Author Topic: Single point LED....  (Read 13283 times)

Offline DannyGruninger

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Re: Single point LED....
« Reply #45 on: November 12, 2014, 03:24:57 PM »
Ok, so I just got off the phone with 2 Saati guys....

Danny, is yours more of a circular unit vs. rectangular? They were thinking you may have the "100" unit, which is more of a circle and they said has been used for post exposing with CTS units.

The "300" unit @ 44" from the glass they said was equivalent to a OLIX(sp?) 3000 watt unit. 

Exposure times vary depending on placement from the glass, mesh, emulsion, yada, yada, yada... But they said a safe or common range they were seeing was 17-27 seconds.

The 300 unit is made up of 3 actual lights focused, the 100 is 1 light and they are working on a 500 unit but are having hurdles keeping it cool enough.

They were actually in the airport on their way to a company that makes exposure units to work out a deal. Sounds like they would IDEALLY down the line like to have a whole unit with vacuum blanket timer and all for under $3K in the future.

They are getting me a handful of contact info for current US users that I can talk to and see what they think....


Alex, yes I have the small circular led.... Pic attached of it sitting in my 3140 unit....... So as you know it's really only meant for post exposing on dts made screens so it's not an ideal application at all.....I would say if the other more powerful designated led was in here it would work great. Do I think it will be better then a starlight, no but it would produce some nice stencils for sure. I would be confident to say though that 100% you can make something like this work...
Danny Gruninger
Denver Print House / Lakewood Colorado
https://www.instagram.com/denverprinthouse


Offline Sbrem

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Re: Single point LED....
« Reply #46 on: November 12, 2014, 06:33:29 PM »
Man, something new almost every day it seems... 3 LED's keeping up with 5K MH would be pretty cool if it works...

Steve
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Offline TCT

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Re: Single point LED....
« Reply #47 on: November 12, 2014, 10:18:03 PM »
OK, light energy in the correct wavelengths is what exposes emulsion.  How many watts?  At what distance?  300w compared to a 5,000 watt Metal Halide?  Proximity to the screen is what helps the Starlight and other LED's to expose emulsion, and most have limited multi spectral capability that dual cures love.  I'd love to hear tests.  Here is the acid test:  Coat a 110 1:2 with your emulsion.  Expose it for the same time at the same distance as you are using now.  I doubt the emulsion will stay on the screen without a far longer exposure using a 300w LED than the 1k and 5k units.  Even the difference between an Olec 8k and 5k is quite a lot as far as emulsion durability.  Weak light = weak screens.  Maybe Ok for plastisol and small runs, but a long discharge run, or worse a long High Solids Acrylic ink run?  no way.  LED's conjure up all sorts of savings in electricity and lamps, but image quality and reject rates, especially on discharge could be painful. 

We have experimented with a variety of LED's from a major LED manufacturer.  We have tested some so strong they burnt holes in the mesh due to being so close.  The best times we came up with in a scanning LED had times equal to the 5k metal halide in the lab, but did not pass a simple ink test with Matsui 301 whereas a multi spectral MH 5k bulb exposure showed no breakdown of the emulsion.  We have seen good results with the Starlight in our tests and it is due to how close the lights are to the screen.  You will see emulsion manufacturers coming out with LED emulsions.  Trouble is they need to be tuned to the wavelength of the sensitizer.  Diazo likes 360 nanometers, SBQ likes 380, 420.  So if the lamp has only a single spike wavelength in the histogram it may not fully expose a dual cure.  It may appear to be fully exposed, even without slime on the inside, but the cross linking going on in the emulsion will be partial and not as complete as a 5k-8k fresh Metal Halide.  Call the emulsion what you will, diazo is the magic ingredient that helps with water resistance and it likes 360nm so how will a 405nm light expose that completely?

LED is in it's infancy.  It's only going to get better.  Anyone with results on any LED lamps using Discharge would be appreciated.  If the screen can hold up to a long discharge run and hold good tonals then the LED light has benefits.  Printers make money when the presses run, if the light source doesn't shoot durable screens the profits suffer.  Short runs, probably won't matter, for the long runs?  I have seen disasters and major headaches at shops running longer discharge and HSA ink print runs suffering screen failure and with plastisol showing major pinhole issues.

