Lens hood: "Must-have" or "ornament"?

[photobug]

I recently acquired a Canon 28-135 IS lens for my 10D.

Some places seem to push a lens hood for such a lens; I can see
where they could be useful in situations where there's a bright light
just outside of the lens's angle of view, but I've never dealt with a
lens hood before -- so here are my questions:

1) Is a lens hood (at least for this type of lens) a must-have,
or a relatively functionless lens ornament?
If it's a "must-have", why?

2) If I should get a lens hood, do I need to get a fancy $25 Canon
hood (the kind with "petals"), or is a simpler/cheaper
extending "accordian"-type hood just as useful?

[cmr164]

I recently acquired a Canon 28-135 IS lens for my 10D.

Some places seem to push a lens hood for such a lens; I can see
where they could be useful in situations where there's a bright light
just outside of the lens's angle of view, but I've never dealt with a
lens hood before -- so here are my questions:

1) Is a lens hood (at least for this type of lens) a must-have,
or a relatively functionless lens ornament?
If it's a "must-have", why?

2) If I should get a lens hood, do I need to get a fancy $25 Canon
hood (the kind with "petals"), or is a simpler/cheaper
extending "accordian"-type hood just as useful?

1. A lens hood is a must-have for pretty much any lens because of flare (http://www.usa.canon.com/eflenses/lens101/glossary/index_d.html).

2. The petals on the fancy canon hood are precisely the length to give the best protection from flare without causing vignetting. A circular hood will either allow more flare or will cause vignetting in the long axis.

[GREAPER]

I also believe a lens hood gives just a bit more protection for your lens glass or even the filters you have on it. It is much harder to bump the lens glass against something with the hood on.

It does make using a polorisor more dificult.

[zero-zero]

While both replies are spot-on, keep in mind that a lens hood is only perfect when it is specifically matched to a fixed lens (i.e. a 135 mm lens with a 15 degree hood, and so on).

With a wide-range zoom, the hood must be kept only as deep as the wide end of the lens will allow to preclude vignetting, so the tele end of your lens could use a way longer hood - a "28" hood on a 135 is almost useless.

That said, I'd rather have some protection than none at all.

[cmr164]

While both replies are spot-on, keep in mind that a lens hood is only perfect when it is specifically matched to a fixed lens (i.e. a 135 mm lens with a 15 degree hood, and so on).

With a wide-range zoom, the hood must be kept only as deep as the wide end of the lens will allow to preclude vignetting, so the tele end of your lens could use a way longer hood - a "28" hood on a 135 is almost useless.

That said, I'd rather have some protection than none at all.
With the Canon 28-70L the deep hood is fixed to the barrel and the lens does the opposite of what one expects by extending as it is zoomed wider and retracting as it is zoomed longer. The allows the lens to keep a proper relationship to the hood length for each focal length. Even a slight familiarity with optics allows me to see this as a fantastic example of optical design and engneering.

[photobug]

Thanks to all who replied to this thread -- as a direct result of your comments, I now have a Canon lens hood on order.

[gus]

Thanks to all who replied to this thread -- as a direct result of your comments, I now have a Canon lens hood on order.


CAN YOU STOP SHOUTING THEN

[wxwax]

CAN YOU STOP SHOUTING THEN
What that's you say? :rofl :rofl

[photobug]

CAN YOU STOP SHOUTING THEN

Geeeeeeeez ... no one shouted (used ALL CAPS) except the above poster!

If you're referring to the font size, I just up-sized it by one stop so that the darned posting was readable. The default DGrin font size is rendered in tiny type by my Netscape 7 browser at both home & work, so I assumed that it was also small for everyone else.

I'll give up on making it readable for myself (apparently deluding myself, thinking I was also helping others) and accept that others either have better eyes than me or a browser that renders the default font for DGrin in a physically larger size...

[wxwax]

There ya go. :nod :lol3