We own a Nikon TE2000 with a first generation PFS. I recently installed a quad-band filter on that scope and realized that now I got a spot in my images and that this spot is due to the PFS, as when I switch it of, the spot disappears from the image.
From the documentation I found, it happens the wavelength used by the PFS system is 770, thus if i modify my emission filter accordingly I should get rid of the annoying signal…
Just to be sure, has someone had to face this issue as well ? What I’m not sure about is the value 770 as this might only be the peak …
You’ll probably have to ask Nikon for help on this one.
It looks like they use an LED (and not a laser): PFS diagram
So the line width is probably not zero. If you are feeling bold Thorlabs has a 770 laser line filter for $100 that you could try: 770 laser line filter.
I finally found where the problem was … inside the PFS there should be a IR blocking filter…and it has been removed some time ago as this filter blocks to a certain extent UV wich by that time was used to perform laser ablation experiments …
I found the original filter and placed it back into the PFS.
Now I got rid of that IR reflection.
What I realized is that it might not be a good idea to put the filter there …a more clever position would be right in the front of the camera.