Filters?

[PoohJen]

I know close to nothing about filters (except y'all said it is worth it not to go with a "cheap" filter).

To protect my lens, I should get a UV filter, correct? I carry a Sigma 18-125. What size filter do I need? do I need a "circular" filter?

I have seen Hoya recommended (but not the cheapest line?). Will I be fine if I run over to circuit city today at lunch and get something there (looks like they only carry something called SunPak.

Finally, I live in the Southeast (= extreme sun on the kids' sports fields); do I need a polarizing filter?

7 photography books from library, none say more than one sentence about filters!

 

[ndelaware]

Jen, you need a 62mm size filter.

The term circular is used for polarizing filters which are much more expensive and block alot of the glare from the sun, like a pair sunglasses would.

As far as wether the SunPac is any good I can't help you with that. But you can pay anywhere from $15 to $125 for a UV or clear protection filter. I use Tiffen or Hoya filters.

 

[PoohJen]

Thanks, Steve. I see alot of Tiffen on Amazon.

How did you know I needed a 62mm filter? How are they measured?

 

[boBQuincy]

The filter size is the diameter of the threads at the front of the lens, in this case 62mm as ndelaware mentioned.
If you plan to leave the filter on, a multicoated one is a good idea. SunPak and others at Circuit City may be multicoated but it's typically not a mass market item so you may have to go to a camera store for those.

A polarizer almost always makes the photo look better but they greatly reduce the amount of light coming in the lens, so for sports they can limit your ability to use a fast shutter speed.
Most autofocus/autoexposure cameras need a circular polarizer and again, multicoated is better.

 

[ndelaware]

62mm is the diameter of the front of the lens. It is usually listed on the front of the lens next to all the rest of the lens info. I got it from Amazon, but you can also get the filter size on most camera websites and http://www.sigma-photo.co.jp/english/index.htm

 

[ndelaware]

Most autofocus/autoexposure cameras need a circular polarizer ......

Sorry Bob, not everyone would agree with that statement.

 

[jann1033]

I asked a question about lens hood vs filter a few days ago and Oblio had posted an interesting link which for somereason i can't get to post here but you could do a search for it http://www.disboards.com/showthread.php?t=1166063 this is the link to the thread

i've always used a uv filter ( tiffen, pretty cheap) to protect but bought lens hoods for all my lens as they are around $30 or less and a good filter might be more and only do one thing...i did notice one of my tiffen uv filters the coating is coming off around the edge by the ring so don't know how much good it is doing any way and the example oblio posted made me think twice about cheapo filters

a circular polarizer gives you more vibrant sky, blocks glare from water( so you see the rocks or what ever in the water rather than the glare on top of the water) i do use it although mine was about $30 a number of yrs ago, not sure how much it would be now but the bigger the MM of the diameter of the lens( would say on it or in the literature for it, not the same as the focal length mm naturally ) the more $$

 

[PoohJen]

Thanks everyone.

sigh. Janet, I have less clue about hoods than filters. I never used either w/ my 35mm. I'm sure (or my kids!) could still manage to scratch a lens with a hood on. Is the idea the hood will keep things from banging into/scratching the lens? What other functions does it have?

 

[jann1033]

Thanks everyone.

sigh. Janet, I have less clue about hoods than filters. I never used either w/ my 35mm. I'm sure (or my kids!) could still manage to scratch a lens with a hood on. Is the idea the hood will keep things from banging into/scratching the lens? What other functions does it have?

http://www.vanwalree.com/optics/lenshood.html

more than will ever want to know about hoods , i just saved my self the headache of figurng it out and got petal hoods

my lens look pretty good from using the UV for protection, not any scratches i see on them but i have to say i have been pretty careful with them ( and no little rugrats to touch them at least till grandbaby figures out how to climb up to where i keep my camera ) but i only had 2 lens with the same diameter so only need one set of filters, now need 3 sets...i bought a step up ring so i can use my polarizer on the 50mm f1.8 but will need to save for the 28-135 one ( amazon had a hood bundled with that one so with the 3.99 over night shipping it comes out to about what the lens alone overnighted would be other places)

 

[muphoto]

Lens hoods and filters are used for two different functions. A VU or haze filter is meant to block some of the bluish tint that you can get from distant landscapes and mostly to protect the front element of the lens. A filter is much cheaper to replace when scratched that a lens.

Hoods, on the other hand, were never meant to protect a lens, althought that might keep it from getting dented. They are to help reduce the glare from the sun or other bright lights that will cause flare on your images.

A hood and filter shoud be used together.

 

[boBQuincy]

Sorry Bob, not everyone would agree with that statement.

Fair enough, and the reason for that is... ?

As I understand it the beam splitters that are used to direct a portion of the light entering the lens to the focus and exposure sensors are affected by a linear polarizer, thus the need for a circular polarizer.

