Have You Tried a Red Filter?

wxwax

Wandering around downtown yesterday, I saw a water tower with some character, with a touch of golden light. So I contorted for a while, and finally got a semblance of a decent composure.

I played with the shot this morning. I decided to use Andy's luminosity toning to add some yellow to enhance the golden light. The only thing I did different was to use the Saturation blending mode instead of Andy's suggested Color blending mode.

So here's what I ended up with.



It's OK, but I had nagging doubts about it. In particluar, I thought it might be too dark. It's like I knew that something was missing, but being a n00b to photoshop post-processing I didn't know what to change.

Then, like a single cloud drifitng across a clear blue sky, a thought crossed the blank canvas of my mind. Hey, I said to myself, they use red filters to make the sky look a deeper, richer blue, don't they? So lemme try some red, see what happens.

So I used Andy's method again, this time with a bright red. Again, I used the Saturation blending mode instead of Andy's suggested Color mode.

The difference to the sky was amazing. It also added a ton of pop to the golden colors, which surprised me. I had to mask out the red from all the shadows - it created a kaleidoscope that looked ugly. And it took some detailed work to mask out the purples etc. from the fine ironwork at the bottom right of the water tower.

But once that masking was done, the red had transformed the piccie, in my opinion. It makes me want to try green and yellow on landscapes, as I believe photographers use those filters.

cletus

Sid,

If I'm understanding your post, it shouldn't make any difference what hue (red, yellow, green, etc..) you use, as long as the saturation stays the same. All the saturation mode does is take the saturation of a pixel on the current layer and apply it to the pixels on the underlying layers.

Example:

Original Image:

Here is a pattern I came up with. The hue changes, but the saturation is a constant 100%:

Now I put the pattern on a layer above the original image and change the mode to Saturation:

And to take things one step further, I modified the pattern. I made a gradient with constant hue (I used red, but any hue would work) and faded the saturation from 100% to 0%:

I placed this on a layer above the pattern and changed the mode to Saturation. The Gradient and Pattern combo looked like this:

Note: Interesting how all six columns ended up being a differnt shade of gray at 0% saturation. Another example of how Photoshop treats Red, Green and Blue differently.

And the Gradient/Pattern Combo in Saturation mode above the original image:

None of the hue changes are visible, but the Saturation gradient is.

wxwax

Very interesting. So the effect on the sky and the water tower would have been the same if I'd used green instead of red?

wxwax

I just tried it with green, and I see that you are correct.

So how do I mimic the effect of yellow and green filters that are placed over lenses?

digismile

wxwax wrote:

I just tried it with green, and I see that you are correct.

So how do I mimic the effect of yellow and green filters that are placed over lenses?

Sid,

If you're using CS, it now has Photo Filters to imitate the camera filters. But to get virtually an identical effect you can do the following:

1. Add a new layer and fill it with the colour of the desired filter, eg. the cool blue would be RGB 0,109,255.

2. Change the opacity to something low, 10 - 20.

3. Then change the blending mode. I usually use Overlay, but sometimes color, the difference is quite subtle. If you want to know the difference between the two, look it up in Photoshop help.

Regards,
Brad

wxwax

Thanks Digi.

I've been playing a bit with the different blending modes the last couple of days. Here's a shot of a local musician from this week. I followed the classic duotone rules, using a mocha layer and Multiply mode.



Almost absent-mindedly I later went back (thank goodness for saving as a layered dcoument!) and tried other blending modes. Here's what the mocha highlights look like in Difference mode. Quite a bit different. I must remember to not get locked into always doing these things the same way, but to play with other options.

Andy

digismile wrote:

Sid,

If you're using CS, it now has Photo Filters to imitate the camera filters. But to get virtually an identical effect you can do the following:

1. Add a new layer and fill it with the colour of the desired filter, eg. the cool blue would be RGB 0,109,255.

2. Change the opacity to something low, 10 - 20.

3. Then change the blending mode. I usually use Overlay, but sometimes color, the difference is quite subtle. If you want to know the difference between the two, look it up in Photoshop help.

Regards,
Brad