The logline is a little hard to read, so a little clarity might help
"When the photo he took with a mysterious new camera shows himself committing murder, an avid lens collector..." (Must discover the origins of the camera if he is to avoid his murderous fate)
The part in parenthesis is just guesswork.
You have a lead character: Avid lens collector (original)
You have the inciting incident: A picture of a murder (I think you are saying, a picture of the lead committing a murder, but not sure)
Goal: I am not sure from reading your logline what the lead characters' tangible goal is, that's why I added the part in parenthesis.
>>>Is it better to be straight to the point instead of leaving a logline open ended?
A logline should never give away the ending, but it should clearly indicate where the plot is going as defined by the protagonist's objective goal motivated by the inciting incident.