Lens Hood edges

[nkeevers]

Not sure if this is the right place to put this thread. But can anyone tell me why my lens hood might be showing on the edges of my picture??
It's for my Canon and the right size but I don't understand why I'm seeing it around the edges.


http://www.pixentral.com/hosted/13BWmUexbSz47eKVJtGAuZGd9Td1l81_thumb.jpg (http://www.pixentral.com/show.php?picture=13BWmUexbSz47eKVJtGAuZGd9Td1l81)

[Chuck S.]

Norma, which lens? And what is the Canon part number on the hood (something like EW-78A)?

[ricklepage]

Lens hood vignetting is pretty common, especially when you're shooting at the widest focal length. You should be able to see it through the viewfinder when you're framing your image, and you can either zoom in a little bit to get rid of it, or just remove the hood for those types of shots.

Some lenses come with a lens hood that isn't perfectly round - it has notches in the body to keep this type of vignetting at bay. They're called 'petal hoods', and you can see one about halfway down the page in this lens review:

http://www.ephotozine.com/article/Sigma-EX-Aspherical-DG-DF-20-40mm-f28

You can also try to get rid of it inside Elements, by choosing Correct Camera Distortion in the Filter menu.

hope this helps.

Rick

[nkeevers]

The lens is my 17-85mm and the hood is EW-73B.

I'll have to watch next time I use it. I'm assuming it only goes on one way so I hope I have it on right. Looks like it bows out a bit so I don't know why it would show up in my picture.

[Grant]

It's for my Canon and the right size but I don't understand why I'm seeing it around the edges.



Oh that is a really wide angle shot! If you have the right lens hood for you camera it should work .... unless. This may be a obvious and stupid question but is the lens hood put on correctly? Wide angle lens hoods are usually of the split type with the larger part being for horizontal and the narrower part being for the vertical.

P.S. One, other thing if you have a filter on you camera say a UV then it will push you lens hood out and this can also cause this type of vignetting.

Only thoughts.

[Chuck S.]

There is 'chatter' on a number of websites about vignetting with the 17-85 mm lens. The culprits range from 'fat filters' to the hood (but unlikely if installed right because it's deeply notched in the corners) to a lens element out of place to a fundamental design flaw. Global warming wasn't mentioned, but should be considered as well...

Norma, could you try some experiments? Remove the hood, take another photo and full wide angle. Still vignetting? If so, remove the filter and repeat. If that doesn't solve the problem, it may be fundamental to the coupling of the 17-85 with your particular camera model. If taking off the filter did the trick, I'll bet you'll be able to put the hood back on and not get any vignetting....

[nkeevers]

I have a skylight and a polarizer on the lens. Maybe that is what is doing it? I'm going to try tomorrow (after my 6 hour trip to CT) and see what happens. I've never had vignetting with the 17-85mm so it has to be the hood. I hope I have it on right. What the heck is a split type? I'm not sure what I have but I can take a picture of it tomorrow. Bear with me because I've never used a hood before...this is my first. There are 2 sides that are longer than the others. I think I'm putting it on right because there is a red dot that matches up with the red dot on my lens. Now that I look thru it, I can see the vignetting (if it's all the way in, I see it) very faint. But then it goes away...I think I have to watch how I zoom. But I was trying for a wide angle shot. Maybe it shouldn't have been so wide angle. And it fits over the polarizer so it can't be pushing it out I don't think.

[Chuck S.]

Norma, I'll bet it's those stacked filters; that was cited by at least one of the folks whose posts I readon other forums. If that's the case, the fix is easy: ditch the skylight filter when you're using the polarizer. (Or....ditch the skylight filter altogether...)

Will be interesting to see hear how you resolve the situation!

[JulieM]

For what it's worth, I have the same lens and the same hood and have not noticed any vignetting but I don't have it fitted with any filters. And, I actually don't think you can put it on wrong.

[Chuck S.]

Norma, one other thing: when you line up the red dots on the camera and the hood, do you then rotate clockwise about a quarter turn the hood to lock it in place? Leaving the two dots lined up will result in the hood being oriented improperly, which conceivably could put the hood's wings in the exactly wrong place.

[Grant]

I can almost guarantee you it is the filters that are causing the problem.

[Jeff Perry]

Norma, I agree with Grant (and others) that the filter is the culprit. Having just returned from Utah and Arizona where I put a 12-24 to good use, I found severe vignetting caused by a polarizer when the lens was racked back to the widest focal length. The angle of view at the wide end in most wide-angle lenses is so wide that it is almost always subject to the vignetting especially from a polarizing filter, which by its design is often thicker than most other filters (because it has to rotate it is really like two filters combined). Combining it with a UV filter only makes the problem worse.

Most manufacturers offer "slim" filters for use on wide angle lenses, but be aware that most of the savings in thickness is due to the elimination of the front threads (that allow you to stack filters) that also serves as the area that your front lens cap grabs onto. Use the slim filters and you may lose the ability to attach your front lens cap.

