Making an UV enlarger

[alanbradford]

Sunlight is fine if you are a casual printer with these processes. Anything more than that and you need consistency and availability that sunlight can't provide.

No, this is nothing to do with consistency., sorry, you misunderstand. This is not using interim media, for whatever reason, 1 per year or 500 per year.

 

[alanbradford]

More or less any kind of enlarger is a commercial dead end. It's all niches within niches, lots of R&D effort for tiny volumes and only 'sensible' if the combination of hobby and a small remuneration is feasible for someone.


I can imagine. Digital negatives are great - if you like that way of working. I personally didn't. The digital part and the inkjet step took the fun out of printing for me. I can imagine I'm not the only one - and that it would make the whole endeavor worthwhile. Yes, as a hobby/enthusiast exercise.

This is where I am for a large part. 55 years plus of B+W darkroom and 10+ of digital which works great, but going through all that is needed to get a Alt Pro print from digital just stops my fun. I spent 40 years in IT in network engineering, so IT does not phase me to use digital means, but is just not inspiring to get a great image result, hence I would prefer to enlarge from the source which is what I am trying to achieve here. I know this is not for everyone, but if it doesn't inspire you just stay somewhat quiet and accept that different view and goals exist. At the end of the day this is for me, art with technology applied. All is justified, but digital on it's own, doesn't give me great reason to continue, so I look for a mored manual enlargement method. No offence, but we all have different philosophies for our final images. That is good!

 

[alanbradford]

I thought you were talking about a UV enlarger, not a reducer!

Cliveh, you did agree previously to differ in your view and drop off this trail as your comments are just not useful and you said what direct to me with "Will do and wish you well."
Yes, you disagree, fine, drop off and leave us to progress if we can. You are adding nothing here and I have no idea what your agenda is - Just not of value to anyone, apologies. The world seems flat for you so, OK stay with that view.
Others here will continue to discuss and look at possible solutions that clearly displease you for some reason, so please drop off if you have no science to add.

Thanks so much, Alan.

 

[alanbradford]

I'd much rather deal with digitally enlarged negatives - no dust, you can deal with any contrast issues or mechanical flaws your original might have prior to printing, and once you learn how to do it properly, it's a very simple set of repetitive steps to make it. And if you're feeling lazy, you can just use curves other people have posted on the internet to skip a lot of the boring, repetitive steps that go into making a digital negative. Plus, if you damage the negative, you can just reprint it.

Having done the digital negative step several hundred times now as part of a project I'm working on, it's a superior technique. I don't want/need a UV lamphouse that is so powerful it can set my negatives on fire and/or blind me. For an investment of $200, I have an LED light source that covers 16x22 inches completely evenly, and produces a properly exposed Palladium print in 2 minutes. I can use it 24/7/365, in any weather.

I won't say the UV enlarger is a waste of time - there's always something to be learned by attempting, even (or especially) if it ends in abject failure, or does not produce a result that is immediately obvious as an improvement. But I would argue that a UV-based enlarger is, commercially anyway, a dead end, as it caters to an increasingly small audience of people who want to do things the really hard way.

Respecting your view, but adding something positive rather than rejecting the view might be a better approach. Funny how people still take film photos and expose that and then digitise.

Of course much better to use 100MP digital cameras and just move on and simulate the film in digital......I do use High end digital with Phase One, Leica S2 and Nikon D810 cameras , I am not a luddite, but ..............Nothing wrong in that per se, but do we want to deny the artists using paint, ink, watercolour etc and other media just because digital methods now exits? Think about it, please. All methods are valid.

 

[ProfessorC1983]

I spent 40 years in IT in network engineering, so IT does not phase me to use digital means, but is just not inspiring to get a great image result, hence I would prefer to enlarge from the source which is what I am trying to achieve here.

This is exactly my feeling as well. There is amazing alt-process art being made with digital negatives, but as I spend all day staring at screens it is simply not enjoyable for me to make photos this way, and so I appreciate the challenge of working through the UV enlargement possibilities.

