Digital plays star role in astro art

When Chris Baker decided he could make his serious astronomy hobby help to pay for itself, it was natural that he’d turn to digital printing.

He has three decades of experience in the printing industry, starting at Crosfield in the 1980s and including 13 years at digital press maker Indigo as UK general manager and European sales manager. More recently he’s worked with digital cutting and creasing maker Highcon and 3D printer maker Objet, now a part of Stratasys.

In the past year he has started to turn his high-resolution astro-photography images into very-large format wall art prints on backlit glass and acrylic, which he calls the Galaxy On Glass series. These are produced by fine art specialist printer Senecio Press in Banbury. This month his images are on exhibition at the M1 Fine Art gallery in Greenwich, which by no coincidence is close to the historic Royal Observatory. 

The prints are up to 1.5m wide. and when fitted into custom-built LED-backlit frames, the price tag can be several thousand pounds. They are already finding buyers – one company ordered four pictures for its meeting rooms, and named the rooms after the nebulae in the pictures. Three of these are 1.2m wide and the fourth is 800mm wide. Another German customer ordered a 1.5x1.2m picture for a house, which was printed last week. 

Baker says he’s always been interested in astronomy. When he was studying chemistry at York University in the late 1970s, he ran the Astronomy Society. Yet it was 2001 before he bought his first telescope. He’s certainly made up for it since: “I developed a passion for astro-photography, gradually building the skills required to image deep space objects in colour and fine detail.” 

He now has a telescope and computerised control and imaging set-up that would be the envy of any amateur sky-watcher. His 6in telescope is now in a hosted site in Spain, up a mountain in the Sierra Nevada range, where there are clear skies for most of the year. It’s operated by remote control from the comfort of his home in England. 

“Originally I built an observatory in my own garden,” he says. However, he lives near Berkhamsted in the South East, which isn’t best known for clear skies. “By the end of 2010, I was doing a lot more, but it was becoming difficult because of street lights, trees and clouds,” he says. “I looked at doing things abroad, and saw the opportunity to have a hosted place. There are a few around the world – not many in Europe but one had been recently established in the Sierra Nevada mountains in Spain. It’s at 5,500ft, totally dark and there are very clear nights. It lets me image very faint things that require a lot of hours. In 2012, I moved a lot of equipment out there and by September that year I’d started to image remotely from wherever I am in the world.”

Final frontier

Since the move he’s only actually visited the site twice. “In the village below there’s an engineer who works for the set-up. Then there are remote software support people. I’d had it a year before I even went out there.”

Baker concentrates particularly on nebulae, which are vast clouds of dust, gas and stars in distant parts of our own Milky Way galaxy, but he also photographs other galaxies too. 

His telescope is a Takahashi TAO 6in refractor. It cost about £10,000, although the mount, camera, robotic remote control software and imaging software add a lot to that. So, about the price of a decent second-hand car? “This is the sort of argument one would use at home!” Baker laughs. 

The camera is a Quantum Scientific Instruments 683 WSG-8, purpose-built for astronomical work, with an 8.3-megapixel Kodak sensor and a motorised wheel for up to eight filters. Working with narrow wavelength bands of light on very distant and faint objects means that the exposures are very long. “These images are 20 or 30 hours in total,” Baker says. “There’s a lot of work and a lot that goes wrong, so you need to build in a lot of redundancy too. You take multiple sub-frame exposures. Say you need 10 hours – you’d never take a 10-hour exposure because in that time there would be maybe 15 satellites come across, two aeroplanes and five clouds. Then with two minutes to go someone would knock the telescope. Also there’d be a massive amount of electronic noise, so it would be unusable anyway.” 

All in all, a single image can be the result of hundreds of images taken across several nights, with more days spent in selecting the best subframes, blending them together for each filter, and then assigning the results to colour channels within Photoshop and further enhancing them to accentuate details and achieve pleasing colours. 

The camera is monochrome, so the colours are built up by taking multiple images through different coloured filters which respond to the light emissions from the main gasses found in interstellar nebulae. 

“These are not just full-colour RGB, but also for Hydrogen-Alpha, Sulphur-II and Oxygen-III,” Baker explains. “The filters have five-nanometre widths to spot these bands in big nebulae. I then work with various software including Photoshop to accentuate the fine detail.” 

