Before You Went LED, What Were You Using?

[alan802]

There have been a lot of posts pertaining to LED and how much everyone loves theirs and I was wondering what the perspective is since one's opinions on them is mainly shaped by what they were using before. 

I'll start, we were using a Richmond Solarbeam with a "10K" bulb and I put that in "" due to the fact that I've had a few guys tell me it's not close to actually being a 10K and more like a 6-7K output.  I've said many times that I thought this expo unit was one of the best ever made and even now after using LED for a few months I feel even more solid about that.  I can understand the opinions of the LED's being so high, especially if you were burning screens with flouro bulb units or lower powered metal halide units, but I'm really wondering if anyone has come from a 5K and up metal halide to an LED unit that thinks the LED is significantly better or even on par with the MH unit.  There are still more pros for our LED than the MH but fully crosslinking the emulsion and getting full exposures is not one of them.  Our MH unit outperforms the LED by a big margin when it comes to the most important part of the equation...burning the image completely through the layer of emulsion.

Has anyone come from a 5K Olec or one of the stronger Trilight units from M&R to an LED?  I'm just looking for some perspective on how LED opinions have been formed.  So if those of you who have gone LED could share what you were using previously and have time to compare/contrast the two I think it would be appreciated.  I'm not knocking LED because even with my issues I think it's a better option than MH right now but in my opinion it's not superior in some ways that it's being assumed to be.  It deserves praise but I think that we need to tap the brakes a little bit and put things in proper perspective so others who haven't pulled the trigger can get the whole story and one that isn't biased in any way. 


* In May, this thread took off again, but devolved into mudslinging and arguments that obscured any real facts and information. I performed a little surgery, but there are probably still some statements that will seem a little odd in their new altered context. Otherwise, most will see it as a great improvement!

[GraphicDisorder]

I would assume most going to LED are doing so form lower power MH or even like you said florescent.

We came from an Ameragraph 150.  1200 watt I believe it is.  Was great for a couple of years. Slowed way down over time, we were seeing exposure times of over 7 minutes on some screens by the time we retired it, and that was on new bulbs. Clearly was something up with it and I wasn't going to fart around trying to fix it. We haven't noticed any loss in detail ON press vs our MH.  I am sure under a microscope some differences are there.

[Homer]

Douthitt 1k MH

[sqslabs]

I've asked many people in the industry (including those who make LED units), what the benefit of upgrading from a 2-screen capable 10k unit to LED would be, and haven't gotten a straight answer besides power consumption and bulb cost.  Which is why I haven't looked into LED, and likely won't anytime soon.  If my current unit crapped out, I'd probably buy this beast before I bought an LED and save some money in the process:

http://www.ebay.com/itm/Richmond-Screen-Maker-/221706439407

Maybe that's counterproductive and I'm living in the past, but to me, the ability to quickly burn multiple screens outweighs the power savings of an LED unit with one screen capability.  Then again, my shop opened with a 2-screen capable 10k unit under the roof, so I can definitely understand the excitement of someone upgrading from a smaller bulb.  I couldn't imagine waiting a few minutes to burn a screen, it would drive me nuts.

[Doug S]

MSP 3140 here.

[3Deep]

While I don't own a LED unit but had the the experience of testing one first hand in our shop, if our current unit broke down beyond repair I would buy one in a heartbeat.  We have now a Atlas 5 way old unit that has something of a point light but quarts, using HXT, image mate dual cure 521 emulsion I get burn times of 3 minutes and 1.5 minutes with HXT holding great detail on yellow mesh, using 521 about 6 minutes on yellow just a little less on white mesh still holding good detail.   Now exposing those same screens using the Starlight I think we burn at 8 to 10 seconds still holding with great detail, now the only advantage I see the LED over my old unit is speed and the cool factor of using LED and no heat build up on the glass plus the bulb life if I had to buy again yes I might go for the LED unit for those factors.  Just got to say this last thing LED vs our old units to me is like Coke vs Pepsi they taste different for sure but in the end they are both still soft drinks and quench your thirst that's my take and I'm sticking to it

darryl

[Homer]

D- my starlight builds up heat if you burn 10 or so in a row....fyi



we didn't purchase our starlight for speed, we bought it to eliminate a variable. we now have a constant for exposure. a 180 S mesh, 1/1 with HXT is 70 seconds. all the time. every time. forever.

[screenprintguy]

D- my starlight builds up heat if you burn 10 or so in a row....fyi



we didn't purchase our starlight for speed, we bought it to eliminate a variable. we now have a constant for exposure. a 180 S mesh, 1/1 with HXT is 70 seconds. all the time. every time. forever.

Are you using HXT for everything? If you are doing plastisol runs, do you expose less time, or just run the same across the board? Just curious. I know if I use one for plastisol, I can expose 75% less cook time and be fine, just have to seriously bump up the time for the wb.

[Dottonedan]

On the other end of the spectrum, I did an install where the customer has been in business for many many years.


