Tag Archives: photography

Raspberry Pi Project – 1st video

*Head over here to see the latest blog post. 

Last July I wrote about our project using a raspberry pi and its camera module to track the decay of a plastic handbag. The project has been running for about 4 months now and we complied the first video not so long ago.

To be honest we were more than a little nervous about this project, as to us, little if anything had happened for the majority of the summer, but as the seasons changed a few things started to happen!

So a number of things are pretty clear from the video – the major one being that it’s not as dramatically catastrophic as we had hoped! Ironically the video doesn’t pick up on the areas most changed – like the great big hole on the lower left side that is blocked by the beehive bag, nor does it pick up just how many crystals have formed as they are mostly on the sides. The second is that the limitations of the camera module mean the resolution is low – but for a £25 camera it’s still good enough to give up some great information.

The sides of the bag have had seen a large formation of crystals over the three months

The sides of the bag has seen a large formation of crystals over the three months

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The large crack on the bottom edge of the bag on the left side of the image (proper right of bag) is not seen forming on the time lapse as its photobombed by the edge of the beehive bag

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The beehive bag, which I’ve talked about before, is still falling apart! Originally one side broke apart faster that the other, now that ‘better’ half is breaking up. The main crack in the bottom of the picture was only a hairline fracture at the start of the timelapse.

If you look at the video closely you will notice two things of real importance. Firstly, each of the cracks that were present at the start have gotten a little bigger and the delamination of the bag is wider. Remember that we are looking at two months data over a 3 month period, so for things to get noticeably bigger in this timeframe is a real shock in a museum environment. The second thing to notice is the way the cracks grow. If you look closely at the top right corner of the bag you will see the shadow and highlights expand and contract. We also see the beehive bag expand and contract. This might be due to the environmental conditions of our science lab and could be what is ripping our bag apart.

Our next job is to try and improve the video quality and also relate the visual information gained to the data from our environmental monitoring system. From this we may be able to come up with an insight into the storage of plastic objects.

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Mini Post No. 9 – Sometimes we get things wrong!

*NOTE – So the lovely people in the media department at the V&A have asked me to blog for them. This is a great opportunity for my work to reach a much larger audience! So I will be posting to the V&A blog 1st and then a little later I will post here. If you wish to keep up to date then check out my newest post over on the V&A Blog 🙂

Let me begin with a little confession – while we like to think of ourselves as immune to them, sometimes we make silly mistakes.

This happened most recently when we began the XRF analysis of some Julia Margaret Cameron photographs to see if the images had been tinted with other elements like gold. Many of you will know that before Instagram and selfies photographs were made with silver salts on paper. So when one is looking for the elements present within a photograph we expect to find silver.

The Darwin image under the XRF machine head. (c) Victoria and Albert Museum, London.

The Darwin image under the XRF machine head. (c) Victoria and Albert Museum, London.

Julia Margaret Cameron took a fantastic photo of Charles Darwin, so we started the analysis with that image only to find the ‘photograph’ contained zero silver. Cue panic from the conservation science team! The analysis was run a second, then a third time (what was the quote about doing the same thing over and over expecting a different result…). We then switched to an image we knew contained silver to see if it was there was something up with the XRF machine – nope, we could clearly see silver on that image. Cue even more panic from the team as thoughts of having to tell people our beloved Darwin image wasn’t what it was supposed to be…

Remember when your teacher would tell you to always read all of the exam question before beginning, turns out you should do that with object lists too… Our Darwin image isn’t a photograph based on silver salts. It is a carbon print and we never spotted this in the internal object description or the object description on ‘Search the Collections’ when we began the analysis. If we had we would never have picked that image to analyse because carbon is too light an element for our XRF to pick up.

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The ‘Search the Collections’ listing for the Darwin image we were working on – See that it clearly states that the image is a carbon print – If i could put a face-palm emoticon here I would…

Mini Post No. 7 – Using a Raspberry Pi to watch a handbag decay

*NOTE – So the lovely people in the media department at the V&A have asked me to blog for them. This is a great opportunity for my work to reach a much larger audience! So I will be posting to the V&A blog 1st and then a little later I will post here. If you wish to keep up to date then check out my newest post over on the V&A Blog 🙂

So a while back I posted an image of one of the plastic handbags we have here in the Conservation Science Dept. We use these non-museum objects as sacrificial lambs in the aid of heritage science. We have a second handbag that has started to dramatically decay. As we will use any excuse here in the lab to play with new toys “science equipment” we got out a Raspberry Pi. The new camera module for the pi along with a little computer code to set up a time-lapse  is a perfect way to track the rate of decay. We are hoping to let this run for about six months, so come back at Christmas time to see (hopefully) a great video of decaying plastics!

The current setup for a long duration time lapse. Its hoped that we might gain some insight into the decay rate by recording the progress over the next 6 months or so.

The current setup of the Raspberry pi for a long duration time lapse. It’s hoped that we might gain some insight into the decay rate by recording the progress over the next 6 months or so – if nothing else we hope to get a nice film.

 

Mini Post No. 6

So I have been researching about Polyvinyl chloride (PVC) over the past while and I came across this lovely example in the lab of the major danger associated with PVC. Many of us have our family photos kept in ‘plastic’ photo albums – most of these are going to be made from PVC. The biggest danger to our valuable family photos isn’t fire or theft, its the album itself! The plasticizer is very prone to migrating to the surface of PVC, if it’s not removed it forms what’s known as sweat beads. These beads destroy photos! Take a look at the two images below to see just what kind of damage can be caused!

Later in the month I’ll do up a more detailed blog post about PVC. Till then, if you want more information about how to protect your photographs have a look what the British Library and The National Archives have on the topic.

A photograph has been totally distroied by the migraetion of plastizer from the album sheets. (c) Victoria and Albert Museum, London.

The photograph has been totally destroyed by the migration of plastizer from the album sheets. (c) Victoria and Albert Museum, London.

Close up on the face of a person in the photograph. The image had lost almost all definition. (c) Victoria and Albert Museum, London.

Close up on the face of a person in the photograph. The image had lost almost all definition. (c) Victoria and Albert Museum, London.