purpose of a hood?

ABCapturesABCaptures Registered Users Posts: 134 Major grins
edited January 14, 2008 in Accessories
ya know those black things you attach to the end of your lens' whats the purpose behind them? is it something (im shooting equine jumping/eventing) that would be helpful?
Hi, I'm Ashley
*Love every creature*
Gear: Canon Rebel XTi 18-55mm & 75-300mm





Comments

  • bkatzbkatz Registered Users Posts: 286 Major grins
    edited January 5, 2008
    The purpose of the hood is to prevent flares from the sun or a sharp light that can cause spots etc in the lens that will show up in the pictures. If you are outside and the sun is at a certain angle you will see these spots or flares across the picture. A hood can keep that from happening.
  • rpcrowerpcrowe Registered Users Posts: 733 Major grins
    edited January 5, 2008
    A hood is helpful (mandatory) for almost any shooting...
    The hood serves a dual purpose:

    1. It shields your lens from reflections and flare caused by light striking it. Any photography will benefit from using a hood.

    2. It protects your lens from dust, dirt, fingerprints and foreign object damage. As an example, I recently stumbled and landed (I weigh 220#) on my camera with the lens hood hitting concrete. The lens hood was damaged but the lens wasn't hurt (cheap insurance).

    I use screw-in, round metal hoods for most of my lenses (except for ultra wide lenses). I think that they (especially with 1.5x or 1.6x sensors) do a better job protecting the lens from light and damage than do most OEM hoods (especially Canon types). These hoods also make using a CPL filter much easier because you can rotate the entire hood as you rotate the filter. The hoods are also very inexpensive.
  • TommyboyTommyboy Registered Users Posts: 590 Major grins
    edited January 5, 2008
    +1 to most of the above.

    Storing your hoods (reversed) on your lenses increases (sometimes substantially) the diameter of the lens. Make sure your bag/case will store the lenses with hoods attached.

    FWIW, I've made it a life-long habit to use lens hoods on all my lenses.
    "Press the shutter when you are sure of success." —Kim Jong-il

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  • TommyboyTommyboy Registered Users Posts: 590 Major grins
    edited January 5, 2008
    rpcrowe wrote:
    I use screw-in, round metal hoods for most of my lenses (except for ultra wide lenses). I think that they (especially with 1.5x or 1.6x sensors) do a better job protecting the lens from light and damage than do most OEM hoods (especially Canon types). These hoods also make using a CPL filter much easier because you can rotate the entire hood as you rotate the filter. The hoods are also very inexpensive.

    This is very intriguing. May I ask a few questions?

    1. If the manufacturer does not produce them, where do you find screw-in metal lens hoods that match the specific properties of a given lens?

    2. How is it even possible that a metal hood would do a better job than a plastic hood in protecting against reflections? The physics doesn't bear out.

    3. Plastic "clip-on" lens hoods can be knocked off if the lens is banged hard. A metal lens hood would be far more likely to damage the filter threads, would it not?

    4. If you use a screw in hood with filters, doesn't that alter the equation? Either the hood or the filter will be moved farther from the outer lens surface than intended, right?

    5. Why would one use a hood and a CPL filter? A CPL filter accomplishes largely the same function (though not entirely) that a hood does by actually controlling the light, for lack of a better phrase. Nikon used to make a hood for their polarizers (or maybe still do), but that idea never seemed to catch on. . . .

    6. A metal screw-in hood can't be reversed on a lens, making storage a problem, no? I can't speak for others, but I never seem to have spare room in my bags.

    I don't mean to be contrary or accusatory; my questions are genuine. I sold cameras for 20 years and nearly always sold the OEM hoods, even when those ridiculous collapsible rubber hoods were so popular. For a lens hood to be maximally effective, it must be designed for that specific lens, or in some cases for a small group of nearly identical lenses. My fear in advising people away from OEM hoods is that they will get the entirely wrong hood or, best case, not achieve maximum results.

    I'd be interested to read your reply.

    P.S. I use all Canon hoods and they're great, with the notable exception of the ET-65III for the 85 f/1.8. I hate the way that hood attaches. All the others are bayonet mount: quick, easy, secure.
    "Press the shutter when you are sure of success." —Kim Jong-il

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  • ziggy53ziggy53 Super Moderators Posts: 23,764 moderator
    edited January 5, 2008
    Tommyboy wrote:
    This is very intriguing. May I ask a few questions?

