Category Archives: digital negatives

Upcoming Classes

I have two upcoming classes this spring at Glen Echo Photoworks, Introduction to Large Format Photography, and Introduction to Platinum/Palladium Printing. I’ve scheduled them so that students of Intro to Large Format can have somewhere to go with their new camera skills. Intro to Large Format runs March 11th – April 22. The course covers what you need to know to take advantage of the medium – we start with the basics of the cameras themselves – different camera types, their parts and how they work, why to choose one type over another, lenses and lens selection. We move on to film selection and film handling, loading film and developing it. There are modules on portraiture, still life/tabletop, landscape and architecture. For the Architecture module we’ll do a field trip down to the National Cathedral.

The Family – my set of student cameras (L to R): Speed Graphic, Sinar F, Sinar A1. The 5×7 Sinar Norma you see peeking in on the right is a personal camera.

Due to student interest, I’ve acquired several cameras for student use in-class. If the popularity continues, I’ll look into getting one or two more and setting up a rental program to allow students to check out cameras for the duration of the class.

The next class is Introduction to Platinum/Palladium Printing. I will be including a module on making and using digitally enlarged negatives for platinum/palladium printing with this course. This class runs May 5th and May 12th. This course covers the history of the medium, materials and techniques. We discuss the various tools for making prints – brushes vs coating rods, UV light sources (the sun, black-light fixtures, other options). We go over paper selection and paper handling. In this intro class we will make palladium prints because palladium is the easier medium to work with, but we will discuss and demonstrate the differences between platinum and palladium. Contrast control techniques will also be covered, and developer chemistry as well. We will work from both in-camera negatives that we make that weekend, and from digital files students bring and/or create from scans.

TeotihuacanPtPdPrint
Pyramids, Teotihuacan – palladium print 4″ x 8″ enlarged on Pictorico OHP using an Epson 3880 printer with Ultrachrome K3 inks from a 6cm x 12 cm in-camera negative

To register for the classes, click on the links below:

Introduction to Large Format, March 11-April 22

Introduction to Platinum/Palladium Printing

 

 

Digital Palladium Sous-Vide

I felt the need to get back into the darkroom and do some printing lately. And I was inspired by watching an instructional video from Bostick & Sullivan on making digitally enlarged negatives for alternative processes, specifically Platinum/Palladium.

I was familiar with the basics of the process, having read multiple books and web tutorials on the subject. What has always tripped me up was the process of creating my own adjustment curve. Well, the generous folks from B&S have put the curve they use on their website to download and use after running the video tutorial. I figured I would give their curve a try.

PtPdTeotihuacan
Pyramids at Teotihuacan, Mexico

This is the first print I made with their curve. The original is a 6x12cm negative shot on Ilford FP4+ black and white film using my Lomo Belair X/6-12 camera. I followed their instructions in the video to the letter, including using a quantity of NA2 contrast agent.

They also mentioned adjusting the ink density down a bit to keep contrast under control. Well, I like the idea of printing pure palladium without adding any NA2 because the NA2 alters the color tone of the prints and makes them cooler.

PtPdPennaAve
Pennsylvania Avenue, looking east

I made the negative for this image (and the following image of the National Gallery of Art) without reducing the black ink, and not using any NA2. I think the balance worked out well – the contrast is where it needs to be, and the color tone remains nicely warm.

PtPdNatGallery
Staircase, West Wing, National Gallery of Art

This staircase was a true test of the capability of digital negatives to render the subtlety of tone possible in a palladium print. I’d say it passed with flying colors. The tone remains rich, warm chocolate, the highlights are delicate and creamy, and there’s surprising detail down into the shadow tones.

My apologies for the image scans – they’re direct scans of the prints, and my scanner picks up paper texture to a degree not visible to the unaided human eye (I can see texture only under a loupe that may be visible in the scan).

So where does the sous-vide in the title come in? Another long-standing issue with the process is that the Potassium Oxalate (PotOx) developer is happiest at around 130 degrees F. I can get water close to that hot out of my tap to use as a tempering bath, but within a short while it returns to room temperature. I found this sous-vide machine and the 18 quart bucket on Amazon for under $100. I put them to use this morning and if the above three prints are anything to judge by, they’re staying in my darkroom! The prints are amazingly consistent from print to print (it took me about 3 hours this morning to get all three prints done, but the developer remained at a constant temperature throughout).

Sous-vide machine heating developer

Something interesting about developer for platinum/palladium printing – unlike film or paper developer, this stuff never really goes bad. Your total volume will drop with use, but that is solvable by replacing lost developer with additional fresh developer. The bottle on the left is the first ever bottle of Potassium Oxalate I bought – I’ve just been replenishing it and filtering it as needed for over a decade now.

Old developer – old but still good!

Technical notes:

Prints are 100% palladium, 6 drops each Palladium / Ferric Oxalate #1. Developer is Potassium Oxalate, 130 F, 2 minutes. Paper is Bergger COT320. Negatives are enlarged onto Pictorico OHP ultra-premium transparent inkjet medium on an Epson 3880 with K3 Ultrachrome inks. All three prints are 4″ x 8″.