Step 1.
You will need a ruler or tape measure, or anything with a scale will do. ideally with big easy to read numbers (The imperial side is great for this), your bike and your phone/camera.
For IPhones: HEIC file type sucks, please make sure to change this -
Settings > Camera > Formats > Change camera capture from high efficiency to most compatible.
Install any accessories, bottle cages and bottles you wish to use with the frame bag
Step 2.
Attach the ruler to your top tube, stand the bike as upright as possible.
Grab a friend to help hold it upright, chuck a zip tie or velcro over the rear brake to stop it rolling, a work stand can help if you have one!
Step 3.
In the highest definition, crouch down low, aiming your lens centre with the main triangle take a photo from around 3 meters back and another photo from 5 meters back.
Zoom in and check you can read the numbers on your ruler and that everything is nice flat and square on.
At around 4-5m back make one chainstay disappear behind the other chainstay for an ultra flat and square photo!
Step 4.
Email photos back or share a drive link.