My Dear friends and colleagues!
Unfortunately I can answer only with some delay. At me the constant time trouble connected with the basic work. But I will try to answer that that I can find, read and I can answer that I know precisely.
I answer to this message with delay because I only have come nearer to it in reading.
On a completely separately note - was just rereading this "Light" post and WAB's responses....do you think the "camera" around Semyon's neck (or as I believe - around his wrist) was this??:
https://d.radikal.ru/d06/1903/4c/ee48ef976978.jpg
It looks just like a camera....plus imagine the implications: Semyon would never have grabbed the camera to photograph something. It would simply have been a light source!!!
If I have correctly understood question here it is told about that, could not be small lamp instead of the chamber round Simeon's neck.
In the photo it is visible that it is subject of form Parallelepiped (
https://en.wikipedia.org/wiki/Parallelepiped ) with the rounded off edges. It is absolutely precisely identified as camera "Zorky" case. Till now it is not known, whether there was there camera or it there was empty case. Probably that before the beginning of events Simeon has left the camera in tent, and round Simeon's neck there is only empty case. It could so arrive because has decided not to remove case, and the camera place there only in the morning.
If it there had camera that his mothers have given the faulty camera will be strange. After such bathing in water the camera necessarily should become unfit for use. It had no protection against water.
The small lamp at it was nearby jacket pocket when they went on skis lengthways the river Auspia. It is visible in photos.
On the Maslennikov scheme is mark that on half of way from tent to cedar the small lamp has been found. Quite probably it also was Simeon's small lamp because on its jacket in the bottom of small lamp have not found.
All events occurred at night (in night-time) therefore such development of actions was quite possible.
But even on photo not so high quality mix small lamp and a case from the camera very difficultly.