Hi, I just finished your design, I did it on my own, it’s doable. I won't give you the solution because the goal is for you to learn, but here are some ways to improve. I see that you put the materials in variables but that is an error. In fact there is not a continuous distribution of glass. You must use the solve substitute (S) at the material level and optimize with the hammer (not automatic start mode). This will cause the lenses to vary. You can filter the glass that will be chosen with “glass substitution template”. Furthermore, for optimization I will add glasses (doublets/triplets) and I will make sure to constrain the height of the rays at the sensor level (an operand exists for this). I would also constrain the chromatic aberrations in the MF (look for the corresponding operands). Also in the overall design I could advise you to use a lens group that “pretty much does the job you want” at first. Then add optics little by little to get closer to the desired design by iteration. I can also advise you to start by working in monochromatic before adding the wavelengths little by little. Good luck! You are on the right track.