Luminous Landscape Forum
Raw & Post Processing, Printing => Colour Management => Topic started by: michael_mutmansky on August 06, 2019, 02:35:45 pm
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Folks,
I know that LED is a bet problematic for print viewing, but as the other technologies become obsolete, LED is taking over the lighting market. I have been looking for a good quality print viewing light but I don't have room for a booth, and I'm not really interested in the SoLux lamps for a few reasons. I have read of people using the Fiilex V70 as a light for this, but it has miserable R9 and R12 values (mid- 70's for both). However, they also have a V360 model, with is much better in both of these characteristics (R9 - low 90's, R12 - Mid 80's). It's around $800 though...
https://www.fiilex.com/products/V360.php#Title4
But this got me thinking about other low power LED video light options, and I looked at at the P360 from Fiilex and the newer P360CL, both of which have better values, and are cheaper than the V360. The P360 is recently discontinued, so it's available on sale as well.
https://www.fiilex.com/products/V360.php#Title4
Also, the Aputure SL Mini 20C is around $280, and it has even better color performance than the Fiilex products:
https://indiecinemaacademy.com/complete-led-color-database-cri-tlci-cqs-tm30-15/#aputure-mini20c
It's actually in the low 90's for R12 and drops to the mid-80's at higher temperatures. Overall, these are good enough to be at least comparable to the high quality fluorescent curves I believe.
I'm thinking that The Aputure SL Mini 20C would make a very good source for a color viewing arrangement. It could also serve double-duty as a continuous light source for macro work, so this would be an all-around ideal solution for my purposes.
Has anyone tried these for this purpose? I'm hoping for some feedback, but I think these could be viable instead of the SoLux route, and much better than the Ott Light approach.
---Michael
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Have you checked SORAA bulbs? CRI 95, R9 95, Rw100.
https://www.amazon.com/SORAA-Radiant-Dimmable-410-Lumen-Equivalent/dp/B075J2R428
You have to search a bit; they do have different temperatures but not sure if all have those ratings.
Dave
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The SORAA's I measured, not so great.
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The Soraa's don't have CCT's that I'd like to use for a print viewing light, so I figured I'd pass on them.
I really don't know whether these video lights would be suitable, but I think they would pass the test for most people, and they are CCT variable, so it would be possible to actually set up a few different conditions with them as well. They also have variable output, so you can tune them down as needed.
I find it an intriguing possibility, which is why I asked.
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I have the P360 “classic” heads for product shoots. They are nice lights but have no readout scale to tell you if the temp or power got changed, bumped or tweaked. Might require frequent measurement or some way to ensure the dials don’t get moved. Looks like the V360 has an LED panel to tell you where things are set.
The newer 360 PRO version has readout, and the PRO plus adds hue (magenta/green)
Dave.
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Yuji VTC D50 https://store.yujiintl.com/collections/standard-illuminant have a CRI 98 and are very stable with constant current power supply. I am using their VTC 5600K as well as D50 (need higher level of illumination) and run fairly stressing tests (4-6 hours non stop at max rated current and 100% PWM duty cycle) with periodic measurement of CRI and spectrum - figures were kept very stable at CR 98-99 with almost no fluctuation in colour temperature (within 160K around rated colour temperature - measured by ArgyllPRO ColorMeter app with i1 Pro).
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Phottix M180 - CRI Ra 98% in whole CCT/brightness range. It recently became my favourite, portable "proofing light" I always put in my pocket ;)
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Marcin,
That looks like a real excellent option... Better than the ones I posted, but I think it won't have nearly as much output. That won't matter for my needs I don't think.
It runs about $100 in the US, so it is a quite inexpensive option. Of course, it doesn't have nearly the control of the light of the Aputure LS Mini 20c, but that may not be an issue depending on the how I set up the print viewing area near the monitors. It does have a CCT display on it, which is nice as well.
---Michael
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Hello Michael,
From the late 60s working in a custom colour lab in Toronto, until early 2017 when I moved my lab business to my home location, I had been using 5000K fluorescent bulbs for print evaluation and they always suited my needs very well as long as I replaced them on schedule. When I did make the move in early '17 I decided to look for perhaps a better solution to print viewing illumination. I did a lot of research, both here on LuLa and otherwise and finally setteld on LED Bars from a supplier in Toronto. Before I left my previous location I measured the intensity of the lighting I had been using, which was approximately 500 Lux. Once I had the 4000K bars installed with a dimmer I then set them to 500 Lux at my viewing work table and they have done the job very well since. You might want to check this approach here - https://lumicrest.com/. You can also check the the LED Bars I use here - https://lumicrest.com/product-category/led-flexible-strip/undercabinet-modular-lighting/. Set the proper LUX value for your situation and I believe you will find these lights to be very efficient.
