58 people volunteered to take photos at the hackathon. Here is the email Chris will be sending out to the group.
If you didnt sign up but still want to help, just comment here!

Hello,
I'm Chris and I’ve been asked by the Wikimania Hackathon organizers to help with our photography efforts for the event. Thank you for volunteering to help take photos of the event.

Your photos help to document the event and share with others the energy and vibrancy of our community.

On to business.

First, a reminder that we will have a photography policy for attendees at the event. Attendees will be wearing different colored lanyards letting you know if they are OK with appearing in photos.

There will be two color options for people to wear to state their preference.

All participants who didn’t agree to have their picture taken are recognizable by special yellow lanyards.
The regular lanyards are red.

If someone asks to not take their photo, but are not wearing a yellow lanyard, direct them to myself, Rachel Farrand, or one of the hackathon organizers to assist with getting them an appropriate lanyard.

Second, It would be great to have your assistance in creating a group photo of everyone. The group photo will be on Thursday at 17:00 in the <location>. If the weather is pleasant, we will take the photo outside.

Third, please put all of your hackathon images uploaded to Wikimedia Commons into the Category:Wikimania 2017 Hackathon (or, even better, into fitting subcategories).

If you haven't uploaded to Commons before, don't worry. Let me know and we can find some time together to figure it out. If you would like to join me for lunch on the first day of the hackathon, I’ll be there with my camera and laptop.

If you’ll be spending any time in Montreal, please take a look at WikiShootMe! for wiki items that don’t yet have a photo! Also, please add a note to the photography phabricator task if you’d like to discuss more about photography, the hackathon, or any plans to venture into the city - maybe as a group?

Thank you again, please let me know if you have any questions and I can't wait to see you all in a few weeks.

Email sent, looking forward to meeting everyone!

In T168752#3501329, @Rfarrand wrote:

Second, It would be great to have your assistance in creating a group photo of everyone. The group photo will be on Thursday at 17:00 in the <location>. If the weather is pleasant, we will take the photo outside.

I will have a DSLR and a tripod at the event, so if no-one else volunteers, I can do this.

I scouted the building and surrounding outside areas. Nothing really optimal. Nothing very attractive outside without walking a distance (which means we'll lose folks in transition) and nothing big and out-of-the-way enough elsewhere in the building. Hence the choice to go with the Ballroom West Lobby (right outside the large hacking room).

@Slashme if you can bring your tripod that would be great! We want to make sure you get in the photo too! :)

OK, will do!

We were able to work with the venue and use the sixth floor terrace for the photo. Much better lighting and a nice little garden area! Please spread the word.

@Slashme, I have your tripod mount plate!

@CKoerner_WMF please add any notes or lessons learned from the volunteer group here so we don't loose them for next time and then close the task when you are ready. If you are not ready to close the task because you have some following up to do or need help with something please also list those details here.