Darkroom Lighting Color Temp considerations

[DennisD]

Even though it's supposed to be a dark room, we sometimes need to turn on the lights !

I'm in the process of improving my darkroom ceiling lighting and would like to have any thoughts regarding color temperature considerations.

Most likely I would be using newer type LED lamps which are commonly available in color temperatures anywhere from 2700K up to 6500K.

What have you found is the best lighting and color temperature for general darkroom use, evaluating wet prints, etc.

Thanks for any thoughts and practical experience.

[Drew Wiley]

I wouldn't rely on LED lighting for any critical judgement about color per se - color prints or precise toning of B&W. For that kind of purpose I use a set of light options, which can be selectively switched on depending on actual display lighting. I have very high quality German 5000K color-matching bulbs (CRI 98) at both my retouching station and in my lightbox for critical lab work. But for personal display I like to use a mid-point between tungsten and daylight, namely 4000 K.

[Doremus Scudder]

I wouldn't rely on LED lighting for any critical judgement about color per se - color prints or precise toning of B&W. For that kind of purpose I use a set of light options, which can be selectively switched on depending on actual display lighting. I have very high quality German 5000K color-matching bulbs (CRI 98) at both my retouching station and in my lightbox for critical lab work. But for personal display I like to use a mid-point between tungsten and daylight, namely 4000 K.

I'm in total agreement with Drew here. I try to recreate what I consider to be "normal" gallery lighting in my darkroom. I don't do color prints, so I don't worry to much about getting a daylight reference close to 5000K, rather, I'm concerned with how the toning of the prints will come across under the usual display lighting, which is often a mix of halogen (from the gallery track lighting) and daylight (from the windows/skylights). Therefore, I have a display area in my darkroom where I can hang up my prints for viewing that is lit by a mix of 3400K halogens and one or two daylight floods. This I use for evaluating dry prints for contrast and toning hue. For viewing in the fix, I simply have a 40W halogen bulb in a reflector on the ceiling over the fixer tray.

I wouldn't use LEDs for critical viewing purposes simply because the don't emit a continuous spectrum and can do funny things with colors/toning hues.

Best,

Doremus

[Tin Can]

I won't use Fluorescent tubes of any kind in a darkroom.

They fluoresce way too long, up to 20 minutes, and can ruin your session.

I use LED for general cleanup and incandescent for use during sessions.

I want to try these. http://lightbulb.aerolights.com/viewitems/neodymium-full-spectrum-lighting-2/neodymium-full-spectrum-lighting

[Bill Burk]

I agree with all the above. The darkroom is the one place I put the highest "quality" light.

Which, for me, is a single 100W Halogen GE Reveal clear bulb.

It's not how much light, it's that you can trust the spectral quality when looking at a print in the fixer or wash.

[Drew Wiley]

Neodymium bulbs truncate the yellow to give cleaner blues. Don't trust em for anything critical in terms of hue repro. At the pricing your link shows, I predict import junk. Good bulbs age going to run around five times the price. Reveal is junk too in terms of longevity - it's from their home center rather than pro division of lighting, but OK for short term use . GE's entire bulb division is closing. Their main business has always been tax evasion, anyway.

[Tin Can]

Don't worry Drew, I won't be buying any CFL Neodymium lamps as they are fluorescent! I hate those things and they are dangerous HazMat.

However, 9 0f the 13 Neodymium lamps Aero-Tech offers are USA made incandescent 20,000 hour with EU glass. I may buy the minimum $25 soon, http://lightbulb.aerolights.com/item/neodymium-full-spectrum-lighting-2/neodymium-full-spectrum-lighting/100a19-fs-20k

I would love to know what exact bulb you are using in your Darkroom, per your post here #2 you wrote, "I have very high quality German 5000K color-matching bulbs (CRI 98) at both my retouching station and in my lightbox for critical lab work. But for personal display I like to use a mid-point between tungsten and daylight, namely 4000 K."

What are they? Who made them? Are they fading?

One reason I am so interested in Color Grade is my recent cataract surgery has opened my right eye to natural lighting outdoors with blue sky. My left will be cut this Friday, but right now I can compare blue sky and yellow filter blue sky. Right eye, left eye. This week I sit in my rocking chair, gazing at the sky switching eyes. Fascinating!

