I don't own a loupe buy I imagine a magnifying glass would do? I'll try making some prints to see what I get.
Take the normal lens off your camera. Set the focus to infinity and open the aperture to the largest opening [smallest s/stop]. Look through the front of the lens and aim the rear [lens mount side] at the negative. Now you have a magnifying lens to use as a loupe.
Warning!! Handling a Hasselblad can be harmful to your financial well being!
Nothing beats a great piece of glass!
I leave the digital work for the urologists and proctologists.