EDIT: I do have a pic of my setup for these Bars but cannot seem to find it. If I do I will post it. However, this is the combination I use -- 2 - 48" bars and 2 - 6" bars, which combined, is a 6" x 48" rectangular setup. The light is diffused so it covers a good area.
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99 CRI:
https://www.waveformlighting.com/absolute-series
Gotta rig them up yourself, but it's easy (can be chained together).
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99 CRI:
https://www.waveformlighting.com/absolute-series
Gotta rig them up yourself, but it's easy (can be chained together).
Waveformlighting absolute is a nearly perfect lighting source for prints viewing. I attach some charts below.
The SORAA's I measured, not so great.
SORAA lamp is not for printing judgement. The problem is the SORAA lamp has 2700K CCT. But BabelColor CT&A shows terrible CRI just because the software calculated CRI to a D50 reference illuminant for ISO 3664 standard. It cannot evaluate lighting quality correctly.
SORAA 2700K lamp can provide a good lighting in lower CCT for home or store. At correct calculating method, which reference illuminant is 2635K blackbody, it has good CRI Ra 95, Re 93, Rf 90, Rg 100 and Δu'v' is only 0.002.
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SORAA did have 5000k and 4000k options before they discontinued them, and they were (are) fabulous. I've set up an entire viewing wall with both 5000k and 3000k soraa lamps, and they are performing extremely well. They are track mounted about 15 feet up to give about an 8 foot sweet spot on the wall, and evenly spaced to provide for maximum uniformity. The idea is that clients can see the difference the lighting color makes when going from D50 print standard to halogen equivalent-- in chromaluxe dye-sublimation especially things can shift quite dramatically (black and white shows considerable color inconstancy).
I can take some photos of the setup and post some spectral plots if anyone is interested-- this is installed as our main viewing wall at Griffin Editions.
Of course, I'm relying on bulbs which are no longer in production, but I've been able to work some magic with Soraa to hopefully maintain availability of the 5000k engines themselves.
I tested a large number of possible LED types, including the Yuji LED D50 strips and Ketra color tunable bulbs, but nothing could compare to the smoothness of the soraa spectrum, especially with regard to spectral power in the cyan range. They also have incredibly good R9 values, which can be difficult to attain. Anyway, proof is in the numbers, so if you guys are interested I'll post some pics.
I'm sure i'm going to have to deal with some color temperature drift, but for now this has been a fantastic asset for our particularly difficult setup (evenly lighting very large prints is HARD). The downside is now I go to many of the galleries that show work that we produce and there's some insane mixture of halogen and CFLs or what have you-- even in the very high end ones!
My dream is to one day set up a photo show that will cover everything from scan/digital file workflow through to lighting and display, but that day has not yet come...
One last note, in my conversations with GTI about their developing LED technology, the main concern they have is drift. I think the solution eventually will be to have some type of colorimeter built in which can re-tune the output of the various phosphors and take care of drift over time, but the industry is developing rapidly, and we are going to start seeing real options very soon
EDIT**
Attaching plots of the lighting for 5000K (ish) and 3000K Soraa bulbs-- should be pretty clear which ones are which ;)
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I didn't realize that editing my post wouldn't push it to the top of the stack-- so in case anyone's interested ^^^
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I didn't realize that editing my post wouldn't push it to the top of the stack-- so in case anyone's interested ^^^
Looking good. Thanks for sharing.
The SORAA's SPD has a unique violet peak around 410 nm (Waveformlighting Absolute too), most brands use blue light base LED.
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Phottix M180 - CRI Ra 98% in whole CCT/brightness range. It recently became my favourite, portable "proofing light" I always put in my pocket ;)
Hi Marcin,
Looking to get started with controlling my print viewing conditions, this sounds like an excellent low cost entry option. Are you happy with the max color temperature of 5600K?
