322Shoot video like a Hollywood pro with the high resolution (4k or 6k) RED Scarlet camera and a microscope or macroscope
Up until now, our LM digital adapters were primarily used to connect DSLR cameras, system cameras or C-mount cameras to stereo microscopes, laboratory microscopes or macroscopes. But how about professional movie cameras? Is it worth using such a camera for microscopy? We got to the bottom of this question with the RED Scarlet camera.
Most digital video cameras record at a maximum full HD mode of 1080p. This generally is sufficient for most professional applications. The RED Scarlet camera is specifically designed for the movie industry with the aim of impressing and dazzling the audience with its images on large projection and cinema screens.
- 4k resolution
- High colour depth
- Extensive dynamic range
- HDR in video mode
The camera uses active cooling in the form of fans which are located on the rear of the camera body. Air is pushed through the camera in order to maintain a constant sensor temperature of approx. 40°C and a body temperature of approx. 60°C. We did not observe any negative impact on image quality. The camera is equipped with intelligent ventilation regulation which can quite effectively decrease the rotation of the fans in shooting mode.
The various connections (HDMI, HD-SDI) are located on the other side.
The camera is very compactly designed and, due to its modular component system, can be used for a variety of purposes. At 2.5 kg, the camera body is rather heavy, and this figure increases even further, to at least 3.5 kg, when the various accessories are added. However, weight is not generally an issue when connecting cameras to the photo port of high-quality microscopes. The camera can also be used on our LM macroscopes without any complications.
At 4k (which corresponds to approx. 19 MP), the resolution of the video camera is very high, thereby offering the possibility to make more structures visible in video mode than with conventional camera systems. Full HD (1080p), by comparison, offers an image resolution of 2.1 MP, which is only one-fourth of the 4k resolution.
The video data are transmitted in “RAW” format and stored in special storage media. The advantage of the RAW format is that only minimally processed data are stored, which means that raw files include more information, and potentially higher quality, than converted data. As a result, white balancing, colour grading, etc. can be optimally adjusted during post processing. This makes post processing that much easier and can even “save” some video material which, in the heat of the moment, has not been shot at the optimal settings.
Especially at lower microscope magnifications (< 100x), the RED Scarlet can demonstrate its strengths. This camera allows the user to achieve an exceptionally high resolution, extensive dynamic range and very good video quality in RAW format.
By using the REDCODE file format, the video data are stored on special SSD cards in RAW format at up to 180 Mb/s.
One of the major benefits of RED cameras, their extremely high resolution, places considerable demands on the microscope. In order for the image data to even reach the camera, only premium microscopes with plan objective lenses should be used.
The RED Scarlet camera features a frame rate of 30 FPS at 4k, or up to 120 FPS at 1k. The Dragon, which is the current top RED model, offers an even better performance (100 FPS at 6k and 300 FPS at 2k). For microscope photography, it is quite common to use special USB2 cameras (C-mount cameras), which in full HD mode never achieve more than 7 frames per second. At this frame rate, focusing is a difficult task, as it only works very slowly with significant delays. Mid-level DSLR cameras, in comparison, usually achieve a frame rate of 30 FPS in full HD via the HDMI port.
In photomicrography, one often hears the argument that 3 MP of resolution are more than sufficient because the resolution is limited anyway by the microscopes’ objective lenses. At high microscope magnifications (> 100x) high resolutions are indeed rarely an advantage. However, this is not true for the RED Scarlet camera and the extensive dynamic range it offers. At low magnifications (i.e. macroscopes and stereo microscopes for life science imaging and quality checks), the RED Scarlet camera is vastly superior to the special cameras available for microscopy, provided the focus of the application is on producing video images.
But enough of the technical specs of the camera – we wanted to see for ourselves how the RED Scarlet performed when working with a microscope. To do so, we mounted the camera to the C-mount photo tube 1x of a Zeiss Axioskop, a fluorescence research microscope with phase contrast and dark field optics. For the connection, we used the DSLREDTWV_Pro adapter, which allowed us to complete the assembly in a matter of seconds.
Unfortunately, the RED camera cannot be controlled from the PC or Mac, and the video material cannot automatically be saved to the computer after recording. As of right now, the camera only stores the video data to the SSD memory cards, and the data must then be transferred to a PC or Mac in another step. The camera can be controlled remotely. In practice, however, working with the camera is relatively inconvenient, especially because no live images can be displayed on the computer.
Particularly if the user only wants to take pictures, handling the camera is a very complicated and unwieldy process in comparison to USB or C-mount cameras and DSLRs, as currently no user software for controlling the camera from a PC or Mac is available.
The camera is operated using the touchscreen monitor. This is where all settings can be adjusted (e.g. resolution, ISO, zoom function, frame rate, image data compression, etc.) and where additional information can be accessed, such as sensor temperature, supply voltage and various histograms.
Currently, the Live View image can only be displayed in HD quality on both the control monitor as well as external monitors. However, according to RED, a broadcast module should be released for the Scarlet Dragon and the Epic Dragon models as of autumn 2014, which will allow for a 4k Live View image to be displayed on external screens. This would be a major benefit for presentations and lectures.
The HDR option in video mode has proven to be very convenient, especially with high-contrast specimens that are captured on video. This leads to an enlargement of the dynamic spectrum, as multiple images can be processed into one individual image.
In photo mode, the RED Scarlet camera cannot match up with the currently available top camera models. Especially the fact that it is not possible to store uncompressed images in RAW format is a regrettable shortcoming. Also, in the DSLR market segment, the race to catch up has already started: Panasonic and Sony have recently announced 4k cameras.
If you are interested in the RED Scarlet, or have any questions about the camera, please do not hesitate to contact us.
Conclusion: At the outset, it should be pointed out that the RED Scarlet is a fascinating high resolution video camera that delivers top quality video material and exceeds the performance of all other cameras (both DSLRs and microscopic cameras) that are currently on the market. When the resolution is stepped down to 2k/1k, superb slow motion images can be captured. With our LM digital adapters the camera is ideally suited for use with almost all high-end brand-name microscopes that are equipped with a photo tube and quality objective lenses. Our plan achromatic LM adapter solutions enable the user to achieve the best possible video quality. However, practical experience has shown that handling the camera is rather inconvenient, as it cannot be controlled via a PC or Mac, as is the norm. Furthermore, due to its steep price, the target group for the RED camera will most likely consist of professional photographers and videographers.
28.07.2014