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Author Topic: Cruse Scanner Does Use LED Lighting  (Read 1392 times)

deanwork

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Cruse Scanner Does Use LED Lighting
« on: July 04, 2022, 09:30:45 am »

I don’t understand why everyone on this forum tells me LED lighting is not accurate enough to copy paintings with?

I just found out that Cruse scanners, the most expensive and most widely used art copying system used by major museums all over the world uses color balancing led lighting.

So all this talk about LED lighting being inferior for this type of work is just wrong apparently.

John

https://crusescanner.us/scanner-options-and-accessories/
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TechTalk

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Re: Cruse Scanner Does Use LED Lighting
« Reply #1 on: July 04, 2022, 09:45:29 am »

The qualifying words are "accurate enough". What constitutes "accurate enough" will depend entirely on where you decide to set the bar which determines your quality standard.

It may well be accurate enough, without meeting a higher standard requiring more accurate or the most accurate spectral coverage available.
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digitaldog

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Re: Cruse Scanner Does Use LED Lighting
« Reply #2 on: July 04, 2022, 11:55:12 am »

I don’t understand why everyone on this forum tells me LED lighting is not accurate enough to copy paintings with?
Who said this and when?
What accuracy in dE was provided with how many samples and compared to what reference?
Do many LED's have potential issues producing some metameric failures due to their SPD? Yes. 
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deanwork

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Re: Cruse Scanner Does Use LED Lighting
« Reply #3 on: July 04, 2022, 01:52:19 pm »

Here is an example and he just clarified - “how accurate is accurate enough” and that was what he originally stated.

Who knows. Not me. I’m not inclined to invest in them at this point to find out. Certainly people have already done these tests.

I’ve just heard the blanket statement - non uniform spectral distribution associated with them several times.

I don’t know anyone on these forums who have actually done tests of various brands and forms of led light within the context of the copying of paintings .

Is there any published material online from someone who is actually using them?

If this involves buying a color meter and doing continuous tests as the lights constantly change as they age I’m not into that

I’d rather use hot lights.

I’m very ignorant of the technical capabilities of led light banks, other than the great light displays of James Turrell. 

I don’t know which types and brands are better for this purpose and how much that matters. They are all apparently sold as video lights. I see none being sold as accurate copy lights, and found nothing written about it. I do know not all led brands are equal, that’s for sure. There are too many original sources, most if not all from China.

Actually I had pretty much written them off until I saw that the very accurate Cruse scanner uses them as a light source. I’ve used lots of Cruse scans and never had issues color balancing painting scans from them at all. I don’t think this lab is constantly profiling them, though Cruse does offer them rgb profiles of some sort.

I just don’t know how random it is with most of these strips…

John



Quote from: TechTalk on June 22, 2022, 03:42:12 pm
There currently are no LED light sources that will output a consistent and uniform spectral distribution. That said, there are some that are very good. Ultimately, it will depend on how critical your demands are for color reproduction accuracy. The Lowel Tota-Lights will certainly be better than any LEDs in this regard, but there is the heat that comes with it. You will likely need to run some tests to decide whether LED lights are a workable compromise for your application.




Who said this and when?
What accuracy in dE was provided with how many samples and compared to what reference?
Do many LED's have potential issues producing some metameric failures due to their SPD? Yes.
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digitaldog

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Re: Cruse Scanner Does Use LED Lighting
« Reply #4 on: July 04, 2022, 02:23:42 pm »

Certainly people have already done these tests.
Where are the results (of colorimetric accuracy)?
Quote
I’ve just heard the blanket statement - non uniform spectral distribution associated with them several times.
Where and by who?
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TechTalk

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Re: Cruse Scanner Does Use LED Lighting
« Reply #5 on: July 04, 2022, 03:56:22 pm »

Here is an example and he just clarified - “how accurate is accurate enough” and that was what he originally stated.

What I've tried to convey, without getting too wordy or deep in the weeds, is that there is no "perfect" solution and that the best compromise will depend on your specific needs and application. By this I mean: how the images are to be used (web, print, master archive, some combination); the budget for capture, not only in terms of money but time; the photographers previous experience and preferences for type of camera or capture system; etc.

There is no better path forward than testing, perhaps by renting or thru loan from manufacturer or reseller. If that is not an option, then I would look at what others are currently using who have experience in the type of reproduction you need to do.

What is sometimes not included in discussions of art reproduction is that there are different types of reproduction. They range from high-speed mass digitization of large collections for the purpose of putting collections online for public viewing to careful and often time consuming creation of high-resolution images as master archives of individual works and everything in between.

For high-speed mass digitization, I have certainly seen high quality LED lights used. For the more individualized approach, strobes are generally being used. If you're working with a scanning system it will by necessity be some continuous light. When I started out using a scanning back with a view camera those were tungsten-halogen hot lights, which actually did include Lowel Tota-Lights like you mentioned. But, that was many years ago before resolution had improved sufficiently in area array digital backs which allowed strobe use.

All this to say... if LED lights work for your needs then I would use them.
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