Thanks,
Erik
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And speaking of small, portable LED lights, how about this one from Aputure:
Aputure AL-MC RGBWW CRI 96+ 100 Lux
This one seems to have 100 Lux in 1m distance, while the Phottix M180 yields 1600 Lux in half a meter distance.
I must admit that I have no idea what brightness level is practical for viewing prints next to the monitor.
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Some time ago I used Godox FL-100 (CRI 98) as Print Evaluation light with good results, but found their lack of UV emission problematic, as I could not see the effect of OBAs. Any experiences in this regard with the LED types you guys mentioned?
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Some time ago I used Godox FL-100 (CRI 98) as Print Evaluation light with good results, but found their lack of UV emission problematic, as I could not see the effect of OBAs. Any experiences in this regard with the LED types you guys mentioned?
Almost all LED lights are lack of UV/none UV. It's a problem when comparing images using papers contain OBA under different lights. Another problem is ICC profiles were build under M1 (or older M0) condition with UV. Adding extra UV-LED is an solution, but how to adjust the relative power to visible light is tricky.
A revision ISO 3664 was under developed by ISO Joint TC 42 and TC 130. One major content is low UV LED lights in practical viewing. Don't know the suggestion from ISO yet.
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I have a small UV torch and some papers with OBAs so I guess I can just play around a bit in an unscientific way.
Other than that, I am still considering those handheld, battery powered LED lights but I am also considering the GrafiLite 2. These are all low cost entry solutions to the subject matter, probably far away from the spectrum coverage and linearity that professional solutions provide.
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Almost all LED lights are lack of UV/none UV.
Adding extra UV-LED is an solution, but how to adjust the relative power to visible light is tricky.
I see an LED proofing solution at JUST website (https://www.just-normlicht.com/en/productgroup.html?id=56). (about EUR 1.600.- inkl. VAT). So I draw the conclusion that there must be any LED vendor/producer JUST uses... Any ideas?
What are your experiences with Yuji/Waveform lighting/Soraa concerning UV ratio?
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After watching a few reviews, I conclude for myself that the Aputure MC will be too dim for my needs. The GrafiLite 2 looks promising but I think I will go with the Phottix M180 as suggested by Marcin as it serves the purpose of print evaluation but can also be taken outdoors for lighting a scene.
If anyone knows even better solutions, please share. Thanks.
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I think I will go with the Phottix M180 as suggested by Marcin as it serves the purpose of print evaluation but can also be taken outdoors for lighting a scene.
If anyone knows even better solutions, please share. Thanks.
The Phottix M180 seems to be "unavailable" at most places in the U.S. usually with a note that "we don't know when it will be back in stock".
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Here in Germany, there seems to be only one source: photospecialist.de
They sell it for 129€. I just ordered it.
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The Phottix M180 seems to be "unavailable" at most places in the U.S. usually with a note that "we don't know when it will be back in stock".
There's newer Phottix M200R, maybe it repleaced M180. The brand name is not very important, you can get similar lamps at different names, most of them have reasonable spectral quality.
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Thank you, Marcin, you have a point there. I didn’t really identify the M200R to be kind of a successor of the M180. A bit more investigation seems to confirm that notion. I asked Photospecialist to change the order.
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If you're looking for a dual-purpose light with enough light output to make it useful for image capture, the Rotolight Neo 2 is worth a look. It is more expensive, but has much more light output producing 2,000 lux at 0.9 m (dimmable from 100% to zero), is widely used in professional video and photo applications, and comes with a number of useful accessories. Though more expensive, it has come down dramatically in price since being introduced in 2017. You can easily find lots of reviews on this light.
The Rotolight Neo 2 can be used as a strobe on still cameras and includes HSS and built-in Elinchrom Skyport receiver for remote control. CRI has been justifiably criticized as a method of evaluating color as two lights with the same CRI rating can have very different overall color accuracy. Where LEDs tend to fall short in color is in the red portion of the spectrum, so it's important when looking at CRI for a rough guide to color to look at the R9 rating, which is quite high on the Rotolight.
Rotolight also publishes spectral data (https://www.dropbox.com/s/35ukfmv0uicl1xj/Rotolight_NEO2.pdf), which is something that I would like to see from any manufacturer. While it has a list price of $299 in the U.S., it currently sells for $189.
https://www.rotolight.com/product/neo_2/ (https://www.rotolight.com/product/neo_2/)
https://www.bhphotovideo.com/c/product/1360356-REG/rotolight_rl_neo_ii_pro_hd_led_neo.html
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I see an LED proofing solution at JUST website (https://www.just-normlicht.com/en/productgroup.html?id=56). (about EUR 1.600.- inkl. VAT). So I draw the conclusion that there must be any LED vendor/producer JUST uses... Any ideas?
