Did this just happen?

[Mark @ Hurricane Printing]

hear me out in this timeline:

One month ago: I upgraded my home security system, and this required getting a new control panel box where all of the hardware and battery goes....and this is in one of my spare room's closet....and this new panel box, when closed has two very small LED's that illuminate to show its powered on.

One week ago: So my drying cabinet can only hold 6 screens (I have no space and i could only build a cabinet so big..6 screens was as big as i could get)....I had a 230 setting in there but didn't need at the moment but i needed the 6 spaces because i coated 6 screens....so i relocated that 230 into that spare room's closet mentioned above. In the room there is one window, which has blinds which are closed and doesn't face the closet...rooms stays dark 100% of the time...I put the 230 in the closet between some hanging clothes....and close the closet....I just stored it there till i need it eventually.

2 days ago: I stored 2 more 230's in the same closet....but not between hanging clothes...just leaned them against hanging clothes...and these 2 screens were facing the security system panel box (with the two tiny LED's illuminating)

1 day ago: I finally need the three 230's stored in the closet.....I take the one that's been in there the longest (between the clothes),...burn it no problem...image comes out perfect.....next I take one of the two that was not between clothes and facing the control panel...burn it...take it to washout booth...NOTHING is there!!!..no image....so now im thinking my exposure unit is broken (its a MSP 3140)....or something...I have no idea because i was not standing by the exposure unit when it was exposing..so then I take that 3rd screen from the closet (that was also facing the control panel)...I burn it..stand by the exposure unit to make sure it comes on...it finishes..i take it to the washout booth..NO image is there!!!!...now im freaking out...how could this be??...So i go back to the closet thinking I may have a 4th screen in there...thinking maybe i missed one or something..so hopefully i could try again....and when i open it that's when i notice the LED's pin lights in the panel...and im thinking "Theres NO WAY that LED exposed those screens..NO WAY!!!!"......BUT....it is the ONLY explanation........the 6 screens in the cabinet once dried burned no problem.

So,,,let me ask...can that actually happen???....They have LED exposing systems I know...but the led lights on this control panel are smaller than an eraser head...there are two of them....i'd estimate the screens were maybe a foot and a half away from the panel box..2ft tops........I will be amazed if that can actually happen. ..the one screen that was there for a week but i placed it between clothes burned no problem at all.

The only other thing i can think of..is when i transported the screens from my cabinet to the closet...i had to walk thru my garage then thru utility room...down hallway, into room..into closet...this is maybe a total of 15 seconds and i'm shielding the screen with my body when i walk by the utility room window and front door viewing window..no direct sunlight hit them and the sun wasn't even shining in at that point of the day.

[244]

here me out in this timeline:

One month ago: I upgraded my home security system, and this required getting a new control panel box where all of the hardware and battery goes....and this is in one of my spare room's closet....and this new panel box, when closed has two very small LED's that illuminate to show its powered on.

One week ago: So my drying cabinet can only hold 6 screens (I have no space and i could only build a cabinet so big..6 screens was as big as i could get)....I had a 230 setting in there but didn't need at the moment but i needed the 6 spaces because i coated 6 screens....so i relocated that 230 into that spare room's closet mentioned above. In the room there is one window, which has blinds which are closed and doesn't face the closet...rooms stays dark 100% of the time...I put the 230 in the closet between some hanging clothes....just store it there till i need it eventually.

2 days ago: I stored 2 more 230's in the same closet....but not between hanging clothes...just leaned them against hanging clothes...and these 2 screens were facing the security system panel box (with the two tiny LED's illuminating)

1 day ago: I finally need the three 230's stored in the closet.....I take the one that's been in there the longest (between the clothes),...burn it no problem...image comes out perfect.....next I take one of the two that was not between clothes and facing the control panel...burn it...take it to washout booth...NOTHING is there!!!..no image....so now im thinking my exposure unit is broken (its a MSP 3140)....or something...I have no idea because i was not standing by the exposure unit when it was exposing..so then I take that 3rd screen from the closet (that was also facing the control panel)...I burn it..stand by the exposure unit to make sure it comes on...it finishes..i take it to the washout booth..NO image is there!!!!...now im freaking out...how could this be??...So i go back to the closet thinking I may have a 4th screen in there...thinking maybe i missed one or something....and when i open it that's when i notice the LED's pin lights in the panel...and im thinking "Theres NO WAY that LED exposed those screens..NOW WAY!!!!"......BUT....it is the ONLY explanation........the 6 screens in the cabinet once dried burned no problem.

So,,,let me ask...can that actually happen???....They have LED exposing systems I know...but the led lights on this control panel are smaller than an eraser head...there are two of them....i'd estimate the screens were maybe a foot and a half away from the panel box..2ft tops........I will be amazed if that can actually happen. ..the one screen that was there for a week but i placed it between clothes burned no problem at all.