Al

Thanks for the insight Alan, I don't think there has ever been a single post of yours I didn't learn something from!

Would I be right in assuming that in your opinion a 300 watt single point LED light source at say 30"(for sake of argument) wouldn't have much of a advantage over a 1000 watt MH unit at 30"? Aside from power consumption.

The nature of our printing is heavily on the DC/WB side of things with HSA's gaining. We have used HVP for years but in the last year probably, switched over to the SP-1400 because we were having breakdown issues with the HVP. I know some people can go thousands of imprints with it and be fine, but we would be lucky to hit 500. The switch to SP-1400 probably only "band-aided" our problem. We were burning the HVP@ like 50sec. and now the 1400 is @ 4:20. I have the same Workhorse 1K watt unit I bought 9 years ago when I started, the shutter system has finally just bit the dust. That coupled with a 4:20 exposure time and the pot smoking jokes that go along with it paints a clear picture we need to upgrade. I have 2 perfectly good exposure units(minus the shutter box) with 3 vacuums, 3 blankets and 3 sets of glass, so buying a total new unit is a waste of money. We were going with the Vastex retro fit kit, but the "ease" of this single point one was really appealing. It could be used in the Workhorse unit we have or set up with the Olec unit that I have had sitting since I got it.
Alex

Hopefully I'll never have to grow up and get a real job...

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Offline GKitson

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Re: Single point LED....
« Reply #48 on: November 13, 2014, 06:24:49 AM »
Had a demo of the single unit last week and for the money looks like great results in our CTS shop.


I think we will be going forward with the triple soon, although the concept of no integrator is a bit counter to my upbringing.


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Greg Kitson
Mind's Eye Graphics Inc.
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Offline Frog

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Re: Single point LED....
« Reply #49 on: November 13, 2014, 09:27:02 AM »
Had a demo of the single unit last week and for the money looks like great results in our CTS shop.


I think we will be going forward with the triple soon, although the concept of no integrator is a bit counter to my upbringing.


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But, of course, you were brought up with bulbs which weakened over time, necessitating a way to compensate. The question would be, do LED's truly give out the same "shine" throughout their whole life? If so, I'll refer you to the recent thread here about cameras, which along with all of the other advances and changes you've experienced in this business, make this new adjustment pale in comparison. Good times ahead!
That rug really tied the room together, did it not?

Offline Sbrem

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Re: Single point LED....
« Reply #50 on: November 13, 2014, 11:49:08 AM »
Had a demo of the single unit last week and for the money looks like great results in our CTS shop.


I think we will be going forward with the triple soon, although the concept of no integrator is a bit counter to my upbringing.


Sent from my iPhone using Tapatalk

Almost everything we do is different from the way I learned, but I like it. I'd rather work in Photoshop than a darkroom anytime, and the creation of the flash was boon to mankind (OK, printerkind). Our staple gun is for putting up pictures, canvas stretching pliers, well they're a conversation piece...

Steve
I made a mistake once; I thought I was wrong about something; I wasn't

Offline blue moon

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Re: Single point LED....
« Reply #51 on: November 13, 2014, 12:12:15 PM »
contrary to popular belief, LED's do deteriorate with time, but significantly slower than the MH bulbs. It is possible that there would be no difference after a year, but I would imagine 5 years would be a different story. This is just a guess on my end based on what I've heard.

also, heat is significant factor in the life and output of the LEDs. So there will be variations from shop to shop.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline ZooCity

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Re: Single point LED....
« Reply #52 on: November 13, 2014, 12:38:10 PM »
contrary to popular belief, LED's do deteriorate with time, but significantly slower than the MH bulbs. It is possible that there would be no difference after a year, but I would imagine 5 years would be a different story. This is just a guess on my end based on what I've heard.

also, heat is significant factor in the life and output of the LEDs. So there will be variations from shop to shop.

pierre

This was my thinking on deterioration.  So a unit like the Starlight contains no integrator?  I guess I should've asked!  That seems like a no-no to me. 

