lens hood..whats the difference..

[nikonsiao]

Hi fellow clunsnappers,
Just want to check something, why are some len hood petal shaped and some normal? i noticed that wide angled len have petal shaped. does the convex shape len play a part in the petal shaped hood? thanks

[Amekaze]

Wide-angle lens have the petal-shaped hood (shorter at the sides) so it won't block the view... as for the rest I also don't know le. I'm still very new to all these

[user111]

petal hood is usually for zoom lens. the petal shape is because the original shape is cylindrical which is provides good shading for the long end of the zoom but they have to cut away some parts at the 4 corners to avoid vignetting at the wide end of the zoom ie petal shape is a optimised shape.

[ortega]

it has something to do with the Angle of view and the blocking of the light causing the lens flare. Think about it.

[Zerstorer]

user111 has supplied the answer. A petal shape allows the most shading while avoiding vignetting(compared to a cylinder) and is crucial for wide-angles. Telephotos with their narrow angle of view can just afford to use deep cylindrical ones.

[coldman]

Originally Posted by Zerstorer user111 has supplied the answer. A petal shape allows the most shading while avoiding vignetting(compared to a cylinder) and is crucial for wide-angles. Telephotos with their narrow angle of view can just afford to use deep cylindrical ones.

and i always thought the shape of the hood is dependant on the way the lens work....

front element(lens) turn when focusing = cylindrical
front element(lens) don't turn when focusing = petal

shame on me..

[nikonsiao]

thanks to all for providing the answer to a relatively simple question....

[markccm]

Usually a lens that features an internal focus mechanism will have a petal hood.

A lens that has its external body revolving while focussing uses a cylindrival hood.
An example of such a lens is the Sigma 70-300mm APO Macro II.

[smallaperture]

Originally Posted by coldman and i always thought the shape of the hood is dependant on the way the lens work.... front element(lens) turn when focusing = cylindrical front element(lens) don't turn when focusing = petal shame on me..

All newer lens hood are petal shaped to be more effective than cylindrical.

For zoom lenses, hoods are designed for the wide end only, so, at the longer end, not as effective. Also, the hood is designed for full frame, so, with the FLM, what actually happened to the light outside the sensor? Well, I guess it has got to be absorbed somewhere in the camera.

[espn]

Originally Posted by smallaperture All newer lens hood are petal shaped to be more effective than cylindrical. For zoom lenses, hoods are designed for the wide end only, so, at the longer end, not as effective. Also, the hood is designed for full frame, so, with the FLM, what actually happened to the light outside the sensor? Well, I guess it has got to be absorbed somewhere in the camera.

Sorry, but I got no idea what you're talking about

Can elaborate?