There are some photos but yeah none that are unchangeable to a nay-sayer or a genuine skeptic. However I don't find that lack surprising.But now? Where the hell are the photos now? :)
- If there are any ETC or ODC buzzing Earth then clearly, in areas of tech, they're ahead of humanity. Also clearly they don't want to make a public appearance. Given those two things I'd expect that could cloak in ways that prevent clear images. Add in that reported effects range from stopping electronics to exert a strong mental influence and even altering memory and it seems quite plausible.
OTOH if what someone sees is some sort of human craft, I'd expect that they'd snap a reasonably clear photo.