Would it be worthwhile to create a collaboration space, either here on Photrio or through something like Groups.io, for those of us willing to put in time on this effort? For my part, the optical science is far beyond my background, but I do like to play.

Currently I am working with a 100W 395nm LED adapted onto an Omega B600 condenser enlarger and cheap El-Omegar lens, and getting ~30min exposure times for cyanotype with manageable heat issues, but I have plans to build a diffuser enlarger as well. I have a design ready to 3D print which incorporates some cooling fans between the diffuser and the neg holder. Will post results here once I get around to it, but also happy to try out other pathways that would benefit our common pursuit here.

 

[koraks]

I have a design ready to 3D print which incorporates some cooling fans between the diffuser and the neg holder.

This sounds very promising; I think it's worth a try. If anything it will tell us how bad the problem of IR radiation is vs. direct transfer. If IR is the main culprit, the fans won't help. But to be honest, I think they will help - a lot.

 

[TheFlyingCamera]

Respecting your view, but adding something positive rather than rejecting the view might be a better approach. Funny how people still take film photos and expose that and then digitise.

Of course much better to use 100MP digital cameras and just move on and simulate the film in digital......I do use High end digital with Phase One, Leica S2 and Nikon D810 cameras , I am not a luddite, but ..............Nothing wrong in that per se, but do we want to deny the artists using paint, ink, watercolour etc and other media just because digital methods now exits? Think about it, please. All methods are valid.

Yes all methods are valid. I still shoot film. I shoot a LOT of it. This past weekend I shot 22 rolls of 120 in 2 1/2 days, and I have another 8 in the can I have to develop, so this week I'll be souping 30 rolls in my Jobo. I COULD process all of that by hand in 2-reel tanks, but that would be painfully inefficient in both time and chemistry. In the last 7-8 weekends I've made over 150 palladium prints. If I did the enlarged analog method to make the negatives I needed, I'd A: be broke from all the large format and ultra-large format film I'd have to buy and B: still be making enlarged negatives. So there's a serious productivity factor to the digital negative process.

Of course much better to use 100MP digital cameras and just move on and simulate the film in digital

No it's not- the qualitative outputs are not equivalent. The film simulations are just that, simulations, not the same thing. The outputs of each camera style are distinct. That does not make either one invalid, or lesser, just different. I too shoot digital - I have a Fuji XT2 that I use because I love the quality of the colors it produces. But it's a tool for a purpose. As is my Rolleiflex, as is my Canham 14x17.

If I were so tech-focused as you're suggesting, then I'd not even be making palladium prints, I'd be "simulating" them with inkjet. I've done wet plate before. If I wanted the look it creates, I wouldn't hesitate to do it - making a fake wet plate image in Photoshop is NOT the same. But even if I did, I would still make prints from a scan of my original, not the original plate.

 

[alanbradford]

Yes, burning and dodging should be possible with a projection enlarger method if exposures get to around 20 minutes or less - A bit laborious but still should add more ease and control than doing so above the contact image, which does have some validity but is hard to get right.

 

[alanbradford]

This is exactly my feeling as well. There is amazing alt-process art being made with digital negatives, but as I spend all day staring at screens it is simply not enjoyable for me to make photos this way, and so I appreciate the challenge of working through the UV enlargement possibilities.

Would it be worthwhile to create a collaboration space, either here on Photrio or through something like Groups.io, for those of us willing to put in time on this effort? For my part, the optical science is far beyond my background, but I do like to play.

Currently I am working with a 100W 395nm LED adapted onto an Omega B600 condenser enlarger and cheap El-Omegar lens, and getting ~30min exposure times for cyanotype with manageable heat issues, but I have plans to build a diffuser enlarger as well. I have a design ready to 3D print which incorporates some cooling fans between the diffuser and the neg holder. Will post results here once I get around to it, but also happy to try out other pathways that would benefit our common pursuit here.

Not too sure about splitting out another group - Extra input is useful mostly, though as ever, some is not productive, but other views are non the less a way to control your own enthusiasm. If you start a new group I would be involved for sure, but wonder if that is the best way forward...

