Why do Leica lenses have vented hoods?

Years ago, there was a radio show called "The Goon Show", starring Spike Milligan, Harry Secombe, Peter Sellers (and others). I seem to recall one episode in which the character Bluebottle discovers a hole in Ned Seagoon's trouser leg. "Whats this hole for?" "It's for looking through!"

Same concept applies to vented hoods. The hole allows you to (partly) see through that section of the hood, which would otherwise obscure part of the viewfinder frame! Elementary, my dear Watson! (Another literary misquotation.)
 
lubitel said:
... I think its so that it doesnt block your view through the VF as much.
Yes, that's it. And it's not true that only Leica had such hoods. The Canon 50/1.2 has a giant vented hood, as well as the Nikon 50/1.1 (which was even more giant). Smaller lenses/hoods do not intrude in the viewfinder frame, that's why most Nikons/Canons lenses had unvented tubular or conic hoods.
Didier
 
Didier said:
Yes, that's it. And it's not true that only Leica had such hoods. The Canon 50/1.2 has a giant vented hood, as well as the Nikon 50/1.1 (which was even more giant).

Or you can get one machined.

(sorry, webcam)
 

Attachments

  • 圖片 012.jpg
    圖片 012.jpg
    3.8 KB · Views: 0
  • 圖片 010.jpg
    圖片 010.jpg
    11.2 KB · Views: 0
  • 圖片 011.jpg
    圖片 011.jpg
    9.8 KB · Views: 0
When you lens is a certain size, a close hood would block the VF and the RF window, a 80mm-ish hood on the big canon lens would block the RF window.
 
They are vented for photographer comfort in hot climates. They actually built a small A/C unit too--but it's hell on the meter battery.
 
Bosk said:
I ask because I haven't seen any vented hoods on Nikon/Canon/Pentax lenses, and I'm wondering what the rationale behind the design is. Thanks.

Well obviously it's because Leica lenses are smoking hot 😀, and to see through.

Todd
 
kshapero said:
So if the lens hood is vented to allow the eye to see the subject, doesn't that also allow light thru and negate the reason to have a lens hood?

Ligth coming from the back of the lens will do no harm to the picture nor will reach the front of the lens.
Strong light coming from out of the lens viewing area but reaching the front lens anyway, would be refracted by the same front element and sent into the lens barrel, where it can produce unwanted reflections.

Usually this reflection shows up with the iris shape in the neg. or a strong decrease in picture quality.

Ernesto
 
Leiz lenses are "hot", so any cooling system is useful. Like a efficient radiator in a Mercedes cabrio. Oh well, I am trying ....


Raid
 
The vented hood for my Hexanon 35/2 has a very nice feature. Once it is screwed on tight to the lens it can be pivoted back about a quarter turn without unscrewing, to allow perfect positioning of the hood.


.
 
Well, i like the airflow/go faster/hot lens/radiator theory best.....:angel:
But i confess that my first thought when i looked the question was that the vents helps the lens to stop the image ... like in ventilated brake disks....😎
 
RayPA said:
The vented hood for my Hexanon 35/2 has a very nice feature. Once it is screwed on tight to the lens it can be pivoted back about a quarter turn without unscrewing, to allow perfect positioning of the hood..
Thoughtful design. I've replaced any vented hoods I have with regular hoods from heavystar. I think RF cams should be small if possible... 🙂
 
Back
Top Bottom