In their screen room, they still currently have 3 working competitor DTS machines (two of them are from the same company) and the 3rd is another Co. Now, they added the M&R STEII and will still be using the others. They first, got into DTS approx. 13 years ago or more and may have started and got rid of a 4th brand.


They expose 8 screens at one time. I looked to get the specifics on the exposure light but it was older and the info worn off.
It was a lamp that stands on a pole with one large tube in the center. I think they ma yahve had tow of them but mostly used one. The screen rm guys didn't know how strong the light was, but I imagine it had to be 7-10k


They use Dual Cure emulsion and their larger quantity orders can be over 10,20 and more pieces, but they do tons of low quantity orders at 1-4 colors as well. This is some of the info Al Buffington had been looking for. (large quantity using discharge and LED). Apparently, they had been doing discharge and large quantity for years with DTS but not with LED until now. Thye have have been doing LED for a while now and have not had any issues.


Considering the quantity of work they do per day, the # of screens they can already expose, it becomes interesting for them to make the decision to add another, using LED.  The number of screens per day versus exposing one at a time on the STEII should be a wash on exposure time if not more time invested on exposure time compared to exposing 8 at time.


The benefit in this extreme situation (they might find) to be, the time it takes to 1st print a screen, then remove the screen, and load it, x 7 more, versus touching each screen once on the STEII.  I can't say for sure. All I know is they decided it was worth going this way.  For very large shops, they are looking at every little thing that can save a step that may justify a decision.

[Homer]

Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.

[IntegrityShirts]

Based off what I learned from my DIY LED project, I'm sticking with my 5k Olec for as long as I can keep it alive.  LED will serve as a solid backup if the Olec goes down, but it's not a replacement.

[ebscreen]

We're currently using two 1200 watt MH units to keep up with screen production. We use SP-1400 diazo emulsion,
probably one of the more difficult emulsions to fully expose. I'd start exposing with a candle before I switched
emulsions, I like the stuff that much.

Our exposure times are long, 4-600 LTUs, probably roughly five minutes, never timed one though.
Obviously it would be a no brainer if we could significantly reduce that time. Not to mention heat, power
consumption, bulb replacement, etc.

I am absolutely unwilling to sacrifice image quality and complete exposure for the above mentioned benefits however.
I'd sooner buy a couple 8K Olec's and to hell with the bulbs and power costs.

So far I have been unable to get a straight answer, from either manufacturer or user, as to whether or not
I'd have to accept a degradation in screen quality from a LED unit for diazo emulsions. Every time I ask for
quantifiable information all I get back is "it's so fast". I hear whispers from trusted sources that my assumptions are
correct though, this post being yet another one.

It seems the majority of LED units are being used with photopolymer emulsions, which is kind of confusing as
exposure times with most MH units are going to be in the sub-minute range already, and going from 50 seconds
to 10 with the possibility for less complete control seems like a losing game. I guess if you were coming from
fluorescent it would make sense. Indeed, Workhorse's LED user manual states that the machine is intended for
use with photopolymer emulsions.

That one MFG has a generous return policy, but I'd honestly feel bad about sending the thing packing right back if it
doesn't cut the mustard. I'd rather know the straight dope beforehand.


So, really, honestly, diazo and LED, yay or nay?

[screenprintguy]

Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.

Thanks for the feed back bro. I'm still using both Chroma blue and HXT and getting tired of having both on hand. I love HXT, If I could expose it faster that would really help to go with it exclusively. That stuff holds such awesome detail and is rock solid, and really good price as well. I've been looking at the Starlight, and the CCI unit, the one CCI has now is kinda big, can do up to 4 23x31 screens at 1 time, stands vertically which is reaaaaaally nice, but I was just told by my rep that they are launching 2 new units that are smaller, can shoot 2 23x31 or 2 25x36 at once, and will have more of the multispectrum led lights than anything on the market today. What is attracting me to that one is the vertical mounting of it, takes up no space at all, and they are developing it around the use of diazo and dual cure emulsions that they make. We will see, we are in the middle of lots of big decisions right now and it gets freakin overwhelming and stressful to say the least. One thing HXT does stink bad when exposing, really noticeable now that I am in a dedicated imaging room. I'm putting a couple of duct hoses on the blowers of my Trilight to send that stank outside, but if we go LED, that wont be an option and will probably have to put an exhaust fan in for use during exposures. In the confined space it gets overwhelmingly stanky , lol. Sorry for the topic derail.

[ZooCity]

Stay tuned.  We're about to make this comparison,  in as scientific a manner as possible.  5kw halide,  dialed in with the highest quality bulb, new photocell and good integrator shooting 2up v starlight led shooting 1up.  High d max,  good d min film.  Exposure time,  exposure quality,  power consumption,  resolution will be the main points of comparison.  If anyone wants me to add another item to the testing or has suggestions please let me know.   I'm hoping to get an accurate handle on of this tech is ready for prime time.

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[ebscreen]

What emulsion(s) Chris?

I look forward to your feedback, I know we're pretty similar in our demands from our screens.