I'm not nearly as old as some of you ancients on here talking about stat cameras but I'm in the camp, it really goes against my basic understanding of exposure to not have an integrator.   I suppose one could be added and wired into the controls....seems like that should be included with the units for the price.  Clearly nobody has done a 5yr test on any of these yet.

Offline GaryG

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Re: Single point LED....
« Reply #53 on: November 13, 2014, 12:43:50 PM »
I was surprised at this-

mk162-here's the thing...LED's are only about 11% efficient.

Why so much waste?

Offline blue moon

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Re: Single point LED....
« Reply #54 on: November 13, 2014, 01:23:14 PM »
I was surprised at this-

mk162-here's the thing...LED's are only about 11% efficient.

Why so much waste?

OK, so I did some digging. The numbers are different between the manufacturers and there is quite a big difference in quality of the LEDs.
Good stuff if driven (proper voltage and amperage) will lose 5% at around 10,000 hours. So at 40 hours per week, that's 5 years! So check your exposure once a year and you are good to go!

As far as the efficiency, I was surprised to find out the 15% is correct (up to 20% for high end). The funny part is, this is pretty much the same as the MH!!! go figure. . .

as previously mentioned, temperature has high impact too.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline ZooCity

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Re: Single point LED....
« Reply #55 on: November 13, 2014, 01:31:21 PM »
Well I think we can all stomach a 5% drop over 5 years (less if not exposing a full 8 hrs a day).   

I would just watch out for shooting ultra fast times on an LED as the minute and a half exposure isn't going to be effected too much by a 1-5% drop but that 5s time might be.  According to Mr. Greaves a very fast PP exposure is not ideal anyhow.

Offline Sbrem

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Re: Single point LED....
« Reply #56 on: November 13, 2014, 03:59:42 PM »
contrary to popular belief, LED's do deteriorate with time, but significantly slower than the MH bulbs. It is possible that there would be no difference after a year, but I would imagine 5 years would be a different story. This is just a guess on my end based on what I've heard.

also, heat is significant factor in the life and output of the LEDs. So there will be variations from shop to shop.

pierre

This was my thinking on deterioration.  So a unit like the Starlight contains no integrator?  I guess I should've asked!  That seems like a no-no to me. 

I'm not nearly as old as some of you ancients on here talking about stat cameras but I'm in the camp, it really goes against my basic understanding of exposure to not have an integrator.   I suppose one could be added and wired into the controls....seems like that should be included with the units for the price.  Clearly nobody has done a 5yr test on any of these yet.

I know I should catch some crap for this, but we've never used the integrator, which be because they weren't invented when I started with an Arc Lamp. However, we could always tell when the bulb was fading in our MH, they just looked "different", very scientific, I know... We usually need a new bulb around every 9 months or so. We do want to upgrade, but since this is still evolving, we're moving slowly...

Steve
I made a mistake once; I thought I was wrong about something; I wasn't

Offline TCT

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Re: Single point LED....
« Reply #57 on: November 13, 2014, 04:45:26 PM »
I'll be catching crap with ya! Never had one on our exposure unit either and when I bought ours it was light years ahead of the one I learned on at the shop I worked at in high school. Like Sbrem I just knew we had to change the bulb every year or so.
Alex

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Offline Gilligan

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Re: Single point LED....
« Reply #58 on: November 13, 2014, 04:56:51 PM »
Creating light is not an efficient process in general, that is why there is so much waste.

Conversion of energy is a hell of a process.

Offline mk162

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Re: Single point LED....
« Reply #59 on: November 13, 2014, 09:54:32 PM »
it is terribly inefficient...but I thought the numbers would at least be out of the teens...

but even if you hit 100% efficient, will it save you THAT much money?  I mean a 60w equiv. LED uses about 6-7w...even doubling the efficiency would put it at 3...3 watt savings...hardly worth rushing out to the store for that.

Compared to MH bulbs though, they are better, and they are much cooler(the heat is from the power converters)...on busy days it should make non-conditioned screen rooms more comfortable.