A diverging lens with a focal length F1 = -15 cm is placed between the light source and the telescope at a distance h = 85 cm from the source. Where in the gap between the source and the diverging lens should a converging lens with a focal length of F2 = 16 cm be placed so that the light source is visible sharply through a tube set to infinity? At which of the possible positions of the lens will the image in the tube have the largest angular dimensions?

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