Have an 8x10 enlarger...

RoBBo · Mar 11, 2008

On the way at least...

But no light source...

Considering the price of a Dichro or cold light head I think I'd like to build my own but I'm not 100% sure on what all I have to keep in mind.
I'd like it to have the same spectrum, or near so, to that of a standard condenser enlargers so that I can print VC without a major change over.

I remember reading somewhere that you could just get neon tubes in the right color for that and have relatively even light source for rather cheap?
Anyone know if there are any problems with that?

And I've heard things about inconsistency in light with cold lights, is that only with fluorescent tubes? Would I get something like that with neon tubes?

If I can build it cheaply enough I'd like to make it large enough to later convert the whole setup to 11x14.

I've got no idea on sizes, materials, power, or anything in general regarding cold light enlarging or enlarging larger than 4x5.
Any help would be very very much appreciated.
Same goes for negative carriers I suppose.

The enlarger is a Saltzman by the way.

jeroldharter · Mar 11, 2008

I have no expertise with this but an LED light source would be great with an array of blue, green and red LED's. I keep wishing one of the electrically skilled people on APUG would come up with a good, homemade LED lightsource for 4x5. Seems like it would be even harder to use a flourescent source. Curious to read the responses.

konakoa · Mar 11, 2008

jeroldharter said:
I keep wishing one of the electrically skilled people on APUG would come up with a good, homemade LED lightsource for 4x5.

I did. White LEDs. Minimal hassle as I used pre-made LED modules and assembled them as a light source for my homemade 4x5 enlarger. VC with ordinary plain-vanilla VC filters. It works great!

jeroldharter · Mar 11, 2008

Danny Spence said:
I did. White LEDs. Minimal hassle as I used pre-made LED modules and assembled them as a light source for my homemade 4x5 enlarger. VC with ordinary plain-vanilla VC filters. It works great!

I might remember some posts about this. Did you use mat board as an enclosure? You might post some photos, how to, where to buy parts, exposure times, quirks, details for dummies, etc.

RoBBo · Mar 12, 2008

jeroldharter said:
I might remember some posts about this. Did you use mat board as an enclosure? You might post some photos, how to, where to buy parts, exposure times, quirks, details for dummies, etc.

Yeah that would be wonderful.
About how much did the whole thing cost to do too?

munz6869 · Mar 12, 2008

I haven't made an 8x10 version, but I've nearly finished a 4 x5 version (below) - it runs super cool, and is the same brightness as the lovely (but wretched to use) cold light head it will replace (the dark blobs in this pic are the temporary blu-tac spacers so I could figure out the best diffusion distance)!

Marc
Dead Link Removed

ic-racer · Mar 12, 2008

munz6869 said:
I haven't made an 8x10 version, but I've nearly finished a 4 x5 version (below)

Awesome post. More details please!

ic-racer · Mar 12, 2008

jeroldharter said:
LED light source would be great

I think if I were building a light box from scratch I personally would first consider refurbishing a broken unit of some sort.

Next easiest, I think, would be to use an array of those thin fluorescent bulbs. There is no magic in the Aristo coldlight heating system. Just 4 power resistors shorted to the mains. It just heats up the box, not the bulbs themselves.

More difficult, but perhaps a slicker end product would be to use blue and green (and white to focus?) LEDs. One could just hook each circuit (green and blue) up to a separate timer (or build a dual timer). You could run both timers at the same time or sequentially.

Steve Smith · Mar 12, 2008

I have started to make a 5x4 enlarger and I am thinking about LED light sources.

A modification of one of these might work: Dead Link Removed

Steve.

jeroldharter · Mar 12, 2008

munz6869 said:
I haven't made an 8x10 version, but I've nearly finished a 4 x5 version (below) - it runs super cool, and is the same brightness as the lovely (but wretched to use) cold light head it will replace (the dark blobs in this pic are the temporary blu-tac spacers so I could figure out the best diffusion distance)!

Marc

That looks great. How are you rigging it up and timing it? How even is the light? Is it instant on/off? I suppose you are using below the lens filters. Is the output reasonable for the use of filters. Would be nice to have a filter drawer above the negative.

konakoa · Mar 12, 2008

jeroldharter said:
I might remember some posts about this. Did you use mat board as an enclosure? You might post some photos, how to, where to buy parts, exposure times, quirks, details for dummies, etc.

Yes, white mat board. Plenty of aluminum tape (heating/ac kind) on the inside to make it light-proof. I started a thread on it a while back here on APUG:

(there was a url link here which no longer exists)

And it's all in a webpage (how to, parts, times, quirks) I made as well.

www.deadbread.com/crumbs/23c.html

BTW, that looks nice Marc! SuperbrightLEDs.com?

munz6869 · Mar 12, 2008

Mine's a prototype - it will go in a nice MDF box shortly, to replace the Taucoli cold light head on my Durst CE1000. The LEDs are from here
http://www.jaycar.com.au/productView.asp?ID=ZD0462&CATID=&keywords=led+strip&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
and the diffuser is 3mm white acrylic. I've used 4 LED strips, which I added one at a time until the brightness was the same as my existing head (very scientific). So there's 108 LEDs in total, and the evenness of light is pretty good. The light seems "instant on", and as "instant off" as a tungsten bulb, probably slightly quicker. I am using under-the-lens VC filters currently, and I'm still testing - I'll post another pic when it's in a box and I'm printing...!

The "idea" of the whole thing is great - lightweight, low power (under 450mA so far, so not more than 5.4W), and cool - which is the best thing because the cold light I had to leave on for ages to keep the output constant, and this would invariably buckle rollfilm negs = grrr!!

Marc

jeroldharter · Mar 12, 2008

That looks great. Unfortunately the LED strip lights are still pretty expensive.

I have 2 almost mint Beseler 45S Dichro heads so I will wait for prices to come down.

Do you think there is room to mount alternating strips of Blue, Green, White (each on a different circuit) and still have even, sufficient light?

munz6869 · Mar 12, 2008

I've seen the LED strips cheaper (like AUS$27) ea. but that particular shop is only 50 metres away from my work, and I'm clearly an impatient fellow...!

I reckon you could quite easily alternate strips, and still diffuse nicely - the level of evenness I'm getting with my board has the white acrylic only 17mm away from the light source...

How nice would that be though? Just dialling in your contrast from the light source!!!

Marc

Will S · Mar 14, 2008

RoBBo said:
On the way at least...

But no light source...

The enlarger is a Saltzman by the way.

I'm glad someone picked that up. I was very close to taking it, but I don't have room right now for something that tall. Good luck with it!

Will

RoBBo · Mar 14, 2008

Will S said:
I'm glad someone picked that up. I was very close to taking it, but I don't have room right now for something that tall. Good luck with it!

Will

Someone else actually managed to grab it out from under me!
But my concern with the light source remains, as a friend found a Durst with no head in Michigan we'll be going to get in a few weeks instead.

vet173 · Mar 17, 2008

I have an 8x10 salsman. I really love the way the carriage and focus work from down low. Heavy? Lets just say their is 300# of counterweight in the column. One thing you mentioned, that no one else has commented on, was you wanted to be able to keep your standard for a condenser enlarger. Are you planning on using condenser's in the new system also? The vast majority of suggestions are for a diffused light source. It is also my preference. A condenser enlarger wants a neg with a C.I. of .45 and a diffused source wants a C.I. of .6. Since we are talking about an 8x10 enlarger, my assumption is that you are looking for more than just adequate. Keep your negs keyed to the light source chosen. condenser enlargers lend themselves to better separation on the bottom end, and diffused will lean to get better separation in the highlights.

Have an 8x10 enlarger...

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