I had to do a re-calibration of my spectrometer because I took it apart and removed the IR filter underneath the cmos lens (you must very carefully) pick it out with an Exacto knife, then I had to refocus the lens for 152.39mm (6") - Distance from cmos to front face of cuvette holder, and re-align the DVD diffraction grating.

The results are excellent! I have a pretty descent double peak at the green band and a very sharp peak at the second blue band for a quality calibration fit of 7.

The PNG graphic at the top right corner is the actual spectral capture from Plab's spectral workbench 2.0

You can see some very nice pixel resolution, so I think the new metal razor blade slit design is a real winner, it eliminated a lot of aberrations that were caused by the acetate film slits.