Photographic technique Red Filter 25A
As you can see from some of these entries, I like walking in wild places, and taking landscape photographs …… another means of expression, of who I am, I suppose.
Mostly, I do colour transparency, wide angle [20mm] with a polarizer filter. My treatment of Black and white landscape technique though, is different to every other subject I’m interested in.
I shoot almost exclusively with a red 25A filter, to add a shovel-load of drama to a photograph. At least a third and sometimes two thirds of an image, is of the sky. Without adjustment, this ends up over-exposed, resulting in a huge white space. And leads to quite uninteresting work really!
A red filter, darkens blue considerably, and hence adds contrast to the scene, accentuating the clouds, beautifully. With traditional printing technique [ie: in the darkroom] , it means a print is a lot easier to make, without excessive need for the dodging in of the sky.
Now, with digital photography, there is a convergence between these techniques and materials.
This picture here was shot on colour slide. Fuji Provia 100asa 35mm. You can see the full colour version, in the previous blog entry, below. However, have just learned this technique. After scanning image in the usual way. Can now make a black and white image as if shot using a 25A red filter, derived from a colour transparency.
Open in PhotoShop. Go to Image > Adjust > Channel Mixer.
Channel Mixer dialog box opens, sliders add or subtract colour from each colour channel. Click the monochrome option.
Then, adjust slider to the following values:
Red +200
Green 000
Blue -100
Exposure can then be lightly adjusted using the ‘Constant’ Slider. Contrast can be tweaked, in the brightness & contrast slider dialogue as usual.
So long as ‘all’ the values add up to 100, image will be adjusted without any loss of highlight or shadow detail.
Earlier examples of the technique, with some pictures of Snowdinia last month.
http://tash_lodge.blogspot.com/2002_09_15_tash_lodge_archive.html#81683594
