Test slide made by Optical Insights Spectral Imaging Solutions

[microcosmos]

I came across this interesting slide whose manufacturer's logo is a zebra:


It has a smooth bronze-coloured reflective surface and a pattern of see-through square grids and circles.

I put it under my Olympus BHSP. The following images are white-balance-corrected for the illumination source.


The 4x objective view has very slight barrel distortion, but it may or may not be from the objective. It could be from the other optical components in the light path or it could be because I did some "illegal" modifications to my system.

Sorry for the absence of a scale bar in the following images.


With the 50x MSPlan objective, there is some slanting somewhere so one side of the picture is out of focus in the opposite direction from the other side of the picture, as revealed by the green and purple CA fringes on opposite sides of the picture. Maybe the stage is not perfectly perpendicular to the light path or maybe one of the optical components is tilted? I am also wondering if the lines of different thickness could have some kind of quantification purpose.


The different-sized circles and ring in transmitted and reflected light. It looks as if the slide is designed for both diascopic and episcopic use. I am wondering if this slide could be for testing CA/bokeh/diffraction characteristics of the objective, as defocusing these rings and the grid lines will allow you to see the diffraction patterns and the bokeh/CA.

Does anyone have a better idea what this slide is used for?

[Macro_Cosmos]

Oh, I know what this is for. Quite esoteric in nature too. You scored here, depending on how much you paid. I would love a slide like this.

So Optical Insights is a company that made dual-view camera systems. Essentially, a giant box splits the image into two, this is used to excite two types of dye for simultaneous observation, each image occupies half of the camera's sensor. It seems morbid and the obvious question is "why not just mount 2 cameras via a beamsplitter", the answer would be speed.

This is similar to the Hamamatsu W-View Gemini and Cairn Research UK OptoSplit.
Here is a simplified view of the internal workings of the W-View Gemini:



The slide is used to compensate for the various aberrations that exist in such setups.

Screenshot 2023-01-16 115851.jpg (87.03 KiB) Viewed 830 times

These systems are very uncommon and fills an extremely niche market. In nearly 2 years, I have only had one customer seeking such a system (W-View Gemini) and his grant fell flat, unfortunately.

[MichaelG.]

A perfect forum thread !!

Two posts …
One interesting, well-illustrated, question
One exemplary answer

MichaelG.

[tpruuden]

Interesting technology. There is quad version here:

https://www.biovis.com/bodies/automatio ... ights.html
https://www.ebay.com/itm/364083343014

[microcosmos]

Thank you all for your replies. The slide doesn't belong to me but I was fortunate to borrow it.

So Optical Insights is a company that made dual-view camera systems. Essentially, a giant box splits the image into two, this is used to excite two types of dye for simultaneous observation, each image occupies half of the camera's sensor. It seems morbid and the obvious question is "why not just mount 2 cameras via a beamsplitter", the answer would be speed.

Could you explain how projecting two emission channels onto two halves of a camera sensor is faster than projecting them simultaneously onto two separate cameras? Is it the speed at which the data can be written to disk or some time lag between exposures?

[Macro_Cosmos]

Thank you all for your replies. The slide doesn't belong to me but I was fortunate to borrow it.

So Optical Insights is a company that made dual-view camera systems. Essentially, a giant box splits the image into two, this is used to excite two types of dye for simultaneous observation, each image occupies half of the camera's sensor. It seems morbid and the obvious question is "why not just mount 2 cameras via a beamsplitter", the answer would be speed.

Could you explain how projecting two emission channels onto two halves of a camera sensor is faster than projecting them simultaneously onto two separate cameras? Is it the speed at which the data can be written to disk or some time lag between exposures?

- Bandwidth limited, imagine yourself doing 100fps on two cameras, you will need x2 frame grabber cards and probably x2 work stations for that, as many manufacturers will not officially endorse and guarantee the functionality of 2 cards being installed
- Cost, extra camera and card exceeds the cost of systems like the W-View Gemini
- Signal intensity, a beamsplitter halves the signals' strength, you might be missing out on vital data if the signals are weak

Also:
- How are you going to make sure the two cameras are 100% aligned? That will take a lot of time to calibrate and it could go out of calibration if anything in the system changes.

The product is still very niche and most institutions are well-funded, so they will just get a second camera. Hamamatsu's website offers a lot more information.

[microcosmos]

Thanks for the explanation, it's clear to me now!