Author Topic: Converting an Exposure unit  (Read 673 times)

Offline 3Deep

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Converting an Exposure unit
« on: July 15, 2019, 03:06:54 PM »
Need some advice and where to get it, I have an older model exposure unit which is a Atlas 5 way unit that has a point light and two fluorescent bulbs that I can no longer get so it seems, (F893T12-SDI-HO-BP), but I can get 36" T8 fluorescents which would need a different ballast.  My question is anyone ever change out bulbs and ballast in there unit...the unit is fine, just can't find those two bulbs, trying not to buy a new exposure unit as I just put a new point light bulb in this unit, but if I must I must :-\
« Last Edit: July 15, 2019, 04:14:01 PM by 3Deep »
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Offline Sbrem

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Re: Converting an Exposure unit
« Reply #1 on: July 15, 2019, 03:41:10 PM »
There are folks making their own point source LED units to replace bulbs. I started to do this, but bought a Saati Pro-Lite 450 instead. Well, I finished the project over the 4th when I had a few days off, and it works. I have to make an exposure test sometime this week, and I'll try to post the results. I didn't really need to do this, but I had all the parts, and figured I'd finish it. We still have our 5K MH as well for backup. Parts, including the box (which really could have been an inch bigger in each direction) just under $300.00.

Steve
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Offline Prince Art

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Re: Converting an Exposure unit
« Reply #2 on: July 16, 2019, 11:12:14 AM »
There are folks making their own point source LED units to replace bulbs. I started to do this, but bought a Saati Pro-Lite 450 instead. Well, I finished the project over the 4th when I had a few days off, and it works. I have to make an exposure test sometime this week, and I'll try to post the results. I didn't really need to do this, but I had all the parts, and figured I'd finish it. We still have our 5K MH as well for backup. Parts, including the box (which really could have been an inch bigger in each direction) just under $300.00.

Steve

How far away are you putting that from bulb to glass?
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Offline Sbrem

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Re: Converting an Exposure unit
« Reply #3 on: July 16, 2019, 01:00:21 PM »
I still need to determine that, but there are results of some other folks tests, and I seem to recall 20" or in that neighborhood. I still have to fashion a reflector to collimate the rays. Some suggestions for that are a small plastic bowl that could have the bottom cut out, and cover the inside of the bowl will foil. I'm going to experiment with T9, which is LED friendly as I understand it. After getting some other's test times, I'll do a step test around those to see where I'm at, and home in from there.

Steve
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Offline Frog

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Re: Converting an Exposure unit
« Reply #4 on: July 16, 2019, 01:23:20 PM »

How far away are you putting that from bulb to glass?

I still need to determine that, but there are results of some other folks tests, and I seem to recall 20" or in that neighborhood. I still have to fashion a reflector to collimate the rays. Some suggestions for that are a small plastic bowl that could have the bottom cut out, and cover the inside of the bowl will foil. I'm going to experiment with T9, which is LED friendly as I understand it. After getting some other's test times, I'll do a step test around those to see where I'm at, and home in from there.

Steve

Since this seems like a component for a DIY project rather than a complete unit, I would have expected Saati to offer some suggestions from their testing.
The old 1.5 times the diagonal of the image area goes out the window with some purpose-built reflectors. Olec has one that is meant for lower profile applications and uses something like .8 times.


« Last Edit: July 16, 2019, 04:43:07 PM by Frog »
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Offline Logowear

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Re: Converting an Exposure unit
« Reply #5 on: July 16, 2019, 02:07:07 PM »
I have the Ryonet FXCTS exposure unit that I believe uses the Saati Pro-Lite.
The distance is 23" from the LED's to the screen.
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Offline Orion

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Re: Converting an Exposure unit
« Reply #6 on: July 16, 2019, 02:09:17 PM »
Kaules Screenworks did a video of a Vastex conversion using a Saati lamp. Looks to be set at least 20 inches from the glass.


Read here for more info on screen imaging.

edit: a note to Dan, just skip over the water base vs. wax ink stuff.  :D

« Last Edit: July 16, 2019, 02:14:49 PM by Orion »
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Online DannyGruninger

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Re: Converting an Exposure unit
« Reply #7 on: July 16, 2019, 02:31:46 PM »

edit: a note to Dan, just skip over the water base vs. wax ink stuff.  :D


here we go again  :P
Danny Gruninger
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Offline Sbrem

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Re: Converting an Exposure unit
« Reply #8 on: July 16, 2019, 04:35:26 PM »
Kaules Screenworks did a video of a Vastex conversion using a Saati lamp. Looks to be set at least 20 inches from the glass.


Read here for more info on screen imaging.

edit: a note to Dan, just skip over the water base vs. wax ink stuff.  :D

That will be a fast lamp, at 20". We are using our Pro-Lite (450 watt) at 30" to 34" I think, I'd have to check with my screen guy. My little build is 200 watt. I made mine based on a similar project.

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

Offline ABuffington

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Re: Converting an Exposure unit
« Reply #9 on: July 16, 2019, 04:54:04 PM »
Distance to screen should be enough that a line from the outside of the screen to the light source is less than 45 degrees. greater than 45 can cause light to bounce off of glass or hit a CTS screen at too severe an angle.  This can also help prevent over exposure in the center of the screen compared to the edges if the lamp is too close.
Alan Buffington
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Offline 3Deep

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Re: Converting an Exposure unit
« Reply #10 on: July 16, 2019, 06:07:07 PM »
LOL, now I know how to build a led unit, but what about old unit ;D
Life is like Kool-Aid, gotta add sugar/hardwork to make it sweet!!

Offline Frog

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Re: Converting an Exposure unit
« Reply #11 on: July 16, 2019, 06:15:15 PM »
LOL, now I know how to build a led unit, but what about old unit ;D

I see the tubes at Interlight, but only by the full case of 45. So, it appears that at least they exist.
What does Atlas say?
"It's crackers to slip a rozzer the dropsy in snide"

Offline Frog

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Re: Converting an Exposure unit
« Reply #12 on: July 16, 2019, 06:20:15 PM »
Brings up another question. Is yours the 1000 watt Metal Halide as the single point light?
If so, what did these tubes do?
 Or is is it just the low UV Quartz type?
I seem to remember some units like this that had MH for exposure, then fluorescent tubes to double purpose it as a light table.



"It's crackers to slip a rozzer the dropsy in snide"

Offline Sbrem

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Re: Converting an Exposure unit
« Reply #13 on: July 17, 2019, 08:32:22 AM »
LOL, now I know how to build a led unit, but what about old unit ;D

Sorry Darryl, I didn't mean to derail. I just thought it might be an inexpensive project for the future, as those bulbs are getting scarce, yes?

Steve
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Offline 3Deep

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Re: Converting an Exposure unit
« Reply #14 on: July 17, 2019, 10:09:17 AM »
@Frog, yes it is the quartz uv 1000 watt point with tubes, and Atlas couldn't get them and yes I found out I could get them by the case for around 1200 bucks from voltarc, I guess a case would last longer than I might live LOL.
@ Steve, your cool, you provided much updated info someone else can use in building there own led unit, but I think I'm going to change the ballast to a Fast start T8 and purchase the T8 bulbs which I can find almost anywhere.
Life is like Kool-Aid, gotta add sugar/hardwork to make it sweet!!