    1. If the manufacturer does not produce them, where do you find screw-in metal lens hoods that match the specific properties of a given lens?

    2. How is it even possible that a metal hood would do a better job than a plastic hood in protecting against reflections? The physics doesn't bear out.

    3. Plastic "clip-on" lens hoods can be knocked off if the lens is banged hard. A metal lens hood would be far more likely to damage the filter threads, would it not?

    4. If you use a screw in hood with filters, doesn't that alter the equation? Either the hood or the filter will be moved farther from the outer lens surface than intended, right?

    5. Why would one use a hood and a CPL filter? A CPL filter accomplishes largely the same function (though not entirely) that a hood does by actually controlling the light, for lack of a better phrase. Nikon used to make a hood for their polarizers (or maybe still do), but that idea never seemed to catch on. . . .

    6. A metal screw-in hood can't be reversed on a lens, making storage a problem, no? I can't speak for others, but I never seem to have spare room in my bags.

    I don't mean to be contrary or accusatory; my questions are genuine. I sold cameras for 20 years and nearly always sold the OEM hoods, even when those ridiculous collapsible rubber hoods were so popular. For a lens hood to be maximally effective, it must be designed for that specific lens, or in some cases for a small group of nearly identical lenses. My fear in advising people away from OEM hoods is that they will get the entirely wrong hood or, best case, not achieve maximum results.

    I'd be interested to read your reply.

    P.S. I use all Canon hoods and they're great, with the notable exception of the ET-65III for the 85 f/1.8. I hate the way that hood attaches. All the others are bayonet mount: quick, easy, secure.

    I'm not the poster that you originally refer to but I may have some insight.

    The original manufacturer lens hoods for full frame lenses are usually designed for the specific properties of that lens on a full frame camera.

    On a crop camera, the lens has a narrower field of view, and could benefit from a lens hood that likewise is smaller in diameter. Canon has a chart showing which hood is appropriate for many of its lenses, depending upon full-frame or crop camera application. I'll try to find the chart and post a link here.

    Polarizing filters work completely differently and do not eliminate the need for a hood.

    In addition to light which might cause flare, a proper lens hood will also eliminate light coming at strong angles accross the lens front surface which reduces contrast.

    I too am wary of screw-on hoods in addition to filters. In conjuntion with a wide-angle lens you can get vignetting in the corners. With the longer telephoto lenses this is less of a problem.

    Matching hoods to specific lenses, especially zoom lenses, can be challenging to say the least. What works at the longer focal lengths might be way too restictive for the wide-angle portion of a zoom.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • ABCapturesABCaptures Registered Users Posts: 134 Major grins
    edited January 5, 2008
    perhaps im not saying it right... not the lens cover/uv filter/glass that goes over the lens/exc...i have one of those on each of my lens for security of the glass itself.. i meant the black thing that sticks out off the lens, i believe it shields the lens from excess sunlight
    Hi, I'm Ashley
    *Love every creature*
    Gear: Canon Rebel XTi 18-55mm & 75-300mm





  • ziggy53ziggy53 Super Moderators Posts: 23,764 moderator
    edited January 5, 2008
    ABCaptures wrote:
    perhaps im not saying it right... not the lens cover/uv filter/glass that goes over the lens/exc...i have one of those on each of my lens for security of the glass itself.. i meant the black thing that sticks out off the lens, i believe it shields the lens from excess sunlight

    That is a "lens hood", sometimes described as a "lens shade".

    To see how it works (primarily), mount the camera on a tripod and put a strong flashlight on a table or sill, propped so that the light from the flashlight shines directly onto the lens (without the hood attached).

    Swing the camera on the tripod until the light from the flashlight shines into the corner of the lens. Now move the camera so that the lens is at right angles to the light. You should see a rather dramatic difference between the two positions, especially with many complicated zooms.

    Now mount the lens hood and repeat the experiment. The lens hood should allow a greater degree of swing before the lens glare becomes objectionable, because it is shading some of the light from entering the front of the lens.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • ABCapturesABCaptures Registered Users Posts: 134 Major grins
    edited January 5, 2008
    I dont have one.. i was just curious if its something worth picking up for my camera (would it be used on the 75-300mm?) tough to do your experiment without it :ivar
    Hi, I'm Ashley
    *Love every creature*
    Gear: Canon Rebel XTi 18-55mm & 75-300mm





  • ziggy53ziggy53 Super Moderators Posts: 23,764 moderator
    edited January 5, 2008
    ABCaptures wrote:
    I dont have one.. i was just curious if its something worth picking up for my camera (would it be used on the 75-300mm?) tough to do your experiment without it :ivar

    Gotcha.

