Hello Michael, when you enter challenge "cost" of challenge is certain amount of credits (which equal votes). So as example, if challenge moderator set that cost of entry is 10 credits, every photo that enters will add 10 allocated votes, and if there are 200 photos there will be 2000 allocated votes (you can call them reserved votes for that challenge). When voting starts users will vote for that challenge certain amount of time, same (or close to) amount as number of allocated votes.
Thank you for your prompt response and the clear explanation.
However, are the allocated votes applied equally across the images in the challenge or does some 'weighting' take place depending on the position of an image within the challenge once voting has started?