snubbr.com

are these reflections from my filter? (1 image)
Hey everyone, I bought a circular polarizer filter a few days ago, took some pictures with it. and I found this one... it looks great but theres random lights in the sky, heres what I mean..

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

It looks like theyre reflected off the street lights, is that because of my filter?.

Thanks.

Steven.

Http://steven-hotroddude.smugmug.com/..

Comments (7)

Hotroddude wrote:.

Hey everyone, I bought a circular polarizer filter a few days ago,took some pictures with it. and I found this one... it looks greatbut theres random lights in the sky, heres what I mean..

They are not random, they are symmetrical with your highlights vs the image center. It's called ghosting..

It looks like theyre reflected off the street lights, is that becauseof my filter?.

It's either your filter or some part of the lens. More probably, the filter. Try it without the filter. You already know the setup: something very dark with a bright light. If it ghosts without the filter, it ain't the filter..

Thanks.

Steven.

Http://steven-hotroddude.smugmug.com/..

Comment #1

Thanks for your reply, I took a picture of some blue LED's in my room with the filter on, they were there. I took it off and they were gone, are there any tricks for getting rid of them withought removing the filter? I bought it mostly to protect my lense, and that kind of defeats the purpose..

Steven.

Http://steven-hotroddude.smugmug.com/..

Comment #2

Hotroddude wrote:.

Thanks for your reply, I took a picture of some blue LED's in my roomwith the filter on, they were there. I took it off and they weregone, are there any tricks for getting rid of them withought removingthe filter? I bought it mostly to protect my lense, and that kind ofdefeats the purpose..

This is the reason why many people refuse to use a filter when it's not totally necessary..

Those reflection in your shot show up because you've got very bright reflections on a dark background. But, if you think about it, the light from the reflections would still be there if the background were brighter. They just wouldn't be as obvious..

When you shoot during the day you've got lots of bright areas - all of which will reflect in the filter just as much as the street lights. These reflections won;t be distinguishable from the bright background - but they will be there, and they'll help reduce the contrast of your image..

Frank HollisMass Spectroscopist in the UKCan0n 2oD and 4oD..

Comment #3

Hotroddude wrote:.

Thanks for your reply, I took a picture of some blue LED's in my roomwith the filter on, they were there. I took it off and they weregone,.

So, it's the filter..

Are there any tricks for getting rid of them withought removingthe filter?.

You won't like it... don't use the lens with the filter on it .

I bought it mostly to protect my lense, and that kind ofdefeats the purpose..

Hold on a bit... you bought a circular polarizer to protect the lens?! You realize you are loosing 1-2 stops of light all the time?.

It will protect your lens alright... if you get that kind of ghosting, the lens will remain nice and secure in the cupboard..

My advice would be use the CP only when you need it. Probably the polarizer effect will overcome the ghosting effect. Or you can try to sell it..

Now you all know why when somebody asks "what filter", I always say "no filter, unless it's needed" .

The other poster is right: you'll get image degradation even if you don't see the ghosting..

/d/n..

Comment #4

Hotroddude wrote:.

Thanks for your reply, I took a picture of some blue LED's in my roomwith the filter on, they were there. I took it off and they weregone, are there any tricks for getting rid of them withought removingthe filter? I bought it mostly to protect my lense, and that kind ofdefeats the purpose..

-Steven.

Hi Steven. You get what you pay for. You said the ghosted highligts aren't there if you remove the CPL, which says it's reflections off the back of the CPL (from the lens) that are causing the problem. Better quality CPLs have suitable coatings on both sides to reduce this kind of reflection..

It's not really different from having appropriate coatings on the back of the rear element of your lens. The image sensor (and it's cover) are so smooth and reflective that you can get similar ghosting problems if you use a lens that doesn't have a properly coated rear element. Lack of the right coating means that light can reflect off the shiny sensor and back off the rear element to the sensor again to create ghosted highlights..

As others have said, a CPL is not a good option for protecting your lens as it robs you of 1-2 stops of light, which is nuts. If you're worried, use a UV filter. It won't rob you of lots of light like a CPL will. However, make sure you get a good quality UV filter with coatings that will keep those unwanted rear reflections at bay. I'm really like B+W MRC fitlers, but they're more expensive than most. I don't use UV filters on my lenses, but I use B+W MRC CPLs..

