How does a HOOD work?

B://

I want to know how the HOOD works, and how beneficial they are. Why is it that petal ones work for wides and why the round ones work for telephotos, or am I wrong? the difference between a shoot with hood and one with out it. Please help me with this question, what's their use?

Thank you very much again

Andy

B:// wrote:

I want to know how the HOOD works, and how beneficial they are. Why is it that petal ones work for wides and why the round ones work for telephotos, or am I wrong? the difference between a shoot with hood and one with out it. Please help me with this question, what's their use?

Thank you very much again

I'm not an engineer but a lens hood will do two things:

1) protect you, to a degree, from lens flare due to harsh light

2) protect your lens, to a degree, against scrapes and dings

Xtopherous

They're used to block glare and flare. The longer round ones (cones) can be used on telephoto lenses because of their small viewing angle. Because wide-angle lenses have...well, wide angles, the petal style was created to block as much outside light as possible without blocking the field of view.

Nikolai

Andy, you forgot one thing...

Andy wrote:

I'm not an engineer but a lens hood will do two things:
1) protect you, to a degree, from lens flare due to harsh light
2) protect your lens, to a degree, against scrapes and dings

3) Protects your camera from breaking when dropped down by HarryB

glovedesigner

I think it also makes your lens look cool!

Andy wrote:

I'm not an engineer but a lens hood will do two things:

1) protect you, to a degree, from lens flare due to harsh light

2) protect your lens, to a degree, against scrapes and dings

Andy

Nikolai wrote:

3) Protects your camera from breaking when dropped down by HarryB

True Story!

Antonio Correia

It is for aesthetic reasons.
Only.

:

Andy

Antonio Correia wrote:

It is for aesthetic reasons.
Only.

:

:nono my friend, I promise you, it's not. Can't tell if you're serious or not but I always recommend using a lens hood.

Antonio Correia

Andy wrote:

:nono my friend, I promise you, it's not. Can't tell if you're serious or not but I always recommend using a lens hood.

Sometimes humour is very difficult to understand... mainly if we belong to different environments and cultures...
Though we have some culture in common...
So, you have thought that I, the portuguese, who owns a 70~200 IS, was so naive to think that hoods existed only for aesthetic purposes ???
I got you !!! rofl

Andy

Antonio Correia wrote:

Sometimes humour is very difficult to understand... mainly if we belong to different environments and cultures...
Though we have some culture in common...
So, you have thought that I, the portuguese, who owns a 70~200 IS, was so naive to think that hoods existed only for aesthetic purposes ???
I got you !!! rofl

Antonio Correia

Andy wrote:

thumb

wxwax

Antonio Correia wrote:

It is for aesthetic reasons.
Only.

:

Yes, only men are allowed to buy lens hoods.

Mongrel

Prosthetics are nothing to laugh about!
"It is for aesthetic reasons.
Only.

: "

In fact prosthetics help people to assume normal lives after devasting and traumatic events. It is almost unthinkable what life would be like for these poor souls without prosthetics!

Prosthetic reasons are perfectly valid in todays society and if a photographer is unfortunate enough to need one, then I say hats off to him or her.

If you, as a photographer decide that you want to go around without your prosthetics, then so be it, but to joke about those photographers that need them well....well....that's just pathetic....


(pssst...."aesthetic" reasons...a-e-s-t-h-e-t-i-c...).....








nevermind.....

Antonio Correia

wxwax wrote:

Yes, only men are allowed to buy lens hoods.

Antonio Correia

Mongrel wrote:

"It is for aesthetic reasons.
Only.

: "

In fact prosthetics help people to assume normal lives after devasting and traumatic events. It is almost unthinkable what life would be like for these poor souls without prosthetics!

Prosthetic reasons are perfectly valid in todays society and if a photographer is unfortunate enough to need one, then I say hats off to him or her.

If you, as a photographer decide that you want to go around without your prosthetics, then so be it, but to joke about those photographers that need them well....well....that's just pathetic....


(pssst...."aesthetic" reasons...a-e-s-t-h-e-t-i-c...).....








nevermind.....

but could not resist.
Yes. You are right. I will not do it again...

ziggy53

B:// wrote:

I want to know how the HOOD works, and how beneficial they are. Why is it that petal ones work for wides and why the round ones work for telephotos, or am I wrong? the difference between a shoot with hood and one with out it. Please help me with this question, what's their use?

