Why are petal lens hoods that shape

DayDreamer

DayDreamer

Messages
3,739
Name
John
Edit My Images
Yes
As the title really as I am mystified :thinking:
 
It is to let in a rectangle of light, the same shape as the sensor. I could be wrong but I'm sure someone will explain it more if I'm not.
 
because otherwise there would be vignetting in the corners

just look at the sky, then turn your petal hood, as soon as you turn it you will see the 'prongs' of the hood move into the field of view- so this shows us that the notches in the hood are precisely aligned to the corners of the image

this happens on my 30mm 1.4, so maybe it won't happen on your lens



the more telephoto the lens the longer the hood can be, with a wide angle lens obviously the wide field of view can be so wide that it would include the hood, so they have to put notches into the corner to avoid this
 
Last edited:
jonoooo125 said:
It is to let in a rectangle of light, the same shape as the sensor. I could be wrong but I'm sure someone will explain it more if I'm not.
Click to expand...

it's not so much about letting in light as much as it is about blocking light

think about it in reverse, the hood is shaped to allow the sensor to see an unobstructed rectangle of light
 
Last edited:
Thanks Jonooo & mrJ I've learnt something new today(y)

But why is it for my 18-105mm with 67mm filter size I can buy the same type that came with my 35mm 1.8f with no sexy shape just a cylinder:thinking:
 
And I see there are rubber hoods that fold into three different sizes:thinking:
 
DayDreamer said:
Thanks Jonooo & mrJ I've learnt something new today(y)

But why is it for my 18-105mm with 67mm filter size I can buy the same type that came with my 35mm 1.8f with no sexy shape just a cylinder:thinking:
Click to expand...
DayDreamer said:
And I see there are rubber hoods that fold into three different sizes:thinking:
Click to expand...

Hi John

Anything circular is going to be sub optimal unless it's on a telephoto lens.

David
 
Petal lens hoods should not be use on a lens where the end rotates.
 
Terrywoodenpic said:
Petal lens hoods should not be use on a lens where the end rotates.
Click to expand...


Logical I guess but only when I know - which I do now - as long as I don't forget :runaway:
 
minnnt said:
A sexy lens hood... John you need to get out more... :D
Click to expand...

Sex on the brain - not much else to think about when you're retired :LOL:
 
Petal hood is for flower photographers innit?

Real reasons are covered above.
 
You must log in or register to reply here.
Back
Top