Check for image distortion Peripheral image distortion is the most serious problem for loupes. Viewing distorted images strains the eye and affects your judgement. Canon's 4x loupe correct image distortion and show a crisp, clear image that is easy on the eye. Loupe Features: The Canon 4x loupe is certainly worth the investment. If you demand the highest quality from your pictures, an equally high quality loupe is indispensable when it comes to checking your negatives or slides. Text and photos by Philip Chong. Copyright 1999 by Canon Marketing (M) Sdn Bhd << Back to Main . 1 . 2 .