"Jumping" when close to first image

[Romsha]

When the user comes near a picture for the first time (since the page was loaded), a small "lag" occurs when the description opens and the camera is sent backwards somehow.
Two ideas for the reason of this:

1. There is something wrong with the initial values of the variables regarding picture "closeness" handling, which gets in the way of the moving animation.
2. (more likely) Opening the iframe for the first time is resources - consuming and cuts the movement

[Romsha]

After more debugging I believe this is in fact caused by turning on the lights for the first time. Notice that starting with one light on does not help.
The effect is a big decrease in FPS (60 -> 5) when the light is turned on, which causes a major jump in the animation (may move the camera, go through walls and such). The variable representing the FPS in the code is "deltaTime", so my quick fix was to set its upper boundary to 25 FPS (1/25 seconds). This prevents "jumps", but still doesn't fix the small "hang" when approaching a picture for the first time.