My UV exposure unit.

[Sergey Chekh]

Hello, friends! My name is Sergey. I'm from Ukraine. For more than 12 years I have been doing alternative photography. Reading the forum, I often meet the question of UV unit on the LEDs. I made such an installation for my workshop. The first thing I wanted was compactness. I have to conduct workshops, and the possibility of transporting a unit is a great bonus.
For installation, I chose 5050 UV-A LEDs with an emission band of 365-400 nm. 5 meter tape with a total capacity of 45 watts. 300 LEDs. LED strips were mounted on a sheet of aluminum. This is the basis and the radiator for heat dissipation. Although the LEDs are not very warm, this can extend the life span. The body is assembled from 6 mm plywood. The size of the LED panel is 48x36 cm, the size of the glass is 42x62 cm. I installed a timer that I bought on Aliexpress.
The test results are simply pleased.
Oilprint - 50 sec.
Carbon - 50-65 sec
Cyanotype - 80-120 sec.
The device is simple, very economical, compact.
I will be glad if my experience helps someone solve the problem of UV lighting for their work. I will be glad to answer all the questions.
Best regards, Sergei

 

[koraks]

Looks very good Sergey, congratulations! Those exposure times are nice and short, which is probably helped by the short distance between the light source and the print. I think you've shown very nicely that a perfectly functional unit can be constructed at a low budget and with great simplicity.

 

[Sergey Chekh]

Looks very good Sergey, congratulations! Those exposure times are nice and short, which is probably helped by the short distance between the light source and the print. I think you've shown very nicely that a perfectly functional unit can be constructed at a low budget and with great simplicity.

Thank you)) I am glad to meet you.
In LED devices, I apply the "5" rule.
The distance between the LEDs multiplied by 5 = the minimum distance of the scattering plane. In this unit, the glass is located at a distance of 6 cm from the LEDs, and has completely uniform lighting. The installation budget can be estimated at about 30 USD

 

[Jerevan]

@Sergey Chekh - it's looking very nice!

I am just wondering since I am thinking of building something similar ... I assume that you soldered the LED strips to each other? I can't see any wires, but maybe they are hidden.

 

[Sergey Chekh]

[QUOTE = "Ереван, должность: 2298706, участник: 3360"] [USER = 91986] @Sergey Chekh [/ USER] - это выглядит очень мило!

Я предполагаю, что вы спаяли светодиодные ленты друг с другом? Я не вижу никаких проводов, но, возможно, они скрыты. [/ QUOTE]

 

[Sergey Chekh]

Извините, что я не ответил некоторое время. Да, конечно, ленты запаяны. Я установил две шины по краям пластины. К ним припаиваются ленты с полярностью + на одну шину и полярностью на противоположную. лента запаяна тонкой проволокой., после чего вся шина изолируется. Чуть позже нарисую схему.

 

[Jerevan]

Thanks, @Sergey Chekh - I think I can figure out what you mean.

 

[keechoon]

Hi Sergey,

You mentioned that the lights are 365-400nm, is it a mix of the 2 types of LED strips? What I can find online are either 365 or 395 strips.

Thanks!

 

[Sergey Chekh]

Congratulations, Sergey, the lights are just awesome. Nice job. I want to make a similar installation. So I have already ordered some led lights from aliexpress. Unfortunately, my previous package with LED lights got lost. But this time I got it safe and very fast. All due to my new discovery- these great tips- https://alitools.io/en/blog/warning-tips-and-checklist-to-avoid-scams-on-aliexpress/ so if you shop online often please check the article. it was very useful for me.

thanks a lot for the link. very glad that my experience helped you. I am currently building a new large plant with a vacuum system and more advanced controls. Your link will be very useful in your work. Thank you.

 

[Helge]

What do you use such a UV unit for?
Contact prints I presume?
The cyano types?
Tinted negatives with UV information (pyro, selenium etc.)?

 

[koraks]

Like he said, alt process prints. Cyanotypes, carbon transfer, salted paper, kallitype, pt/pd, gum, etc etc

 

[Helge]

Like he said, alt process prints. Cyanotypes, carbon transfer, salted paper, kallitype, pt/pd, gum, etc etc

He wrote “alternative photography”. That’s a hell of a lot of things.
I’m curious exactly what stuff you might use such a unit for and how.

 

[MurrayMinchin]

Thank you for sharing the "5 Rule".

I will be building my UV exposure unit soon, so appreciate the advice.

 

[Sergey Chekh]

I constantly practice the following printing methods: oilprint, carbon transfer, kallitype, cyano. Gradually moving towards the copper photo engraving. There is practically no market for related products in Ukraine. You have to invent something yourself. My wife has mastered oilprint very well and she really likes it. in any case, we now buy twice as much paper)))

What do you use such a UV unit for?
Contact prints I presume?
The cyano types?
Tinted negatives with UV information (pyro, selenium etc.)?

 

[Andrew O'Neill]

Sergey, I'm surprised that you can get a decent carbon exposure under a minute. I use a 1000W halogen exposure table, and my exposures are 15 minutes. I'd be curious to hear what your exposure duration would be with minimal pigment, thick tissue... for max black and relief. Cheers!

 

[Helge]

I constantly practice the following printing methods: oilprint, carbon transfer, kallitype, cyano. Gradually moving towards the copper photo engraving. There is practically no market for related products in Ukraine. You have to invent something yourself. My wife has mastered oilprint very well and she really likes it. in any case, we now buy twice as much paper)))

I’d love to see some examples when you feel like it.
Do you have an IG or Flickr account?

Have you considered bitumen printing? That would probably be pretty straight forward with a strong UV source.
The first lasting photographic process.

 

[koraks]

I use a 1000W halogen exposure table

Halogen is phenomenally inefficient if you use it to make UV. I'm not surprised UV leds would be two orders of magnitude faster per Watt dissipation.
But your halogen (or is it actually HMI??) is a point source. With your thicker carbon tissues, a diffuse light source such as Sergey's is NOT a good idea. You'll run into a couple of problems with it, of the unresolvable kind as well.

 

[Andrew O'Neill]

Halogen is phenomenally inefficient if you use it to make UV. I'm not surprised UV leds would be two orders of magnitude faster per Watt dissipation.
But your halogen (or is it actually HMI??) is a point source. With your thicker carbon tissues, a diffuse light source such as Sergey's is NOT a good idea. You'll run into a couple of problems with it, of the unresolvable kind as well.

Thanks koraks. Yes, mine is point source. Side by side comparison of prints made with the halogen unit, and my BLB table are very different. The halogen has more contrast, and looks sharper. The highlights are really nice though, on the BLB. My BLB exposure is 25 minutes long! I don't like to go longer than 15 minutes on the halogen, as quite a bit of heat is generated, and can run the risk of melting a tissue.

 

[koraks]

Yes, I know what you mean, tissue tends to get sticky.
I also suspect too diffuse a light source (e.g. blb's at close distance of 4-5" or so) would aggravate final transfer adhesion issues of highlights, i.e. small high value areas not making the transfer, resulting in a lack of (zonespeak) zones VIII and IX and a sharp transition of VII right to paper white.

 

[Sergey Chekh]

Hello there! Portfolio on Flickr is shown in the near future. I rarely used this platform. As for the glop with a small of pigment. My excerpted was about _230 seconds. You need to clarify by records. In the coming days I will make a small video, with this material. Halogen lamps for UV is not very convenient for me.