Assuming all images are in the images directory and has the .jpg suffix, the following little script will print out all image files that has no corresponding .tif file on UNIX:
#!/bin/sh
find images/ -type f -name "*.jpg" |
while read j; do
t=${j%.jpg}.tif
if [ ! -f "$t" ]; then
echo "Lacking tif file: " $j
fi
done
Paste this to a file, and save it a folder above the one where your images are stored. You could call it find-images. For example:
├── find-images
└── images/
├── 1.jpg
└── 2.jpg
└── ...
Now, open Utilities/Terminal.app, and use the cd command to navigate to the folder where your script is, e.g. if the script is on your Desktop, just enter cd Desktop.
Then, enter chmod +x find-images. Now you can run the script by just calling ./find-images.