Declining to be photographed in a polite and respectful manner is important to maintain good relationships with your classmates or colleagues. Here are a few options you can consider:

1. Address it in the moment:

   • “Hey everyone, I just wanted to let you know that I’m not comfortable being in photos. Could you please avoid including me in any group pictures? Thanks!”

2. Catching the photographer before the photo is taken:

   • “Excuse me, would it be alright if I’m not in the picture? I’d rather not be photographed. Thank you for understanding.”

3. After the photo is taken, but before it’s shared:

   • “Hi [Photographer’s Name], I’m not really comfortable with having my photos shared. Could you crop me out or just not include the ones with me in them? Thanks!”

4. Consider addressing it in the group chat:

   • “Hey everyone, I noticed some photos were shared in the chat. I’d prefer not to have my photos shared publicly. Can you guys keep group pics without me out of the chat? Appreciate it!”

5. Speak privately with the person who took the photo:

   • “Hey [Photographer’s Name], can I have a quick word? I’m not very comfortable with having my photos shared in the group chat. Could you kindly not share the ones with me?”

Remember to acknowledge their understanding and cooperation to keep the atmosphere friendly. Most people will understand and respect your wishes if you communicate your boundaries clearly and politely.