Most times I make a screen shot using my ancient PaintShop Pro 10 program and do minor stuff like cropping, etc.
If I want to make a larger image, then I'll "Save As" in PNG format. The Height & Width for PNG will go up 8,000 pixels, but I don't post those here.
As for rendering, I basically use "Quality / LightWorks / Raytrace Full"; as it's the fastest (uses all the cores/threads available).
Designer, Deluxe, (Professional, Expert, Basic), Platinum
Windows 10 Pro (1803), 64-bit