FAQ (frequently asked questions)

from Michael’s Visual Phenomena & Optical Illusions


Questions & answers ordered roughly by frequency

Preamble: My replies below have a somewhat caustic quality, so I hasten to add: the very vast majority of communications I receive on this site is very positive and often include useful feedback, helping my to improve. However, with many of you I share a communcation overload, and the topics below may help to fend off some communications which might receive disappointing responses.

  1. Can you send your files for me to include in a powerpoint presentation? (this comes in various shades of politeness)

    Answer: I understand, I also do lots of presentations. However, I stopped using PPT years ago. I know it can be difficult, especially since micro$soft actively hinders the embedding of QuickTime movies; for Flash it becomes difficult if the content uses more recent features of Flash. There’s always the possibility to link externally and play in the free QuickTime or Flash players.

    As to sending the files: I get this request very, very often, and my patience has worn a little thin (I feel more inclined to help for educational purposes). Anyway: the files here are not protected, they (or their references) can easily be grabbed directly out of your browser; so you can help yourself. Credit is appreciated.

  2. Can I use your illusion xy on my site?

    Answer: Yes, provided that adequate credit is given (e.g. by back link). Also, be aware that some content here is copyrighted by 3rd parties. Permission to publish here does not automatically transfer to your site. I reference the original wherever possible, so you can contact them directly.

  3. Will you link to the new top site xy?

    Answer: In general, no. Especially if it’s commercial. It totally escapes me why I should link to a casino site or such.

  4. Will you put the advertisement xy on your site?

    Answer: Sorry, no. While displaying adverts certainly seems to be a successful business model, I disenjoy adverts, and usually use a blocker anyway. I also do not enjoy emails with ads at the end.

  5. I have the following new illusion for your site…

    Answer: That’s a very nice offer. A few of the best started that way (e.g. the Lilac Chaser). But please be not disappointed if I don’t take it up. I have a queue of material waiting to be polished. And it is quite time-consuming to program the interaction, do the background research etc. So I can’t include everything (in fact, sometimes it’s already in the collection), and it will take a while anyway.