Maybe someone could share their knowledge about cameras from that time.
It's easy to do. But it is necessary to limit oneself to the models that the Dyatlov's group and the participants of the search had. Otherwise it will be a very big and thick "novel".
They had cameras like "Zorky" and FED (ФЭД - in Russian). It is the same model only of different companies and different years of development. This model is a clone of the German Leica camera of 1934.
On the left is an original “Leica” camera (firm “Ernst Leitz Wetzlar”, Germany), on the right is a FED camera (USSR, Kharkov Mechanical Plant). Such cameras were in the possession of the participants of the search, for example, Yury Yarovoy.
The “Zorky” camera was produced by the Krasnogorsk plant, which is located near Moscow. Exactly these cameras were in Dyatlov's group. They did not have any others. They had four such cameras. The talk about a fifth camera is speculation, because for many years it could not be confirmed that they had one at all.
The participants of the search had FED cameras. In principle they are the same model, only with slightly different optical and mechanical characteristics. The “Zorky” camera was more advanced because it was slightly reworked after WWII and newer materials and better optical glass were used.
You can see all the features of this camera in this photo. This is my original shot of this camera in real life.
The features of this camera are:
1. The lens has to be extended (raise the front part) before shooting
2. The film rewinds to one frame and the shutter is cocked by turning the handwheel which you can see on the right. It has a notch to prevent your hand from slipping when working. There was no multi-frame spring. Each shot was taken separately.
3. Next to this handwheel is the button to start the shutter. Even further to the left you can see the shutter head. It was also set separately (manually). It was either calculated in my head from my previous experience or determined by a separate exposure meter and set separately.
4. You can see three optical windows at the top. These are the two windows for rangefinder (determining distance - they are from the edges), and the central one for determining the limits of what comes into the picture frame. Sharpness was determined by matching the two contours of the same object (where the camera was pointing) which these side windows gave. This was done by moving (rotating the spiral thread) the lens by that lever visible on the far right, below the lens.
5. On the left you can see the handwheel, which is needed to rewind the film into the light-tight cassette after all the film has been used up. This was done so that the film was wound on a separate, but not light-protected, reel when it was shot. Of course all the film was inside the camera and was covered with a cover which did not let the light in from outside. That's why it was possible to use such a reel.
You had to have a lot of different skills to take pictures, so not everyone could take good pictures. All the automation of the process was invented much later. The fact that many of the group members use cameras on the trip only tells you that they do it only under the supervision and prompting of those who have mastered the camera operation well. This is a bit confusing because it gives the false impression that all of them could do it in a row, and at the same time that many had their own cameras. At the time, a camera was a "luxury item", expensive (about half of an engineer's monthly salary) and required careful training to operate it.
The group had their own cameras: Krivonischenko, Slobodin, Zolotarev, and Dyatlov. Lyudmila Dubinina's parents probably had a camera, but she did not take it on this trip and could hardly have had good skills in working with it independently. The rest of the participants belonged to a less well-off segment of the population, so the camera was not a basic necessity. They had many other expenses. This was especially true for students who lived in the university dormitory and were from other cities.
I would question if they would waste film on such a joke,also if they had a camera that could take quick succession (time lapse) photos , why there were not more photos of that nature?
Since most of Dyatlov's group were students and very young people, they could do many things that seem illogical or unnecessary to an older person. They fooled around a lot on the trip and joked around. Sometimes even to the detriment of proper film consumption. But as far as I know, they had no shortage of film, so they didn't think about saving it.
The number of mock shots was small only because it was only the beginning of the whole trip and the conditions they were in didn't always allow for it. They had many other concerns and the winter weather was very limiting to their free jokes. That's why there couldn't have been more pictures like this during that time. And then, why did it have to be all the time? When fatigue builds up, the desire for an extra joke doesn't always appear...