Here's the detailed explanation on how you can create the lomo effect with Photoshop CS5.
Step 1: create a vignette
- Select Marquee tool, and set the "feather" to 66px (assuming your image width is 800px). A rule of thumb is to divide the width in pixel by 12 to get the feather number. Draw your box over the image;
- From the menu chose select ♥ inverse;
- While the image is still highlighted by the Marquee tool, create a new layer;
- Select paint bucket tool, and fill the image with black. Press "CRTL D" to deselect;
- Select "Levels". A levels box with histogram will appear. Adjust the levels by moving the middle grey slider to the right, to darken the edges to create the effect;
- In addition to the above level adjustment, you can also chose to pull the white slider to the edge of the histogram mountain, where it begins to rise. Do the same to the black slider on the left side.
- First flatten the image by selecting all layers, and go to layer ♥ merge layers. Or right click the selected layers and click on "merge layers";
- Next, add a new curve layer, and create a slanted "S";
- Create a new layer (on top of the other two layers). Select paint bucket, pick a black color, and fill the new layer with black;
- In the layer window, at the top left scroll down selection, click "Hue" to change the blending mode. Your image should be grey in color. Reduce the opacity to 40%, and colors will start to appear.
- Flatten the photo once again, by selecting all layers, and go to layer ♥ merge layers;
- Then sharpen by selecting image ♥ mode ♥ lab color;
- Under "channel" window, click on "lightness channel". The other 3 channels will automatically be deselected.
- Go back to the "layer" window, select filter ♥ sharpen ♥ unsharp mask. Set "amount" to 50%, "radius" to 50%, and "threshold" to 0;
- Go to image ♥ mode ♥ RGB color;
- Save as Jpeg.