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

Fairly good. I now use this and a similar target to calibrate my lenses and am very glad I didn't pay more for these 'professional' ones? those who do essentially the same thing. I like that it's small and doesn't add clutter to my camera gear. But I have to say the history is a bit simplified and the other target I bought works better for the most part due to the variety of markers. This target with its scale/slope is too close to a 45° ruler position - it could benefit from adding marks/templates.