From Hoya's website:
How to select the correct Polarising filter:
Many of today's cameras use semi-silvered mirrors or prisms to split the light entering the viewfinder in order to calculate exposure and focusing distance. PL (Linear Polarising) filters can sometimes interact with these items to give unpredictable exposure or focusing. So we recommend that you choose a PL-CIR filter unless you have a manual focus camera which has no beam splitter.

 

[Mellie0119]

Okay- looking for a simple answer here.

I'd like to buy a filter for my 28-135 IS Canon Lens (that goes on my Rebel XT). I want something to protect the lens surface and that I won't have to remove in different lighting situations (if this is possible). I don't mind paying for quality, but don't want to (read DH has forbidden me from) spend a ton of money on a filter. I'm thinking $50 to $75.

Can someone tell me what I should buy?

(I probably should understand why I need/want this fully but I'm trying to grasp more basic photography lessons/principles right now )

 

[jann1033]

Okay- looking for a simple answer here.

I'd like to buy a filter for my 28-135 IS Canon Lens (that goes on my Rebel XT). I want something to protect the lens surface and that I won't have to remove in different lighting situations (if this is possible). I don't mind paying for quality, but don't want to (read DH has forbidden me from) spend a ton of money on a filter. I'm thinking $50 to $75.

Can someone tell me what I should buy?

(I probably should understand why I need/want this fully but I'm trying to grasp more basic photography lessons/principles right now )

i don't know how good the quality is cause i couldn't find any reviews but today amazon has a canon filter for that lens ( uv, what you are looking for i am thinking) for around $20..not sure if it's a sale or maybe cause i bought that lens there it came up a good price but you can check it out there....would also like to know what anyone thinks of canon filters...i couldn't find that particular one reviewed. i know it's tons cheaper than hoya but is it really stinko?

 

[ndelaware]

Okay- looking for a simple answer here.

I'd like to buy a filter for my 28-135 IS Canon Lens (that goes on my Rebel XT). I want something to protect the lens surface and that I won't have to remove in different lighting situations (if this is possible). I don't mind paying for quality, but don't want to (read DH has forbidden me from) spend a ton of money on a filter. I'm thinking $50 to $75.

Can someone tell me what I should buy?

(I probably should understand why I need/want this fully but I'm trying to grasp more basic photography lessons/principles right now )

Get this one:

http://www.amazon.com/gp/product/B0...4891-6802406?_encoding=UTF8&v=glance&n=502394

It's $19.94 at Amazon.

 

[ndelaware]

Fair enough, and the reason for that is... ?

As I understand it the beam splitters that are used to direct a portion of the light entering the lens to the focus and exposure sensors are affected by a linear polarizer, thus the need for a circular polarizer.

From Hoya's website:
How to select the correct Polarising filter:
Many of today's cameras use semi-silvered mirrors or prisms to split the light entering the viewfinder in order to calculate exposure and focusing distance. PL (Linear Polarising) filters can sometimes interact with these items to give unpredictable exposure or focusing. So we recommend that you choose a PL-CIR filter unless you have a manual focus camera which has no beam splitter.

After reading your response to me I think I may have misinterpreted what you were trying to get across. In your first post on this thread it sounded to me like you were saying that using a polarizing filter was a must at all times. That was all I was disagreeing with. You were absolutely right about the fact if you are going to use a polarizing filter, you should use a circular polarizing filter. My apologies.

 

[boBQuincy]

After reading your response to me I think I may have misinterpreted what you were trying to get across. In your first post on this thread it sounded to me like you were saying that using a polarizing filter was a must at all times. That was all I was disagreeing with. You were absolutely right about the fact if you are going to use a polarizing filter, you should use a circular polarizing filter. My apologies.

And I apparently misinterpreted your original response, my apologies also.

I do like to use a polarizer whenever there is sufficient light to do so, I feel it is the one filter that can improve almost any image. But I have to admit that as you noted, not everyone would agree with that.


best regards,

boB

 

[jann1033]

Get this one:

http://www.amazon.com/gp/product/B0...4891-6802406?_encoding=UTF8&v=glance&n=502394

It's $19.94 at Amazon.

that 's the one i got...then read it isn't coated and should be one place then that it was pretty good another so ...guess i'll have to see for my self and maybe use Kelly's redundancy with filter and hood? anyway it should all get here at the same time today

 

[ndelaware]

jann, I only bought the filter for protection. If wanted a multi-coated filter I would have bought the Hoya for $50. This filter will work fine for you. It will protect your lens from dust and dirt and scratches without affecting your images.

Just so you know, the hood on the 28-135 will block the built-in flash a little in the bottom of your image. I only say that in case you are going to leave it on all the time for protection.

 

[OCSurfCity]

Bob is correct. If you own an AUTOFOCUS SLR, you must use a Circular Polarizer filter. If you have a film SLR camera, you use a Linear Polarizing filter.

On a Circular Polarizer, you rotate the outside polarizing after autofocusing to its darkest point. Then take the image.

 

[PoohJen]

fwiw...foundthis article discussing filters in general and comparing brands.