How did I capture these intriguing feedback loop photos?

[LaurieAG]

Feedback loops can be very cheap and can be modified easily by things to produce some interesting photos.

I used the attached setup to capture these images over 12 years ago and they are accurate to what you actually see on the screen within the maxed out limits of the hardware/software combination used at the time.

To make this interesting, especially as this is a physics forum, I will set forward a couple of questions below with regards to what I had to do to capture the images that I will be posting. I will post the first images and answer the question to show what I did to give you the general idea.

I invite anybody else to answer the questions or post their own feedback loop pictures and pose their own questions with regards to what you did to get the image. Note: none of these images have been modified in any way shape or form apart from the original reduction in size so please don't post modified images. Only the names have been changed to protect the innocent

(1) How did I create 2-PerfectOrb?

(2) What caused 3-Startled to become startled?

(3) (a) What happened straight after 4-DamnedSpot was captured?
(b) What happened if you did not capture 4-DamnedSpot

(4) What is the only thing altered between 5-Blue and 6-Orange?

(5) What is different between 7-Fractal, 8-Flare and all the other pictures so far?

Answers

(1) I gradually skewed 1-1-Winiverse until I had 1-2-FernShell. 2-PerfectOrb was not far away.

 

[LaurieAG]

Sorry, limit of 3

 

[LaurieAG]

And the next 2

 

[LaurieAG]

And the next pair

 

[Andy Resnick]

Sheesh- first Borek, now you... I'm never going to get any work done :)

 

[LaurieAG]

Sheesh- first Borek, now you... I'm never going to get any work done :)

Enjoy Andy,

I call the whole series 'within 90 degrees of reality' to explain why (3) (b) is possible with this setup. Any other ideas on this anomally?

Here are some hints,

(2) If you have one you probably won't not be able to put your finger on it.

(3) (a) It's not the same as (b) but it's the same as what you get when you disturb (b).
(3) (b) Einstein predicted it, Zena had one and you too can have one if you turn your loop into a shadow trap.

(4) You are either too close and too far or too left and too right or too up and too down.

(5) If you reflect on this problem again and again at the same time you surely can not fail.

The loops hardware/software is constant, each image has one discrete distance, three discrete angles and any other optical interference is constant/fixed/, for anybody who wants to try to work out the maths behind it.

Here's another one.

(6) On reflection What part of 9-sphere is not an illusion?

 

[Andy Resnick]

Feedback loops can be very cheap and can be modified easily by things to produce some interesting photos.

I remember doing this 'back in the day', just to see what would happen. There was a little burst of lab activity because it's a feedback loop- a particularly easy to visualize feedback loop.

I had a *really* hard time replicating this with my (digital) USB camera, IIRC all I needed to do in the analog age was to play with the 'synch' dial on the monitor and the NTSC signal protocol did the rest..

This morning I was able to get something by tweaking the camera frame rate relative to the monitor refresh rate, but it wasn't much more than a vague approximation to a strobe light.

 

[LaurieAG]

Hi Andy,

This morning I was able to get something by tweaking the camera frame rate relative to the monitor refresh rate, but it wasn't much more than a vague approximation to a strobe light.

I think the ratio of the lag in the old PC hardware has to be similar to capture images like these, that's why I posted the setup specs. I have tried to do similar things on newer hardware but I couldn't replicate the images because the resolution, capture speed, monitor size, tv/video card lag was different and the on screen window had an ugly thick skin around it.

I'll let you know how the (3) images were generated after you've had a go. (3) (b) is an amazing sight to behold so, if you can find any, you can post astronomical images of (3) (b) on this thread as well. Cheers.

 

[LaurieAG]

Some answers.

(2) If you have one you probably won't not be able to put your finger on it.

Just put your finger on the edge of 2 PerfectOrb on the screen and hold it there to distort the image as shown.