[Drew Wiley]

Gosh Randy, I bought a case of those bulbs decades ago, both for personal use and for the color matching stations at my old workplace. I'd have to see if they're still made. They are small fluorescent tubes for swinging high-end desk lamp or inside a lightbox, not for general darkroom lighting. MacBeath probably still sells their Prooflite series, for their own color stations. My 4000 K's are GE Commercial fluorescents. The afterglow drops off very quickly, unlike cheap fluorescents. I also installed them in the office of the company owner, who had eye problems including cataracts and couldn't tolerate conventional
fluorescents.

[Tin Can]

One case of bulbs cannot last decades unless you never use them.

They fade rather quickly.

I have replaced miles of them.

[Ted R]

In response to the original poster's question it depends on how the how the darkroom is organized. If it has an area in which you are making critical evaluations of images then color temp matters and I would trust incandescent more than I would trust LED or CFL because of color fidelity issues, both LED and CFL have poor CRI ratings compared to incandescent.

On a related topic the safelight I prefer for B&W work is yellow (Ilford amber). Some praise the red LED types however I find that red light is disturbing whereas amber seems OK.

[DennisD]

Thank you to all who replied.

It's clear that LEDs are ok only for general illumination while incandescent (tungsten or halogen) best for more critical viewing with consideration given to CRI if possible.

My setup is such that I have sockets conviently located above the developing trays so incandescent bulbs are no problem.

I've never liked fluorescents or the CFL varieties in the darkroom. The fluorescent afterglow can be a problem.

[Drew Wiley]

They don't fade quickly Randy. These are German, not made in some Taliban cave like Phillips bulbs or consumer GE. The bulbs are dependable for decades. No ballasts - that helps. These are real-deal scientific instrumentation bulbs and would probably cost a hundred bucks apiece today.

[Jac@stafford.net]

If the display of your prints' environment, for example your home or a gallery do not approximate your viewing light from the darkroom, you are at a profound disadvantage. Viewing conditions are critical. If your work is shown as a collection an astute conservator will have the gallery lighting adjusted properly.

[calebarchie]

These are the ones Drew is talking about
https://www.bhphotovideo.com/c/search?view=LIST&ci=638&fct=fct_brand_name%7cjust-normlicht%2bfct_brand_name%7cgti&setView=LIST&N=3989452948&

[Drew Wiley]

Well, not quite the same. Mine are even higher rated; but the Just Normlicht 5000 K's are more realistically priced and plenty good. The only minor problem with their own lightboxes per se is that they don't take into account the slight warming of the plexi diffuser, which ideally needs to be offset with a diffusion lining inside which cools the color temp about 200K or so. I've long forgotten the exact figure, but its doable. I have only one such critically calibrated light box; but it's invaluable for matching work like precision dupes. For just sorting color trannies or casual viewing I have a big light box with 1/4 inch sheet glass over it.

[StuartR]

MR16 Halogen track lighting with Solux bulbs. I stick to the 3700 in the darkroom, and use 3700, 4700 and 5000K for print evaluation in the main studio. Solux Halogen gives great CRI (100 for the 5000k), very short afterglow (10 seconds or so), and the track lighting means you can set it up in critical areas without having it light your paper safe as directly etc. It is also dimmable without any constraints, which is helpful for long sheet film loading or printing sessions. Finally, the bulbs are cheap(ish) and last for a long time. I standardized on them in my lab years ago and have been very happy I did ever since.

[Bob Salomon]

I'm in total agreement with Drew here. I try to recreate what I consider to be "normal" gallery lighting in my darkroom. I don't do color prints, so I don't worry to much about getting a daylight reference close to 5000K, rather, I'm concerned with how the toning of the prints will come across under the usual display lighting, which is often a mix of halogen (from the gallery track lighting) and daylight (from the windows/skylights). Therefore, I have a display area in my darkroom where I can hang up my prints for viewing that is lit by a mix of 3400K halogens and one or two daylight floods. This I use for evaluating dry prints for contrast and toning hue. For viewing in the fix, I simply have a 40W halogen bulb in a reflector on the ceiling over the fixer tray.

I wouldn't use LEDs for critical viewing purposes simply because the don't emit a continuous spectrum and can do funny things with colors/toning hues.

Best,

Doremus
Fluorescent tubes also don’t have a continuous color hue!

[Jac@stafford.net]

Fluorescent tubes also don’t have a continuous color hue!