    Yes, a hood is almost always a benefit.

    1) Preventing, or reducing, glare from stray light, no matter the orientation.
    2) Preventing damage to the front surface of the lens through physical contact.
    3) Reducing the amount of dust that accumulates on the front surface of the lens. (It does this by providing a relatively "dead air" space in front of the lens.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • TommyboyTommyboy Registered Users Posts: 590 Major grins
    edited January 5, 2008
    ziggy53 wrote:
    The original manufacturer lens hoods for full frame lenses are usually designed for the specific properties of that lens on a full frame camera.

    On a crop camera, the lens has a narrower field of view, and could benefit from a lens hood that likewise is smaller in diameter. Canon has a chart showing which hood is appropriate for many of its lenses, depending upon full-frame or crop camera application. I'll try to find the chart and post a link here.

    Polarizing filters work completely differently and do not eliminate the need for a hood.

    In addition to light which might cause flare, a proper lens hood will also eliminate light coming at strong angles accross the lens front surface which reduces contrast.

    As usual, Ziggy, you've given me a great deal to think about.

    Although I understand clearly the impact of a crop sensor on the apparent focal length of the lens, I still have a hard time wrapping my mind around some of the minutiae surrounding its secondary and tertiary effects.

    Thank you for clarifying. I did a preliminary search for that chart. If you can find it, I would love to see it.
    "Press the shutter when you are sure of success." —Kim Jong-il

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  • TommyboyTommyboy Registered Users Posts: 590 Major grins
    edited January 5, 2008
    Here's a linky to once chart. I can't speak to its authenticity, and--predictably--it considers only a handful of lenses.
    "Press the shutter when you are sure of success." —Kim Jong-il

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  • Art ScottArt Scott Registered Users Posts: 8,959 Major grins
    edited January 5, 2008
    A lot of REAL camera stores (not Best Buy, Ritz or others of this genre) will have lens hoods for sale....I prefer hard rubber because if I drop the camera and it goes lens first the rubber actually acts like a shock absorber, metal lens hood will save the glass but since it is hard metal it can still allow damage to the inner workings of the lens....the plastic ones that come with your prize lens are junk as far as actual lens protections goes, they are brittle and will break in a quarter of a heart beat......I make it a point to go into the olde camera stores and rummage thru their "hood" boxes just to see if their is an exta one that will fit any of my current lenses......and last but not least the collaspable hoods are junk also{at least the ones I have been running into}, it takes no time at all for thses made to day to start splitting out and leaking light, a hundred or so years ago collapsable hoods was all I used but they got to be cheaply made and do not work well at all.

    There should be a hood on every lens and any hood is better than no hood at all.............
    "Genuine Fractals was, is and will always be the best solution for enlarging digital photos." ....Vincent Versace ... ... COPYRIGHT YOUR WORK ONLINE ... ... My Website

  • swintonphotoswintonphoto Registered Users Posts: 1,664 Major grins
    edited January 5, 2008
    I had a hood save my camera and lens on a shoot about 2 years ago. I was doing an in-studio shoot and had my camera sitting on a table I have right below one of my strobes. A little kid went running to the back of the studio and tripped on the sync cord between my camera and the strobes. My camera fell to the ground (I have concrete floors in my studio) and landed at an angle on the lens hood and the hotshoe adapter on top of the camera. I damaged the hood and the hotshoe adapter, but no problems to the camera or the lens. I always use a lens hood. And I also never keep my camera sitting while connected to the cord either.
  • jaysonmcjaysonmc Registered Users Posts: 3 Beginner grinner
    edited January 5, 2008
    One other thing, a hood will often times increase contrast significantly, thus providing a better image overall. Imagine standing under a shaded tree in the middle of the afternoon versus being out in broad daylight.
  • PhotoskipperPhotoskipper Registered Users Posts: 453 Major grins
    edited January 6, 2008
    download lens hoods
    I put the lens hood on my lens all the time to avoid flare and protect the front lens.

    it may make the lens and camera look great (the size matter)

    If you want something cheap and disposible, try the website www.lenshoods.com.uk they have very wide range of lens hood design which you can download and print on either B4 or A4 size then cut it out from the cardboard or black plastic sheet to roll it up as the temparory lens hood.

