I now own a large format enlarger!

The light is not as bright as a bulb would be and that Wiki quote is also correct - it is not as bright as a 300 watt stage light when in its original use as a PAR 64 light. However, I was very surprised at the light output of these stage lights when I first saw them. I didn't think anything would ever replace incandescent for stage use but for small stages in marquees, etc, they are very good.

However, I didn't pay anything for it (it was a spare after I repaired another one for a sound company I occasionally work for) so I think it is well worth experimenting with.

For graded papers I can either give separate blue and green exposures or even three exposures - blue and green together, then separate blue and green exposures or I could make a continuously variable PWM system with a single control going from 100% green, 0% blue through to 0% blue, 100% green.

Whilst I like the idea of having a single 'contrast' control, this will effectively halve the output and increase printing time.

The fit is perfect. There is a plastic plate behind it with four M5 bolts which fit in the cold light transformer mounting holes and also three M3 pillars which line up with some existing holes in the PCB.


Steve.

I am also testing with a Par56 led .
In the future I want to replace the light in my CLS 1840 head.
A friend of mine had a broken Par56 led light with DMX control.
It is an 153 leds system, with 5mm leds. 1850 lux /1m
It is this one http://www.bax-shop.nl/led-par-56/bax-led-par-56-kort-zwart-/product-details.html
Very cheap and has DMX control
I tested the Par56 with my 10x10 lightbox but got uneven lighting.

Than I removed my 100 box from the CLS1840 and hold between the lightbox and the Par56, lighting is now more even.


The Pro with this head is the cost (less than 50 euro) and the possibility to control with DMX.
With an USB DMX controller and some freeware DMX software you can program your densities.
And for example lit for 5 seconds the red leds before the actual lighting, nice when doing dodging and burning.
And this is only with 5mm leds, suppose you build your own system with 3W leds.
This is not something I want next week, I will continue printing with my CLS 1840 and ignore the noisy fan that run about 3 minutes when you even expose for 0.1 second

Steve Smith said:

Here it is in my darkroom and fixed to the wall, waiting for its new light source. I had a day off work today - unfortunately the LED PCB is at work so it will have to wait until tomorrow. With me being the impatient type, I'm surprised I didn't go to get it.

I think the PCB will fit in the removable top half of the head quite easily. I'm wondering if I should keep the strange water filled diffuser or put something else there. Does anyone know how much water should be in it? When it is level there is a 2" x 3" air pocket in the middle of the image area. I'm thinking it should be filled up a bit more to optically couple the front and back surfaces but I don't really know how it should be.

I did put a 5x4 negative in, fitted my 105mm lens (I need to get a 135 or 150) and with a desk lamp held above I focused an image onto the baseboard (I told you I was impatient!).

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Have you found a lens for it yet? I have an old Liesegang, Dusseldorf - Parastigmat 135mm enlarging lens. I'm not sure of the mount size, but it does have an adapter flange that it screws into. You can have for the price of postage from the USA.

mhulsman said:

This is not something I want next week, I will continue printing with my CLS 1840 and ignore the noisy fan that run about 3 minutes when you even expose for 0.1 second

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Which power supply? EST1000N? I know that some of the power supplies (like my EST2000N) only 'overrun' the fan if the temp in the housing goes above ambient temp. So, my fans shut off as soon as the lamp goes off. It only stays on if I run a bunch of exposures right after another, then it stays on until its cool up there again.

That LED conversion looks promising, but I would imagine that the heat from 1000watts of LED (if you could ever get that much) would still require the fans

Thats cool that you got a 4X5 enlarger. I recently bought a Crown Graphic camera and an Omega DII Enlarger. The enlarger was $75. It has a Bausch and Lomb f4.5 139mm lens. The problem was the lens was frozen at f11. The fix required some carburetor cleaner and a large pair of pliers. f-stop ring is very smooth now.

cj8281 said:

Thats cool that you got a 4X5 enlarger. I recently bought a Crown Graphic camera and an Omega DII Enlarger. The enlarger was $75. It has a Bausch and Lomb f4.5 139mm lens. The problem was the lens was frozen at f11. The fix required some carburetor cleaner and a large pair of pliers. f-stop ring is very smooth now.

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Nice 'All American' setup there. Some Kodak film and you are ready for Memorial Day.

Steve and Mike it sounds like some real innovation and ingenuity is going on there. It looks very promising. I've harped enough about the absence of a head for my Durst so I'm watching this very carefully.

Curt

ralnphot said:

Have you found a lens for it yet? I have an old Liesegang, Dusseldorf - Parastigmat 135mm enlarging lens. I'm not sure of the mount size, but it does have an adapter flange that it screws into. You can have for the price of postage from the USA.

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Thank you very much. I would like to take you up on the offer. Let me know how much the postage is. I can send Paypal if that is convenient to you.

My postcode is PO33 2SE if you need it to work out postage cost.

I currently have a 105mm lens which appears to project the whole of the 5x4 frame but until I make a print I will not know how much light falloff there is at the edges. It would be nice to do my tests with a lens designed for 5x4 as this takes another unknown out of the equation.


Steve.

mhulsman said:

I tested the Par56 with my 10x10 lightbox but got uneven lighting.

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I am only at the very early stages of experimenting with diffusion - initially with sheets of kitchen roll!

I have found that the best results so far require a diffusion layer very close to the LEDs and another just above the negative. With just one or the other, I see obvious patches of red, green and blue light. With both diffusers I see a very even white light over the whole of the open area which is actually 5" x 7" despite this being marked as a 5" x 4" enlarger.

I'm not sure if my PCB is from a PAR 56 or PAR 64 light but mine also has 153 LEDs and looks very similar to yours, if not identical.

What is your distance from PCB to negative?


Steve.

ic-racer said:

Which power supply? EST1000N? I know that some of the power supplies (like my EST2000N) only 'overrun' the fan if the temp in the housing goes above ambient temp. So, my fans shut off as soon as the lamp goes off. It only stays on if I run a bunch of exposures right after another, then it stays on until its cool up there again.

That LED conversion looks promising, but I would imagine that the heat from 1000watts of LED (if you could ever get that much) would still require the fans

Click to expand...

IC.
I have got an EST 1000N. The EST2000N does have some thermal sensor.
I do not think I need 1000W of leds see this Apug thread: (there was a url link here which no longer exists)
With about 30 leds, 2 ¾ stops faster than an 1000 watt quartz halogen dichroic.