Lens hoods

[rjlhughes]

I picked up 3 from Baltronics today, and I'm wondering what the concensus is on these very expensive little metal donuts.

I note that these days they fit onto the lens backwards when not in use, but do most people use them for outside shoots all the time?

[Paul]

I use mine all the time incase of an accidental knock and for it's intend use to stop stray light entering the lens.
When my lens are in my bag I always reverse them to save space and ensure the dust end caps are atteched.
The only time you may have a problem with the kit lens is when using the onboard flash at the 18mm end of the range as you can get shadows appearing on the top corners of your pictures, however remove the hood or purchase the wonderful SB-800 and your problem is solved!

[phillipb]

Hum.. Paul, you're forgetting that you're in the Canon forum now. Your comments other then the SB-800 and the kit lens a valid though.

[Paul]

woops
Sorry wasn't paying attention!
Will do my 100 lines now, "I must pay attention to the Forum Index"

[rjlhughes]

We're ecumenical here! (as we should be!)

the lens hood with my sigma 20mm gets in the way of the on camera flash on the 350d, so you raised an issue that's worth noting.

I put the subject here to stir up some action down in the corral.

[Wacky]

Can you get lens hoods for all lenses? Like the 350D kit lense, the 50mm f1.8, and others?

Are they Canon brand? How much would an average one be? Will they all reverse onto all lenses?

Oh, I found this site for them but thye only have a few hoods...maybe B&H etc have more...hmmm

[rjlhughes]

I don't know all the answers - http://www.baltronics.com.au - may give detail. Or give them a call - they're in Artarmon.

http://www.qualitycamera.com.au also has some listed on line.

Yes, they're Canon - I got one for the 50 1.8, 35 2, and 85 1.8. All are bayonet and reversible.

I wish I'd seen the $11 ones you list, Wacky, I paid more than that.

They go against my discreet shooting intentions, by making the camera that much bigger.

And I still got some flare today shooting around the sydney fish markets in the afternoon facing west over the water to anzac bridge, you gotta expect that, I guess.

[Wacky]

The ones on Adorama were about the same price as Qualitycameras...don't feel too bad.

One question that you may or may not know the answer to. Why are most of those lens hoos round and flat, rather than having the classic petal (2 large, 2 small) edges?

[rjlhughes]

I thought round and flat was the classic.....

I don't understand the petal shape. I should ask Walter Glover, he'll know.

There was a rubberised one I had on a 50m lens in the 80's that I quite liked...it was bendy

[rjlhughes]

"Petal shaped often protect better than non-petal (round) types. This is because petal-style hoods take into account the aspect ratio of the camera's film or digital sensor, and so the angle of view is greater in one direction than the other."

from

http://www.cambridgeincolour.com/tutori ... -flare.htm

I learn something every day here on this forum! (Even if I'm prompted to look it up myself).

[leek]

I learn something every day here on this forum! (Even if I'm prompted to look it up myself).

[WadeM]

I learn something every day also. Even if some days I have to read the Canon forum

Always wondered why they are petal shaped, never bothered looking into it tho!

Thanks,
--Wade

[rjlhughes]

the petal ones are specially designed for taking flowers.

has something to do with the number of blades on the f stop and the number of petals on the flower.

important for carnations, but not so much for roses, because they have different flower structure.

Also apparently important for some sorts of corals that have similiar multi symmetrical structures.

I wouldn't have thought you'd need them underwater, but there you are.

original idea came from Diego Rivera (Frida Kahlo's husband) who was inspired by the look of mexican hats.


JK

[daniel_r]

I use mine all the time incase of an accidental knock

I can certainly back that up - the lens hood on my D70 kit lens saved the lens from being destroyed on my recent trip to California. I had a bit of a whoops moment and dropped the D70 on a concrete foothpath from eye level.

The camera landed lens down directly on the lens hood - the lens hood was pushed back over the hood mounting bayonet and chunk of plastic is missing out of the hood. BUT... the lens escaped undamaged

Lens hoods are now fitted on all of my lenses.

[Sheetshooter]

The lens hood used as bumper bar is a long-standing ancillary benefit - in fact the rigid lens hood is considered by many to be a better option in this case than the collapsible rubber type because they will prevent the front element or filter smooching damaging surfaces with greater certainty.

But back to the real purpose of lens shades and why some have 'petals' or are scalloped:

The primary purpose of the lenshood is to reduce the entry of non-image-forming light into the optical system. There is an inherent level of flare in all optical systems which is increased by the addition of this non-image-forming light. Coating and then multi-coating of lenses reduces flare somewhat but still the most effective way of containg the ill-effects is to block the culprit before it enters. Enter the lens hood!