If the lens hood is OEM that came with the lens, it should not be the problem. That would be a major design flaw. In most modern lenses, the hood attaches directly to the lens barrel and is not attached to the filter ring so adding filters does not extend the hood out any further.

Jeff

[Chuck S.]

Jeff, you make a really good point about the lens hood mounting. I should have noticed that as I was playing with some of my lenses and hoods in trying to figure out Norma's problems, the hood slips over the front of the lens where the filters would be and mounts on its own ring perhaps 3/16 inch back. Unless the hood was mounted cock-eyed, it was an unlikely culprit.

[Ric Cisson]

NOrma, I have the same lens and hood. I use a skylight filter most of the time, and have not experienced your issue. However, just to echo a couple of things that have already been mentioned. I just tried one of my "thicker ring" filters on my lens, attached hood, set at 17mm and no vignette. Then I attached my "thin" ringed skylight and hood, again no vignette. Then I removed and "partially" reattached the hood and I got vignette in the corners similar to your issue. I believe it was Chuck that mentioned the hood alignment marks, make sure when attaching the hood that you have an alignment, if it is not aligned then the hood is mounted at a slight angle, which I see before me now on mine and that can cause the vignette you are seeing. Just one possible answer to your issue. FWIW.

[cjcrawford]

At least one person has put up some templates to make lens hoods out of cardboard (fun design idea - you could use old photographs). One site I found quickly was:

http://www.lenshoods.co.uk/

I think there are others.

Chris

[nkeevers]

Sorry I haven't gotten back to you guys. I'm on vacation up North and I've been super busy visiting.

I just came back from Mass taking some photos around the area. I tried with the hood lens. I have a UV filter on the camera and a polarizer and guess what...the problem is still there. So it isn't the hood; it must be the lens. I forgot to take them off and experiment so I'm getting ready to go in the backyard and take the polarizer off and take a shot and then take the skylight off and put the polarizer back on and try it. See what happens. Will get back to you guys. I don't want to scratch or damage my lens so there has to be some filter on it.

(noticed it on an image I took on manual with my 17-85mm lens at 20mm, f/4.0.)

[nkeevers]

Well, I did a test and just used the polarizer...no vignetting. Then I tried just the UV filter...no vignetting. So I guess it's because I had two lenses on the camera.

Grant, you were right about the lenses. I did see the thin ones advertised so you can have more than one attached. My polarizer is not that thin and with the other lens guess it was just too much. Glad it wasn't the hood since I just bought it.

Well, you know it's a learning experience. I'm learning something new every day. This one I will definitely remember!

[Biglug]

I had the same problem once with my camera. Except the effect was in opposite corners. It turns out that I didn't have the hood latch to its furthest extent. I have a pedal hood.

[nkeevers]

Norma, one other thing: when you line up the red dots on the camera and the hood, do you then rotate clockwise about a quarter turn the hood to lock it in place? Leaving the two dots lined up will result in the hood being oriented improperly, which conceivably could put the hood's wings in the exactly wrong place.

Chuck, sorry I hadn't answered you...but yes, I did that so it was on right.Course now we know that wasn't the problem...LOL!

[Grant]

Grant, you were right about the lenses.

Norma this is a know problem with wide angle lenses so it is not that I am a smartie pants I just have a long memory.

Now there is another problem that you will come up with if you continue to use a polarizer on a wide angle lens. Polar filters work best at 90˚ from the sun. At 180˚ from the sun there is almost no effect when using a polar filter. If your lens is very wide angle then the effect of the polarizer will give the sky a patchy effect. Because of this it is not wise to use a polarizer on ultra wide angle lenses. Unless of course you are after the patch sky effect :twisted:

.

[nkeevers]

Grant, nah you're not being a smarty pants! And I appreciate the info. I didn't know about the wide angle-polarizer problems. So does that mean I probably should not use a polarizer on my 17-85 and just use the UV filter? I don't want a patchy sky either. Or as long as I'm taking a shot that isn't so wide angle. Is there a focal point on a wide angle where it starts to become okay to have the polarizer on the lens? If I was out changing the focal point all the time, then I'd have to take the polar on and off...that would be a pain.Guess it wouldn't be a problem not using unless I'm on the water or something like that.

[Grant]

Hi Norma

It is a hard call to make but the general consensus is that anything wider than 24 mm is too wide.

You have to dial-in the polarizing effect of your filter so conversely, if you don't want to keep swapping filters off and on, you can also dial it out. There are three downsides to this practice. First your lens effectively becomes slower, second you run the risk of vignetting at extreme wide angle and finally you have to remember to dial it out.


The first year I found found out about a polarizer I think I shot every picture with it. Then I realized all my images were looking the same, but that was me. Now I use it when needed and that is not all the time, so I have learned taking one on or off is not a big problem.

[nkeevers]

Thanks so much Grant! I think I'll do what you do...take it on and off when needed.