Erin,
On your cropped sensor, the best all around lens (and I love it for interviews) is the Canon 35mm 1.4L. And it makes a huge difference! This was the first L series I had ever bought and it became my go to lens for my 60D, which is cropped as well. Depending on your distance to the subject, you can make it a wide shot or moderately tight interview shot (it’s not a tight shot by any means, but as far as a tight interview shot, it is just perfect!) The math here is that a 35mm on a 1.6x crop, which is what a 70D is, would actually be 56mm. This is why my opinion is not to rent anything tighter than a 35mm for an interview shot on a cropped frame.
LensProToGo price (4 days) = $66.00 + tax
Brad Fugere
Brad Fugere Media LLC
https://www.centralarkansasvideography.com