Calculators
Object Visibility & Sky Position
Telescope & Eyepiece Performance
Brightness & Visibility
Imaging & Astrophotography
Tools
Field of View (Imaging) Calculator
What This Calculator Tells You
Calculate exactly how much sky your camera will capture when attached to your telescope. This helps you choose the right focal length for your target and understand what will fit in your frame.
Calculator
×
×
2.55° × 1.71°
(153' × 102')
1.53"
per pixel
3.72 μm
pixel size
5.1
Moons across (width)
What Fits in Your Frame?
| Object | Size (approx) | Frame Fill | Fits? |
|---|---|---|---|
| Full Moon | 31' × 31' | 30% | Yes |
| Orion Nebula (M42) | 85' × 60' | 59% | Yes |
| Andromeda Galaxy (M31) | 178' × 63' | 116% | No |
| Pleiades (M45) | 110' × 110' | 107% | No |
| North America Nebula | 120' × 100' | 98% | Yes |
| Carina Nebula | 120' × 120' | 117% | No |
Common Sensor Sizes
| Format | Size (mm) | Diagonal |
|---|---|---|
| Full Frame | 36 × 24 | 43.3mm |
| APS-C (Canon) | 22.3 × 14.9 | 26.8mm |
| APS-C (Nikon/Sony) | 23.5 × 15.6 | 28.2mm |
| Micro Four Thirds | 17.3 × 13 | 21.6mm |
| 1" (Popular astro cams) | 13.2 × 8.8 | 15.9mm |
Click a row to use those sensor dimensions.
Framing Tips
- Leave some margin: Aim for the object to fill 60-80% of the frame for good composition and cropping flexibility
- Consider mosaics: For objects larger than your FOV, plan a mosaic with 20-30% overlap between panels
- Focal reducers: A 0.8x reducer increases FOV by 25% and decreases image scale proportionally
- Check rotation: Remember you can rotate the camera to fit elongated objects
Related Calculators
- Image Scale Calculator - Resolution per pixel
- True Field of View (Visual) - FOV for eyepiece viewing
- Sampling Calculator - Match setup to seeing conditions