I need to photograph something small (around 15mm) and I want to capture as much detail as possible. I have two cameras: Camera Sony with 24 megapixels, and Camera Canon with 12 megapixels. Both sensors are 24x36mm. I need to choose between purchasing a 1:1 macro lens for the Sony or the Canon. The problem would be easily solved now by choosing the Sony, because it has more megapixels, however there is this additional detail: for the Canon, I also have at my disposal an extension tube of 12mm, whereas I do not have it for the Sony. The 1:1 macro lens for the Canon has a focal length of 100mm. So: would I get more detail with the Sony and a 1:1 macro lens, or with the Canon together with the macro lens plus additional 12mm extension?
You would achieve more detail with the Sony camera and a 1:1 macro lens. Here’s why:
1. Sensor Resolution and Pixel Density
- Sony Camera:
- Resolution: 24 megapixels
- Sensor Size: 36 mm × 24 mm (Full-frame)
- Pixel Dimensions: Approximately 6000 × 4000 pixels
- Pixel Pitch: ~6 µm (micrometers)
- Canon Camera:
- Resolution: 12 megapixels
- Sensor Size: 36 mm × 24 mm (Full-frame)
- Pixel Dimensions: Approximately 4240 × 2830 pixels
- Pixel Pitch: ~8.5 µm
Impact:
- The Sony sensor has a higher pixel density, capturing more pixels per millimeter.
- This means finer details are recorded when the image is projected onto the sensor.
2. Magnification and Image Size on Sensor
- Macro Lens Magnification:
- Both macro lenses achieve 1:1 magnification natively.
- Canon with 12 mm Extension Tube:
- Additional Magnification: ( \frac{12\,\text{mm}}{100\,\text{mm}} = 0.12× )
- Total Magnification: ( 1× + 0.12× = 1.12× )
Impact:
- The Canon setup magnifies the subject slightly more (1.12× vs. 1×).
- For a 15 mm subject:
- Sony: Image size on sensor = ( 15\,\text{mm} × 1 = 15\,\text{mm} )
- Canon: Image size on sensor = ( 15\,\text{mm} × 1.12 ≈ 16.8\,\text{mm} )
3. Detail Capture Comparison
Sony Camera:
- Subject Coverage on Sensor:
- Vertical coverage: ( \frac{15\,\text{mm}}{24\,\text{mm}} ≈ 62.5\% )
- Pixels Covering Subject:
- Vertical pixels: ( 4000 × 62.5\% = 2500 ) pixels
Canon Camera:
- Subject Coverage on Sensor:
- Vertical coverage: ( \frac{16.8\,\text{mm}}{24\,\text{mm}} ≈ 70\% )
- Pixels Covering Subject:
- Vertical pixels: ( 2830 × 70\% ≈ 1980 ) pixels
Conclusion:
- Despite the Canon’s higher magnification, the Sony captures more pixels over the subject (2500 px vs. 1980 px).
- This results in greater detail in the final image from the Sony camera.
4. Diffraction and Effective Aperture
Effective Aperture Calculation:
- Effective f-number: ( \text{f-number} × (1 + \text{magnification}) )
- Assuming shooting at f/8:
- Sony (1× magnification): ( f/8 × (1 + 1) = f/16 )
- Canon (1.12× magnification): ( f/8 × (1 + 1.12) ≈ f/16.96 )
Impact of Diffraction:
- Diffraction limits resolving power at smaller apertures (higher f-numbers).
- At effective apertures around f/16 to f/17, both setups are nearing diffraction limits.
- The Canon’s higher effective f-number due to increased magnification results in more diffraction, potentially reducing image sharpness.
5. Lens Performance
- Macro lenses are optimized for 1:1 magnification.
- Pushing beyond 1:1 with extension tubes may degrade image quality due to lens aberrations and decreased sharpness.
- The Sony setup operates within the lens’s optimal range, maintaining better optical performance.
6. Practical Considerations
- Extension Tubes Limitations:
- May introduce additional aberrations and light loss.
- Can affect autofocus performance and exposure accuracy.
- Sensor Technology:
- The Sony’s newer sensor may have better noise performance, dynamic range, and color reproduction compared to the older Canon sensor.
**Answer:
You will capture more detail with the Sony camera and a 1:1 macro lens. Despite the Canon setup achieving slightly higher magnification with the 12 mm extension tube, the Sony’s higher-resolution sensor records more pixels over your subject, resulting in greater detail. Additionally, the Sony lens operates within its optimal magnification range, maintaining better image quality without the potential drawbacks introduced by the extension tube on the Canon. Therefore, for photographing small subjects like your 15 mm object with maximum detail, the Sony setup is the better choice.
