I'll be photographing digital at NASS (an extreme sports festival) with my newly invested nikon D70s. I found a great deal on a used sigma HSM 70-200mm 2.8 zoom which will be useful for the indoor skatepark comp but as some of you will know fisheye's are the most commonly used lens for extreme sports. I have a 15mm film fisheye which will give me a focal length of about 22.5mm and will lose some of the fisheye effect. I can afford the nikon digital 10.5mm fisheye but if i get that i won't be able to get the 70-200mm 2.8 zoom. What would be the better lens for the job? Also, my camera will be delivered this week so I haven't had a chance to look at the film fisheye lens on the D70s AND i fear the 70-200mm will sell quick! thanks for your help.