snubbr.com

How to purchase Polarizer
Hello,.

I just purchased polarized sunglasses and realized what an improvement it makes on the landscape. Now, I'm interested in purchasing a polarizer filter for my XTi (70mm)..

One site suggested that circular polarization was necessary for auto-focus in modern DSLRs. Is this true for the Canon XTi also?.

Also, prices vary greatly ($30 $200). I'm not interested in paying for "the best" quality, but a good bang-for-buck model. Any price point or brand/model suggestions?.

Thanks in advance!.

JP..

Comments (17)

Bitpusher wrote:.

One site suggested that circular polarization was necessary forauto-focus in modern DSLRs. Is this true for the Canon XTi also?.

Yes..

Also, prices vary greatly ($30 $200). I'm not interested in payingfor "the best" quality, but a good bang-for-buck model. Any pricepoint or brand/model suggestions?.

Go tohttp://www.2filter.com. Good prices, just stay away from non-multicoated filters..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #1

Hoya are an excellent & not too expensive make - bear in mind that if you have a wide angle lens you will probably need a "slim" filter if you want to avoid vignetting.

Simon.

Http://www.landscapephotographyuk.com/.

North Wales photographs - Snowdonia & Anglesey..

Comment #2

Get a Hoya Pro (or Pro1 not sure what they call them now) circular polarizer off of Ebay...real cheap and they are also very good..

These have multiple coatings on them..

The pro's are good b/c they are very thin (do not buy the one termed "slim" as they will not have front threads and are quite annoying)..

Bitpusher wrote:.

Hello,.

I just purchased polarized sunglasses and realized what animprovement it makes on the landscape. Now, I'm interested inpurchasing a polarizer filter for my XTi (70mm)..

One site suggested that circular polarization was necessary forauto-focus in modern DSLRs. Is this true for the Canon XTi also?.

Also, prices vary greatly ($30 $200). I'm not interested in payingfor "the best" quality, but a good bang-for-buck model. Any pricepoint or brand/model suggestions?.

Thanks in advance!.

JP.

Pak K So'Enjoy your life, guy'.

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

Comment #3

The filter is for the lens which has a 70mm diameter for filters right? Just checking..

Also, circ pol has nothing to do with auto-focus...I don't think it affects the auto focus one way or the other..

Bitpusher wrote:.

Hello,.

I just purchased polarized sunglasses and realized what animprovement it makes on the landscape. Now, I'm interested inpurchasing a polarizer filter for my XTi (70mm)..

One site suggested that circular polarization was necessary forauto-focus in modern DSLRs. Is this true for the Canon XTi also?.

Also, prices vary greatly ($30 $200). I'm not interested in payingfor "the best" quality, but a good bang-for-buck model. Any pricepoint or brand/model suggestions?.

Thanks in advance!.

JP.

Pak K So'Enjoy your life, guy'.

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

Comment #4

Bitpusher wrote:.

One site suggested that circular polarization was necessary forauto-focus in modern DSLRs. Is this true for the Canon XTi also?.

For some definition of the word "necessary", yes..

Chances are that in most cases you won't notice a problem if you use an old-fashioned non-circular polarizing filter. Maybe sometime you might have a problem, but it won't be anything like "all of the time"..

Long and boring explanation follows:.

Autofocus SLRs like your XTi/400D use a half-silvered mirror as a beam-splitter. This sends part of the light up to the viewfinder and part to the autofocus sensors. On the XTi/400D, 60% of the light coming in the lens during framing and focusing goes to the viewfinder, and 40% goes to the autofocus sensors..

Polarized light does not necessarily behave the same way as unpolarized light does when it hits a beam-splitter. You might get a different fraction than the designed 60/40 split. Autofocus will actually work fine, because you would almost never use a polarizer when there wasn't plenty of light to spare (as it costs you about 2 stops of brightness). But the exposure metering is performed off of the focus screen, based on the assumption that the beam splitter is reflecting 60% of the incoming light. If the fraction is substantially different from 60%, metering will be accordingly inaccurate..

So there's the theory. Now, on my XT/350D I've played around just a little bit and haven't been able to see any noticeable changes in reflectivity of the beam-splitter due to polarization. I've seen a few reports from people who have had no trouble with non-circular polarizers on Canon DSLRsI can't guarantee that they knew what they were looking forand I have yet to see a report of exposure trouble attributed to a non-circular polarizer on Canon DSLRs..

The circular polarizer is the theoretically correct thing to use, and it is the safe thing to use. Which doesn't mean that using a non-circular polarizer will necessarily cause you any grief..

Also, prices vary greatly ($30 $200). I'm not interested in payingfor "the best" quality, but a good bang-for-buck model. Any pricepoint or brand/model suggestions?.

