red filter

[ifurlong]

I am wondering, if the intention is to produce a B&W image, if using a red filter(like with film) will, in the usual way, improve the the final result, anyone try this or know. I use a 10d. Thanks, Ian.

[PacAce]

Or you can try just pulling the image info from the Red channel.

[ifurlong]

nice, Iwill try that

[msvadi]

As I understand, a red filter is used to improve contrast for film B&W. I don't believe it's useful for digital, there are so many different ways to improve contrast in PS.

Actually, PS has photo filters (adjustment layers). I'm not sure what's the purpose of it. Sometimes I use yellow filter for toning B&Ws.

By the way, IMHO, a B&W image pulled from the red channel alone is quite soft and not contrasty, so, it's, probably, the oposite of what you want.

[kb244]

A red filter is often used to increase contrast, but can also be very useful if you are shooting with Infared Film ( although its best to use an IR filter with IR film, depending on what kind it is, to block out all the light you dont want interfering ).

Far as film goes, I'm not sure how the pulling of the red channel works, I know with digital, you can in Photoshop, Goto Lab mode, select lightness channel, choose greyscale , discard the other channels, duplicate the layer, and do multiply blending, and decrease the opacity to where you feel appropiate, should give it a much more dinstintive look in terms of BW.

[PhotosGuy]

B&W film + red filter: It will make red items look 'whiter' & blue-green items look 'darker'.
So, blue sky may look dark. Red berries will look light.

[LaiLai]

I've used an orange filter a couple of times with my rebel. I've found in daylight, it is so so. The Rebel has problems with focusing a bit with it on, definitely not as sharp all the time as it is without the filter. (Using the kit lens)

[kb244]

I've used an orange filter a couple of times with my rebel. I've found in daylight, it is so so. The Rebel has problems with focusing a bit with it on, definitely not as sharp all the time as it is without the filter. (Using the kit lens)

I've avoided using filters of that nature with digital, except in the case of something like an IR filter, or polarizer to get effect you would not normally or would be hard to get done in photoshop.

[INV]

Interesting Post. I am looking at purchasing an orange 21 filter for Crime scene work. We use it with the Alternate Light to bring out the detail on a Latent Fingerprint. It will be interesting to see how well it works.

:?

[Desperate Dan]

I read a field-test that concluded that IR filters and heavy-red glass filters don't really work on the Canon EOS digitals.

For B&W art photos, have a look at these filter-simulating Photoshop Actions (and avoid the Channel Mixer like the plague!)...

http://www.creativestoke.org.uk/action.html

http://www.fredmiranda.com/DBWpro/

[Flyball Rebel]

Interesting Post. I am looking at purchasing an orange 21 filter for Crime scene work. We use it with the Alternate Light to bring out the detail on a Latent Fingerprint. It will be interesting to see how well it works.

:?
Sounds interesting work INV, Let us know how it goes. [F.R.] :)

[Dixcee]

To get the most out of filters with the Canon 10D and Rebel Digital it's suggested you disable AWB(Auto white light balance) or it will override the filter color. change the setting to 'daylight'. This also applies to using color correction filters. Shooting with B&W filters (red, green, yellow, orange etc) will help your image(as it would with film) when you convert it to monochrome in image post-process software.

[PhotosGuy]

...it's suggested you disable AWB...
Good point!