So, their claimed K is in error?

[Drew Wiley]

Bob, if you know where to find em, there are fluorescent tubes with very high CRI values which closely simulate continuous sources, and I don't mean the BS ratings symptomatic of cheap consumer and home center products. They also have the advantage of being cool. Halogen lights can melt cast iron, I suspect. At least it feels like it sometimes. But Solux is a good brand to look at for bulbs. I prefer traditional tungsten track lighting; but certain products have been discontinued due to shortsighted energy consumption concerns which totally overlook the implications of neo-lighting alternatives on human health and safety.

[Bob Salomon]

So, their claimed K is in error?

No, CRI is a different rating the color temperature.

[Bob Salomon]

So, their claimed K is in error?

No, CRI is a different rating then color temperature. The box interior was painted with specificiallynformulated paints that evened spikes in the tubes and replaced missing colors. The diffuser was also selected to further correct the output to obtain the best CRI at 5400K as well as at 3700K. Tubes alone don’t do the job. The complete system does!

[Pere Casals]

I wouldn't use LEDs for critical viewing purposes simply because the don't emit a continuous spectrum and can do funny things with colors/toning hues.


Doremus, today there are a lot of CRI 98 LEDs (or CRI +95) that are perfectly suitable even for light tables, illumination for video, cinematography, etc.

It's just a matter to check the CRI of the LEDs in the light source before buying.

The single difference one can perceive when compared with matching sunlight or halogen is the way lower heat generation.

[Drew Wiley]

Don't rely on just advertised CRI figures. If it's the real-deal there will be a published spectrogram. What "full spectrum" LED's seem to do at this early point
in their history is simply fool the eye into thinking you've got a continuous spectrum. That might be OK for gallery lighting; but for critical evaluation in a
darkroom, with metamerism potentially at risk, I'm very skeptical. There are going to be spikes and gaps in the spectrum. And if the bulb is anything from Phillips or Consumer GE, don't believe a word they say. If something sounds too cheap to be true, it is.

[Pere Casals]

Don't rely on just advertised CRI figures. If it's the real-deal there will be a published spectrogram. What "full spectrum" LED's seem to do at this early point
in their history is simply fool the eye into thinking you've got a continuous spectrum. That might be OK for gallery lighting; but for critical evaluation in a
darkroom, with metamerism potentially at risk, I'm very skeptical. There are going to be spikes and gaps in the spectrum. And if the bulb is anything from Phillips or Consumer GE, don't believe a word they say. If something sounds too cheap to be true, it is.

Drew, if you are skeptical just check these datasheets:

http://www.lucent-lighting.us.com/media/104109/xtm-9mm-les-artist-series-datasheet_0.pdf

https://eu.mouser.com/datasheet/2/228/LZ9-00GW00-255475.pdf

https://eu.mouser.com/Optoelectronics/LED-Lighting/LED-Emitters/High-Power-LEDs-White/_/N-8usfj?P=1yo1i7l

179393

179394

Or better, just buy a 97 CRI LED or video illuminator and check it on your own for $66, search amazon for: GVM Dimmable Bi-color LED Video Panel Light Variable 29W

[Drew Wiley]

Well, there is a big burp in the spectrum at a critical spot, so I'd never trust a light source like that for critical color evaluation or matching work. The example posted is also obviously very warm K, so of little use in display; and I don't know if their cooler K versions are going to be any better. I've been looking into these for awhile. They're basically mixing LED's in the same bulb, an interesting advance that has been going on a few years, but hardly the holy grail. Basically, the "usable" CRI rating is based on a spectral hump quite different than what I'd want. That doesn't mean they're not on the right track, but
there are still some conspicuous limitations. LED video panels are a joke, a poor man's poor substitute for HMI.

[Pere Casals]

Well, there is a big burp in the spectrum at a critical spot

That minimal blue spike has no practical effect, at all, and by far. Just buy a cheap CRI 95 LED bulb for home usage and see. The 98 rating is even better, but it's really difficult to tell a difference from the 95 one.

Drew, there is no need to rely in the CRI rating, just using an spectrometer you see the reality. Another way is checking the datasheet of the LEDs used if one does not have an spectrometer.


LED video panels are a joke, a poor man's poor substitute for HMI.

LEDs are not only the future, LEDs are also the present.

