somewhere around 200-300mm at the top end is great from rc stuff.. I use a 70-200mm lens.. One of the best lenses i used was on a canon, i think it was 35-300mm (or there abouts) which was a perfect range, it meant i could get shots of cars on tables, or views of the track, and then get close up action shots without having to change lenses..
__________________
If your PM doesn't at first succeed - try, try again. I'll reply in the end, honest. 
|