How to Swap Optics with Composer Pro II and Sweet 35
By Lensbaby | Published: 2026-10-19
Category: How-to Guides
Learn how to safely change the optic on your Lensbaby Composer Pro II and install the Sweet 35 for dreamy blur effects. Step-by-step guide with common mistakes to avoid.
Quick Answer
Swapping optics on the Composer Pro II is a quick process: press the optic release button, twist the current optic off, align the Sweet 35's dots, and twist it on until it clicks. The whole swap takes under 30 seconds once you know the steps.
Why the Composer Pro II Makes Optic Swaps Easy
The Composer Pro II is designed for quick optic changes without tools. Its bayonet-style mount uses a spring-loaded release button, so you can switch between optics like the Sweet 35, Twist 60, or Edge 50 in seconds. This makes it ideal for photographers who want to experiment with different looks on the same shoot.
One trade-off: the optic release button can be stiff when new. If you feel resistance, don't force it — press firmly and evenly. Over time, the mechanism loosens slightly.
What You Need Before Starting
You only need the Composer Pro II base and the Sweet 35 optic. No screwdrivers, wrenches, or adapters. Work on a clean, dry surface to avoid dust getting inside the lens chamber. If you're swapping in the field, shield the camera body from wind and debris.
Steps to Swap Optics on Composer Pro II + Sweet 35
- 1. Remove the current optic: Hold the Composer Pro II base steady with one hand. With the other hand, press and hold the small silver optic release button on the side of the base. While holding the button, twist the attached optic counterclockwise until it stops, then lift it straight off. Common mistake: twisting without pressing the release button can damage the mount. Always press the button fully before turning.
- 2. Align the Sweet 35 optic: Pick up the Sweet 35 optic. Look for the two small alignment dots on the optic's base ring. Align these dots with the two corresponding dots on the Composer Pro II base. The dots should line up exactly before you try to attach. Checkpoint: if the dots don't match, rotate the optic 180 degrees. Forcing it on misaligned can scratch the contacts.
- 3. Attach and lock the Sweet 35: With the dots aligned, gently press the Sweet 35 optic onto the base. Twist it clockwise until you hear a firm click. The optic should sit flush with no gap. Release the optic release button if it's still pressed. Common mistake: stopping before the click. A partial twist leaves the optic loose and can cause it to fall off. Always twist until you hear and feel the click.
- 4. Test the connection: Gently tug the Sweet 35 optic upward without pressing the release button. If it stays firmly attached, the swap is complete. Mount the lens on your camera and check that the aperture ring turns smoothly and the sweet spot of focus shifts when you tilt the Composer Pro II. Checkpoint: if the optic wobbles or the aperture feels stuck, remove it and repeat step 3. A loose optic can affect image sharpness.
Product Facts
- Composer Pro II + Sweet 35: The Composer Pro II with Sweet 35 places your subject in a sharp sweet spot of focus surrounded by beautiful increasing blur at 35mm. This means you can create portraits or detail shots with a dreamy, painterly background blur while keeping the main subject tack sharp — something a standard lens can't replicate.
Composer Pro II + Sweet 35