Thank you very much again

Maybe it's easier to explain what happens to a lens without a hood. Stray light can hit the lens at an angle that is not conducive to the forming of the image. Instead, this stray light, reduces contrast by adding overall light exposure to the image in the form of flare and glare.

The same thing happens with human eyes, which is why we use our hand or other object to shade our eyes to promote a better view. In the case of our human eye, we can respond knowing where the glare is coming from, and provide a shade where it is necessary.

With a lens, it is better to provide the shade completely around the lens, so the lens is protected from any angle.

Simple lens shades/hoods typically come in two styles: circular and rectangular.

Simple circular hoods are best used on lenses that rotate the front elements of the lens. Rectangular hoods are more effective, and work with lenses whose front elements don't rotate. The shape of the rectangle needs to match the aspect ratio of the image format to be most effective.

"Petal" shaped hoods are a compromise between circular and rectangular hoods, and became popular with zoom lenses, which require a compromise hood to begin with. (The shading requirements at "long" zoom are different than those at "close" zoom. Most zoom hoods only really accommodate the short end.)

In the motion picture and video industries, you often see "bellows" hoods and matte boxes. These are extendable devices that use rails to support, guide and adjust the bellows material. They are used so that the camera operator has a single, consistent solution to multiple lenses, even though the bellows needs adjustment after a lens change.

http://www.cambridgeincolour.com/tutorials/lens-flare.htm
http://forums.dpreview.com/forums/read.asp?forum=1029&message=16718086
http://en.wikipedia.org/wiki/Lens_hood

ziggy53

ziggy53

Mongrel wrote:

...nevermind.....

"Emily Litella"
"What is all this fuss I hear about the Supreme Court decision on a "deaf" penalty? It's terrible! Deaf people have enough problems as it is!"

Endangered Feces
Making Puerto Rico a Steak
Presidential Erections
Pouring Money into Canker Research
The Eagle Rights Amendment
Busting School Children
Conserving our Natural Racehorses
Sax and Violins on Television

---

Good memories Mongrel. Some people aren't going to have a clue...

ziggy53

B://

Thank you everyone, for your information, Andy, Xtopherus, Ziggy53 thanks for the whole explanation, I found all the light behavior logic in it, and sorry, but unfortunately... I'm an engineer, hahaha, thanks.

You know, I'm so happy to know there's a place where I can find and gather all the information I'm looking for, although I'm going to be bothering you more often, so that's not a good news for all of you, hahaha.

Let see, I have a Canon EOS 20D, and I only have one lens, additional to the kit's lens, a Canon EF 24-85mm f/3.5-4.5 USM, and because of the 1.6x factor for the focal lenght I think this lens can't be considered as a hybrid between wide angle and telephoto right? because it's actually a 38-136, even though the 38mm end is not that angled, so, do I need a petal hood for that one? or am I doing a stupid question? hahaha.
I found this site with some paper models to do home-made hoods: http://www.lenshoods.co.uk
I'm going to do some tests to see how they work, because where I'm from (Guatemala), if I need an accessory I need to order it through the internet, and that my friends can take a lot of time.

Another question, what's the best flash for my camera? the Speedlite EX 580? as a master I mean, can I use those ones as slaves too? is there a better flash out there in the market for me? a more recent one?

Thanks for all the help, I'll be checking you soon.

One more thing, hahahaha, for the lenses' nomenclature, for Canon I mean, what's the L stand for?
I know that:
USM = Ultrasonic Motor
IS = Image Stabilizer
L = ?
Any other abbreviations?

THANK YOU :D:D

ziggy53

B:// wrote:

...
One more thing, hahahaha, for the lenses' nomenclature, for Canon I mean, what's the L stand for?
I know that:
USM = Ultrasonic Motor
IS = Image Stabilizer
L = ?
Any other abbreviations?

THANK YOU :D:D

The "official" Canon explanation is that the "L" lens designation is a "Luxury" lens. My own take is that it really stands for, "Less" as in ...

Less money in your pocket,
Less time with the "better-half" when they find out what you spent on a lens,
Less free time, because you want to use these lenses more and more.

They are simply Canon's best line of lenses, not always the best value (although often they are a great value.)

ziggy53

wxwax

ziggy53 wrote:

Simple lens shades/hoods typically come in two styles: circular and rectangular.

