The negative tends implies you want them to participate in the action.
It depends on what you mean. If you want them to take a picture of you then 撮ってくださいshould be fine, whereas 撮っていただけませんかis more like take the picture on your behalf.
As long as you make it clear that you want to be in the photo they take either is ok. Unless you really just mean that you want them to use their awesome photography skills to take a landscape for you.
If you rephrase it then it’s fine.
Please take our picture.
If you say it like that it’s really obvious you mean your group, but it’s a bit direct.
Would you please take our picture (for us).
Which is also fine and less direct.
Does that help?