SJBlake

... Black and White photo filters. Hi folks, I'm brand new to this ng and this is my first post. I've been an amateur photographer for 30 years and use Photoshop 7 with a Nikon Coolscan IV as my "darkroom".

I think that the channel mixer is a fantastic tool for creating B&W images from colour ... definitely more versatile than using B&W film (apologies to purists ... my view).

Can anyone tell me or point me to an info source that lists the RGB values that correspond to different B&W filters? Again, if you were shooting B&W it wouldn't be practical (or cost effective) to carry around scads of different filters for different situations, when it can be done in PS.

Sure I can fool around with the sliders (and do) but for better pre-visualization, it would be nice to know the exact values to duplicate filter factors. I've attached an example. This picture started out as a rather nondescript picture in colour ... it looks better this way.

Sorry for the long post. Please let me know if this is generally too long for this ng.

Thanks for all replies.

SB

Stroker

Sorry for the hit-n-run, but I'm in a time crunch right now.

For starters, I recommend getting to know Image > Adjust > Curves.
Intro to Curves by Steve.
Once you start getting the hang of Curves, some really cool things can be done. I'll explain a really cool trick later. BTW, good idea to use Curves as an Adjustment Layer.

If you really want to simulate a lens, I'm sure there is a way. I think it would involve scanning the lens (or getting the lens colour), and then using Blending modes, Apply Image, or Calculations.

SJBlake

My mistake was only looking at the file size requirements and not the pixel dimensions ... this one should work.

SB

Stroker

I got to thinking about it and realized that I'm confused.

Okay, you are starting with a B&W photo. Taken with B&W film.
Or are you starting with a colour photo and looking to change to B&W with PhotoShop?
I believe the latter considering your comment about the purists.

Also, what kind of special lenses are you talking about? From what I remember, there are two basic categories: colour tinted and groovy effects.
I believe the former due to, again, your comment about the purists.

I just want to be absolutely clear about this.

SJBlake

Thanks Stroker. Sorry for the confusion ... starting with a colour negative/file. I'm not talking about spec effects filtrations. Talking about the kinds of filters that B&W photogs will use with B&W film eg Wratten #25 Red ... this filter with B&W film will have a specific effect such as turning the sky black.

I want to do the same thing in PS and need to know the filter values for "standard" B&W filters that a photog would use with B&W film. There's a lot of them.

Cheers.

SB

Stroker

Thank you.
I know several approaches to this.
So do some of the others around here.
Unfortunately, I don't have the time right now.

It's a race to get the cookie!
To get a jump start on the competition, read Brush Making. In there, I chat briefly about using Adjustment Layer > HSB and Adjustment Layer Curves to convert colour to B&W with better control.

wbiss

Welcome to the forum SJBlake!
Sorry, not specifically... in fact, I did a search and couldn't find anything remotely like what you are looking for. [confused]

In my opinion, it's a matter of playing with the various RGB channels. For example, take a look at these tips http://robertdfeinman.com/tips/tip12.html

I hope that this helps!

SJBlake

Thanks Wendy. I have in fact visited this site before and there's lots of good info. I'm not sure that he's entirely accurate in saying that the green channel is equivalent to a Wratten#11 ... maybe it is, maybe it's just close. He also mentions a Wratten #8 Yellow but doesn't give the RGB values.

I know the info's out there somewhere but I too came up blank when I googled it.

Thanks for your thoughtful reply.

SB

Stroker

I'm going to break this down into two different things:
1. Simulating a lens with proper info and application.
2. Tricks for turning a colour photo into grayscale, and/or colour correction.

I've thought about it, and I will not help with #1. I hate to say it, but I'm not going to.

On the plus side, I am more than willing to help with #2.

What say you, SJBlake?

SJBlake

Thanks for the offer Stroker ... I already do #2 fairly regularly. I'm looking to refine my overall approach with some of the filtration info I'm looking for.

OTOH I'm always interested in learning new tricks and shortcuts.

SB