    You may need some time to learn how to do it right and how to attach on the lens without falling out.

    Good luck!
    Photoskipper
    flickr.com/photos/photoskipper/
  • rpcrowerpcrowe Registered Users Posts: 733 Major grins
    edited January 10, 2008
    I think that everyone agrees that hoods are good ideas..
    However, I still state that I personally prefer the round metal screw-in hood to the canon type hoods except in the case of very wide lenses. I use a Canon OEM hood on my 17-55mm f/2.8 IS lens and a Tokina OEM Hood on my 12-24mm Tokina because at the wider focal lengths, these lenses will vignette with round hoods.

    1. If the manufacturer does not produce them, where do you find screw-in metal lens hoods that match the specific properties of a given lens?

    The size of a screw-in metal hood is determined by the filter size. There are deeper hoods that are designed for tele lenses as well as slightly more shallow hoods designed for wide angle lenses. I have had no problems using a normal size metal hood with my 24-70mm f/2.8L or my 28-135mm f/3.5-5.6 IS lenses and of course there is no problem using a round filter on the 70-200mm f4L IS lens. As I mentioned above, I do use OEM hoods for my 17-55mm and 12-24mm lenses due to vignetting at the wider angles.

    2. How is it even possible that a metal hood would do a better job than a plastic hood in protecting against reflections? The physics doesn't bear out.

    It is not the material that makes the difference, it is the size and configuration of the hood. All my lenses are full-frame capable except my 17-55mm f/2.8 IS lens. Canon produces lens hoods for these lenses of a size that will not vignette on a full frame camera. IMO, they are overkill on 1.6x cameras and being larger as well as having a butterfly shape could allow more light/foreign object penetration. I can tell you that the round metal hoods will not vignette the image on a 1.6x camera using any of the following lenses 24-70mm and 28-135mm. I havent tried sticking finger prints on lenses using either round or OEM hoods but, if I wanted to - it seems like it would be easier on an OEM hood.

    3. Plastic "clip-on" lens hoods can be knocked off if the lens is banged hard. A metal lens hood would be far more likely to damage the filter threads, would it not?

    I won't speculate on this one. I will describe an actual incident. I fell on concrete and landed on my lens. My 220 pound plus body ruined the metal hood but, the lens was not damaged a bit. If you want to me to try that with a Canon lens hood, please send me your camera, your lens and your hood and I will replicate the accident and tell you which of the hoods protected the lens better. As a courtesy, I will do this at no charge except for the price of returning your lens or what is left of it.

    4. If you use a screw in hood with filters, doesn't that alter the equation? Either the hood or the filter will be moved farther from the outer lens surface than intended, right?

    I have never had a problem with that. In fact, the moving of the lens hood with the filter should prevent flare on the filter.

    5. Why would one use a hood and a CPL filter? A CPL filter accomplishes largely the same function (though not entirely) that a hood does by actually controlling the light, for lack of a better phrase. Nikon used to make a hood for their polarizers (or maybe still do), but that idea never seemed to catch on. . . .

    You are absolutely wrong in the assumption that a hood and a CPL accomplish the same effects. Gosh, if you sold camera gear for twenty years, you should have learned that CPL and Hoods do not do the same thing.

    6. A metal screw-in hood can't be reversed on a lens, making storage a problem, no? I can't speak for others, but I never seem to have spare room in my bags.

    Most metal hoods can be reversed, however I never do... I want my lens ready to use when I am carrying it - that means being equipped with the hood. By the way, I also carry my lenses mounted on two or more camera bodies. The much larger diameter Canon hoods take up a lot of room - not in length but in diameter. To me a camera in a bag without a lens is not a very practical way to carry equipment if you need to use it quickly. Also, I would not use a lens without a hood - period. That is outdoors or indoors.

    I don't mean to be contrary or accusatory; my questions are genuine. I sold cameras for 20 years and nearly always sold the OEM hoods, even when those ridiculous collapsible rubber hoods were so popular. For a lens hood to be maximally effective, it must be designed for that specific lens, or in some cases for a small group of nearly identical lenses. My fear in advising people away from OEM hoods is that they will get the entirely wrong hood or, best case, not achieve maximum results.

