Adjust aperture by rotating the Sweet 35's front ring so that the ƒ-stop lines up with the solid white dot on the Composer Pro's front-most ring. The instructions note that most cameras will work in aperture-priority mode, and I had no problem getting great metering with the camera I used. In certain situations, selective-focus optics can play havoc with traditional camera metering, however. One way to correct for this is by setting up automatic bracketing in your camera. This will snap a burst of images at a designated range of exposure levels. If your camera has one, using the Live View mode will tell the camera to meter directly from the sensor for better exposures.
The Sweet 35 aperture ring extends from the front of the lens barrel with click stops for each aperture. Line up the aperture with the white circular dot on the Composer Pro base to set depth of field. Use the smallest aperture (ƒ/22) for the subtlest effect and a large aperture (ƒ/2.5) for the strongest bokeh. Sometimes this effect can be too much, so be sure to experiment with apertures a stop or two below wide open for a more natural look.
Composer Pro with Sweet 35 Optic
Determining the sweet spot and positioning it is a matter of experimentation and image review. Lensbaby suggests beginning with a still subject until you're used to the process. It's best to tilt first, lock in your composition and then focus. With the range of movements, it's easy to end up with an image that's a completely different composition than the one you began with. Experiment with different apertures and compositions on the same subject to see how drastic the differences can be.
Be aware that vignetting may occur when using the Lensbaby at extreme angles on full-frame cameras. This isn't necessarily a problem, however, as vignetting can help to emphasize the nature of the Lensbaby optics when used correctly as part of the composition. What's more, these optics are compatible with video-capable DSLRs, making them a fun tool for stills, as well as video projects and filmmaking.