 

[MatthewDunn]

Yes, burning and dodging should be possible with a projection enlarger method if exposures get to around 20 minutes or less - A bit laborious but still should add more ease and control than doing so above the contact image, which does have some validity but is hard to get right.

How do you do burning and dodging under UV safely? I am not trying to be smarmy - that is a legitimate question (albeit perhaps a dumb one). You can protect your eyes with goggles, but assuming you are moving your hands under a UV light for an extended period of time, any concerns about unhealthy amounts of UV exposure? Again, apologies in advance if this nut has been cracked and the answer is obvious.

 

[MattKing]

Dodging tools?

 

[MatthewDunn]

Dodging tools?

I know and understand how to use dodging tools, thank you. I was asking how you use the tools safely.

Unless the length between your hand and the actual dodging implement is significantly longer than normal, I would still worry about undo levels of UV exposure. But that is why I ask. Maybe that risk is overstated.

 

[MattKing]

Sorry, I should have said dodging tools and protective clothing.
Perhaps the gloves and clothing used by welders.

 

[nmp]

I would be more worried about the eyes - you can wear goggles but then you can't really see the image well and also if the exposure times are long, like half an hour, it can get tedious.

 

[koraks]

I would be more worried about the eyes

Certainly. The eyes are a real risk and protection MUST be ensured!!
The skin is a little less of a problem (far less in fact). Let me put it this way: do you go out in summer when the sun is at it's most powerful without wearing gloves? (But DO wear sunglasses!! Cataracts aren't fun)
Keep in mind that we're only dealing with 365nm and longer wavelengths. The really nasty wavelengths are shorter.

 

[alanbradford]

I use the dodging tools and paper with torn cutouts for burning - Just white gloves as for handling negatives - Maybe this is not enough, I will investigate, should be just like protecting yourself on a beach from the sun.
This is currently somewhere like 30cm below a 600WQ UV grow lamp and canopy - Protective glasses plus full face mask.

 

[koraks]

should be just like protecting yourself on a beach from the sun.

The UV levels at the stage where you'd hold your hands for dodging will be far lower than outside on a sunny day.

This is currently somewhere like 30cm below a 600WQ UV grow lamp and canopy

I don't think that's an accurate comparison. Remember we're talking about an enlarger setup here. The actual luminous flux is far lower than under a barely-shielded lamp. Also consider that old-fashioned discharge lamps put out a much broader spectrum which does in fact include significant amounts of UV light of shorter wavelengths than the relatively benign >365nm (i.e. they tend to emit some UV-B next to UV-A, while most UV-C will be mostly filtered by the glass). In leds, we don't really have to worry about UV-B and UV-C as they're simply not being generated in the first place. From a safety perspective, this is a major benefit of leds over discharge lamps.
Btw, to the best of my knowledge plant growth lamps are not engineered for their UV output. In fact, today's solutions seem to rely mostly on a combination of (visible) blue and (deep) red leds. No UV or IR or other arcane stuff.

 

[MatthewDunn]

The UV levels at the stage where you'd hold your hands for dodging will be far lower than outside on a sunny day.

Great. Sounds like someone has thought this through. Don't/didn't want to derail the thread, but just wanted to make sure this was considered, which it clearly has been.

 

[nmp]

On the other hand, a lot of the BLB bulbs are sold for use in disco parties - I wonder aren't those guys worried about exposure to skin and eyes?

 

[koraks]

On the other hand, a lot of the BLB bulbs are sold for use in disco parties - I wonder aren't those guys worried about exposure to skin and eyes?

The total flux that party-goers receive on a night out won't be sufficient to cause damage. You generally have fairly limited amount of UV light in the mix and exposure would be limited to a few hours a night. Like I said, much (MUCH!) less than one hour of sunbathing on the beach.
The risk in the disco scenario is if there's not a lot of visible light, but a significant amount of UV, this can apparently contribute to corneal damage / glaucoma since the pupil remains dilated due to the lack of visible light, so it will let through a lot of the incoming UV. I doubt this risk is significant in a disco due to the generally low levels of UV light, but I think it's important to keep an eye on (...) when working with the kind of light sources discussed in this thread. Esp it actually bare, unfiltered UV COB leds with power levels over 10w or so are pretty nasty if you look straight into them without eye protection.

