I’m not a huge HDR (High Dynamic Range) fan. I see a lot of people putting a lot of effort into an image to expand the dynamic range of their photos only to convert it back to an 8 bit JPEG to show on the web. A lot of them are over done and not realistic looking.Наливной бетонный пол
In theory, HDR is useful when your scene has a wide range of tones, deep blacks and bright highlights that’s hard to get right in the camera. You know the frustration, to expose for the really bright areas means the photo goes too dark or you get the main photo right and too much is blown out.
So the basic principle is that you bracket your shots in camera, one shot to record shadow detail, one to record mid-tone detail and one to record highlight detail. Then you bring the three photos into Photoshop and blend them pulling the good parts into view. There are a lot of techniques for doing this but the principle is that of most compositing where you erase what you don’t want to let the lower layers show through. Depending on the complexity of the photo, the masking/erasing part can be very time consuming.
I’m lazy and I really don’t care for the whole HDR look anyway. But there are times where you really need to use the techniques to save a photo. Now in my case, I typically do not plan well enough in advance to bracket in camera, but I shoot RAW and that gives me a great tool to try and salvage highlight and shadow detail. Sometimes I’ll only use two exposures of one frame, one is the base exposure and the second one to “fix” my problem.
Yesterday we had a fantastic sunset. There were all kinds of incredible hues and cloud textures. I’m very impressed with my Nikon D200. I set the camera to -1.0EV while shooting in Aperture preferred mode to get richer hues and avoid the natural over exposure from the bright sky. But I left the camera in Auto white balance. However, there are NO whites in the scene, but somehow the camera did a good job getting the colors right. But realizing that the AWB was unpredictable in this situation, I set the camera to daylight, to simulate daylight film.
The sky had some rich orange and red hues and there were blues from the approaching twilight and a band of sky blue just above the horizon. When I got the images off camera, I had lost my blues. Remarkably, the AWB shots were the closest. But this seemed like a great opportunity to get this right using my faux HDR technique, but instead of dealing with light and dark, I chose to do it with white balance instead.
The first thing I did was expose in Camera Raw for my oranges. I set the white balance to 5200K, which is daylight and made my normal contrast and saturation settings and loaded that image into Photoshop.
My normal settings bump contrast from +25 to +50. I boost Clarity from 0 to around+35. Vibrance gets bumped to the +25 range and then Saturation gets set to what every I feel like. For this image, it was around +6.
Then I went back to Camera Raw and set the white balance to 3200K which gave me the blues that I needed and loaded that image in. Since ACR remembered all my previous settings, I could just mess around with the white balance until I got the light blue band I remembered. Clicking “Open Image” brought the second copy into Photoshop.
Once I had both photos loaded, I used the “Move” tool and dragged the Orange image onto the Blue image. At this point, I’m done with the Orange image, so I closed it. The photo I have left now has two layers, the blues are on the background layer and the oranges are on layer 1.
I could have used the eraser tool and erased holes, but i would have not looked very smooth. I could have taken hours using masks to try and deal with the complexity of blending the oranges and blues. But Photoshop makes this easy.
There is a wonderful tool called “Select Color Range”. Its under the “Select” menu and called “Color Range”. This tool lets you use the eye dropper and click on a color and it selects colors close to it. You can adjust the fuzziness to select more or less colors. This is the primary tool for doing chroma key knock outs.
So for this photo, I clicked on the EyeBall in the Layer pallet for the orange layer to hide it. Then using Select->Color Range, I clicked on the blues in the sky. This tool is really good and dealing with smooth partial area selections.
On the actual photo, it shows whats being masked out in red and whats being selected in its natural colors. In the dialog box, you get a black and white mask. Unfortunately my screen capture tool I use requires pressing the Apple key which in Photoshop causes the dialog box to show the actual colors, so the screen shot on the right isn’t accurate to what you will see.
With this tool, you pick your color. You then adjust the fuzziness to select what you want. You can use the +dropper to add additional colors to the color range, or -dropper to take out some colors you want to keep.
When you click OK, your main image is left with marching ants that show the rough area that will be selected.
At this point, I clicked on the eyeball on the hidden orange layer and made sure it was the selected layer.
I then hit the <DELETE> key to erase the selection from the top layer to let my blues through. At this point I’m almost done. My sky blue band at the bottom didn’t select well using this technique. I could have gone back using the tool a second time to select that color range, but for this stripe, it was easy enough to grab a 200px soft eraser brush and erase the hole.
Finally I saved the multi-layer file as a Photoshop PSD file, flattened the image to make it into a single merged layer, resized and saved as a JPEG for uploading to Flickr.