Going to attempt contact printing with no enlarger. Advice?

[nascarfann]

I am going to attempt contact printing with no enlarger with some printed out paper negatives. Any advice on exposure time?

 

[jimgalli]

If Weston can do it, you can do it. Exposure time depends on . . . everything. Azo with my 100 watt bulb and a bulletproof galli negative; turn on the light go make a sandwich. Or do the dishes. Or take a shower.

Oh, and Christ is most definitely Lord. Of everything created.

 

[koraks]

Azo with my 100 watt bulb and a bulletproof galli negative

But regular VC paper with a fairly normal negative...use a much lower wattage bulb and prepare for some quite short exposure times. I'd start with something like a 15W bulb at 3-4ft.
If this is going to be your same experiment as with the instax/Polaroid chemistry, you seem to be juggling two variables which is likely to result in some problems. I'd recommend starting with normal developer and fixer to get a feeling for your contact printing setup and only then try the alternative chemistry.

 

[scheimfluger_77]

...Oh, and Christ is most definitely Lord. Of everything created.

While I whole-heartedly concur, this is an interesting comment in the middle of something unrelated. Or have I missed something?

 

[MattKing]

While I whole-heartedly concur, this is an interesting comment in the middle of something unrelated. Or have I missed something?

Note the OP's screen name.

 

[nascarfann]

But regular VC paper with a fairly normal negative...use a much lower wattage bulb and prepare for some quite short exposure times. I'd start with something like a 15W bulb at 3-4ft.
If this is going to be your same experiment as with the instax/Polaroid chemistry, you seem to be juggling two variables which is likely to result in some problems. I'd recommend starting with normal developer and fixer to get a feeling for your contact printing setup and only then try the alternative chemistry.

I was planning on using a LED video light. Would that work fine? And yes, this is the same experiment as with the Instax/Polaroid chemistry. I am starting with a very high contrast negative that is literally black and white.

 

[scheimfluger_77]

Note the OP's screen name.

Ah! That’s what I get for not paying attention.

 

[tedr1]

this might be a good place to discuss contact printing https://www.photrio.com/forum/forums/contact-printing.91/

 

[MattKing]

I was planning on using a LED video light. Would that work fine? And yes, this is the same experiment as with the Instax/Polaroid chemistry. I am starting with a very high contrast negative that is literally black and white.

The LED video light might be too bright, and it's somewhat discontinuous spectrum might either be well suited to the spectral sensitivities of the variable contrast paper's two or three emulsions - or it may not. It is hard to tell without testing.
It might also be hard to take advantage of the contrast control possibilities built into the paper, while still insuring evenness of illumination.

 

[Luckless]

I was planning on using a LED video light. Would that work fine? And yes, this is the same experiment as with the Instax/Polaroid chemistry. I am starting with a very high contrast negative that is literally black and white.

I've only started on this myself, but the typical advice I've seen has been to aim for a point light source, ideally centered above the negative - The goal being to have the negative cast as sharp of a shadow on the paper as possible.

So far I've been using a cheap nightlight on an extension cord that plugs into an old timer circuit, and it is working well enough for the handful of prints I've made from medium format negatives.

As fan of math/computer science, I ran variant on Binary Search Tree for my test strip exposures to get my initial timings - Run two rough tests, first one with widely spaced timing so I can quickly say "What I want is clearly somewhere between these two points", then another strip with more tightly spaced timing.

Since I hadn't used that paper or light source, I started with 5, 20, 80, and 320 seconds to give an initial baseline.
With my bulb the 20 was far too light, but the 80 seemed a tad dark.
Second test sheet was given 20, 25, 30, 40, 50, 65, 80 for rounding off to the nearest 1/3 stop, however I probably could have run that spread closer to 80 from the start.

 

[mshchem]

Go to an agricultural supply store and buy a hanging "brooding lamp" that is used with a heat lamp to keep chickens warm. Should have a nice wide aluminum reflector about the diameter of a dinner plate. They have a built-in hanger, I would get some light weight chain and a ceiling hook.
Don't get the heat lamp!
Buy a 15 or 40 watt bulb hang it 2 feet above your print area. If you can find an enlarger timer cheap or plug the lamp into a Gra-lab timer all the better

 

[koraks]

I was planning on using a LED video light. Would that work fine? And yes, this is the same experiment as with the Instax/Polaroid chemistry. I am starting with a very high contrast negative that is literally black and white.

The video light will work, but as Matt points out it may be too bright. Note that you can greatly reduce the amount of exposure by increasing the distance between the light source and the paper; intensity decreases exponentially with increasing distance.
Do you want to get continuous tones in your prints or do you want them to be pure black and pure white like the negative you describe?
On the large format forum, Pere Casals recommends using a remote controlled variable color led bulb (they can be had for a few bucks these days); you can vary the contrast of VC paper by adjusting the color of the bulb. Some form of light filtering (particularly blue/green) will be helpful if you're planning to use VC paper.

 

[John51]

I have one of those remote controlled variable color led bulbs. It does well on the cd test. Just a hint of green when set to red. A lot better than the strip of red leds I bought.

If you put a 15w pygmy bulb on a dimmer, you can get it down to a soft glow.