If you want a particular narrow band then you have a LED doing it every 5nm... with no filter, and for white LEDs you can design the exact spectrum you want. That minimal blue spike you see in some spectrums could be eliminated with an absorbing dye, if it was not done this is because it is irrelevant.

HMI is not bad, but it has a way weirder spectrum than a high cri led, see the HMI spectrum:


Osram HMI 575W Sel UVS

179399

[StuartR]

Personally, I am most willing to trust my eyes. I look forward to trying the new LED's at some point, but I still have yet to see anything that comes close to the Solux bulbs. To me, this makes sense. The sun, halogen and incandescent all produce blackbody radiation. Other technologies produce light with different techniques, and then try to correct the spectrum as best they can. Halogen and Incandescent already have it more or less right, they just need adjustment in color temperature. As far as I can tell, the only disadvantages of halogen are heat generation and efficiency as compared to LEDs. Their relative longevity is lower, but extends for years in good bulbs. In exchange, you get the best color reproduction, unconstrained dimmability, instant on and off, a pleasant, directional light (useful for different areas of the darkroom...more light over the viewing area than the enlarger, paper safe etc), and cheap bulbs. Where I live all the energy is renewable, so the extra energy is offset by the lower environmental impacts of the bulbs and fixtures themselves (no ballasts, circuit boards, mercury vapor etc).

This is a few years old, but the list on the website is still maintained. Pretty interesting regarding the LED's. Good stuff is out there, but it seems like it can be tricky to find.
https://www.cinema5d.com/led-light-accuracy-tlci/

[Pere Casals]

Personally, I am most willing to trust my eyes. I look forward to trying the new LED's at some point, but I still have yet to see anything that comes close to the Solux bulbs. To me, this makes sense. The sun, halogen and incandescent all produce blackbody radiation. Other technologies produce light with different techniques, and then try to correct the spectrum as best they can. Halogen and Incandescent already have it more or less right, they just need adjustment in color temperature. As far as I can tell, the only disadvantages of halogen are heat generation and efficiency as compared to LEDs. Their relative longevity is lower, but extends for years in good bulbs. In exchange, you get the best color reproduction, unconstrained dimmability, instant on and off, a pleasant, directional light (useful for different areas of the darkroom...more light over the viewing area than the enlarger, paper safe etc), and cheap bulbs. Where I live all the energy is renewable, so the extra energy is offset by the lower environmental impacts of the bulbs and fixtures themselves (no ballasts, circuit boards, mercury vapor etc).

This is a few years old, but the list on the website is still maintained. Pretty interesting regarding the LED's. Good stuff is out there, but it seems like it can be tricky to find.
https://www.cinema5d.com/led-light-accuracy-tlci/

This doc states CRI 90 "is widely regarded as the minimum for television use", but we are talking about CRI 98 LEDs !!!! there is a big leap from 90 to 98. At 98 no pro colorist will see a flaw.

[StuartR]

Did you watch the video? CRI is not infallible...it is a 1960s standard that applies only to standard pastel like colors, it is not a great measure of accuracy or a lights suitability for use in color critical applications. It is a basically a minimal standard, but the only one we have. The colorist mentioned how some high CRI lighting is actually worse than lower CRI in some cases etc. There is a comprehensive list of lights that they have tested. I do not disagree that there are LED's available that are great at color reproduction, but I think your chance of getting one off the shelf is still pretty low unless you specifically seek out particular brands and models, or have the time and ability to test.

[Tin Can]

Thanks for the Link which has a Link to actual lights we could buy. The Filex at B&H looks interesting and affordable.

So many obfuscate with unproven theory and dim references to high personal standards.

Here and now available product referral is welcome.



Personally, I am most willing to trust my eyes. I look forward to trying the new LED's at some point, but I still have yet to see anything that comes close to the Solux bulbs. To me, this makes sense. The sun, halogen and incandescent all produce blackbody radiation. Other technologies produce light with different techniques, and then try to correct the spectrum as best they can. Halogen and Incandescent already have it more or less right, they just need adjustment in color temperature. As far as I can tell, the only disadvantages of halogen are heat generation and efficiency as compared to LEDs. Their relative longevity is lower, but extends for years in good bulbs. In exchange, you get the best color reproduction, unconstrained dimmability, instant on and off, a pleasant, directional light (useful for different areas of the darkroom...more light over the viewing area than the enlarger, paper safe etc), and cheap bulbs. Where I live all the energy is renewable, so the extra energy is offset by the lower environmental impacts of the bulbs and fixtures themselves (no ballasts, circuit boards, mercury vapor etc).