The only other thing i can think of..is when i transported the screens from my cabinet to the closet...i had to walk out of my garage thru utility room...down hallway, into room..into closet...this is maybe a total of 15 seconds and i'm shielding the screen with my body when i walk by the utility room window and front door viewing window..no direct sunlight hit them and the sun wasn't even shining in at that point of the day.

I can say for sure the LED units on the alarm did not expose anything. Most LED's produce no u.v. And the ones who do need to be much closer than you state. Probably happen during the walk to the closet. Once the emulsion starts to expose it will continue to cross link on its own.

[mimosatexas]

I would question how UV safe both the walk to the closet and the actual closet are, and at some point UV started the reaction in the emulsion during that trip or during storage, but it likely wasn't the led's.  If it was the LED you would likely have gotten variation in exposure related to the position of the screens in relation to the lights, meaning the screen closest would be more exposed than subsequent screens and areas closer to the light would be more exposed etc.

[Dottonedan]

I don't know. It might be possible.  Look at this, He took his first screens to that closet (via the same path) and that Exposed fine. Now consider that you can cook a turkey with a light bulb if held in the oven long enough under that light bulb. This doesn't cook just the skin, but the inside as well. Now this is a far stretch, but LED lights might produce enough strength (if keep i. Front of them long enough over time) to expose those screens.

Like the last guy said, you would expect then to have varied exposures based on distance and location of the lights, but just like the Turkey, if exposed long enough, eventually 100% coverage if exposure is 100% coverage. In other words, the distance of exposure could creap out to 100% coverage over time.

I've seen recently just how strong these LED lights are.  For example, on some pure photopolymer fast  emulsions, a 1 inch area can be properly cured in a fraction of a second. A 17" design can be fully exposed while taking near 5 seconds or less to fully pass under the LED exposure bar on an STE. I didn't time that? So those numbers are pretty close guesses.

Taking that info, and using two LED lights could possibly pre expose a screen if left in there for two days similar to how moisture could creap into the center of the emulsion over time.

What I don't know us if all LED lights are equal.

[mimosatexas]

I'm sure Rich knows a hell of a lot more about the specifics than I do, but just quickly googling shows that most of the cheapo LEDs used for indicator lights like this are well out of the proper spectrum to expose emulsion, and the ones that are in the proper spectrum are a lot more expensive and less common. http://en.wikipedia.org/wiki/Light-emitting_diode

[Frog]

I also vote that the LED's are not guilty since they are unlikely the UV specific type.

I'm thinking much more likely is inadvertent pre-exposure during the trip to the closet.

[Dottonedan]

Well, then there goes my Turkey idea. Anyone want a drum stick?

[abchung]

I think the room is not totally dark. If he stayed in the room for several minutes to allow his pupils to adjust to the light level. He might find out where the light is coming from.
For me, it is the window.  Light can sneak around or penetrate a thin blind.

[Northland]

Were the two faulty screens exposed to heat ?

[alan802]

I really don't think the 15 second walk would have exposed those screens unless he had them facing the sun the whole time or was walking through a room of exposure units pointing directly at him.  If that exposed them then why didn't the other screen in the closet have the same result? In a setting meant to expose screens with a 10K metal halide 15 seconds is enough for a 230, but that's optimum settings and atmosphere for that to happen but only with a pure photopolymer emulsion.  There are numerous members here with lower wattage exposure units and dual cure emulsions that burn screens for 3-5 minutes and still have underexposed screens and I'd venture to guess that there is less exposure walking the screens through his house than a screen would have several inches from a fluorescent bulb and 60 seconds.  We bring our screens out in the well-lit production area for sometimes minutes at a time with no exposure issues.  We put our screens on the light table and for film positioning dozens of times a day and they don't get pre-exposed so I doubt the walk through his house exposed his screens enough...just my opinion. 

I bet there is UV light creeping around in that closet like a thief in the night . 

[Northland]

Is there any chance the emulsion cross-linked due to heat.... was your glass surface hotter than normal ??
I don't know how much heat it would take.... but heat can cause poor wash-out.

[mk162]

it's easy to figure out...change nothing and leave a screen there again for the same length of time.  make sure to try and do everything else the same as far as exposure, the walk to the closet, the position of the screen etc.

[Mark @ Hurricane Printing]

I may do the recreation routine one day.

And i can assure you in that spare room the blinds stay closed..the light stays out...and the window is on side of the house...not in line with the sun at all....the closet door are the double door kind...i am confident that no sunlight gets thru to the closet...and i was exposing screens right before that and right after it....so the exposure unit was not the issue.