The colours in the image are artistic interpretation, he says. “I use the ‘Hubble Palette’. Sulphur-II is assigned to red, Hydrogen-Alpha is green, and Oxygen-III is blue, generally. There are other things as well that manipulate or accentuate the colour. Calibration is a big part of the process.”

The idea of printing and selling images came comparatively recently, Baker says. “Over the years I’ve sent my images to people who aren’t necessarily interested in astronomy, and they are often really intrigued, about the distance or the enormity. I was thinking: I wonder if I could turn this into something people would want on their walls? 

“I wasn’t interested in paper posters, because anyone can do that. You can download an image from Hubble for $39 and have it delivered the next day. I started thinking about acrylic and glass, and obviously being in the printing industry was a help. I contacted a specialist art printer called Senecio in May this year and we started to do some tests.”

Senecio Press is in Banbury and has always specialised in fine art print since it was set up 45 years ago by Adrian Lack. Today his son Alexander is a director of the business, which switched from lithography to digital printing about 20 years ago. As well as printing artwork, the company handles catalogue and art book printing and this month is installing a Ricoh Pro 7100X digital press with white and clear toner as the fifth unit options. It also sells its own art papers and inks and is a reseller for Epson and Mimaki inkjet printers. A pair of Inktec Jetrix flatbed UV inkjet printers handle rigid media such as glass, or metal. 

UK first

Alexander Lack says that his company was the first in the UK to install the Korean-made Jetrix, with the first one going in five years ago. He handles all UK training on the Jetrix for other UK customers, he says. Today he has two machines, a 3x1.5m bed 3015FQ and a smaller KX3 with a 1.2x1.2m bed. 

Baker’s Galaxy On Glass images are printed on the larger 3015FQ. “Fine art is very subjective – it’s not the same as printing a poster for someone,” says Lack. “Every image is an original and you’ve got to do colour retouching to match the originals near as we can, that becomes tricky.

“Chris Baker comes to us with the size he wants, then we print on clear acrylic, multiple layers, and then frame it up and off it goes. We’ve done a few glass frames too. With all of Chris’ work we colour-correct and we tweak it, proof it, then put samples onto light panels to check that the density is right, especially the blacks because they are space images. There’s quite a lot of work goes into it, not just taking the files. We will proof it three or four times until we’re totally happy with it. We’re never sure how big we can go with an image, so we’ve done some 2.5m or 3m strips, which look absolutely fine, if he needs that.”

Multi-layer printing is used. This prints a CMYK image, then a white diffusion layer, and then a repeat of the CMYK. This means that the image can be viewed in daylight, with the second colour layer preventing washout when the backlighting is switched on. 

Senecio also makes the backlighting frames for Baker’s images. These are “mitreless,” meaning they are made from solid wood with no corner joints to leak light. “We cut them out on our CNC machine, a Tekcel,” says Lack. “We put the LEDs and electrics in too. The panels are made in the UK. Everything is custom made so we’re not restricted on size.

“When Chris first came to see us he was talking about printing onto glass and mounting on standoffs, but I printed a sample for him and when he came in we put it on a light panel, and he just went ‘Wow, yes!’ It’s all gone from there. He’s done amazingly well with it. He’s very proactive with the people he deals with and knows, and his images are absolutely perfect for back-lit print.”  


The Soul Nebula

“Located 7,500 light years away from Earth in the direction of the constellation Cassiopeia, lies the spectacular Soul Nebula. This is an enormous area of dust, hot gas and plasma spanning thousands of trillions of miles and glowing at a range of wavelengths. Contained within the Nebula are young hot stars, which themselves are energising the surrounding gases. Left of centre is the strange looking object which is a vast column of dust hiding yet more recently born stars.

This image comprises over 20 hours of exposures and was captured over many nights from my observatory in the Sierra Mountains of Spain. To capture such detail I imaged using specialist filters at narrow wavelengths. I then used the data as the starting point, creatively mixing and interpreting the colours to reveal the intricacies of the Soul.

This image contains the wondrous detail of a stellar nursery revealed by the combination of rich blues and golds against the backdrop of black interstellar space.”

Chris Baker


Galaxy On Glass is exhibited until the end of December at the M1 Fine Art gallery in Greenwich, London: www.m1fineart.com

Chris Baker’s website, blog and Galaxy On Glass details are at www.cosmologychris.co.uk

Senecio Press is at www.senecioeditions.co.uk