Transparent Photoshop

Okay guys I have an issue with photoshop. I completed a render of a house which had a white background, and when I imported it into photoshop elements, the white background automatically became transparent. which was helpful.

I then completed a render on a unit with a white background, however when i import it into photoshop, the white background still remains white (with no transparent)

I've read how you can use the wand tool to go around the outline of the picture, however there are tree models with leaves everywhere which makes it difficult to draw around and what not.

what im wondering is, is there some mode, or tool, or just something, which would make the white background transparent automatic?

just incase, i modelled the unit using the Sketchup Pro 7 and used V-Ray to render.

When you render, be sure to save the image as a .tif and include the alpha channel. Then when you open the rendered image in Photoshop you will be able to go into the Channels palette and easily extract the rendered image from the background by Ctrl+Clicking on the alpha channel.

i cant seem to find the channel palette

im using photoshop elements 7 if that helps

Yeah, it looks like photoshop elements doesn't have a channels palette.

Ok, so another option would be to save your render as .png format. Then when you open it in elements, there should be no background. Just the rendered elements.

that worked, thank you!!