The annoying vignetting of lens hood.

[cyracles]

Hello everyone, I recently acquired an 18-55mm canon kit lens. Filter, check. Lens hood, check.....er, no...not yet. No matter how I screw it on, it shows some part in the frame when I zoom out below 24mm.

Note: it is not canon-made(those are really scarce), it is the petal type(that's the only available one).

Am I to scrap the whole hood idea or avoid 18mm(I got the lens for its wideness) or is there a way to make the lens hood conform better?


Thanks.

[RustBeltRaw]

I use a lens hood religiously on my 20mm. There's no reason why a lens hood should cause vignetting on any focal length. Who's the manufacturer?

If you can't source another hood, it's pretty easy to sand away parts of the hood (use coarse paper around 60 grit and a relatively slow wheel, or a coarse file). That will take some tweaking, but should be a good solution. There's also a website that provides free templates for cardboard or paper lens hoods.

[cyracles]

Thank you Lex. Which part of it should I file off precisely?

[Polar01]

Ife the easiest thing to do, like I do is remove it when shooting wide, put back on later. I have a Nikkor 16-35mm and when I shoot at 16mm with the lens flare hood I get vignetting a small amount in the corners so I remove it, not a lot of effort. The thing is, it is not on the lens most of the time as I use a CP filter and with the hood I cannot rotate the filter so the hood is usually in the kit bag.

Cheers:

Allan

[RustBeltRaw]

Thank you Lex. Which part of it should I file off precisely?

That's the tricky part. Before you begin, take the same shot with and without the lens hood, then compare. It's possible that your vignetting issues are from the lens, not your hood.

Is the vignetting stronger in one area? If so, start there. Regardless, move slowly and carefully, removing material only in small chunks and testing as you go. On the other hand, you could print out one of the LensHood.co.uk templates, and file your hood to match its profile.

As Allan said, removing the hood when shooting wide is also an option (and is probably the best one).

[Manfred M]

Thank you Lex. Which part of it should I file off precisely?

I rarely use a lens hood. I am someone who does most of his outdoor shooting with a polarizer, so the lens hood just gets in the way.

The only time I might use one is when I am getting lens flare by pointing towards the sun. Even then I find that I can use my hand to shield the lens and get a good shot. The only time I use one regularly is when it is raining out and it helps keep the rain off of the front lens element.

[cyracles]

Thank you all. I can assure you it is not from the lens Lex. Allan, as for removing it when I don't need it, I'm quite paranoid about breaking the AF. I bought this lens to replace a similar one with bad AF....

How does the printing of hood template work?

[Mike Buckley]

Also make sure that it's not a filter that is producing the vignette. Certain (usually expensive) filters are made with a very thin ring to avoid producing a vignette even at the shortest focal lengths.

[Manfred M]

Thank you all. I can assure you it is not from the lens Lex. Allan, as for removing it when I don't need it, I'm quite paranoid about breaking the AF. I bought this lens to replace a similar one with bad AF....

How does the printing of hood template work?

Having a lens hood will not necessarily protect your autofocus mechanism. It will protect your len's front element and that's about it. If anything, it will likely increase the chance of mechanical damage to your lens. Anything that adds to the lenses length is going increase the risk of mechanical damage and if you do hit something with the lens hood, it will increase the amount of stress on the lens mount.

Damage to the autofocus is likely due to either electronic failure, mechanical failure (something that you can't necessarily do anything to prevent) or damage from it being dropped.

[Donald]

I would agree with Manfred that removing the lens hood should have no impact whatsoever on the functioning of the lens. I do a lot with Graduated Neutral Filters and a Neutral Density Variable filter and I have lens hoods on and off all the time.

In terms of why your hood is causing this problem, you did say in the first post that it is not a Canon hood. I'm afraid that this can be one of the consequences of purchasing a 3rd party brand which, although it might claim to be specifically for a given lens, might often not be built to the same precise specification as a Canon-own product or other higher quality 3rd party products.

[chrisletts]

The genuine Canon hood is very shallow - if as you say yours is a petal type it's almost certainly too long.
Genuine Canon hood is only £20 or so - why not buy one of those instead of messing with sandpaper ?!

