Beginner Contact Printing Negatives

eeyore

eeyore

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In a little be of preparation for the impending 8x10 landing at Hoof photo hq I'm going look at learning and practicing contact printing some of my 5x4 negs.
I have some photo paper left from a pinhole project, Ilford multigrade iv deluxe 5x7 and have a set of Ilford paper developer chemicals. So seeing as I have the stuff I don't at the moment want to spend too much more...

Reading up, basically I need a light source, a negative, paper, a sheet of glass and a stop watch.

The paper goes down on a flat surface with a negative on top. The glass is placed on top to keep negative and paper together as any gaps between them will distort the picture. On the couple of bits on the net I read about having a low wattage lamp 15w approx 3 feet away. Then its a little bit of experimentation as to exposure times.

I was thinking, with regards to clamping down the neg and glass, could an old picture frame work or does glass need to be special? Various people say it needs to be thick but that's to hold the negative down a frame with a board could clamp it. Also some people say frosted glass helps as it helps defuse the light.

Lighting wise, would I need use an old school filament bulb rated for 15w or would one of the newer 7w energy saving types be better (I'm aiming for a slower long exposure as i will be timing the switch myself!)
As for distance, is 3ft about right?

Comments welcome
 
I haven't any experience with this but at a guess I would think that the newer energy saving bulbs would be unsuitable. Purely on the basis that they take time to warm up and therefore don't give a consistent amount of light (dimmer to begin with).

Please feel free to shoot me down if I'm talking twaddle.
 
That's a good point, I think it would be worth discounting them on that alone
 
I started with the glass "borrowed" on an ad hoc basis from a photo frame, and simply used a low wattage bulb. In those days (1950s) the papers for contact printing were called "gaslight papers" and you could get away without a safelight. You will need one, unless you're planning to work in darkness with modern enlarging papers.

Remember that the negative/paper sandwich has the emulsion sides of both in contact.

I have no idea about the new lightbulbs; I cleared out our local hardware shop (they were closing down and selling everything off anyway) of all their 15/25 watt incandescent bulbs, so I will probably leave a stack behind for my executors to clear up. Hopefully in several decades time...

I didn't have a clock or timer - I just counted the seconds when I started.
 
You know to do a test print first, with varying strips at differing exposures to save on paper and time?
 
srichards said:
LED bulbs don't have a warm up time.
Click to expand...

Indeed. If anything, they actually have a warm down time. Their power efficiency drops as the junction temperature rises and, contrary to general incorrect opinions, LEDs do heat up.

For serious reproductions where consistency absolutely matters, this may be worth characterising, as results will vary between bulbs and specs etc.
 
Woodsy said:
Indeed. If anything, they actually have a warm down time. Their power efficiency drops as the junction temperature rises and, contrary to general incorrect opinions, LEDs do heat up.

For serious reproductions where consistency absolutely matters, this may be worth characterising, as results will vary between bulbs and specs etc.
Click to expand...
However, they would be fine for this.

I have red, blue and green LEDs in my enlarger.

If you get one of those LED lamps which comes with a remote control to change the colour, you can vary the contrast with the proportions of green and blue light you use.


Steve.
 
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Steve Smith said:
However, they would be fine for this.

I have red, blue and green LEDs in my enlarger.

If you get one of those LED lamps which comes with a remote control to change the colour, you can vary the contrast with the proportions of green and blue light you use.


Steve.
Click to expand...

Where did I say they wouldn't? What I am saying is that their brightness will change over time and that, for absolute consistency, they should be characterised. Further, because of the way they work, different colour LEDs may also change brightness at different rates.
 
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Woodsy said:
Where did I say they wouldn't?
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I'm not arguing with you, I'm agreeing with you...but if you are using the same bulb all the time, any variances between bulbs is irrelevant... until you need a new one!

Changing brightness over time or between bulbs would be compensated for by printing test strips at the start of each session anyway.


Steve.
 
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Woodsy said:
Indeed. If anything, they actually have a warm down time. Their power efficiency drops as the junction temperature rises and, contrary to general incorrect opinions, LEDs do heat up.
Click to expand...

I recently had to remove a domestic LED light that was locked on because the pull switch had broken. I used a towel as insulator, but discovered that the glass part was only warm, while the plastic part near the bayonet was pretty darn hot! I think I could have removed it bare-handed with care though.

I was going to remark that given the wide variation in prices from Poundland upwards, there may well be a wide variation in quality too. But it struck me that these days you can't really tell in what circumstances you get what you pay for, and when you just pay to inflate someone's profit. But, OT, sorry.
 
Steve Smith said:
Changing brightness over time or between bulbs would be compensated for by printing test strips at the start of each session anyway.
Click to expand...

I'm not talking about between bulbs or between different makes/brands/etc. My point is that a single bulb will change brightness over the period of a single session! Printing a test strip at the start is surely no use if the brightness changes over a period of 10-30 minutes? Surely you'd want to wait until it stabilises?

ChrisR said:
I recently had to remove a domestic LED light that was locked on because the pull switch had broken. I used a towel as insulator, but discovered that the glass part was only warm, while the plastic part near the bayonet was pretty darn hot! I think I could have removed it bare-handed with care though.
Click to expand...

Exactly.

Also, if printing colour frames, I'd guess there would be a difference in the results between using RGB LEDs and blue/yellow LEDs?
 
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Woodsy said:
I'm not talking about between bulbs or between different makes/brands/etc. My point is that a single bulb will change brightness over the period of a single session! Printing a test strip at the start is surely no use if the brightness changes over a period of 10-30 minutes? Surely you'd want to wait until it stabilises?
Click to expand...

An LED should reach full temperature pretty quickly and either stabilise or run away and burn out, I'm sure it would be fine for contact prints even with some natural variation it should be consistent enough assuming we're talking more than few seconds exposure and not a flash.
 
If an ordinary bulb is consistent enough, which I'm sure it would be, an LED lamp will be as well.


steveo_mcg said:
assuming we're talking more than few seconds exposure and not a flash.
Click to expand...
Which brings up another idea. You could use a flash. Might need some diffusion over the glass.


Steve.
 
Ish....I dunno, its all a bit Heath Robinson, like scanning your negs with light boxes, toilet roll tubes and stickey back plastic

I'd just get an enlarger, any cheap junk will do for contact printing and you'll have control over everything, its all contained in one unit, nothing held together with rubber bands and sellotape, no light leaks, all timed exposures, the only thing that has to be moved is the card for exposure testing...:)
 
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