Author Archives: eleanor11

Cyanotype experiments at Grezzo – chemicals in the cantina

Following on from the successful Austinmer cyanotype experiments, I have bought cyanotype chemicals to make my own. I brought the dry chemicals, along with the necessary instruments (scales, measuring cylinder, brown glass bottles, syringes) to Grezzo. I used the cantina (a naturally dark and cool space) as my lab. 

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Yi camera lens correction test

I was interested to find out what the difference was between filming with and without the Yi’s inbuilt lens distortion correction, once additional correction of the barrelling from the wide-angle lens had been corrected in After Effects.


The images on the left are taken without the Yi’s distortion correction, and all correction in the lower image in AE, using Optics Compensation effect, FOV 74, Reverse Lens Direction on. The images on the right are taken with the Yi’s distortion correction. Further, correction in AE, using Optics Compensation effect, FOV 48, Reverse Lens Direction on.

The result (once all barrelling is removed) is very similar between the two. However, as the correction entirely in AE means that the image is being digitally blown up, a better image quality is probably obtained by using the camera’s inbuilt correction.

Additionally, when using the camera’s distortion correction the raw footage has less distortion in more distant objects. For some footage without near objects with identifying barreling features (such as straight lines), it may be possible to avoid using the AE effect entirely.

Cone shadows continued

In viewing the cone shadow footage I realised that I need to decide if the projection should just be on a single surface, such as the back wall, or floor. This could use a shadow puppet arrangement, with the camera filming from behind a translucent screen. This could also work for filming the floor – the camera would be under the floor, which would also show the footprints of the forms, as well as their shadows. It would need to be strong enough to support the models, i.e. perspex.

The clip above takes the previous footage and only shows the back wall. I think this works well, although the shadow of the side wall and ceiling should be avoided by removal of these elements from the model. Again, the texture of the back wall is particularly strong, and a neutral surface may work better and act as a “screen” to receive the projection of the moving shadows.

Cone shadows

This is a test of a cone shadows model, using the found card as the “space” into which the cones’ shadows are projected. The intention is that the form of the cones is communicated entirely by the shadows, and this form is reconstructed by the mind of the viewer/reader.

The two edits below are made from the same piece of time-lapse footage (shot at 1frame/0.5 seconds), taken while the sunshine was very intermittent. The left hand edit just speeds up the entire recording to 120x real-time, while the right hand version edits out all of the sections where the sunlight has disappeared, and then speeds it up to 60x real-time, to allow more time for the moving shadows of the cones.

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New found card model

Initially to test whether the Yi 1 will record for long continuous periods, I assembled a new model with the found card. As the Yi no longer has the back case it will not stand by itself, so I hastily assembled a lego stand. The camera successfully recorded continuously for several days and was manually turned off.

The triptych below shows the three days of recording, all with speed increased to play within 3 minutes. The majority of the “night” time (black screen) has been removed. The camera was set to lens distortion correction (as part of the lego stand was visible in full wide-angle), and did not need any further correction in after effects.

The oblique light across the undulating wall is particularly effective, and better than the last model where the light was direct.

Yi camera 1 working

The first Yi camera that completely stopped working in the last test is now working when both the back of the camera has been removed, including the battery. The picture above show both front and back removed, although I have since reattached the front (which allows me to use the makeshift focus ring), and it also works like this.

Yi camera problem investigations

I have now numbered each camera (just visible on the photo in the previous post), in the order they were purchased. Each camera has a different version of the firmware, and the later two are a different model to the first.

Camera 1 Wifi: YDXJ_2326644 SN: Z23A60252326644 FW: 1.2.13 Model: 23A
Camera 2 Wifi: YDXJ_3144435 SN: Z25L630ACN3144435 FW: 1.3.0 Model: 25L
Camera 3 Wifi: YDXJ_4476443 SN: Z25L640ACN4476443 FW: 1.4.8 Model: 25L

Using the found card model on the previous post, I noted each camera’s performance. Continue reading