How Can I Improve the Sharpness of My Photographs?
If you think your photos aren’t sharp, start by reading the section on blurry photos. Motion blur is often the cause of unsharp photos. The section on blurry photos offers a number of possible causes and solutions.
Some photographers drive themselves a little crazy with lens testing and other technical details in order to obtain the sharpest images possible. Unless you’re making large prints from your paintings, most of these tips are going to have a negligible effect upon the sharpness of your photos. When you post images online, they have to be low resolution so they will load quickly. The small gains in sharpness that the following tips provide probably won’t be visible in these low resolution photos.
The sections on mirror lockup and live preview only apply if you’re using a DSLR (A Digital Single Lens Reflex camera). If that doesn’t apply to you, skip ahead on the section about sharpening in Photoshop.
Mirror Lockup Option (DSLRs Only)
If you’re shooting with a DSLR then there’s still one more way to improve sharpness. A DSLR has a mirror that flips up when you take a picture. The mirror diverts the image to the viewfinder so you can compose the image. When you take a picture the mirror flips up to allow the light to pass through to the sensor so it can record the image.
When the mirror flips up it creates a small vibration that’s enough to create a slight blur. You may not notice it unless you view the photo at a high magnification in Photoshop. Motion blur from the mirror flipping up is only a problem when you use slow shutter speeds.
Many DSLRs have a “Mirror lockup” function where the mirror will flip into the up position on the first press of the shutter button and holds it there. On the second press of the button it takes the picture. This pause is enough to allow the vibration caused by the mirror to subside before it records the picture. My camera has the mirror lockup option buried under the custom functions menu.
Having to push the button twice for every picture is somewhat time consuming if you are bracketing your exposures. I then had the idea to use the “Live View” function instead and it turns out it’s just as effective as the mirror lockup.
Live View Function (DSLR’s Only)
Point and shoot cameras have a continuous live preview on the LCD that allows for instant feedback. Early DSLRs lacked this feature but almost all of the current ones have a “live view” function that will produce a live image on the LCD. I realized that this may work as well as the mirror lockup function because the mirror has to be in the up position in order to create a live image on the LCD.
The results were surprising. I believe that it works as well as the mirror lockup feature, and it might even be slightly better. If you’re interested in reading technical information about why this is so, search for “mechanical first shutter curtain.”
Keep in mind that the live view will drain the battery faster. If this is a problem then buy an AC adapter that will allow to you power the camera directly from an electrical outlet. Another thing to consider is that the slight improvement in sharpness won’t be visible in the small thumbnails that you share online. It may be worth it if you’re having large prints made from your paintings though.
Turn off Image Stabilization (IS)
Many camera manufacturers recommend turning off image stabilization when your camera is secured to a tripod or copy stand. This applies whether the stabilization is in the lens or camera body. Canon does a good job of explaining how older versions of their IS lenses could negatively affect sharpness on their website. Read the section about using IS on a tripod for more information.
To paraphrase Canon, when the camera is attached to something solid the IS system can detect its own vibrations and tries to correct for it. This creates a feedback loop and the extra motion can negatively affect sharpness. Newer equipment can detect that it’s on a tripod but you would have to figure out if that applies to your lens or camera.
There’s no advantage to using IS when your camera is attached to something solid. The stabilization system will drain the battery faster so I don’t use IS for photographing my artwork.
Sharpening in Photoshop
Most cameras apply some form of sharpening to the photo before it saves it. I normally turn the sharpening down to a lower setting. It’s possible to apply more sharpening to an image but it’s difficult to remove it if the camera overdoes it.
The apparent sharpness of a photograph can improve slightly by applying some sharpening to them. I wrote more about how the Photoshop sharpening feature works in another post.
Aperture and Sharpness
If you’re using a compact camera then there’s not a big range of f-stops to choose from. They typically range from f2 to f8. With this narrow of a range of apertures, there’s not much difference in sharpness between them.
As for DSLRs, the optimum f-stop varies for each lens but the general idea is to avoid the widest and narrowest apertures. I find that the sharpest images come from an f-stop somewhere in the middle. For that reason I try to use an f-stop between f8 and f16. To test a lens, you can take a series of pictures using different apertures and then compare them in Photoshop.
For more technical explanations, search for “optimum aperture.”
Taking the time to improve the quality of your photographs of your artwork is worth the effort. It’s satisfying being able to post images online that accurately represent your paintings. It’s even more rewarding to receive feedback from collectors who say that the colors in the original painting match the photos they saw online.
I hope my tips will help to improve the quality of the photographs of your paintings.