To begin with the construction of the zoetrope structure I first designed the outer cylinder, a 30 inch longer piece of card, in which I cut 15 slits into, each 2 inches wide. This was the most crucial part of making the moving image work as the width and placement of the slits determine how the motion is perceived. In order to achieve the desired effect, I had to meticulously sketch out the slits before cutting, alining the centre of each image with the centre of each slit. This involved measuring the width of each frame, (which I already knew as I designed them to be 2 inches/ 50.8mm wide) finding the middle section of that measurement (25.4mm) and then marking each point out on paper. Every midpoint was 2 inches/ 50.8mm apart from the next.
When it came to the width of the slits I first had to do a bit of research to determine how wide they needed to be in order for the motion to work, whilst still having the right balance of lighting and clarity for the images to be seen. There were sources online to suggest 1/8th of the frame width would be a suitable width for the slit, 50.8 รท 8 = 6.35mm wide. However, when looking into traditional designs, there sources saying the slits shouldn’t be any wider than 4mm as this would make for a sequence that is too choppy. Because of this, I felt concerned that if I did make the slits 6mm wide it wouldn’t work, therefore I decided on 4mm wide for each slit.
I feel happy with this slit width as it does work well with the images, it creates an incredibly smooth motion of the wolf moving which is the result I wanted it to have. However I am questioning whether a 6mm wide slit would make for a more defined image as I feel currently, the shadow image itself is obvious to see, but the hands less so. Im not sure whether this is because they’re a more fine-line drawing and therefore do not have the darker contrast needed for the eye to see at speed, or whether it’s because the slits are too skinny, therefore not allowing enough time in each shutter for the brain to properly pick up on what it’s seeing. I am going to continue working with these 4mm slits for now, adding elements I know will help to define the image, however if toward the end I am still not completely satisfied with the result, I will make a second external cylinder with 6mm wide slits.
First Prototype –
After cutting out each slit, I made a first prototype, blue tacking both the inner and outer cylinder into the circle shape and placing them on top of a record playing at 45 rpm on the turntable. I knew that the 45 rpm speed would work for this project as when beginning to research how to create the motorised base for the zoetrope I looked into rotation speeds. For this zoetrope, with 15 images, it needs to rotate roughly at 10- 15 fps (40 -60 rpm), meaning the speed of the turntable at 45 rpm works well, however 60 rpm does make for a smoother motion.
In the video above, it doesn’t quite capture the effect that the human eye does as the frame rate of the phone is different to the frame rate of the zoetrope. Additionally, the whiteness of the outer cylinder doesn’t create enough contrast between the flicker of each image so it all starts to blur together. However, you can still see the desired affect, just not with much clarity or to it’s full extent.
In order to combat this lack of contrast, I painted the outer cylinder black using acrylic paint. I painted both sides of this external cylinder, meaning that when it rotates the only white you see is the internal strip of images. The quick shutters of black help direct your eye to the images, making them appear brighter and therefore clearer.
Second Prototype –
When comparing this video to the first, there is a clear difference between the results and the contrast of the black makes for a huge improvement of motion. However there is still the issue of recording this motion due to the frame rate difference and also my phones lack of ability to focus up close.
Playing Alongside an Existing Record –
Once I had completed this second prototype that I felt happy with, I began thinking about the more mechanical aspect of the rotating base layer. Originally, going into this project I wanted to create the entire structure from scratch, making a rotating platform that the zoetrope sits on. I planned to motorise this base using the Bela board. However as this project has moved forward I am beginning to rethink this idea due to both practical and technical reasons.
First of all, the task of building the base is intense, it is a lot of new work that I haven’t done before, specifically working with motors using the Bela as this is something we have not touched on in class. I did however, feel excited and enthusiastic to work in unknown territory and learn new skills that will continue to come in handy for my practice. However, as time goes on I am realising this might have been too ambitious for this project, as not only is this aspect new to my practice, so is Pure data and using the Bela. With 2 weeks left until the deadline, I still have the Pd aspect of the work to navigate, as well as finishing the construction of the zoetrope and completing the written work. And so, I just feel, in order to complete all the aspects to a high quality, I need to prioritise the ones that have no alternate option like the Pd code to ensure everything gets done.
Furthermore, after finding out the rotation speed of a record player works for this project, I did question whether I should just use this as my base and create a structure that is able to attach onto the turntable. It is an incredibly polished design that is made to rotate at even speed with a stable motor and good balance, all the aspects I need to create a smooth flowing moving image.
Therefore I have made the executive decision to use a record player as the turntable for this project, creating a structure that will sit on top. I feel this gives me more time to focus on the important aspect of the technicalities, including; the Pd code, the placement of the LDRs, the light set up and sound quality. Additionally it ensures that the zoetrope will actually work as it is the right speed of rotation, moving on an even balanced surface with a reliable motor source.