Is there a period costumes geek in the house?

These are some old family photographs a relative showed me, which I then snapped with my digital camera. I suspect these are family members, but I have no idea who or when. The costumes in some cases suggests Victorian, but I can't identify them any better than that. Is there anyone reading this who can do better?

( Click here to view the images )

The last of these photos is printed on a shiny metal plate that has corroded somewhat, leading to the photographic imprint coming away in some places. This suggested to me that it might be a daguerreotype (appeared 1839, peaked 1847-1854, dwindled 1855-1860)^*.

* The dress, less unusual by today's standards, had suggested to me it might be later, and the other possibility is the tintype (appeared: 1856, peaked 1861-1870, dwindled: 1872-1900), however the cited web page does not mention the tintype (which is actually made out of iron) as reflective, and Wikipedia informs me that the tie as we know it dates back to the 1850s. I suppose the answer is to go back to my relative and get her to wave a magnet at it.