Signal to Noise Ratio

Image quality is the core concern in imaging, which can be evaluated through two concepts - resolution and signal-to-noise ratio. ORCA FusionBT has 5.3 million pixels (2304x2304), combined with a pixel size of 6.5 μ m, providing excellent resolution. In terms of signal-to-noise ratio, ORCA FusionBT has achieved unprecedented heights in sCMOS.

The signal-to-noise ratio of camera imaging is mainly related to four factors: (1) the intensity of the sample signal and the signal collection ability of optical systems such as microscope objectives; (2) Exposure time, generally speaking, extending exposure time will lead to an increase in signal-to-noise ratio, but it will sacrifice frame rate; (3) Quantum efficiency QE; (4) Read out the noise. From the perspective of a camera, quantum efficiency and readout noise correspond to signal and noise, respectively. The higher the ratio, the higher the signal-to-noise ratio.

The perfect quantitative camera has always been the direction that Hamamatsu tirelessly pursues, and the continuous improvement of signal-to-noise ratio is the core of it - with a 95% high quantum efficiency that is in line with the top configuration, and an unparalleled low readout noise of 0.7e rms, which greatly surpasses all previous sCMOS cameras.

High frame rate

The frame rate of mainstream high-end sCMOS cameras is generally 420 MHz (front facing chip, 100 frames per second @ 2048x2048). ORCA Fusion BT improves camera speed by 12% on this basis.

Hamamatsu not only achieves the industry's peak signal-to-noise ratio, but also never compromises on speed. The pixel readout frequency of ORCA FusionBT is as high as 470MHz, and it can achieve 100 frames per second at a resolution of 2304x2048 (4.7 million pixels). Choosing the appropriate ROI size can even increase the frame rate to 41000 frames per second.

　　Excellent MTF in back illuminated sCMOS cameras

The MTF (Modulation Transfer Function) of an imaging system refers to its ability to reproduce the spatial structure of the captured scene, and is defined as the ratio of output modulation to input modulation as an input spatial frequency function, also known as CTF (Contrast Transfer Function). The quality of the MTF/CTF camera directly affects the image resolution and clarity of the entire optical system.

In high-end imaging applications, the front-end imaging system (such as microscopes, telescopes, lenses, optical systems, etc.) has undergone fine MTF optimization. If the camera cannot guarantee the same level of MTF, it will lower the performance of the entire imaging system. The previous generation of back illuminated sCMOS cameras sacrificed some MTF performance while ensuring high QE, making it difficult to achieve good MTF curves (especially in the long wavelength range). ORCA FusionBT has excellent MTF comparable to front facing sCMOS cameras under the same conditions

Through testing with resolution boards of 533 nm and 670 nm, it can also be seen that the MTF curve of the long wavelength part of the same camera is generally worse, so excellent MTF curves are needed for the long wavelength and even infrared parts to ensure imaging quality.

　　Test conditions:

Microscope: Olympus IX81

Objective lens: PlanApo 2x /0.08

Resolution board: USAF 1951 Test Target (R1DS1N)

Wavelength: 533 nm and 670 nm

　Detailed parameters:

　　Interface Description