On Sat, 1 Feb 2003 18:27:50 -0600, you wrote: > >I want to put a hood on my FA 100/2.8 macro, 58mm filter thread (I get >aperture ghosts that I don't want). Is there any rule of thumb that >will give me the numbers to evaluate suitable hoods? > >Dan Scott
Someone on PDML mentioned a site which went into great detail about hoods. I've lost the URL. I think the rule of thumb for 35mm lenses is to use the hood which will mask all light except that entering the angle of view for that focal length. The angle of view of a 100mm lens is 13.7 degrees vertical and 20.4 degrees horizontal. Since the film area is a rectangle, a perfectly sized tulip hood masks the most light without vignetting. Nikon hoods are listed at http://www.geocities.com/rick_housh/camera/nikon/lenshoods.html The HS- 4 hood for the 105/2.5 135/3.5 105/4.0 won't work because it is 52mm filter size. But it hints at a size Nikon thinks is appropriate for a tubular hood - 69mm in diameter, and 57mm long. The Canon site at http://www.usa.canon.com/eflenses/accessories/ shows pictures of the Canon hoods, but no measurements. The ET-67 hood for the Canon 100/2.8 Macro should be a good size. The lens is 58mm filter threads, but I don't know if the hood screws in or bayonets on. The hood for the Pentax 80-320 and 100-300 might work. Filter Size: 58mm Lens Hood: 38701 RH-A58. The only other Pentax hood I know about which might work is the nicely made metal hood for the Takumar-Zoom 1:4.5 85-210. It actually looks great on my FA 100/2.8 Macro, and does not vignette looking through the finder of an LX even at 1:1 magnification.. -- John Mustarde www.photolin.com