You want a coated filter, probably multi-coated. Uncoated filters (Tiffen, Canon, various budget-priced lines) are bad news on a digital camera..

The more expensive filters (B+W, Heliopan) have brass threads that won't get stuck to your lens. The really expensive filters (kaesemann type) are sealed against weather and dust..

& A final note: don't expect miracles from a polarizing filter on a digital camera. I've quit using mine entirely, even though in my film days I never ventured outdoors without one...

Comment #5

Doug I misunderstood the OP...yes you are correctamoondo.Pak K So'Enjoy your life, guy'.

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

Comment #6

I use a Tiffen filter, and am happy..

BAK..

Comment #7

I bought the Hoya Pro 1 from Amazon and can already tell that it will work great on my next outing..

I plan to put it at the end of my filter stack when using it. Is there any reason to put it behind (toward camera body) the UV filter or does it not matter?.

Thanks,.

JP..

Comment #8

& A final note: don't expect miracles from a polarizing filteron a digital camera. I've quit using mine entirely, even though in myfilm days I never ventured outdoors without one..

How does using on a polarizing filter on a digital differ from a film slr? One of the things I enjoyed using my old slr was being able to have a polarizer..

Jeff..

Comment #9

Jturn00 wrote:.

How does using on a polarizing filter on a digital differ from a film slr?.

How? I don't know. It just does. With my Rebel XT I just don't need a polarizer the way that I did when shooting slides with my AE-1. The photos come out just fine without one. (I'm mainly interested in the effect on skiesI can't speak to the ability to cut reflections from water surfaces and such.).

Here's a sample shot from my XT with no polarizer:.

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

(http://www.flickr.com/photos/dougpardee/451196936/)..

Comment #10

Why add an extra layer of glass?.

I wouldn't use a UV filter but that is a totally different subject  Johnnyhttp://tuxbailey.zenfolio.com..

Comment #11

I would put it at the end of the stack, with nothing on the female threads. This way, since turning the polarizing filter can sometimes loosen it, you will not have your stack come off in your hand at an inconvenient moment..

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

Comment #12

Hello,.

By default, I have a UV filter at the end of my stack mainly to protect the lens. I do this because I heard it from several sources and it sounds reasonable to scratch the cheap filter instead of the lens..

Since the polarizer will be used sometimes, it's most convenient to just stick it on the end when needed (instead of putting it in the middle of the filter stack somewhere)..

Please let me know if my premises are not sound..

Thanks,.

JP..

Comment #13

I have polarising filters for both my Bridge Digital and my film slrs. The polarizer has a definite impact on reflections (try it on the glass of a store window- @ about 30 degrees to the glass, it's like the glass isn't there!), also, it takes the reflection off the surfaces of water (not always desirable) and the "glare" off buildings and foliage (including flower petals), thus "saturating" the colour. It definitely darkens skies and "brings out the clouds". However, with wide angle, the sky effect can be a bit "patchy". Experiment, it's fun!.

Now, changing filters in the field is not fun. You'll find it easier to have just the one (a polarizer) on your lens and leaving it there for the session..

The only "disadvantage" in using them is the loss of about 2 stops @ full strength, as they have a neutral density effect. Also, sometimes the specular reflections (which the filter eliminates or minimizes) can add to the "feel" of the scene (as in sparkling water ripples, as can store or car window/duco reflections)..

Mine are all "circular", and I haven't noticed any problems regarding AF or AE...

Comment #14

Good point, AmanitaM,.

Yes, the polarizer, by virtue of it's operation is not easily tightened (or removed if too tight) from the lens..

This reminds me of another ploy, which is to screw in a "screw-in" rubber lens-hood into the outer (female) thread of the polarizer (which, obviously, then has to be on the outer end of your arrangement). With the hood in place, you can then adjust your polarizing effect by turning the hood (which, being attached to the polarizer, results in turning the polarizer as well)..

This works very well..

"Hoya" makes adjustable rubber hoods, which cater for the wide end of zoom lenses (approx A$30-00)...

Comment #15

My Hoya Pro1 is easy to turn. I can feel if the filter is moving on the threads, and can get used to always turning it clockwise to avoid unscrewing it... I don't foresee this being a problem with this model..

Thanks,.

JP..

Comment #16

There are generally two camps on using "protective" filter or not. You can do a search in dpreview and there are many threads for it..

I go with the camp that extra filter just degrade the performance of the lens. And if you want to "protect" an expensive piece of glass, you want to get a high quality filter for it. Using a cheap one kind of negate the point..

This is a good reading on filters:http://www.bythom.com/filters.htm.

Johnnyhttp://tuxbailey.zenfolio.com..

Comment #17

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.