Will Lightroom do this? If not how do I do this in Photoshop?
RGB is not a file format, but a color model. TIFF and PSD files can be RGB files, but they can be CMYK too for example. So what exactly do you want to convert? A RAW image perhaps? Yes, Lightroom will do this when you export the image.
Thank you so much for your prompt reply. I didn't realize RBG was not a file format. As you may have guessed, I am a newbie to the world of photo editing. I am trying to figure out the best way to convert photos to files that I can send to a company (Decals4Artists) to create decals for me that I can fuse on glass. The company requires files in tif or psd. Ideally, I would send them black and white. I may need to convert color to black and white. So one question is how to do this. Second question. A friend sent me the photo they want me to use in a piece in RBG and now I am wondering if and how I can convert it to a Tif.
"A friend sent me the photo they want me to use in a piece in RBG and now I am wondering if and how I can convert it to a Tif."
You are still confusing RGB and file formats. What file format did you friend use? What is the file name extension?
*.rgb is not a standard filetype, at least on the Windows platform (and I've never come across it on the Mac platform either). Ask you friend what app they used to create that file, and ask if that app has an option to save it as a different filetype, such as Tif or Jpeg.
I will. Thank you.