This is a few years old, but the list on the website is still maintained. Pretty interesting regarding the LED's. Good stuff is out there, but it seems like it can be tricky to find.
https://www.cinema5d.com/led-light-accuracy-tlci/

[Pere Casals]

CRI is not infallible...

Yes, a CRI 60 can be better or worse, because a manufacturer can desing the spectrum to have a better measurement.

...but a CRI 98 matches the blackbody spectrum in a 98% average in 8 checking points, so it would be really difficult that a CRI 98 source isn't of extreme quality.





it is a 1960s standard that applies only to standard pastel like colors, it is not a great measure of accuracy or a lights suitability for use in color critical applications. It is a basically a minimal standard, but the only one we have.

CRI was revised in 1995, while the most widely used color space today is CIE 1931, since 1931 !! Another popular space is 1976 CIELUV.




The colorist mentioned how some high CRI lighting is actually worse than lower CRI in some cases etc.

It is true that low CRI light sources may match more or less the bayer dyes on the pixels, or the dyes/sensitization in the color films, but a 98 CRI matches (I reiterate) 98% average of the SPD in 8 checking points of the black boby spectrum, so it's extremly difficult you find a flaw.





I do not disagree that there are LED's available that are great at color reproduction, but I think your chance of getting one off the shelf is still pretty low unless you specifically seek out particular brands and models, or have the time and ability to test.

You can get some variable results with a CRI 80 light, but not with a CR 98. Just spend $25 in a +95CRI household LED bulb and judge on your own.

[Drew Wiley]

There is a vast difference between interpolating a curve based upon eight spaced readings versus a continuous reading. Those kind of spectrophotometers
are now less common because they're much more expensive to build and fussier to maintain. But I worked hand-in-hand with the gradual evolution of industrial spectrophotometers right up to their current practical applications, not as an engineer, but as a user involved in feedback to engineers. Sometimes
I made a game of submitting color samples I knew would throw a curve ball at their latest design. I also taught color matching. At a certain point there is no
substitute for a trained eye, but I emphasize trained, because its's not all about visual physiology but also about experience and understanding just what to
look for. Machines are nice for reducing overall eye fatigue, but must be used in relation to trained vision. Note that I'm referring to critical color evaluation,
not what might be acceptable for display lighting. Of course, one can simply install a selection of lights in the lab to simulate different display conditions,
and then walk outside to check the color under actual sunlight. That's what I do, in addition to critical light sources in things like the lightbox and retouching
station. My wife once worked with a six million dollar spectrophotometer that was such a trade secret that her personal lab was behind a timed bank vault
door. That was in biotech where big big pharmaceutical bucks were on the line at the prototyping phase. No two people in the entire corporation were allowed to know the complete formula behind how that machine worked. But one wannabee industrial spy was caught.

[Pere Casals]

There is a vast difference between interpolating a curve based upon eight spaced readings versus a continuous reading.

Drew, if you like HMI:

http://www.largeformatphotography.info/forum/attachment.php?attachmentid=179399&d=1529055704&thumb=1

...then you will find that any CRI 98 light source is perfection:

http://www.largeformatphotography.info/forum/attachment.php?attachmentid=179394&d=1529011913&thumb=1

Just try it...

[StuartR]

Thanks Pere. I looked at the online sites of the local lighting stores, and they only have two MR16 LED bulbs available, both CRI 80. I looked for regular bulbs, and they were also CRI 80 (Osram and Phillips). I found some strip lights that were CRI90, but that is the highest I found. I am sure things in mainland Europe and the US are better, and perhaps they have some special lights hiding in the back, but it seems my current best option is to stick with what has proven to work for me, SoLux. By the time the bulbs die, things will probably have gotten better anyway...I should also say that I run a Hahnemühle Certified Studio for digital printing, and the color correct lighting was part of the certification process, and SoLux was approved for that. If I changed anything, I would need to make sure it was still approved. Anyway, that's my situation. LED's are certainly the future (and the present for a lot of applications). I am just glad that fluorescent is going the way of the Dodo!

