LightField - Automating Acquisition with MATLAB® as Camera Temperature Changes [+][-]
Before certain experiments, it is useful to take a series of measurements while key acquisition parameters change. The resultant data can then be utilized to optimize acquisition conditions. There are several situations involving temperature in which this approach may be beneficial. For example, the researcher might want to characterize the dark current of a camera so as to monitor its performance. Another situation involving temperature is when you want to ensure the best signal-to-noise ratio for an experiment whose SNR is affected by an inherent tradeoff between quantum efficiency and dark current, as is the case when working with particular wavelength ranges in the near-infrared region.
LightField - How do I use LightField to do absorbance measurements? [+][-]
Quick guide to setup an absorbance measurement with LightField formulas
LightField - How do I normalize my data? [+][-]
Q: How do I normalize data?
A: To normalize intensity, use the following formula:
This formula scales the data so the highest peak is normalized to one.
This can be applied during acquisition under Online Processes, or in post processing under Processes - Formula
IMPORTANT: Do not use normalization during live acquisition when running step and glue because it will normalize every frame as acquired resulting in mismatches between the spectral data when it is stitched together.
LightField - Do you offer any drivers for LightField software? [+][-]
Q: Do you offer any drivers for LightField software?
A: Yes, we offer the following:
- LightField Automation
- DLL for LabVIEW
Contact your sales representative for additional information.
LightField - Create a binary image using LightField Math [+][-]
Threshold: output = threshold(input, 975)
This formula basically creates a binary image. Intensities below the threshold level are converted to zero (0), while intensities above the threshold are converted to a value of one (1)
Notes: In this example, intensity data of 975 and above is converted to a value of one (1), while data with intensity below 975 is converted to zero (0).
You should change the threshold value of 975 to a number that corresponds to the desired threshold level in your specific data file.
LightField - Calculate Average Pixel Intensity in Real Time [+][-]
Calculate Average Pixel Intensity in Real Time: output = reduce(input[53:293,47:186], average)
This formula courtesy of Dr. Sebastian Remi, PI’s Northeast Sales Engineer, displays the average pixel intensity of an ROI in real time during Run or Acquire. You can also select F6 to display statistics for the file or ROI. This will update during live acquisition, however only at a rate of approximately one update every 1-2 seconds.
Note: The numeric input “53:293,47:186” shows the ROI for the formula. Instead of typing in the numbers that define the ROI, you can use the input selection wizard in the formula editor. It looks like this:
When you select Run or Acquire, average intensity is displayed live however you will not see a live image.
LightField - Formulas: Set threshold for an image and multiply by the orginal input [+][-]
Clipping: Line 1: k = threshold (input, 1000) Line 2: output = input * k
This formula sets a threshold for an image and then multiplies this result by the orginal input (image intensity data). All the data above the threshold remain unchanged while data below the threshold is set to a value of zero (0).
Note: The formula example above includes a threhold of 1000 counts. You should change this value to correspond to the intensity dtaa in your specific experiment.
Original image (top) vs. Image after LightField Math (bottom)
Note: Both images above were scaled to show background intensity. Peak intensities are equal for the original and modified images, while the background in the bottom image has been completely subracted.
LightField - is not displaying individual frames [+][-]
LightField - I need to reinstall my software but have lost the password. What do I do? [+][-]
Please submit a copy of the Sales Order to: TechSupport@princetoninstruments.com
A new key will be provided. If you do not have the sales order, please provide the serial number of the camera that was purchased with the software.
LightField - Wavelength Calibration with Synchronized Data [+][-]
Why should you perform a wavelength calibration when collecting an image, especially when the image only displays pixel position?