[rpcrowe]

Ife... I use non-Canon hoods on all of my lenses that did not have a hood supplied from Canon. I have had absolutely no problems with these hoods.

1. I would ensure that the hood that I was using is the correct one for the lens. All of my non-Canon hoods have Canon I.D. numbers. If you have the wrong hood; that might be the problem.

This link to Adorama shows all of the Canon OEM lens hoods. You might compare what your hood looks like to the corresponding one on this Adorama site:
http://www.adorama.com/searchsite/de...non+lens+hoods

2. I would make sure that the longest sides of the hood are at the top and the bottom when the hood is mounted and that the shorter sides are at the left and right. I had a friend who installed the hood with the shorter sides on the top and bottom and she had vignetting problems. You can also get vignetting if the hood is installed slightly off center.

Best of luck...

[RustBeltRaw]

Genuine Canon hood is only £20 or so - why not buy one of those instead of messing with sandpaper ?!

My suggestions are based on a tight budget and limited or nonexistent access to the genuine Canon hood. Naturally, getting your hands on the real thing, if possible, is the ideal solution.

[FootLoose]

How bad is the vignetting? Can it be removed in pp?

[Ken MT]

At wide angle you will need a narrow hood, whether petal or not, while at telephoto a longer hood can be used. The EW 60C is quite a flat hood, and while it may be OK at wide angle, shading the lens with a hand or hat etc may be a better option.

[Gospelflier]

I thought you only needed a lens hood when shooting directly into the sun? I have two of them, and have yet to use even one ;P

[William W]

Thank you all. I can assure you it is not from the lens Lex. Allan, as for removing it when I don't need it, I'm quite paranoid about breaking the AF. I bought this lens to replace a similar one with bad AF....How does the printing of hood template work?

You could try buying third party one (from China etc) on e-bay. . . but -

These hoods are OK. You just download the pdf and print it. Then cut out the template.
I make them two sided (two thicknesses) from about 240gsm paper. (MATT BLACK on the inside).Yellow looks quite pretty on the outside, but Hot Pink is very snazzy.
Two thicknesses of paper makes quite a sturdy lens hood.
An elastic band is useful to hold it on tight.



***

Choosing either to use a lens hood or not to use a lens hood, will NOT affect the workings of the AF.

***

There are two types of Vignette:

A Physical Vignette will be (more) difficult to remove in PP, because it is caused by a physical barrier between the sensor and the Subject. Arguably to remove a Physical Vignette cloning would be required and thus not a true image (if that is important), none the less: likely a lot of work.
An Optical Vignette, (Lens Vignette), on the other hand is easier to remove, because basically it is an “exposure thing”. The edges of the image just being a little less exposed than the centre and at a constant rate, usually. So an automated Post Production program can be employed to correct it.

***

In regard to arresting Flare:
Lens Hood are of little or more likely absolutely no use, when shooting ‘directly’ into the sun: but are of use when shooting if the sun is in front of the camera (at any angle).
Also Lens Hoods are useful when shooting with the sun behind the camera, as there can always be a reflection from a surface either in or out of the scene, which could cause Flare.


WW

[Mike Buckley]

I thought you only needed a lens hood when shooting directly into the sun?

I always use the lens hood in case there is a strong reflection throwing light toward the lens that I don't notice.

I also always use the lens hood because it does such a nice job of protecting the lens if I accidentally drop the camera or knock over the tripod. The latter happened once on a concrete floor. The cheap lens hood was ruined but the camera and lens were entirely unaffected. I am guessing that that's because the lens hood absorbed the initial shock of the fall.

[Andrew76]

The genuine Canon hood is very shallow - if as you say yours is a petal type it's almost certainly too long.
Genuine Canon hood is only £20 or so - why not buy one of those instead of messing with sandpaper ?!

This was my thought exactly - are you sure you have the OEM hood, Ife?

This is what it should look like for the 18-55 Canon kit lens:



or



I had one of the top types when I had my 18-55, and never had any issues.

**EDIT - My apologies, I didn't quite read through your opening post, where you mentioned that it is NOT an OEM Canon hood. Sorry, you can ignore this post.

[Mike Buckley]

OFF TOPIC

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