Potentially useful LEDs for darkroom/alt applications

[Michael R]

No worries, hijack away. Just started the thread for discussion so whatever direction it goes in is fine with me, especially if you end up with a solution.

I am hoping not to hi jack Michaels thread but I have a somewhat related question.

I make up to 30 x 40 pt pd and multiple gums, I currently have a 30 x 40 Nuarc system with a 1000k Metal Halide head, I am finding my exposures too long for my workflow ( I do multiple images each day and would like more power)
I have been talking with Ian Leake about modifying one of his density measuring devices to connect to a power supply that will shut off after a set exposure is met. He believes it is quite simple, I want to just use the base vacuum systems to hold my material I have two units ( one has already been modified so the vacuum turns on independently of the exposure) I would do the same to the other unit. I have a small exposing room where I walk out of the room as work is being exposed and I do need this automatic shutoff system.(important)
I would like to hang a light above each unit. If 1000k is what I have now I am thinking I would like 4000 k - 6000k to speed up my large printing time.

Is there a unit available Used and or New that can do this for me and of course replacement bulbs and parts for the future.
If I designed a bank of these types of lights or Led lights that would work with Pt, gum, cyanotype and salt... do you think the power could equal my needs posted above.. Somehow I think Sandy in the past has talked about (Carbon Arc hanging units) and I think this is something Calvin Grier in Spain may be using.
I have seen Jon Cones system which is quite good, but my space would really work well with a hanging light system above the vacuum table so I can take large film in and out of the unit with ease and not worry about lifting the whole head as I currently do with my
Nuarc 32 1KS unit.

any help

Bob

[sanking]

Somehow I think Sandy in the past has talked about (Carbon Arc hanging units) and I think this is something Calvin Grier in Spain may be using.

Bob

Bob

I am getting older, but still not as ancient as you think!

The carbon arc light was invented in the first decade of the 1800s and was the first practical electric light. It was widely used starting in the late 19th century for street and large building lighting until it was replaced by the incandescent light in the early 20th century. The carbon arc was used in more specialized applications where a high intensity point light source was needed, such as movie projectors and printing until after World War II.

I knew an elderly gentleman (in his 80s in the 1980s) who used a carbon arc, but I never saw one used in practice.

Sandy

[Ron McElroy]

I am hoping not to hi jack Michaels thread but I have a somewhat related question.

I make up to 30 x 40 pt pd and multiple gums, I currently have a 30 x 40 Nuarc system with a 1000k Metal Halide head, I am finding my exposures too long for my workflow ( I do multiple images each day and would like more power)
I have been talking with Ian Leake about modifying one of his density measuring devices to connect to a power supply that will shut off after a set exposure is met. He believes it is quite simple, I want to just use the base vacuum systems to hold my material I have two units ( one has already been modified so the vacuum turns on independently of the exposure) I would do the same to the other unit. I have a small exposing room where I walk out of the room as work is being exposed and I do need this automatic shutoff system.(important)
I would like to hang a light above each unit. If 1000k is what I have now I am thinking I would like 4000 k - 6000k to speed up my large printing time.

Is there a unit available Used and or New that can do this for me and of course replacement bulbs and parts for the future.
If I designed a bank of these types of lights or Led lights that would work with Pt, gum, cyanotype and salt... do you think the power could equal my needs posted above.. Somehow I think Sandy in the past has talked about (Carbon Arc hanging units) and I think this is something Calvin Grier in Spain may be using.
I have seen Jon Cones system which is quite good, but my space would really work well with a hanging light system above the vacuum table so I can take large film in and out of the unit with ease and not worry about lifting the whole head as I currently do with my
Nuarc 32 1KS unit.

any help

Bob

Bob

Olec, Nuarc and I believe other companies made 5kw units for exposing plates and proofing during the film days of offset printing. I am not sure how easily they can be found at this time. I reached out to my former employer, I retired at the first of the year, to see if they still had the unit sitting unused in storage, but alas it along with the Douthitt vacuum frame were tossed during a warehouse purge. I would not recommend using carbon arc lamps. I used them in the late 70s / early 80s and NASTY. They need lots of good forced ventilation due to the ash produced when the carbon rods burn.

[koraks]

> Is there a unit available Used and or New that can do this for me and of course replacement bulbs and parts for the future.

Bob, I'm a bit far away from you geographically, but what you want isn't insanely difficult for someone with a little electronics engineering acumen. I'd go with a light head of an array of 50w or 100w UV COB leds mounted onto appropriate aluminium heat sinks with fans; fortunately these are standard off the shelf parts these days. Power supply can be an off the shelf unit; 48V would do. Driver and timer circuitry could be either off the shelf or custom engineered. Lately I've reengineered my enlarger light source (RGB color, ca 365W across all channels total) and made a tiny UV printing source (mostly for PCB's, but it does alt. process as well). The electronics aren't insanely complex. See if you can locate someone with a decently functioning "amps and volts" brain where you live. If I hadn't been a continent away I'd have been happy to do this for you.

[Tin Can]

My latest plan is getting bigger, but modular. I now have 10 of the 50 watt 365mm Everclear.

I also await a bench from a mfg I already know, Amazon was way cheaper. Seville Classics (UHD20247B) UltraHD Lighted Workbench (48L x 24W x 65.5H Inches) Stainless Steel

By using 10 lamps in different configs hanging over my pressure plate, I can switch them on and off, as needed

Yes, I will install curtains or metal light shields, making a simple rack to hang from, allowing adjustment of lamp pattern and height

Ventilation will be determined, if needed at all

Use timers, temperature and power meter to identify variation

I may put wheels on it

[sanking]

My latest plan is getting bigger, but modular. I now have 10 of the 50 watt 365mm Everclear.

I also await a bench from a mfg I already know, Amazon was way cheaper. Seville Classics (UHD20247B) UltraHD Lighted Workbench (48L x 24W x 65.5H Inches) Stainless Steel

By using 10 lamps in different configs hanging over my pressure plate, I can switch them on and off, as needed

Yes, I will install curtains or metal light shields, making a simple rack to hang from, allowing adjustment of lamp pattern and height

Ventilation will be determined, if needed at all

Use timers, temperature and power meter to identify variation

I may put wheels on it

Wow,

You da man!

That unit should give you a great exposure unit for UV processes. With floods placed at 8-12" from the exposing plane you should have fast exposures and very even exposure over a large printing area. For consistent exposures, especially in warm conditions, you might consider installing a light integrator designed for 365 nm. Some of the old Olix sensors would be perfect for this.

I like the idea of wheels!!

Sandy

[Tin Can]

I have hesitated too long almost, you are a very good resource

I have PPM-1 LightMeasure UV Exposure Meters

and another UVA-B meter

Thank you

Wow,

You da man!

That unit should give you a great exposure unit for UV processes. With floods placed at 8-12" from the exposing plane you should have fast exposures and very even exposure over a large printing area. For consistent exposures, especially in warm conditions, you might consider installing a light integrator designed for 365 nm. Some of the old Olix sensors would be perfect for this.

I like the idea of wheels!!

Sandy

[Jeffz]

I found this as a recommendation on YouTube for Cyanotype UV light source. Anyone have experience with this light for other forms of Alt Processing?

https://www.amazon.ca/NEW-2020-MODEL.../dp/B0863HD955

[Tin Can]

Adding a link from 2008

Alternative Process Darkroom










There are many more to find

[Michael R]

Just a note of extra info for any fellow “white light” folks regarding Waveform Lighting plug-and-play stuff, based on a response I received from them. Their standard PWM dimmer operates at 25kHz.