Simple circular hoods are best used on lenses that rotate the front elements of the lens. Rectangular hoods are more effective, and work with lenses whose front elements don't rotate. The shape of the rectangle needs to match the aspect ratio of the image format to be most effective.

"Petal" shaped hoods are a compromise between circular and rectangular hoods, and became popular with zoom lenses, which require a compromise hood to begin with. (The shading requirements at "long" zoom are different than those at "close" zoom. Most zoom hoods only really accommodate the short end.)

In the motion picture and video industries, you often see "bellows" hoods and matte boxes. These are extendable devices that use rails to support, guide and adjust the bellows material. They are used so that the camera operator has a single, consistent solution to multiple lenses, even though the bellows needs adjustment after a lens change.

http://www.cambridgeincolour.com/tutorials/lens-flare.htm
http://forums.dpreview.com/forums/read.asp?forum=1029&message=16718086
http://en.wikipedia.org/wiki/Lens_hood

ziggy53

Excellent!

ziggy53

B:// wrote:

... Another question, what's the best flash for my camera? the Speedlite EX 580? as a master I mean, can I use those ones as slaves too? is there a better flash out there in the market for me? a more recent one?...

I expect that the best flash you can buy is the Canon EX 580. It does have some great features. It is the easiest to use, considering all the features. It is built pretty well.

It is also pretty expensive.

You might also consider the Canon EX 550, if you want similar power, with only slightly less utility.

I went with the Sigma 500 DG Super. Similar power to the 550 and similar features to the 580, at about half the price of the 580. It is a little more difficult to use, but not bad, and the construction is not up to the 580 standard, but not bad, and some other minor features are different. It is probably the best overall value, just not the best flash overall.

Some folks see some underexposure under certain circumstances, and I fall into that group. I know when it will happen, and I see it happen, so I just compensate with some FEC. Not a biggee to me.

ziggy53

Raz

If I may, I would like to revive this thread.

Are there any circumstances in which it is not recommended to use the hood? e.g. when using the on board flash on close objects? on gray days? at night?

Thanks
Raz

Pupator

Raz wrote:

If I may, I would like to revive this thread.

Are there any circumstances in which it is not recommended to use the hood? e.g. when using the on board flash on close objects? on gray days? at night?

Thanks
Raz

You don't want to use it in low light situations, whether grey days (if you mean dark grey) or at night. A hood will, in those circumstances, reduce the amount of available light to the camera.

Red Bull

I pretty much always keep a lens hood on my lenses. I can't tell you how many time's my lens hoods have bumped into something and I have gone "phew! I'm glad I had the hood on". They save the front element of the lens from scratches, dust, fingerprints, etc.

ziggy53

Raz wrote:

If I may, I would like to revive this thread.

Are there any circumstances in which it is not recommended to use the hood? e.g. when using the on board flash on close objects? on gray days? at night?

Thanks
Raz

The only time I would not recommend using a lens hood is when using filters in front of the lens, and then a hood in front of that. The lens hood/shade can vignette the image in that situation. It's not a problem when the hood couples via its own bayonet mount, which is how most modern lenses work.

ziggy53

Andy

ziggy53 wrote:

"Emily Litella"
"What is all this fuss I hear about the Supreme Court decision on a "deaf" penalty? It's terrible! Deaf people have enough problems as it is!"

Endangered Feces
Making Puerto Rico a Steak
Presidential Erections
Pouring Money into Canker Research
The Eagle Rights Amendment
Busting School Children
Conserving our Natural Racehorses
Sax and Violins on Television

---

Good memories Mongrel. Some people aren't going to have a clue...

ziggy53

I miss her :cry

claudermilk

Raz wrote:

If I may, I would like to revive this thread.

Are there any circumstances in which it is not recommended to use the hood? e.g. when using the on board flash on close objects? on gray days? at night?

Thanks
Raz

The only situation I've run into is using onboard flash with a UWA. You DO get a nasty hood-shaped shadow. I have had no trouble with using one any other time--overcast days, night, even darker theaters. I haven't seen that the metering changes enough to worry about.

jdryan3

Andy wrote:

I miss her :cry

And she was married to Gene Wilder! Tell me that wasn't a fun house to be in. I understand he adored her.

Harryb

Nikolai wrote:

3) Protects your camera from breaking when dropped down by HarryB

Actually that was a scientific test to study how high an 828 would bounce. I was kind of disappointed that it had very little bounce to it. Andy did demonstrate quite a bit of "bounce" though.