> the 105 micro Nikkor loses 2 stops of light at 1:1, becoming a 105/5.6. We need to put an end to the assumption that Micro-Nikkors maintain their focal length when extended to 1:1. From my upcoming Nikon Lens Guide (Field Guide, Flash Guide, Lens Guide, when will he stop?): At 1:1 focal length is approximately 74mm For the 60mm, at 1:1, the true focal length is about 49mm. For the 200mm, at 1:1, the true focal length is about 102mm. > The 200/4, however does not lose any light, due to its IF construction, and remains an f/4 lens at 1:1 Sorry, but due to the extension involved, it loses slightly over a stop of light at 1:1 (Moose says 1 1/3 stops). Thom Hogan Executive Editor, BACKPACKER Magazine author, The Nikon Field Guide (Silver Pixel Press) www.bythom.com
