Incense

by Bart Arondson

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

This question already has an answer here:

In the last decade or so, I've seen more and more lens hoods for long lenses that aren't simply round in front. I was reminded of that by this answer, which shows the inside of a neatly packed camera bag. In particularly, here is the telephoto lens from that picture:

In this case, it looks like the lens hood can be detached and flipped backwards on the lens for easier storage.

I thought the point of a lens hood, particular for a long focal length lens, is to shade the lens from angles it's not going to make a picture of anyway. This is useful, for example, for keeping the sun off the front of the lens when you're not trying to include it in the picture. This prevents internal reflections from bouncing around and getting into the picture, even though the sun or other bright light is not actually in the picture.

A round lens hood, like on my old 300 mm lens makes sense for that. So what's the advantage of this tulip-shaped lens hood? Either you want the hood to shade the lens or you don't. As long as it doesn't get in the way of the picture, more is better, right? Presumably the peaks of the tulip don't get in the way of the picture, so how can the cuts in between the peaks be helping?

What am I missing?

share|improve this question

marked as duplicate by mattdm, AJ Henderson, MikeW, Dan Wolfgang, John Cavan Mar 20 at 0:05

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

1  
a picture is worth a thousand words... i.imgur.com/PzNh9rz.png –  dav1dsm1th Mar 20 at 6:30

1 Answer 1

up vote 4 down vote accepted

The tulip shape is designed for the shortest focal length and therefore fore the widest angle that your lens supports.

Look though it with your eye where the camera lens would be and you see that the shape of the hood is -very roughly- a rectangle. Doing so try to imagine how a round shaped hood of the same size would shade the corners of the image.

Thinking this though you will quickly come to the result that such a lens is less than optimal for any of the longer focal length of your zoom lens. It is advisable using a different hood at its long end.

share|improve this answer
    
Thanks. I hadn't realized that the tulip shape actually presents more of a rectangular shadow shape on the image plane. Makes sense now that you point it out. –  Olin Lathrop Mar 19 at 20:15

Not the answer you're looking for? Browse other questions tagged or ask your own question.