 07, 2017, 04:05:30 PM »

Tim you got that?

Andrew, shouldn't you be out on a ledge somewhere?

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digitaldog

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Re: Light for print viewing
« Reply #71 on: December 07, 2017, 04:11:12 PM »

Andrew, shouldn't you be out on a ledge somewhere?
I will take that as a no answer.
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Andrew Rodney
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Tim Lookingbill

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Re: Light for print viewing
« Reply #72 on: December 07, 2017, 05:26:59 PM »

Having measured the spectrums from various supposed high color rendering LEDs, including Hyperikons, they all have negligible uV. Which means they should be used with OBA free paper or M2 based profiles with any paper containing OBAs. Fluorescent lights, OTOH, typically have uV to various degrees so you may also need to consider a M0 ro M1 profile for those.

Since it's been established that Epson Ultra Premium Glossy paper has OBA's, I'm not seeing what your measuring devices are claiming what OBA paper should look like under various full spectrum lights and in this case the 5000K Hyperikons where the company has updated their definition of 5000K as an actual hue of light reflected back on white surfaces. (See the two hues' affect on OBA paper below.)

I can't separate visually the look of OBA's effect from the Hyperikon's change to color temp hue. I don't define how my prints should look according to how a measuring device defines it.

I want to know why all this technical and scientific analysis doesn't line up with human perception.
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digitaldog

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Re: Light for print viewing
« Reply #73 on: December 07, 2017, 06:06:26 PM »

Since it's been established that Epson Ultra Premium Glossy paper has OBA's, I'm not seeing what your measuring devices are claiming what OBA paper should look like under various full spectrum lights and in this case the 5000K Hyperikons where the company has updated their definition of 5000K as an actual hue of light reflected back on white surfaces. (See the two hues' affect on OBA paper below.)

I can't separate visually the look of OBA's effect from the Hyperikon's change to color temp hue. I don't define how my prints should look according to how a measuring device defines it.

I want to know why all this technical and scientific analysis doesn't line up with human perception.
Someone here needs to teach you the difference between color appearance and color perception.
« Last Edit: December 07, 2017, 06:19:51 PM by digitaldog »
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Andrew Rodney
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David Eichler

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Re: Light for print viewing
« Reply #74 on: December 07, 2017, 06:25:36 PM »

And I only use CRI as a guide on whether I should consider their color rendering capabilities. I'm not looking for perfection because my eye's adaptive nature to changing lights from different devices takes care of the rest. The CC chart results I posted are adequate enough for me.

I am not an expert, but I believe that the eye's adaptive abilities relate to color temperature, not to uneven tonal response. There is a very good reason why photographers still prefer tungsten lights when the highest level of precision in color representation is required. At this point, no other artificial light source compares with tungsten for this purpose.
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Tim Lookingbill

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Re: Light for print viewing
« Reply #75 on: December 08, 2017, 01:12:39 AM »

I am not an expert, but I believe that the eye's adaptive abilities relate to color temperature, not to uneven tonal response. There is a very good reason why photographers still prefer tungsten lights when the highest level of precision in color representation is required. At this point, no other artificial light source compares with tungsten for this purpose.

Since you've admitted you're not an expert, have you seen what you describe about the adaptive effect induced by color temp hues on color perception and have actually seen tungsten deliver the highest level of color precision? Most of what you've said appears to be second hand knowledge based on subjective statements from god knows who except maybe the points on the adaptive effect.

I'm not an expert, either. I just observe and report what I've seen with my own eyes which I've been told since I was a teen and graphics professional that I have a good eye for observing detail.
« Last Edit: December 08, 2017, 01:16:40 AM by Tim Lookingbill »
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David Eichler

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Re: Light for print viewing
« Reply #76 on: December 08, 2017, 03:51:56 PM »

Well, many museums have switched to using LED lamps. The impetus for the change has been conservation, but they wouldn't want to use lamps that impair the viewing experience. It is not clear to me which lamps they are choosing to use.
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