Difference between revisions of "Clipping and Gradient"

Revision as of 08:01, 15 August 2013

HyperSync pushes cameras and strobes to their limits. You may find that your images are not entirely or evenly lit across the full frame at your camera’s fastest shutter speeds. If HyperSync hits a limitation of the camera or flash, you may capture some portion of the shutter curtain or the falling tail end of your strobe’s flash in the picture, which we call “Clipping” or a “Gradient.”

Clipping occurs when the camera’s shutter curtain is captured in the image. It looks like a black bar at the top or bottom of the image, where no flash information has been recorded.

A gradient occurs when the fading “tail” of a flash pulse (where most of the energy has been expended) is captured in the image. It looks like the light is “falling off” from brightness at the bottom to darkness at the top. This means the flash coverage is not even throughout the photo.

There are several ways to minimize and manage the impact of clipping and gradient in your images, including:

Using the Best Combination of Camera and Flash

HyperSync works best with certain cameras and flashes. Cameras with a fast shutter work best because they are able to capture precise portions of a flash curve. Faster cameras have more evenly-illuminated frames without clipping. Strobes with long flash durations are better for HyperSync because a longer flash duration lets the camera capture a smoother, higher energy part of the flash duration. Speedlites and IGBT-controlled strobes may not be ideal for HyperSync, and should be used at full power for best results. See the “IGBT flashes vs. Voltage Controlled flashes” page for more details.

You can see sample HyperSync images captured with your combination of camera and flash when you follow these links:

Properly Configure Your Radios

Be sure to properly configure your ControlTL transmitter and all receivers for HyperSync. Visit our HyperSync Setup page for detailed instructions. If you are using a ControlTL receiver, like the PowerMC2, PowerST4, or FlexTT5 with AC9 AlienBees Adapter, be sure to consider the “Optimize HyperSync Automation For:” setting. This setting will greatly impact the appearance of clipping and gradient. You can read more about “Optimize HyperSync Automation For:” on this page.

Use a Slower Shutter Speed above X-sync

Not all shots will require the use of your camera’s fastest shutter speed. If your image can be captured at 1/500 instead of 1/8000, you might consider doing so, in the interest of minimizing clipping and gradient. At HyperSync speeds just above X-sync, you might consider using Highest Energy.

Use Full Power Flash

It is often best to use full-power flash for HyperSync. Typically the higher the flash power, the longer the duration, which will improve flash evenness in frame.

Crop if Necessary

Often minor hard clipping can simply be cropped out of a final image. Some photographers will plan ahead for this, composing their images knowing that a small portion will be cropped out later. Some Nikon shooters will use their camera’s Auto DX Crop to cut out clipping in-camera, assuming they don’t need to maximize their image area.

Compose for Flash Coverage

Some photographers will orient their cameras such that any gradient falls in the far background of their image, where light from the flash would not fall anyway. By composing in this way, the photographer prevents the gradient from contributing to the scene. Many photographers find that what appears to be an unacceptable gradient in the studio is not as apparent when they shoot outdoors.

Make an Overlay in Post-Production

Once you have chosen your camera, flash, power and exposure settings, it is possible to capture a “white wall” image, to be used later as an overlay in post-production, such as in Adobe Photoshop or Adobe Lightroom. Shoot a frame under the exact conditions that will be used for the final image, with a plain background (preferably white.) Once you have captured your final image, you can use the “white wall” shot as a mask for a curve, levels, or other type of layer or tool to minimize or remove gradation. This technique is perhaps the most labor-intensive, and may not be applicable to all photographic situations.