They used a device which transported an image of a scene onto the canvas (can’t remeber the name right now, camera obscura maybe?) Teresa were other devices too hat many artists used. Van Gogh used a “drawing aid” in some of his paintings to get perspective right as he struggled with drawing.
The use of drawing aids for art is pretty common- more so,now that folks have computers and photoshop to experiment with- they can even try out different co,or schemes of a scene before committing to canvas.
Yes, the camera obscura. If you had to make a “pinhole camera” to see an eclipse, it’s the same sort of thing. There’s also the theory that the earlier Renaissance painters did things with mirrors, but that’s more controversial.