What are your experiences with Yuji/Waveform lighting/Soraa concerning UV ratio?
Sorry, I don't have a spectrometer could measure UV rays. All I can do is comparing their SPD (attached below). All the spectrum powers were normalized to the same luminous (according to CIE 170-2 cone-fundamental-based spectral luminous efficiency functions).
Which I believe waveform lighting and Yuji's D50 lighting contain no UV. The JUST LED Proof Light has a raising up curve at 380 nm. That might be a 365 nm LED which is commonly used on market for OBA checking. But other two lights have a natural downward curve. As you can see, these 3 lights have 4 similar wavelength peak. But only JUST LED Proof Light has a 515 nm green light peak, and narrowest band. Unfortunately, it's not my own light, I cannot disassemble it to find out any producer mark or SKU.
data calculating from SPD (base on TM-30-18):
JUST LED Proof Light Ra 97.9 R9 98.6 R12 93.0 Rf 97.4 Rg 101.8 CCT 5007K
waveform lighting Ra 98.8 R9 90.5 R12 98.7 Rf 97.5 Rg 100.3 CCT 4955K
Yuji VTC D50 Ra 97.8 R9 95.7 R12 88.1 Rf 97.2 Rg 101.7 CCT 4849K
edit: waveform lighting SPD in the diagram is D50, D65 is a typo.
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Sorry, I don't have a spectrometer could measure UV rays. All I can do is comparing their SPD (attached below).
That's more than I could have hoped for :-) Thank you very much.
I will have a look for UV led strips, get me some Yujis and report back if I could find a working DIY proofing solution including UV.
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Thought since this topic was just mentioned recently in light of the closure of Solux I'd chime in on some recent developments--
Waveform Lighting is generally my favorite all purpose solution these days, but I also found a pretty impressive product from Yuji LED that can be set up really easily and has an impressive power output: https://store.yujiintl.com/products/cri-max-cri-95-150w-high-bay-ufo-led-light-4000k-5000k
I've got two of these set up on articulated TV mounts (they're meant as down-lights for warehouse use I guess, but I'm not sure who would need such high quality units for their warehouses... maybe automotive?) I had to drill holes in the middle of the cheap mounts, but then they attach with a single (12mm? i dont remember exactly) bolt. I'm using two of them to cover an 8'x12' viewing area quite nicely.
Sorry for the hilariously low quality spectral plot, It's an incredible device, but ancient. Blue peak is at 460nm.
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Indeed, the Waveform Lighting LEDs I just purchased and tested (in a thread (https://forum.luminous-landscape.com/index.php?topic=141796.0) I had to close down due to the local troll (https://forum.luminous-landscape.com/index.php?action=profile;u=72202)) are most impressive.
(http://digitaldog.net/files/WaveformLEDs.tif)
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According to product specification Wayform Lighting usees blue LED with green and red phosphor.
There are also violet LED with red, green, blue phosphors, that are slightly better (I use SunLike and find it noticeably better than my previous Yuji BC, Phottix/Viltrox/Godox with blue LED R+G phosphor emitters):
(https://www.yujiintl.com/static/home/images/item15.png)
Seoul Semiconductor SunLike:
http://www.seoulsemicon.com/en/technology/sunlike/
available products wtih SunLike emitters:
http://www.seoulsemicon.com/en/technology/sunlike/casestudy/
Yuji VTC:
https://www.yujiintl.com/high-cri-led-lighting.html
BridgeLux Thrive:
https://bridgelux.com/products/vesta-thrive
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Came across a new product from Ilford for print viewing and evaluation.
ILFOLUX Color Viewing Lamp (https://ilford.com/product/ilfolux/)
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Came across a new product from Ilford for print viewing and evaluation.
ILFOLUX Color Viewing Lamp (https://ilford.com/product/ilfolux/)
ILFOLUX is not that good, check the R9 & R12. It's a good desktop lamp, but not a standard viewing lamp.
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I just tested a Sunlike LED panel.
Here is what it gives. I think it uses Nichia Optolis LEDs