Tuesday, March 12, 2013
Unleash Unlimited Depth Of Field
Use stacked focus to create images that overcome the bounds of optics for your macro shots and more
1 Process the entire stack of RAW images with your normal editing software, making sure they're all processed identically. With current and older versions, it was necessary to save RAW images as TIFFs, PSDs or JPEGs, as the program didn't see the edit changes to RAW files. I'm currently testing a beta version of Helicon 6, and it appears it will be able to read many types of RAW files, eliminating the need to save out a separate set of images.
2 Open the Helicon Focus software and load in your stack of images either by clicking on Add Images and navigating to the folder that contains them, or simply drag and drop them into the Source Images area of the program.
3 Select the Render Method. I always use Method B.
4 Select the Radius and Smoothing. For detailed images of nature, I personally start with a Radius of 3 and Smoothing of 2. If that results in halos around images, or significant focus skipping in large, smooth areas, I increase those numbers. The default is a Radius of 8 and Smoothing of 4. The lower you can keep the numbers, the sharper your results will be.
5 Click on Render. You'll be treated to a show of the stack being aligned and analyzed by the program. It then will produce an output image made up of the sharpest pixels from the stack.
6 Zoom in on the image to see if any areas were skipped or if double images were created by the subject having moved between exposures. If there are, you can click on the Retouching tab at the top of the display area. This gives you two screens. One shows the source image highlighted in the Source Images, and the other shows the output image. Adjust the brush as needed and clone from the source image you've selected into the output image.
7 Click on the Saving tab and save in your desired format to the desired location.
Steps 1 through 3 are the same as with close-ups, making sure to compose while focused on the closest element in your composition.
4 Focus at the hyperfocal distance for the lens and ƒ-stop you're using and make your first capture (the composition will have changed some, due to the change in magnification when you changed focus, but don't adjust it!).
5 Carefully pull the focus forward one depth of field zone and make your next capture. Continue to shift the focus and make captures until you've worked your way all the way to the front of the composition.
The steps for processing the images are the same as for close-ups.
Extended/Selective Depth Of Field.
This is used when you have a subject with some depth to it that you wish to have entirely sharp, isolated against a soft background. A common subject for this would be a tall flower stalk. The problem we traditionally encounter when using selective depth of field (selective focus) is trying to find an ƒ-stop that provides ample depth of field on the subject, while rendering the background sufficiently soft. We solve this by first using the stacked focus technique to create the subject component of the image, then making an additional image for the background at whatever ƒ-stop provides the desired amount of blur. This technique also can be used where the subject blends into the background and we want a very short transition zone from very sharp to very soft.
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