another orange filter question

I have a "Pro Quality 58mm YA2" orange filter, and I am not sure I

know all that I should about using it in B&W photography.

 

I would appreciate any info specifically on the uses of orange

filters.

 

And finally, a 1980s National Geographic Field Guide book advises

using an orange filter with color film 'in order to make colors

warmer' - is there smth wrong here? Or do orange filters have uses

with color film as well?

 

Many thanks

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=002jz6

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=000N4z

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0009oI

I think the article referred to a warming filter, with a very light brownish tone, like the 81 A filter.

I don't know what a YA2 Orange filter is. As mentioned above, the ones used for color have a very slight orange tint. If the filter is for use in B&W photography (turns everything orange when you look through it), it would be normally used outdoors to darken the sky and improve cloud contrast on a sunny or partly sunny day. On a completely overcast day, an orange filter will be much less effective. TTL lens meters may cause underexposure with orange filters, so you may need to adjust accordingly.

As Mark said color filters are used in B&W photography outdoors most often to change the appearance of sky by absorbing blue to different degrees. Red filters absorb lots of blue (can make skies look dark to black) while yellow filters absorb less blue making skies look more natural than unfiltered shots. Orange falls somewhere in between. Because each filter absorbs and transmits colors to different degrees we can use them to alter the relationship of various colors in the scene to effectively change their appearance. Certain colors can appear very much alike on B&W film. Filters can help with that problem. Although I use only B&W films, in my experience filters for use with color films are much more subtle in color. An orange filter intended for use with B&W films would certainly turn a color picture - well err - orange.