Tool · 360° spins
Sharp Zone Planner
Will the whole product stay sharp through a full 360° spin, viewed at full sensor resolution? The planner compares the volume your product sweeps on the turntable with the Focus Envelope of your lens and aperture, then shows where diffraction caps stopping down and what focus stacking would cost.
Beta. Results use thin-lens optics and Canon sensor data; verify critical setups with a test spin.
Depth and diffraction collide
The spin needs f/229 for depth, but diffraction caps this standard at f/6.1. Pick a trade-off below.
Camera view
A simulated frame through your camera: a 3D model of the product (a real model for most presets) at this distance, focal length and aperture. Every pixel is blurred by the same thin-lens math as the planner. Colors show the zones: green is sharp, blue is too near, purple is too far. By default the blur is exaggerated so you can see it at a glance; turn that off and zoom to 100% to judge the photo pixel for pixel, the way a deep-zoom viewer shows it.
The 3D view loads when you scroll here (about 0.6 MB, needs WebGL).
Sneaker: real 3D model at true size, 298 × 153 × 116 mm.
Blur at the nearest and farthest point of the product appears here once the 3D view has loaded.
Dark lines on the product mark the near and far limits of the sharp zone.Drag to pan, scroll or pinch to zoom, double-click for 100%.
3D model “Materials Variants Shoe” by Shopify, CC BY 4.0, modified (changes listed in the license file). All model licenses.
- Rotation volume depth
- 320 mm320 mm across, worst angle 69°
- Focus Envelope at f/16
- 22 mm7% of the needed depth
- Angle of view
- 18.0° × 12.1°field at the axis 439 mm × 293 mm; 19.5° focused at infinity
- Magnification
- 0.082×lens to axis 1.39 m, sensor to axis 1.50 m
- Pixels across the spin
- 5,963 pxpixel pitch 4.4 µm
- Sharpness standard (CoC)
- 4.4 µm1.0 sensor px, full resolution (coc = 1 pixel)
- Depth needs
- f/229focus 18 mm in front of the axis
- Diffraction ceiling
- f/6.1effective f/6.5 at this magnification
- Airy disk at f/16
- 23 µm5.3 px; edge blur 14.6 px
- OKRotation volume fills 73% of the frame width and 52% of the height.
- ProblemAt f/16 the Focus Envelope is 22 mm deep; the spin needs 320 mm.
- CheckDiffraction at f/16 softens the image beyond the standard (Airy disk 23 µm = 5.3 px; ceiling f/6.1).
Your options
Single shot at the sweet spot
f/36
Lowest combined blur: 8.7 px at the volume edges. Sharp everywhere up to about 684 px across the spin, 36 frames.
Focus stacking
46 slices at f/5.6
Full resolution everywhere. 1,656 exposures for a 36-frame spin (10% overlap), plus stacking time per frame.
Deliver at a lower resolution
684 px
Switch the standard to delivered size to see which apertures keep a smaller output sharp in one shot.
How the planner decides
Rotation volume
In a spin every part of the product passes the front and the back of the turntable. The planner treats the product as the cylinder it sweeps: radius R = √(W² + D²) / 2 plus any off-center offset, height H. Seen by a camera raised by angle θ, that cylinder is 2R·cos θ + H·sin θ deep along the lens axis.
Focus Envelope
The Focus Envelope is the depth band in which defocus blur stays within the sharpness standard. It uses the same thin-lens formula as our depth of field calculator: H = f²/(N·c) + f, near = (H − f)·s / (H + s − 2f), far = (H − f)·s / (H − s). Focus at the harmonic mean 2ab / (a + b) of the volume's front a and back b splits it evenly.
Full resolution means one pixel
For deep zoom the standard is strict: the circle of confusion equals the sensor's pixel pitch (4.39 µm on an EOS R5 Mark II). The f-number that covers the whole volume is then N = f²·s·(1/a − 1/b) / (2c·(s − f)), which close up behaves like depth · m² / (2c·(1 + m)): depth needed grows with magnification squared.
Diffraction sets a ceiling
Stopping down spreads every point into an Airy disk 2.44 · λ · N · (1 + m) wide (λ = 550 nm). Once its radius passes the pixel pitch, a smaller aperture stops adding sharpness. When the depth needs a higher f-number than that ceiling, no single exposure is sharp at full resolution, and the chart shows the best compromise.
Angle of view
The cone in both drawings is what the sensor sees: 2·atan(sensor / 2v), where v = f·(1 + m) is the lens-to-sensor distance at this focus. Focused at infinity it is the catalog value 2·atan(sensor / 2f); close up the view narrows a little.
Camera view
The simulated frame renders a 3D model of the product (a real model at true size for most presets) and reads the distance of every pixel. A point at distance z blurs into a circle f²·|z − s| / (N·(s − f)·z) wide on the sensor, exactly the circle the Focus Envelope limits to one pixel, combined with diffraction. With the blur exaggerated, everything beyond that pixel is drawn twice its full-resolution size; without it, at 100% one screen pixel is one sensor pixel.
Focus stacking
Stacking shoots several focus slices at a sharp aperture and merges them. It restores full resolution, but each slice multiplies the exposures per frame, so a 36-frame spin quickly runs to hundreds or thousands of shots.
Distance from the sensor or the lens
In the studio you measure from the sensor-plane mark on the camera body; the optics need the distance from the lens. For a thin lens u = s/2 · (1 + √(1 − 4f/s)). Choose which one you entered; the difference matters most at close range.