Art & Design 265
Course Home Page | Image Drop Boxes | Semester Schedule |
Week: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16
High Dynamic Range Images on Flickr |
These three images, below, vary in exposure — they are bracketed exposures.
The left image is about 2 stops over-exposed,
the middle is "correctly exposed" and
the right image is about 2 stops under-exposed.
Using Photoshop's Merge HDR tool, the three exposures — the three images — can be combined to produce an HDR image in which a much broader range of value contrasts are sustained throughout the image.
Photography has always been limited by the range of light and dark that can be captured by film or by digital sensors, campared to the dynamic range of luminance that the human eye can see. Basically, a camera cannot capture the full range of light and dark that you can observe.
High Dynamic Range imagery involves using several different exposures to create a single image.
Background and Info: WikiP | CambridgeColor*** | Pixiq |
Flickr HDR Group Discussion Topics | Bracketing Exposure Bracketing |
Samples: | Captain Kimo | HDRCreme | Smashing |
Tutorials: A collection of tutorials | Handheld-HDR Shooting | Photoshop Steps | Photoshop Basix Video Tutorial on HDR***
Photoshop Steps | Photoshop-Photomatix Steps | PS-Photomatix Steps & HDR Intro |
This website has an abundance of outstanding, practical and impressive information on creating HDR images.
Pics To Play With
This photographer has shot some outstanding HDR images -- some of which are posted here. However, he has also posted several sets of source images so that you can download his sets of exposure bracketed images, and then try Photoshop/Photomerge, or HUGIN to manipulate the images yourself.
For next week's Photoshop exercise, you'll use (at least) three images and create at least 3 images.
You can use the highly-automate Photoshop tools, or you can dare to take more power to yourself with more manual methods.
Photoshop CS5 Merge HDR
Creating an HDR Image from a Photo Set — a useful step-by-step written tutorial.
Create enhanced HDR images with HDR Pro — a very nice video tutorial on the entire process in CS5
Richard Harrington's UAP Intro to HDR Pro — a very good video on the process and tools.
Features that support 32‑bpc HDR images — Photoshop can create, and edit "deep" 32-bit image files. These offer far more nuance and range of tone and color than can be displayed in a single image. However, not all of Photoshop's tools can be used on a 32-bit image. The Photoshop tools listed here can be used to refined the traits you want to pull out of that deep image. (see also: Adjusting Dynamic Range in 32-bit Images)
Try Hand Stacking and Masking Images:
In Photoshop, put each image on its own layer...
ideally you've got several identically framed images (i.e. you used a tripod).... if not, drag the images so that they line up correctly.
You may set the upper image(s) to 50% transparency so you can see the alignment.
You may have to rotate one or more images.
The tricky part involves creating layer masks to expose the best exposed region of each image.
— in intense highlight areas, your masks will expose your darkest, or most underexposed image.
— in intense shadow areas, your masks will expose your lightest, most overexposed image.
— midtones will usually come from your "correctly exposed" images.
All of this, above, is done by manually usually using the airbrush tool to lighten and darken regions of each layer mask.
Do all that, and you'll likely have a decent HDR image...and you'll appreciated the automated tools offered by Photoshop's PhotoMerge tool.
Photoshop: File: Automate: Import to HDR Pro
File: Automate: Merge to HDR Pro...
Browse to select the images to be merged. (OK when all selected)
Once Photoshop loads the images and does some initial processing, one version of your HDR image will appear, along with thumbnails of your source images, and a panel of settings you can adjust on the right.
Explore the presets which are in a drop-down menu at the top of the settings panel.
Explore the impact of various settings.
When you're satisfied, Click OK and Photoshop will merge all of your source photos using your settings into a single-layered image.
Hugin — for elaborate, tough, large or alt projections
Hugin also has tools for manipulating HDR images.
Workflow Description(old) | Video Tutorial*** |
Camera Raw — one image only
Note: this technique isn't "real" HDR, but its a quick way to get some of the advantages of HDR using a single RAW image.
Open a single RAW file in Camera Raw.
Use the Exposure Brush tool to selective under- and over-expose regions of your image.
This simple technique offers many of the advantages of stacked HDR images by allowing you to "pull" higher exposures out of some portions of your image, push lower and darker exposures into some areas, and keeping the general existing exposure for the rest.
Faux HDR Toning from a single photo (video tutorial)
Again, this isn't "real" HDR, but the technique produces images that have some of the visual traits of an HDR image using only a single original image.
— Use at least three different exposures of a single image that you shoot.
— Use a tripod to frame your image and maintain a constant viewpoint for your images
— Bracket your photos -- take underexposed and overexposed images. ( -2EV, normal and +2EV)
The articles linked/discussed above deal with basic stacking techniques.
Those are the key skills you'll needed.
Goal: Create 3 different versions of HDR images based on your 3 source images.
Select subject matter that benefits from a very broad range of value.
Your full-size, Photoshop image should be at least 4mpix.
Create a lower-resolution version of your images for uploading to DropBox.
Follow the steps illustrated here to create a 2-megapixel version of your image for in-class viewing.
Save those images to your DropBox Art265_Photography folder.
Create a folder called: Ex8_HDR
a) the three low-res versions of your original images saved as JPG
b) the final 3 images, each as low-res JPGs.