 

[alanbradford]

The UV levels at the stage where you'd hold your hands for dodging will be far lower than outside on a sunny day.


I don't think that's an accurate comparison. Remember we're talking about an enlarger setup here. The actual luminous flux is far lower than under a barely-shielded lamp. Also consider that old-fashioned discharge lamps put out a much broader spectrum which does in fact include significant amounts of UV light of shorter wavelengths than the relatively benign >365nm (i.e. they tend to emit some UV-B next to UV-A, while most UV-C will be mostly filtered by the glass). In leds, we don't really have to worry about UV-B and UV-C as they're simply not being generated in the first place. From a safety perspective, this is a major benefit of leds over discharge lamps.
Btw, to the best of my knowledge plant growth lamps are not engineered for their UV output. In fact, today's solutions seem to rely mostly on a combination of (visible) blue and (deep) red leds. No UV or IR or other arcane stuff.

The "grow Light" I have is a 600W Metal Halide working from a ballast. At 50cm from the lamp canopy I get a very even light spread over a 45x33 cm glass plate above my vacuum base and about a 7 minute exposure with SALT printing, I added some photos here.

 

[koraks]

The "grow Light" I have is a 600W Metal Halide working from a ballast.

I suspected this. Using one of those for UV purposes is an extremely inefficient choice. It used to be a common choice, but given the availability of UV tubes and now LEDs, it's completely outdated. You're basically wasting something like 550W (if I'm generous) out of 600W input.

7 minute exposure with SALT printing

That's roughly similar to what I get with 200W worth of UV tubes.

 

[radiant]

I just got my first print made with UV enlarger. Not the fresnell / douwe version but I just wanted to try with regular enlarger. Did I get print made? Yes. Was it a success? Well, tomorrow we will see. Was the exposure time long? Hell yes. I won't even tell you how long. It was long. But hey, it exposes by itself so no rush?

I can now see why you want to focus all the light to the enlarger lens itself. There is just too much going to waste on regular design. Or you can put many hundred watts to your light chamber but then you have a toaster in hands.

I was using only 50W COB. 100W would be more fine but cooling down a 100W led is another story. I actually burned two leds because of non-sufficient cooling.

Why did I convert "regular" enlarger to UV? Well, mostly for the experience. I thought if I get any prints made with that, it is a victory. No matter how long the exposure is. I wanted to see if I even want to enlarge UV prints. I need to do few more to get a feeling if this is something I want to do in the future.

First thoughts based on huge one print experience is; could it be that normal density negatives would work on salt prints? This first test was made with high contrast / density negative and it looked a bit too contrasty - for a salt print?!

 

[alanbradford]

Glad to see you are having some fun here, I print salt and find that I do not need the very contrasty negatives everyone describes as required for salt, so I am not too surprised. I can get a good toned salt print from what looks to be a normal G2 silver negative without doing anything special - Extra sizing does help a bit. I will soon be in the position to test my 500W device with cooling. The cooling will be liquid cooled possibly using Calcium Chloride as has been suggested, and I have powerful air cooling above and below that and the KG5 - I added a ground glass diffusor, but not sure if I need that yet. Still waiting on some bits, but here is the cooling stage that sits below the original 500W light source. I'll post more details when I am able to get some metrics. Alan

 

[radiant]

I print salt and find that I do not need the very contrasty negatives everyone describes as required for salt, so I am not too surprised. I can get a good toned salt print from what looks to be a normal G2 silver negative without doing anything special - Extra sizing does help a bit.

I will take words back.. The print looks pretty good in contrast. So a contrasty negative was actually good thing.

When I'm making contact salt prints all density in highlights is needed when trying to reach max black to shadows. That makes exposing&developing negatives a bit tricky. If I remember correctly salt is the most demanding method in terms of negative contrast. For example dichromate based methods work fine with "normal" negatives.

Alan that is some serious building! Awesome work. Hope your negatives wont melt with that setup. I suggest measuring temperatures on first exposures..