Hi Peter,
Moving the grating closer to the camera shortens the length of the spectrum. You can calculate the effect using the on line calculator.
http://www.patonhawksley.co.uk/calculator/
You may find that you cannot get the SA200 close enough to the camera sensor when mounted on the camera nosepiece. The SA200 is designed to be used close to the sensor, for example in a filter wheel, not on a camera nosepiece. The best model to use for this application is probably the SA100. You can use the calculator to decide which model is best
Robin