    Hoods are not exactly brain surgery. I have used round hoods for 50 years (although I often used square hoods with 6x6 format cameras) with no problems that they are not specifically designed for each lens. However, if I were in the camera sales business I would certainly want prople to buy the OEM hood rather than a less expensive generic hood. Heck, recommending less expensive equipment would cut into profits. By the way, I have never liked the collapsable rubber hoods either!

    I'd be interested to read your reply.

    P.S. I use all Canon hoods and they're great, with the notable exception of the ET-65III for the 85 f/1.8. I hate the way that hood attaches. All the others are bayonet mount: quick, easy, secure.

    Many Canon hoods recommended for lenses by Canon are larger than required on a 1.6x camera since they were designed for full frame formats. There is a cross reference which will tell you which Canon hoods can be substituted for the full frame hoods on each lens when you are using 1.6x cameras. So much for the critical design of a hood for each lens. However, the main reason I dislike the Canon hood style is that the use of a CPL is very difficult. In fact, if you read the manual that comes with the 28-135mm lens, it states that the OEM recommended hood cannot be used with a CPL. And I reiterate - a hood and a CPL do not accomplish the same things.

    I wish that Canon would have incorporated a sliding intergral hood in their 70-200mm series "L" lenses like they have on the 400mm f/5.6L lens. That sliding hood is a joy to work with. i realize that size constraints would prevent using the retractable style hood on any but tele leses, but it seems ther would be enough space for one on the 70-200mm (f/4 or f/2.8) series lenses.
  • jcdilljcdill Registered Users Posts: 225 Major grins
    edited January 11, 2008
    ABCaptures wrote:
    ya know those black things you attach to the end of your lens' whats the purpose behind them? is it something (im shooting equine jumping/eventing) that would be helpful?

    I use a hood on my lens at all times, especially when I'm shooting equestrian sports. It can be a hassle if I'm using a circular polarizer to constantly remove the hood to adjust the filter, but I do it anyway. (I put my wrist thru the hood and wear it like a bracelet while I'm adjusting the polarizer.)

    1) The hood blocks sunlight from hitting the front elements of your lens and causing flare on your images.

    2) The hood helps protect your lens from flyng dirt from the horse's hoofs as they gallop past.

    3) The hood also helps keep dust from wafting in and landing on the front element (or filter - I always use a filter).

    4) The hood protects the front of the lens from being damaged as you move about. I've knocked the lens end of the camera on a fence, on a post, on a chair, etc. My lens hoods have a lot of scars, one has a slightly dinged edge. I'm glad all that damage happened to a cheap and easily replacable hood, not to my expensive lens.

    Tip: When you are near the ring and the horse goes galloping by, tip your camera down and away from the horse so that flying dirt and gravel doesn't fling directly at your lens. Even with a hood, it's still a good practice to always aim the lens away unless you are actually shooting the horse at the moment. (If you want that shot of dirt and gravel being flung in your direction from the horse's hoofs, use a good filter and be ready to replace it!)
    JC Dill - Equine Photographer, San Francisco & San Jose http://portfolio.jcdill.com
    "Chance favors the prepared mind." ~ Ansel Adams
    "Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it." ~ Terry Pratchett
  • claudermilkclaudermilk Registered Users Posts: 2,756 Major grins
    edited January 14, 2008
    jcdill wrote:
    Tip: When you are near the ring and the horse goes galloping by, tip your camera down and away from the horse so that flying dirt and gravel doesn't fling directly at your lens. Even with a hood, it's still a good practice to always aim the lens away unless you are actually shooting the horse at the moment. (If you want that shot of dirt and gravel being flung in your direction from the horse's hoofs, use a good filter and be ready to replace it!)

    This would be a good example of when using a protective filter is a good idea. :D
  • Van IsleVan Isle Registered Users Posts: 384 Major grins
    edited January 14, 2008
    The primary reason for a lens hood is to boost contrast by (striving) to allow only the light that you want in the shot in through the lens elements, and not those funny blues from that building off to your right, or that orange from that sodium light above the bus stop behind you, etc.

    A (close) secondary reason is to reduce risk of lens flare, which is what can happen when a strong singular source of light enters the lens and reflects and bounces all around in those guts.

    Protection of lens, filters, from dust, getting knocked about, etc, are tertiary benefits.

    I use mine all the time unless I am in a situation where the hood causes a shadow if I am using my on-camera speedlight. I even pack my camera in my bag with the hood on; I believe it helps prevent the cap getting knocked off while jumbled in my shoulder bag.

    VI
    dgrin.com - making my best shots even better since 2006.
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