Bournemouth — Jul 15th 2014

With two talks to fit in, Alan called the meeting to order and immediately introduced Peter Shepheard to talk on fractals. A Polish born mathematician called Benoit Mandelbrot is generally regarded as the father figure of fractals (Mandelbrot in Wiki).

His talk centred around three applications that allow fractal artwork to be produced with little or no understanding of the underlying mathematics. Peter started by showing pictures of fractal patterns occurring in nature. He then showed how a tree-like pattern could be generated by a simple, repeated process, illustrating one of the key properties of fractals - self similarity.

Fractals are used extensively for CGI, both in generating photorealistic scenery, flowers etc., and to create fantasy worlds and of course can generate stunning abstract artwork. Peter showed impressive examples in all categories.

The three applications were then demonstrated:


This is free and is available for OSX and for iOS. It essentially enables deep exploration of the Mandelbrot set. This is not as limiting as it might sound - see for example:
(Mandelbrot set). Xaos is really easy to play with and examples of artwork generated with this program can be seen at (fractal arts)

This is available in various versions (Chaoticafractals) and there is a free version for OSX on the App store. It operates in a completely different way from Xaos and provides lots of scope for post manipulation of your initial image although some experience is needed to be able to predict the outcome of such manipulation. The program also can be inconvenient to use on small screens, needing an image window and an editing window to be open simultaneously. A tutorial and example can be seen (deviantart)

This is available from the App store at £20.99. However a 30 day trial version is available  (ultrafractal) It is based on the Mandelbrot set and also has lots of manipulation tools. You can also use other people’s starting points as a way to discover interesting areas of the Mandelbrot set. It has good layer blending facilities to enable complex artworks to be built up from the fractal elements you find.

As well as these three apps, Peter also referred to sources of tutorials and other information, for example:
(graphicssoft), (digital art) and (deviantart).

After a short coffee break, Trevor Noyes took the stand to talk about Audacity. This is a free program (audacity) which Trevor uses to clean up the sound from old records (mainly modern jazz) or family recordings.

By way of example, Trevor presented a recording he had made simply by linking the headphone socket of his hi fi to the microphone socket of the Mac to import a track from an old record. He demonstrated how the program can be used to remove clicks and to reduce noise, stressing that some care was needed to ensure that only unwanted sound was removed!  Trimming of tracks and fading were also demonstrated. 

Once happy with the cleaned up recording, metadata such as track titles can be entered and this carries across to iTunes, making it easy to build up and maintain a library.

Trevor’s talk generated considerable discussions about the scope and use of Audacity, during which the Griffin iMike was mentioned as an alternative (USB) input device, and iRecord and Audio HiJack were recommended for direct radio to iMac recording.

There will be no August meeting of the Bournemouth group so Alan closed another interesting session by wishing everybody a good Summer. I took him at his word, which is why this report is a few days late!



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Roy Rainford said…

A fascinating talk on Fractals which motivated me to play with them afterwards. I have put two first attempts on my blog at: Both produced in the XaoS app. Thanks to Peter for an interesting session and to Trevor H for the helpful report above. Apologies for being unable to stay for Trevor's Audacity session. Many thanks to Alan for organising the meeting. Happy summer to all. Roy.
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