Image created is bigger than source hdd

ok I apologize up front if someone has already posted the same question. The solution option wouldnt allow me choose "I need a solution".

Situation:

Using Ghost to create images as a backup/recovery solution

Issue:

So when I started this project my original saved imaged is sitting at roughly 61 GBs per image. The source SSD is only 120 GBs.

The last image created came out to 161 GBs.  As you can tell this would be difficult to reimage a 120 GB SSD with a 161 GB image.

I am using Ghost64 to create the image. I chose the SSD and then selected the external HDD that I am saving the image to. Ghost prompts for Compress Image and I chose “Fast”.  

So my question would be a. do I need to choose the option of “High” at the “Compress Image” option or are there switches that I can apply in CMD before running Ghost?

Thanks for help