The Difference Between Letter Sheets and Printed Coded Targets

Coded Targets help PhotoModeler solve projects with less work and greater accuracy. Coded Targets are helpful too for setting up measurement planes and performing other types of accurate measurements. They are used to measure marine decks, marine canvas, dashboards, kitchens, glazing, stairs, swimming pool decks, interior siding, etc.

Letter Sheets are a specific combination and layout of Coded Targets. PhotoModeler has functions that can look for and use Letter Sheets for scale and coordinate system setup. This includes automation of scale and coordinate system setup with Presets. The Letter Sheet system includes 8.5″ x 11″ sheets, 4″ x 4″ individual targets, and 2″ diameter individual round targets.

Coded Targets can be printed within PhotoModeler, and Letter Sheets are available for printing from pdf files. In addition, we sell PhotoModeler Letter Sheet targets with rubber backing or card backing that have better utility than paper-printed targets.

Due to the size of the main Letter Sheets (8.5×11), they won’t be suited to smaller projects where the targets might cover too much or overlap, nor suited to very large projects where targets would be too small for detection. In these cases, printing your Coded Targets from PhotoModeler and optionally cutting them apart may fit your needs better.

Note: Mixing Coded Targets and Letter Sheets – generally, one will use either Coded Targets printed from PhotoModeler, or Letter Sheets (printed from PDF or purchased) in a project. They can be mixed, though, with one proviso. If you want to extend the Letter Sheet set of targets with more targets, you may want to print additional Coded Targets. Or you may want to manufacture your own Coded Targets sets. The important consideration is that Coded Target identifier numbers must be unique in one project. Do not add Coded Targets with the same Ids as the Letter Sheets you use. For example, if you use the full Letter Sheet set (sheets A to R, individual targets, and the small rounds), the target ids range from 1 to 213, and to supplement those with printed Coded Targets, you can start printing those at Id 214.