After all the snow another clear night at last....With a bright moon due I decided to stay with M1 and get as many 4 minute subs as I could before the extra illumination became a problem. This time I used the CLS filter and got 25 exposures off before the subs were noticeably getting lighter. The best 15 were selected and combined in Deep Sky Stacker. Together with the modified camera I was more impressed with the performance of the filter than I had been previously when I tried it on M27. The subs were a more natural looking blue compared to the very greenish tinge that had occurred with the the unmodded camera and it made a change to actually be able to boost the red balance for the first time....a real feeling of making some progress against the MK lights! Details: modified 450D +Astronomik CLS filter @ iso 400. 15x 240second exposures in DSS, CS2 + Nebulosity.