Just how much more effective the scalloped lens hoods are than regular round or rectangular lens hoods is a matter of the precision of alignment with the edges of the image that they are engineered and manufactured.

I primarily use a view camera - 'What place have you here ten? I hear you ask ... Well the principles of many aspects of photography apply universally across the board and are sometimes better addressed in other kit. Thing is that with the view camera the lenshood is often another bellows mounted in front of the taking lens which can be adjusted to best shield the optics from extraneous light. In fact, for my Linhof there is a device which can fit in front of this lens hood bellows with four independently adjustable board masks. These masks are aligned precisely with the very edges of the image at the shooting aperture by inspection through cut-off corners of the ground glass in an effort to eradicate ALL but the actual image forming light from entering the system.

The 'petal' lens hood is an attempt to address such a situation with the SLR or DSLR and the ultra-wide angle lens - but, sadly, without the same level of sophistication. For them to make one that would be 100% effective at f16 it would vignette at f4.

Another oft-used device is what is known a a FLAG. This is a separate device- usually a piece of flat black meterial like a card - which is placed in such a way as to prevent harsh and intense light falling on both the front element of the lens and THE LENS HOOD. You see despite the ribbing and matte finish, the internal surface of the lens hood can actually bounce strong light back into the lens, albeit at reduced level, but strong enough to degrade image quality. Flags can also be employed in studio set-up close to lamps to ensure that they do not shine directly into the lens also. The best check is to look at the front element of the lens with it in its shooting orientation and 'flag' any sources that can be seen directly reflecting the front element.

The optical system with its internal reflections is not the only source of image degrading due to flare. BELLOWS FLARE or internal body flare is also a major issue. This is light forming part of the image circle of the lens which is not contained within the image area rectangle but falling on the walls of the mirror box or bellows or whatever. Where this is of particular relevance to DSLRs with APS sized chips is that full-frame 35mm lenses are filling the camera with an image circle of light far greater than is necessary - a great point in favour of using DX lenses on DSLRs.

One last comment on flare: It is also greatly increased by dust and marks on the lens elements. Keep your lens clean and minimise the air-to-glass interfaces by using filters ONLY when essential.

Cheers,

[rjlhughes]

Ah that'll be the definitive response - Streeetshooter welcome!

I often hold a pad or even my hand up just out of view when I'm shooting into the sun and that seems to cut down on flare - I guess as a sort of 'flag'

But I'm still regularly getting multi sided little flares - I think they may be octagonal - I'll go and give my lens a clean.

The other aspect of the petal shape lens hoods may well be the marketing advantage the shape gives, of course. They look cool.

OK now there's an expert here, i admit I just made up the stuff about flowers before.

[Sheetshooter]

RJL,

I wish you had told me that earlier. I just wrote of a brand new D2x and 14mm lens trying for a shot of abalone on the rocks beneath the high tide mark at Little Congwong.

Expensive afternoon that was.

Cheers,

[rog]

Hoods are great in just about any situation, if not for preventing flare, then as a safeguard against bumps, as people have suggested.

If you're using a filter of any kind, or a crappy lens, then you're going to get lens flare, and even cutting out the barely noticeable flare with a lens hood helps the contrast of your shots along more that you might think.

Cheers,
- Rog

[huynhie]

RJL,

I wish you had told me that earlier. I just wrote of a brand new D2x and 14mm lens trying for a shot of abalone on the rocks beneath the high tide mark at Little Congwong.

Expensive afternoon that was.

Cheers,

That sounds like an "oh F$%K" moment, I've had a few of those in my lifetime but not as bad as yours.

Hope it was insured

[DaveB]

My position on hoods is to always use them if possible. I don't consider buying a lens without one. Not only do they help protect your filter/element from knocks, water droplets, licks (ever tried photographing calves up close?) etc but they do the thing they were designed for: reducing flare.
Flare's not just a problem when the sun's shining directly on the front element - it's also there in more subtle forms at other times. But even with a hood you'll still find yourself shooting towards the sun at times and need to shade the front element with your hand/head/hat (a cable release helps if it's a stable subject like a landscape...). Even then the hood's protecting from light from other extraneous areas (even a bright sky can cause flare!).

I have Canon hoods on most of my Canon lenses, although because all my cameras are currently ones with 1.6x crop factors I have non-standard models on shorter lenses like the 17-40 (which on these cameras has a f.o.v. of a 27-64 so I use a hood designed for a 24mm) to give better shading. Your options for this depend on the particular lens model.
On my 100-400mm zoom I've compromised and fitted a collapsible rubber hood. This is to allow me easy access to a polariser and then pop the hood out again.

Sheetshooter: sounds painful!