1. The problem statement, all variables and given/known data A spectroscopist has a spectrometer equipped with a grating with 600 grooves/mm. This grating puts a 1228 nm wavelength range on a spectroscopic plate (a CCD) in order m = 5. The spectroscopist now changes the spectroscopic plate CCD by one that is larger by a factor of 3. What spectral range will be accepted when the spectroscopist observes the lines in order m = 4 with the new, larger spectroscopic plate? λ1=1228 d= 1666.67 m1=5 m2=4 λ2=? 2. Relevant equations mλ=dsinθ 3. The attempt at a solution sinθ=[(5)(1228)]/(1666.67)=3.68 However I can't solve for θ, and plug it into another question for m2=4. What step should I do next? So what exactly does the electroscopic plate do?