There are two diaphragms in the system as per koehler design (field and aperture diaphragms) however to be honest they may very little difference here. Having them completely opened or closed do not improve on this situation.
Modification of the camera lens is possible, there is a complete freedom on that side. What I cannot do is to interfere with the container itself or it's content.
Surely if I did that the image of the elements on the bottom of the container that I am trying to take will be distorted, right?
By the way - is there any software that could be used to model this?
That is what I am thinking, there should be a way to minimise the effect optically (I am sure completely removing it may be difficult). The question is, how to calculate the lens needed.
I also tried the version with just the LED and the diffusor before making it Koehler and the issue was still...
Many thanks for some good replies. To put things into context please see that image below taken from the side of the container showing how the liquid bends inside.
The illumination is from the top and imaging is below.
The system is telecentric, the center of illumination is at the center of...
Many thanks for the answers, I assume post processing may help to certain degree but I think there must also be some additional update to the optics.
I am looking to use something like this:
https://en.wikipedia.org/wiki/Meniscus_corrector
But how do I calculate the curvature I need?
I really wish it was that simple.
Liquid is water based with some medium for microbiology and cannot be changed.
Sadly it cannot be filled in to the top and covered either for handling.
The working volume is about 3/4 of the height of the container.
The solution has to be down to optics...
Yes that is pretty much what I am using here for illumination and I can prove that the beam of light is mostly parallel when it comes out from the illumination system. Then the light seems to be bent when it goes from air to liquid inside the container.
Apologies for the poor quality of the image, seems like upload to the forum downscaled it. I tried to increase the font to make it more readable:
To summarise, yes this is in essence inverted microscope. The illumination is from the top, camera is located below and focusing on the bottom of...
The meniscus it the problem, I tried to check that by gradually adding more liquid to the container and I can see the effect being drastic with small amount of liquid and reducing when I fill the container to the top. Sadly I have no control over the amount of liquid as the system has to be able...
I have attached the diagram of the illumination. Please let me know if that helps.
To clarify the illumination area is much larger than the diameter of the container. The illumination can access areas outside of the container, however the issue is that the centre of the container liquid is nice...
HI
I am currently playing with imaging device that would take pictures of the content of the bottom of the small plastic container. The container is just a tube of 7mm in diameter. When I image an empty tube I get a proper high contrast image of the dust on the bottom of it. However the...