Topics

1

Optics / Relay lens spacing

« on: May 23, 2017, 11:48:11 PM »

It seems that the necessary spacing between the relay and imaging lens is ~50-100 um.
This corresponds to an air gap, that practically is a major hurdle to optimize and maintain.

If I understand correctly the optics behind this, changes in this distance can be compensated by changing the focus using the slider mechanism.
If that is correct, I was thinking about the possibility of creating an "adapter"/"sleeve" that fits the two lenses and maintains a constant ~75um air gap between the two lenses. Then the perfect focus would be adjusted with the slider.

Do you think this is a valid approach?

2

Optics / Imaging deeper - miniscope modification

« on: September 14, 2016, 02:41:18 PM »

We have a few mice for which the cells seem to be quite deep.
To see the cells we are using the 20mm imaging lens and the miniscope focusing position is at the "shortest".

However, this seems to still not be enough.

I was thinking to try the following:
If I shorten a little bit the main housing "tube" as well as the focus slider "tube", I should be able to get the CMOS sensor even closer to the imaging lens.

Do you think this would work or the optics design allows for this minimum distance only?

On a related note: Do you have any suggestions on what we can improve in the surgery part regarding this issue?
I am quite certain we aspirate enough.
We remove the first layer of fibers (capsule) and if I I am right the second "vertical" layer is the alveous which we leave intact.

Do you have any experience/intuition on what would be the effect of not pushing enough the tissue with the lens or pushing too much?

Also, in terms of optics, what is the effect of increased distance between the miniscope and the lens? I see during baseplating that increasing the distance makes the image darker.

Thanks in advance.