The other answers already say that it is not possible in Lightroom. I don't have LR 4 so I don't know. But since I'm from an IT background I like scripts.
I'm fairly certain you can set up a "run program after export" option in your export preset. You could use the command line tools for the Image Magick library to automatically create the output formats you need after you have exported the highest quality one from LR.
I'd put that in a batch file, but I don't konw whether you're on Windows or Mac. I'm on Windows, so I'd make a Windows batch file. On Mac it might work differently. Maybe someone can elaborate in the comments.
Image Magick is a set of image processing tools much like the stuff that happens in LR or PS in the background. Many web based programs that handle images rely on it to resize avatar pictures, create Captchas and similar tools. But we are going to use the command line tools to resize your images and change to compression format.
So first of all you need to download a binary release of Image Magick and install it on your system. (A binary is an exe or setup file).
Once you've done that, let's set up the batch file. Create a new text file using notepad and put the following lines of code in it. Place it, for example, in your output directory and name it
mogrify -path C:\path\to\export\thumb -thumbnail 300x200 C:\path\to\export\*.jpg
mogrify -path C:\path\to\export\tiff -format tiff C:\path\to\export\*.jpg
Now edit your LR export settings to run this batch file after the export is completed.
Let's look at what is happening:
mogrify takes a bunch of images and processes them. Please be aware that they will be edited in place if the filename does not change. Images will be overwritten!
-path option tells the program where to put the output files. In the first line I've created a folder named
thumb, in the second line
-thumbnail option takes care of resizing and removes meta data. You can read more about it here. The
300x200 is a size I picked. You can change the size.
-format option tells
mogrify to convert to a tiff images.
The last part,
C:\path\to\export\*.jpg, is the path to the input directory and images. I wasn't sure where the program will be executed, so I used an absolute path. You can experiment and change that to your liking.
There really is a lot you can do with Image Magick once you've understood how powerful it can be. Using it like this is a very nice time safer that should work without too much learning.
If you want to try out more settings, I suggest you use
convert instead of
mogrify and start with a test image.
I couldn't verify everything and I don't have IM installed right now, so there might be some glitches. I still hope this helps.