chris.bailey
8th of February 2005 (Tue), 10:05
I have been trying to montage together pictures of a number of buildings I have been involved in to create a cityscape that looks at least part way realistic. Other than the problems of light direction etc, a major issue has been to create a realistic depth of field. A tutorial on using Lens Blur in CS for a totally different purpose gave me the hint I needed and as I can see a lot of uses for it its worth sharing the basics. (Aplologies if this is outlined somplace else)
Lens Blur creates a far more realistic bokeh than using say Gaussian Blur but the great thing about it is the Lens Blur dialogue allows the use of a Depth Map or mask. So..
1) Take the picture you want to create a depth of field to.
2) In Channels, add a new channel and fill it with a gradient or gradients so that all black is the area you need to be in focus and white is totally out of focus.
3) Go to the Lens Blur filter and adjust the settings so the wholly out of focus is how you want it to appear.
4) Finally in the Depth Map dialogue load the Alpha1 Channel and bits of the picture pop back into focus. You can then fine tune the Depth Map mask with the the Focal Distance slider.
The end rsult is very realistic.Have a play.
Lens Blur creates a far more realistic bokeh than using say Gaussian Blur but the great thing about it is the Lens Blur dialogue allows the use of a Depth Map or mask. So..
1) Take the picture you want to create a depth of field to.
2) In Channels, add a new channel and fill it with a gradient or gradients so that all black is the area you need to be in focus and white is totally out of focus.
3) Go to the Lens Blur filter and adjust the settings so the wholly out of focus is how you want it to appear.
4) Finally in the Depth Map dialogue load the Alpha1 Channel and bits of the picture pop back into focus. You can then fine tune the Depth Map mask with the the Focal Distance slider.
The end rsult is very realistic.Have a play.