Filters ???

[Bobby Ironsights]

Hi, I've been reading around about filters. But I'm a little confusticated.
(I use film, not digital)

I sometimes notice a yellow cast to indoor photo's taken where incandescent light is present.

I've found this about it.

Standard light bulbs are much warmer than daylight, only about 2900 K for a 100-watt light bulb. In the film days, you would get a very pronounced yellow cast without a blue filter over the lens (Kodak says 80A + 82B).

But why would I need two filters instead of one? Isn't there one filter that is good enough, or is this a "use filter x OR filter y" scenario that I'm just misreading?

Also, while looking around for filters I found this...

UV Protector - Protects lens from dust, moisture, scratches, and breakage.

812 Color Warming Filter - Exclusive Tiffen filter. Improves color of all skintones; absorbs blue cast often caused by electronic flash or outdoor shade. Adds warmth to pale, washed-out flesh tones. Ideal for portraits.

Essential for outdoor photography; deepens intensity of blue skies; reduces or eliminates glare. Use circular polarizers for auto-focus cameras, as recommended by the camera manufacturer.

I'm particularly curious about that last part.....circular polarizers.....

Are circular polarizers just another type of filter, or a whole segment of filters, filters made for autofocus cameras? or....hmmm....

Can anyone point me to a comprehensive lens filter tutorial......or maybe

just maybe...

someone clever should write one and put it in the resource portion of this website......I know I'd be grateful.....

just a thought.:meh:

 

[Big Mike]

Standard light bulbs are much warmer than daylight, only about 2900 K for a 100-watt light bulb. In the film days, you would get a very pronounced yellow cast without a blue filter over the lens (Kodak says 80A + 82B).

But why would I need two filters instead of one? Isn't there one filter that is good enough, or is this a "use filter x OR filter y" scenario that I'm just misreading?

I think they mean either\or. You shouldn't need both. You can also get tungsten balanced film...which wouldn't require a filter (unless you moved back out into the sun or used flash).

UV Protector - Protects lens from dust, moisture, scratches, and breakage.

That's pretty much it. People use them for protection...it's better to replace a $40 filter than a $600 lens.

812 Color Warming Filter - Exclusive Tiffen filter. Improves color of all skintones; absorbs blue cast often caused by electronic flash or outdoor shade. Adds warmth to pale, washed-out flesh tones. Ideal for portraits.

That sound right to me.

Essential for outdoor photography; deepens intensity of blue skies; reduces or eliminates glare. Use circular polarizers for auto-focus cameras, as recommended by the camera manufacturer.

I'm particularly curious about that last part.....circular polarizers.....

Are circular polarizers just another type of filter, or a whole segment of filters, filters made for autofocus cameras? or....hmmm....

Polarizers are a type of filter...and the best filters, IMO. They don't do much (or anything) indoors but when used outdoors when the sun is shining, they can make a world of difference. The circular ones can be adjusted...and will allow a camera to autofocus. If I were to suggest one filter...it would be a circular polarizer.

someone clever should write one and put it in the resource portion of this website......I know I'd be grateful.....

I think something may be in the works

 

[ksmattfish]

Standard light bulbs are much warmer than daylight, only about 2900 K for a 100-watt light bulb. In the film days, you would get a very pronounced yellow cast without a blue filter over the lens (Kodak says 80A + 82B).

But why would I need two filters instead of one?

An 80A filter balances 3200K photo flood bulbs. They are tungsten filament bulbs, but still noticably cooler than household tungsten bulbs (2900K). An 80A filter would take care of a lot of the orange color cast, but not all of it. Actually, I kind of like this look for indoor shots.

An 82B is a medium strength cooling filter. Used with tungsten balanced film (3200K), or daylight balanced film and an 80A, it balances the color temp at 2900K, which is what Kodak is saying a household bulb is.

Polarizing filters come in linear and circular varieties. Linear pols can bamboozle some auto focus systems, so circular pols are recommended for AF cameras.

#80 filters are color temp conversion filters. They balance the color cast from certain bulbs and films.

#81 filters are warming filters. Commonly they use letters: 81A, 81B, etc... Tiffen created the 812 (81-2). It's a slightly different shade of salmon/pink than the others.

#82 filters are cooling filters.

http://en.wikipedia.org/wiki/Wratten_number

 

[Jeremy Z]

This will come in handy. I just added it to my photography favorites:

http://www.aeimages.com/learn/color-correction.html

 

[henryp]

I sometimes notice a yellow cast to indoor photo's taken where incandescent light is present.

An 80B filter should adequately correct your indoor (non-fluorescent) lighting with daylight film.

Are circular polarizers just another type of filter, or a whole segment of filters, filters made for autofocus cameras? or....hmmm....

A pol fillter darkens the blue areas of the sky (the effect varies depending on the angle of the camera to the sun), and blocks reflections from non-metallic surfaces. It's very useful for a variety of shots but practically useless for portraiture. Basically pol filters are divided into two types -- linear (a/k/a top) and circular which are designed to operate with modern autofocus cameras.

Can anyone point me to a comprehensive lens filter tutorial.

Try here.

 

[fmw]

I'll make one comment about linear and circular polarizers. A test we did some years ago showed that the linear polarizers filter polarized light more effectively than circular ones do. The circular ones are a compromise design to obviate any potential problems with autofocus systems - some of which won't work all the time with linear polarizers. Linear works better, circular works with all cameras.

And, yes the 80B should come close to correcting the color temperature of household tungsten bulbs for daylight film. Remember there are different films designed to optimize color at various lighting color temperatures. All these filters are designed to correct one one temperature of lighting for one type of film. Even daylight has different color temperatures depending on the time of day, cloudiness etc. etc. It can be confusing.

Nice to see Henry Posner from B&H posting. I remember his excellent posts from way back in the rec.photo newsgroup days.

 

[RacePhoto]

I'll make one comment about linear and circular polarizers. A test we did some years ago showed that the linear polarizers filter polarized light more effectively than circular ones do. The circular ones are a compromise design to obviate any potential problems with autofocus systems - some of which won't work all the time with linear polarizers. Linear works better, circular works with all cameras.

And, yes the 80B should come close to correcting the color temperature of household tungsten bulbs for daylight film. Remember there are different films designed to optimize color at various lighting color temperatures. All these filters are designed to correct one one temperature of lighting for one type of film. Even daylight has different color temperatures depending on the time of day, cloudiness etc. etc. It can be confusing.

Nice to see Henry Posner from B&H posting. I remember his excellent posts from way back in the rec.photo newsgroup days.

AND... (I've been waiting for someone to add this)

Through the lens light meters, auto or manual are affected by polarizing filters, you need the circular because of this, along with potential autofocus problems.

Here's a nice web page explaining the differences between linear and circular and how to test an unknown filter and see which it is, by looking in the mirror and holding it up.

[SIZE=+1]http://www.popphoto.com/pdfs/2002/0902/Polarizer.pdf

[/SIZE]

 

[fmw]

AND... (I've been waiting for someone to add this)

Through the lens light meters, auto or manual are affected by polarizing filters, you need the circular because of this, along with potential autofocus problems.

Here's a nice web page explaining the differences between linear and circular and how to test an unknown filter and see which it is, by looking in the mirror and holding it up.

[SIZE=+1]http://www.popphoto.com/pdfs/2002/0902/Polarizer.pdf[/SIZE]

Not in my experience. I've never had a linear polarizer foul up TTL metering. Not in 30 years of TTL metering with 20 or 30 different camera bodies. Never. The truth is I haven't encountered any problems with auto focus either although I know some people that have.