# Photometry dialog (dialog)

The “Photometry” dialog is used to start the photometry process. The photometry takes the calibrated working copy of the source frames, detects the objects and measures their brightness and other parameters. Results are stored to separate files, which are called photometry files.

## Activating the dialog

The dialog can be activated:

1. from the main menu: Reduce ‣ Photometry.

2. from the main toolbar:

## Running photometry

Any frame calibration steps (bias, dark, flat and time correction) must be applied before the photometry.

The dialog for starting the photometry

(1) It is possible to apply the operation either on all source files in the project or on the files that are currently selected in the table of input files. This option is useful when you are finding the ideal values of the photometry settings. It is strongly recommended to use a single set of settings for all frames in a set.

Click the “Execute” button (2) to start the operation.

- All calibrations (bias, dark, flat and time correction) must be applied before the photometry.

- The photometry can be applied several times, the old photometry files are overwritten.

## Photometry on aligned frames

If the source frames have been already aligned, for example when they were creating by merging frames, you can alternatively use a special photometry and matching mode.

See also

Match stars (dialog), Express reduction (dialog), Photometry dialog (aligned frames)