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Friday, June 1, 2007

Close-Up Sharpness

The Truth Is In The Details • Make It A Hard Drive • Times Two • When To Use IS • Airports And Cameras • Res It Up

Tech Tips: Close-Up Sharpness

The Truth Is In The Details
I’m using a high-resolution digital camera and just started photographing trees, bark, leaves, etc. Many of my photos don’t show good resolution in the small details, such as bark texture, the small veins in leaves or the edges of paint peels. I shot images today using a tripod, mirror lock and cable release, and I used an f/11 aperture on a 100mm f/2.8 macro lens. The image looks soft in several places. Is what I’m seeing a problem with digital capture?
J. McKinniss
Via the Internet

I can assure you that today’s digital photography has the capability of giving us the greatest amount of detail and quality ever. Without seeing one of your images, I can only guess at what the problem is.

One problem with using ƒ/11 in macro photography is that it doesn’t give you much depth of field, especially with a telephoto focal length, so you'll often find areas in and out of focus. If this is the problem, look into a great program called Helicon Focus (www.heliconfocus.com) for unlimited depth of field.

You’re using a high-resolution camera. All of your techniques are optimizing the capabilities of your digital system. Macro lenses tend to be among the sharpest out there, and ƒ/11 is the sharpest ƒ-stop.

You should be capturing at the largest file size and preferably in RAW format to maximize the amount of image data. Then evaluate your images after they have been sharpened with-in your image-editing software. There‚’s no digital camera that outputs a perfectly sharp image; it needs to be sharpened in the processing.

Another mistake made by many digital photographers is that they view their images on their monitor at a high magnification that doesn’t represent how the image will look printed. Make your evaluation based upon an image magnified at 100 percent on your monitor and then again once it’s printed.

The paper on which the image is printed will also affect the apparent sharpness. If you’re looking for the greatest possible detail, you’ll want to print on a smooth-surfaced paper, such as an Epson luster or a Canon satin inkjet paper.

The image of dried flowers in the snow was taken with a Canon EOS 5D and a 180mm macro lens set to ƒ/16. Actually, nine images were taken to deal with limited depth of field, then they were composited using Helicon Focus software to give the extreme detail and depth of sharpness.

Make It A Hard Drive, Times Two

I’m getting nervous about the security of my images, which are stored on the hard drive of my computer. If the drive goes bad, I’ll lose them forever. Some friends have said to put them on CDs, but I have so many images that such an approach would even require a lot of DVDs. What do you do to protect your image files?
M. Jacob
Denver, Colorado

You need to store your important files in two places. It’s not a matter of if your hard drive will fail, it’s a matter of when. My suggestion is to purchase a pair of identical external hard drives. Units in the range of 250 to 500 gigabytes have become quite affordable. Transfer all your important files to one drive, then back them up on the other. This will clear up space on your hard drive for temporary storage while you’re working on image processing.

When you’ve finished working on an image, store it on the first hard drive and back it up on the second. It may also be smart to store the backup drive in a different location and retrieve it once a week or so to back up your new work. This will protect your images from the consequences of disasters, such as fires or floods.

Because our files have become so large as our cameras get better, backing up onto CDs isn’t very practical. You’d only get a few images on each CD, especially if you’re doing panoramas or files for large prints. I have many files that are so large that only two of them would fit on a single CD, which holds approximately 700 megabytes.

What would make more sense is to save on DVDs (single layer), which hold approximately 4.7 gigabytes of data. I recommend read-only disks because of their higher stability. Coming onto the market are the HD DVD and Blu-ray disks, which offer 50 to 100 gigabytes per disk. These have potential for being great backup platforms for the future. My problem with having multiple disks for storage is the continual searching for a particular image file, which is why I stick with the biggest external hard drives I can get.

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