Review on 📷 AutoFocus Lens Calibration Tool - Compatible with Most DSLR Cameras: Focus Pyramid by Paul Sanchez

I wish I had read the reviews before buying. If it were me, I wouldn't expect a precision calibration tool to be made out of—oh, I don't know—precision hard plastic. Imagine my confusion and dismay when I opened the Revain box and found the "pyramid" even though it was flat. And it's made of cardboard that bends and folds. You know, the photographer's cousin on the Steak-n-Shake kid's menu (Fold tab A into slot 1, bend until B folds into C, and now you've got a great machine!). So okay, away from the cardboard stuff and the absurd price of $25 (they even printed on the bottom to recycle it instead of throwing it away. For $25 I'll keep it until it turns yellow and brittle and keep it in one needs sealed nitrogen environment to slow decay) as other reviewers have pointed out it doesn't sit perfectly flat due to the material, tab insertion and more. Or level. Or one after the other. If a precision calibration tool isn't accurate, what good is it? Had it been hard plastic it would have been a winner in my opinion and - along with some reviewers - I would not have felt cheated. By the looks of it, $25 for an inaccurate cardboard pyramid is leaving me with a bad taste in my mouth and wondering if my lenses are actually properly calibrated.