Rooftop Movies Solargraphs 2025 Complete

 Rooftop Movies Solargraphs 2025 Season

Installing the cameras in October 2024

The Rooftop Movies season for 2024/2025 is done and dusted, so I have brought in all the cameras I had set up there. Keep reading to find out what happened!

A hint of things to come

For those who came in late, a quick synopsis. Solargraphy is the art and science of recording the Sun’s path over a period of days, weeks, months, or even years. You can read all about it here.

The Rooftop Movies Bar sign

If you are not from Perth, or are and have somehow never heard of Rooftop Movies, they are a project of Artrage  (the people behind Fringeworld) that runs from October to April each year. They show classic, cult, and new release movies 5-6 nights a week during that time, along with other special events, all taking place on the roof of the Roe St Carpark in Northbridge. If you have never been it is a wonderful experience - they even have a bar and dinner service inside the area!

A six month solargraph from equinox to equinox

This season was my second time running my cameras at Rooftop Movies, and the first that saw the entire season. As I mentioned above, the season runs from October to April. This covers three of the four key points in the solar year - the Southward Equinox, the Summer Solstice, and the Northward Equinox. This means that the paths the sun follows are doubled - each line is visited once heading towards Solstice, and a second time heading away. It also means that the period from Equinox to Winter Solstice is missing completely, so we only get the upper half of the track.

Leaving the cameras out for about six months did come with a couple of challenges.

What happens when a camera gets opened and crushed.

First up, there was the matter of leaving the cameras out in a relatively exposed location. All up, I installed 25 cameras, with the intention of bringing in half of them on the Solstice. In that first time, I lost one camera to Wardung (the Australian Raven), who pecked out the lid. Then over the second half, one of the smaller round Puck cameras disappeared, and, just a fortnight before the end, one of the other cameras was vandalised. That is not a bad record - I have had five of six go missing or be destroyed over the course of a weekend!

The summer solstice is hard to record!

Second was the matter of latitude. Here in Perth we are at 32 degrees South. This means that the sun at Solstice is 87 degrees above the horizon, or only 3 degrees away from directly overhead. Solargraph cameras are pinhole cameras, so you can draw a straight line to work out where the light will fall when it comes from a particular location. To capture a source of light at 3 degrees from vertical requires something very tall and thin, or you have to tip the camera.

Printed plans failing in a beautiful disaster.

I tried both approaches. Unfortunately, the tall 3d printed cameras I built ended up having some very odd vignetting going on, and they missed the top of the Sun’s path. Further, the Can and Puck cameras that I made wedges for still did not have enough angle to capture the full arc.

Fortunately, solargraphy is very forgiving in many ways. Here are some of the three month results.

The three month results were very promising.

And what happened after the rest of the season? I want to show the process here, so let’s go on a step-by-step journey, shall we?

The raw images are rather plain.

The first thing that has to be done is to scan the image, either with a scanner or a phone camera. This is because these images are not 'fixed' chemically - they will fade in time, and every time they are exposed to light, more of the image will be destroyed. After scanning, this is what an unprocessed solargraph looks like. Depending on the paper and the camera there may be some variations on this, but they all look much like this. So we need to digitally manipulate them, first to make the negative image a positive, and to get rid of any bits of dirt and dust. 

With very little in the foreground, the path of the sun becomes the focal point

The sun rising over the projection booth

The shadows make this almost the scene of some Kaiju movie!

The darker bands show where clouds have covered the sun.

This is looking west from the Eastern side of the cinema. 

So. Much. Drama. Words. Are. Not. Enough.

Sunrises over the Rooftop sign.

After basic reversing (and possibly mirroring - pinhole images are reversed like a mirror), we get something a lot more recognisable in most cases. But there is more we can do. There is a technique called histogram modification, where you can change the way each of the four colour channels (Red, Green, Blue, and Luminance or Brightness) are rendered. Changing all four at once is how you make a negative positive, for example - you make the dark end bright, and the bright end dark. Changing them individually has other effects. With something like solargraphy, there is a lot of fun to be had in being much, much more heavy-handed than you would be with a normal photograph! 

This is actually back to front, so you read the Rooftop Movies bit of the sign!

Fringeworld meets Rooftop Movies!

Let's visit the set of Spacehunter!

This showcases how much you can change things with just a single tool. This one tool, incidentally, is the same tool that cinematographers use (with a much more delicate touch) to tune scenes to have a particular feel to them.

Finally as I was adding the alt-text to the pictures here, I noticed something in one of the images I had discarded. This was a can camera I had set up with a wedge on one of the lighting gantries, looking west. I had dismissed it because the gantry itself had cast a shadow over one side of the image. But then I noticed that the sun's arc was different.

The solstice happened right at the top of the frame!

Let's give it a Fringeworld/Rooftop Movies vibe!

I had successfully caught the solstice - just! I must have positioned the wedge just a little higher, and as a result angled the camera just that little bit further.

The past two years have been quite the journey at Rooftop Movies, and I look forward to visiting again sometime in the future, but at this stage I have no plans. In the meantime I have a number of other projects to work on, and you’ll be able to read about them here, or on my aus.social stream.

A big thank-you to the team at Rooftop Movies, in particular Alana and Linton, for their help and patience, and to the team at Artrage (especially Courtney) for letting me do this in the first place. 

I acknowledge the traditional custodians of Borloo, the place this where ran, and the Whadjuk Noongar people.  I pay my respects to their Elders - past, present, and emerging.