Cheers from John from Adelaide, South AustraliaJohn Harvey Photography http://johnharvey.com.auCanon 40D, Canon 20D & Fuji F10..

Comment #5

John down under wrote:.

As others have said, a CPL is not a good option for protecting yourlens as it robs you of 1-2 stops of light, which is nuts. If you'reworried, use a UV filter. It won't rob you of lots of light like aCPL will..

As Blossom Dearie used to sing in "I'm so hip ..".

".... watching arty French flicks with my shades on..".

Yes. It is a particularly serious error to use a pola filter at night. Not only will it give ghosting problems that show badly, (instead of ones that don't show much!) but it will reduce light intensity by more than HALF. I mean, this is exactly the time you would ordinarily wish to maximise light passing through the lens.... because it's already pretty dark for shooting out there!!.

[Errr... I know this is the Beginners Forum, and we are supposed to make more allowances, but hey, I still find myself wondering......

... What do you use to put out fires around your neck of the woods? Gasoline!?].

Being serious again, you should also take note that......

Because the pola filter reduces the light beyond ordinary night darkness, to get the shot your camera is obliged to increase exposure times, or use higher ISOs than otherwise, both of which generate extra visual noise and so add to your problems..

Conclusions:.

A pola filter is a bad idea as a see-through lens cap, because the lens can't see through it very well at the best of times, and hardly at all in the dark..

If you really must have permanently mounted protection for your front element, get a clear glass filter, or a UV one. Ensure that is coated against reflections, and STILL be prepared to take it off in reflection generating conditions like those of your sample shot..

Use your pola in good strong light to kill sheen in glossy surfaces say, to intensify the greens of horizontally orientated leaves or to boost intensity of blue in skies at 90 degrees to the sun..

Otherwise, leave that polariser in your bag..

I hope this helps..Please don't take my attempts at humour too much to heart!Regards,Baz..

Comment #6

Barrie Davis wrote:.

Please don't take my attempts at humour too much to heart!.

Oh so that is what it was. Humour! Erm I can't bear it anymore. Please stop. (I think I had better not give up the day job either!)..

Seriously there is a lot to be said for using a lens hood to protect your lens rather than a filter. I only now put a filter on when I know that conditions will be adverse. What is the point of putting cheap glass in front of expensive glass. And what is the point in buying expensive glass you don't need?!Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

Comment #7

Click Here to View All...

Sponsored Amazon Deals:

1. Get big savings on Amazon warehouse deals.
2. Save up to 70% on Amazon Products.


This question was taken from a support group/message board and re-posted here so others can learn from it.

 

Categories: Home | Diet & Weight Management | Vitamins & Supplements | Herbs & Cleansing |

Sexual Health | Medifast Support | Nutrisystem Support | Medifast Questions |

Web Hosting | Web Hosts | Website Hosting | Hosting |

Web Hosting | GoDaddy | Digital Cameras | Best WebHosts |

Web Hosting FAQ | Web Hosts FAQ | Hosting FAQ | Hosting Group |

Hosting Questions | Camera Tips | Best Cameras To Buy | Best Cameras This Year |

Camera Q-A | Digital Cameras Q-A | Camera Forum | Nov 2010 - Cameras |

Oct 2010 - Cameras | Oct 2010 - DSLRs | Oct 2010 - Camera Tips | Sep 2010 - Cameras |

Sep 2010 - DSLRS | Sep 2010 - Camera Tips | Aug 2010 - Cameras | Aug 2010 - DSLR Tips |

Aug 2010 - Camera Tips | July 2010 - Cameras | July 2010 - Nikon Cameras | July 2010 - Canon Cameras |

July 2010 - Pentax Cameras | Medifast Recipes | Medifast Recipes Tips | Medifast Recipes Strategies |

Medifast Recipes Experiences | Medifast Recipes Group | Medifast Recipes Forum | Medifast Support Strategies |

Medifast Support Experiences |

 

(C) Copyright 2010 All rights reserved.