[Pere Casals]

I looked at the online sites of the local lighting stores

Just search CRI 95 led bulb at amazon or ebay

[Drew Wiley]

Any real lighting pro can tell you that a lot of the shoot-from-the-hip info on this thread is driven by marketing BS. An 8-point interpolated spectrogram is as
equally useless for matching off-white wall paint as for subtle skintones in a photographic print. Solux is a reputable company, Phillips is not. And I've talked to GE factory reps in person many times over the years, and 100% of the time they spoke sheer BS. They probably sold used cars on the weekends. Pere- I don't do video, so have no use for either LED panels or HMI, which was once sold for old slow scanning-back digi capture. But if I had to choose, that HMI version you posted does look a lot more usable than the LED one. At least it has a healthy green peak. Fluorescent tubes are still important for many applications; the screw-in ones are another story. Ordinary tungsten should be reinstated; it's only now that there's some official recognition that hot halogens combined with junk floor lamps have caused a lot of fires and cost a lot of lives - something which should have been obvious before they were ever approved as substitutes for screw-in bulbs. On the display end of things, all types of halogen including low-voltage track lighting puts out a lot of UV and is going to fade color prints. Filters over the bulbs help only marginally; and no, inkjet prints are not exempt despite the marketing BS inherent to that particular industry too (they contain quite a few susceptible dyes also).

[Pere Casals]

An 8-point interpolated spectrogram is as equally useless for matching off-white wall paint as for subtle skintones in a photographic print.

Drew, here (https://en.wikipedia.org/wiki/Color_rendering_index) it is explained how CRI is calculated. At the bottom there is the "Film and video high-CRI LED lighting incompatibility" section, and why the TLCI standard was generated.

But something changed in the industry, today a high CRI is a different thing: 98

If you explore a bit the math involved in the CRI calculation you will find that achieving a 98 rating it only can come from making perfect illuminator. Yes, a CRI 80 allows for "creative" spectrums, but a 98 rating does not allow for inconsistencies, and since 1995 the CRI calculation includes saturated colors, see 1995 TCS colors in the wiki article.

Well, search datasheets and find a single 98 LED with a not excellent espectrum...


Regarding HMI, this is an OSRAM brand, the spectrum I posted before is the one of Osram HMI 575W Sel UVS.

Beyond HMI we have Xenon arc lamps: https://en.wikipedia.org/wiki/Xenon_arc_lamp

OSRAM also pioneered in the xenon business, it is a good illuminator (spikes are in the IR) that is also used in IMAX theaters. Single problem is that it throws substantial IR/UV. Xenon SPD is not as perfect as a CRI 98 LED but it allows to power an IMAX device.

This is a tipical xenon SPD, as you can see (400-700nm visible section) it's not as good as any CRI 98 LED you can find:

https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Xenon_arc_lamp_profile.png/1024px-Xenon_arc_lamp_profile.png

[Drew Wiley]

Pere, I have decades of experience with this subject. Theory is one thing, specific application another.

[LabRat]

My rule is "If in doubt, try it out"... As a former interior fotog, there were many different balances on different sources, some were very different on paper, but would balance OK, and some would have little visual difference, but would balance weird on the chrome film...

Test, test, test, and don't sweat the details until it hits the light box... :-)

Steve K

[Pere Casals]

Theory is one thing, specific application another.

OK, just just test a CRI 98 light source for the specific application, and you'll see. I did it, and I can recommend it.

[Drew Wiley]

There's simply no substitute for checking color results under more than one good light source, including moderate daylight. Nobody expected to retouch the
dent in an expensive car is going to get away with, "the machine tells me it's a match"! But 16-point readers are far more accurate than 8 pt, but pretty much in use only in factories. The problem with pulsed xenon is that the more you split up that beam, and the the deeper or denser it's expected to read accurately, the more sheer candlepower you need. That's why you don't hear about too many 24 point machines. Basically, the power is allowed to build up in a capacitor like a dam, then instantly released. Once we were working with a 12 point machine and the capacitor popped. The surge echo was so severe that it not only blew out the surge protector in the device itself, but overwhelmed every protector in that building and permanently ruined every computer there. But a CRI 98 bulb in a lightbox doesn't mean you've got than level of viewing at
all. The reflector paint has to be close to ideal, and you even have to offset the color bias inherent to the diffuser plastic or
glass on top, or you can instantly lop about 10% off that alleged CRI rating.