Measure Solar Features Measure the size of features on the Sun from your own imagesUpload an image of the Sun and measure the physical size of solar features such as sunspots and prominences using your imaging equipment's plate scale and the Sun's apparent diameter on your observation date. Plate Scale: (Pixel Size / Focal Length) × 206.265 × Binning
Upload a solar image below, then use the Line tool to draw a measurement line across a feature, or the Circle tool to draw a circle around a feature. The size of each annotation will be shown in kilometres and miles. Click any annotation to remove it. Circles can be repositioned by dragging.
Please note: All measurements are approximations. Results may be affected by the accuracy of your observation date, manufacturing tolerances in your telescope optics, the precision of your line or circle placement, and any image processing (cropping or resizing) applied to the image after capture.
