My buddy has a problem with Siril on his Mac. After stacking, he sees the typical image with all the stars in the Siril preview. For stretching he would like to use Photoshop and so he saves the stacked image as a 16bit TIFF. The TIFF file has a size of about 120MB. When we open the image on a Mac or Windows computer, no image information is visible in the histogram. The image is 100% black. Do you have any idea why this is happening?