You can watermark your photos yourself using an image editing program, creating text and positioning it over the image where you would like for it to show up (remember, put it across the center of the image, not off to the side or not over a prominent part of the image because that can easily be cropped or edited out and someone could easily steal the picture by removing copyright and adding their own, etc), then change the opacity of the text or the text layer to make it lighter so it isn't as distracting.
There are programs and websites out there that will watermark the images with your copyright, though I don't know any off the top of my head.
No, you do not have to purchase a copyright. And you can use the (c) or © symbol (ALT+0169), whichever you prefer. You can use your full name, first name, email address, website, whatever identification you wish.
I usually copyright my photos with either
© 2006 dont-stay.com
© dont-stay.com
© dontstay[@]gmail.com
etc. I'm still weary of putting my fill name on the internet since my last name is pretty unique haha
EXAMPLES
Good:
Bad:
See how, on the second image, the watermark can very easily be edited out? But on the first, it can still be done but will take a little more time and experience with an image editing program
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