UV Filters

[Brianbar]

I need to purchase a 77mm UV filter for my 17-40L lens.
The B+W UVA 010 appears to have a very good rating, but what about Canons own, and for once Canon is less money than B+W.
Any thoughts.

Thanks
Brian

[WestFalcon]

I personally don't think that any quality filter affects your picture....Canon, B&W, Tiffen,Hoya....research(article I read in Popular Photography many years ago) tells us they are all the same.....Cheapos may affect your pix but the good ones will not...go for price...I like the Canon filters

[PhotosGuy]

(article I read in Popular Photography many years ago) tells us they are all the same

The old filters were perfectly flat 'cause film was a dull gray surface. New digital sensors are like mirrors & reflect light back to the lens, which reflects back. So the best digital filters are curved to avoid that.

[Hellashot]

There are different grades of UV filters. There is a standard UV filter all the way up to blocking 100% of UV light. I know Tiffen has these different grades. A standard UV filter will appear like clear glass whereas a 100% or "almost all UV light" filter will appear lightly grey.

[robertwgross]

The old filters were perfectly flat 'cause film was a dull gray surface. New digital sensors are like mirrors & reflect light back to the lens, which reflects back. So the best digital filters are curved to avoid that.

Where did you get that?

It is totally fictional.

Filters are flat, pure and simple.

If a digital filter were curved, it would act like a lens.

---Bob Gross---

[CyberDyneSystems]

I use the Canon filters and am quite content.. the only thing I have noticed as that the Hoya UV I have has stood up t more punishment longer with far fewer scratches resulting (in fact zero)

[WestFalcon]

(article I read in Popular Photography many years ago) tells us they are all the same

The old filters were perfectly flat 'cause film was a dull gray surface. New digital sensors are like mirrors & reflect light back to the lens, which reflects back. So the best digital filters are curved to avoid that.


Show me your research(source of info) on that photoguy...curved glass would bend light and that's called a lens and I don't think filters bend light...not UV filters...they use coatings to stop reflections

[robertwgross]

Show me your research(source of info) on that photoguy...curved glass would bend light and that's called a lens and I don't think filters bend light...not UV filters...they use coatings to stop reflections

My sentiment, exactly.

---Bob Gross---

[PhotosGuy]

LOL! I thought that would get a rise out of some of you! What you've said about filters is true except that "they use coatings to stop reflections" is only partially true if you change 'filter' to 'protective glass', & my source is... wait for it... Canon!
Page 140 of "EF Lens Work III": "Reflective Characteristics of Image Sensors" & Use of Meniscus Lenses".

It relates to the flat protective glass in front of the first lens unit on Super-telephotos, which include the EF300mm f/2.8 IS USM. To prevent internal reflections from the sensor, "meniscus lenses are used as the protective glass on all of Canon's large aperture IS super-telephoto lenses." So "light reflected off the image sensor forms an image in front of the image sensor & then disperse. Since almost all the light which is dispersed does not hit the reflective elements, this prevents ghosting while at the same time achieving high contrast for the resulting image."

So, super-teles already have a protective glass in front of the first lens unit, & if you add a 'protective' UV, etc. filter to the lens, you may degrade your image due to internal reflections from the sensor. I thought that was an important point & wanted to get everyone's attention. Apologies for the cage rattling, & I hope everyone feels better now as you remove the expensive UV filters from your big glass. :wink:

[robertwgross]

LOL! I thought that would get a rise out of some of you! What you've said about filters is true except that "they use coatings to stop reflections" is only partially true if you change 'filter' to 'protective glass', & my source is... wait for it... Canon!
Page 140 of "EF Lens Work III": "Reflective Characteristics of Image Sensors" & Use of Meniscus Lenses".

It relates to the flat protective glass in front of the first lens unit on Super-telephotos, which include the EF300mm f/2.8 IS USM. To prevent internal reflections from the sensor, "meniscus lenses are used as the protective glass on all of Canon's large aperture IS super-telephoto lenses." So "light reflected off the image sensor forms an image in front of the image sensor & then disperse. Since almost all the light which is dispersed does not hit the reflective elements, this prevents ghosting while at the same time achieving high contrast for the resulting image."

So, super-teles already have a protective glass in front of the first lens unit, & if you add a 'protective' UV, etc. filter to the lens, you may degrade your image due to internal reflections from the sensor. I thought that was an important point & wanted to get everyone's attention. Apologies for the cage rattling, & I hope everyone feels better now as you remove the expensive UV filters from your big glass. :wink:

This is all a bunch of bull. If you read the topic, it is UV filters, not front elements on long Canon lenses. So, your point here isn't wrong, it is just misleading. Have you ever considered a career in politics?

---Bob Gross---

[CoolToolGuy]

I personally don't think that any quality filter affects your picture....Canon, B&W, Tiffen,Hoya....research(article I read in Popular Photography many years ago) tells us they are all the same.....Cheapos may affect your pix but the good ones will not...go for price...I like the Canon filters

I agree. B+W, Hoya, Tiffen, Canon, etc. are all good filters. Just say no to Promaster, Sunpak, Quantaray, etc.

There is a point to consider about using a coated filter to reduce flare. It has caught my attention recently, and I am slowly getting multicoated filters for all of my wide-angle lenses and zooms.

Have Fun,

[PhotosGuy]

Misleading I'll admit to & I've already apologized for that, but the info is still relevant to UV filters on lenses.
Plus, using a coated filter won't stop the internal reflections, or Canon wouldn't have had to curve the protective glass in front of the first lens unit.
So be advised.