2008 January | The Daguerreotype: Contemporary work by Jonathan Danforth

Daguerreotype sealing tape? Gold Chloride? The Questions Keep Rolling In

Posted in Daguerreotypes by Jonathan on the January 31st, 2008

Here are my answers to some recent questions that have rolled into my inbox this week.

what kind of tape do you use to seal the photos?

Permacel’s J-Lar Tape from Talas. Jerry Spagnoli also suggested to me back in 2004 that using Filmoplast P90 would be fine; I don’t know if he still agrees. I choose not to use P90 because it is permeable and J-LAR is an impenetrable mastic fortress. For what it’s worth, P90 is probably the closest you’ll come to the original paper tape used in the 19th century. The advantage of P90 is that it is archival and reversible though J-LAR is acid-free. J-LAR has also been endorsed by daguerreotype conservators that are a whole lot smarter than me at the Library of Congress.

do you just take a regular piece of glass and place it over the top of it when its done?

You need to put some sort of mat (even construction paper would do) between the plate and the glass. I use museum glass (AKA “water white”) from the local frame shop. I use brass mats that I have made at a emachineshop.com.

where do you get your gold chloride?

Photographer’s Formulary. You want the solid AuCl3. 1 gram will let you do 20 or so 4×5 plates.

is sodium thiosulfate just fixer?

Not sure. It’s cheap though.

what temperature does the blow torch you use go to?

I use a Bernzomatic propane cylinder (blue) to drive a simple torch. The flame temperature in air is 3,450F. The original daguerreotypists used alcohol lamps to do it though. You need to keep the flame constantly moving so that you don’t get hotspots. Some modern daguerreotypists use a hotplate and a frying pan (see “View Camera” November/December 2004). I like the idea because it provides an even distribution of heat but I’ve never tried it. I seem to remember Jerry Spagnoli using a torch fueled by a Bernzomatic oxygen cylinder (red) that burns far hotter than my propane torch. If you want to split the difference, use a MAPP cylinder (yellow).

How do you check if your picture is developing when the amberlith is covering it?

You’ll see the image through the Amberlith after a few minutes (see picture to the right). A good exposure will start to show in about 10-15 minutes. Highlights come first and the rest of the image develops out over the course of 2-3 hours.

my teacher said that it would cost like 40 dollars for a silver plated piece of copper, and i was wondering how much you pay for it when you get it done.

The plate is about $5-10 and the plating is about $10-15. There’s a lot of time involved though so that’s worth something too. I’d happily pay someone $30 for pre-made plates if I could find somebody reliable. $40 is not unreasonable for a ready-made plate.

If you wouldn’t mind telling me, what is the approximate cost to you for an electroplated half plate?

Copper plate (4×5″): ~$5
Silver plating (4×5″): ~$11

I buy copper from onlinemetals.com. I polish the copper plate to a mirror finish and then take it to the plater. Then I polish the silver again! Fortunately I have a local silver plater to whom I can drive. I charge something like $40 for a 4×5″ plate because of the amount of labor involved.

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Contact Printing a Daguerreotype

Posted in Artist's Journal, Daguerreotypes, Photography by Jonathan on the January 28th, 2008

I recently received this e-mail from ‘Greg’:

I was wondering if you could elaberate [sic] on the process of contact printing. that is taking a photograph and printing it on transparent paper and some how making it into a dag. i want to do a self portrait and i think thats the only way i can do it is if the picture is already taken and i reproduce it on a dag. thanks

Here is my response concerning my method of making contact prints using modern methods.

Contact Printing a Daguerreotype
1839 tech + 2008 tech

Making a contact-print daguerreotype is little different from making a contact print in the darkroom using traditional processes. Other “alternative processes” viz. Platinum, Palladium, AZO, etc. use enlarged negatives. The chief difference in daguerreotypes is that it is a direct-positive format so we need an enlarged positive instead.

There are two methods for making an enlarged positive: wet and dry.

In a traditional, “wet” darkroom, you would place your film negative in the enlarger and expose onto a fine-grain interpositive film such as Arista Litho. This material works in a similar fashion to B&W VC paper and yields a direct positive transparency. Use contrast filters to lower the contrast to match that of a Becquerel daguerreotype.

The dry method is best described by Dan Burkholder in his groundbreaking 1995 study Making Digital Negatives for Contact Printing (Book & Disk)

“A digital negative is like any other negative except that it’s made using the computer instead of by using wet chemistry in the darkroom. The two common types of digital negatives are imagesetter negs produced by sending a file to a ’service bureau’ and inkjet negs made using a desktop printer. Recently the term ‘digital negative’ has been used to describe a type of digital capture file. Don’t be confused. We can actually take our real live digital negatives into the darkroom!”

Despite Dan’s intent for making digital negatives, it is perfectly acceptable to chop off the last step and create a digital positive instead.

You will need:
1. A photo printer (I use an Epson R2400)
2. A supply of Pictorico OHP or Ultra Premium OHP Transparency Film
3. Photoshop or other photo editing software
4. Contact Printing Frame
5. Daguerreotype-making stuff/skills

Open your source image in Photoshop and take a look at the curves. Adjust your curves to reduce the contrast a smidge. Experimentation is key here. Remember that daguerreotypes are orthochromatic (insensitive to red) so anything that’s warmer than green/yellow will be quite dark. You may want to desaturate your reds using the channel mixer in order to give them some greater definition in the final product. Dan has elaborate pre-conceived curves for platinum, palladium, etc and a lot of science to back them up but there’s nothing out there for daguerreotypes as far as I know.

Plenty more after the break:

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Daguerreotype Anniversary!

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