OpticalInstruments

Telescopes

https://www.physicsforums.com/attachments/astronomical-telescope-diagram-jpe.184425/

Look at where the focal points are relative to each other

http://www.a-levelphysicstutor.com/optics-telescs.php#reflecting

Terrestrial (pirate) telescopes

http://www.a-levelphysicstutor.com/optics-telescs.php#terr

Microscopes

http://www.meritnation.com/ask-answer/question/how-to-draw-compound-microscope-ray-diagram-step-wise-how-t/ray-optics-and-optical-instruments/925678