Now that the sky has finally cleared and the moon is gone, I can take pictures of the comet again.   Unfortunately, the area where the comet is located is difficult to shoot and heavily light polluted.  I used a new filter to try and help with the light pollution.   Its a Hoya Image Intensifier (Didymium) 72mm for my 200mm F/2.8 lens.  Below is the first image I created with the filter and lens setup.   .

Comet Machholz on 2/4/05. Canon Digital Rebel, 1600 ISO, 200mm F/2.8 (320mm Effective F.L.,) Didymium filter & eight 30 second images stacked in Registax with a single dark-frame subtraction.  After stacking, I made adjustments to levels, color and brightness/contrast.