Homemade Kohler lighting discovers special lighting methods

[ztfggi]

Homemade Kohler lighting discovers special lighting methods.

[Tom Jones]

Nothing there but a little image icon and the word "image"

[Pau]

Hi ztfggi, welcome to the forum!

As Tom pointed, there is no image in your post.

Please take a look at the forum Image Hosting Procedures:

viewtopic.php?f=20&t=41917
and
viewtopic.php?f=20&t=45751

[Pau]

Thanks for updating the original post, now the images are visible.

Your homemade Köhler is providing oblique illumination, quite nice in your two first images.

[ztfggi]

Thanks for updating the original post, now the images are visible.

Your homemade Köhler is providing oblique illumination, quite nice in your two first images.

Instead of oblique lighting, darkfield sheets are used. Center and place in the concentrator instead of the condenser. Then the concentrator diaphragm is maximized, the condenser diaphragm is minimized, and the condenser position is adjusted to produce blue illumination, followed by purple-green mixed illumination. The three-dimensional sense is strong, and there are no disadvantages of oblique lighting, which I don't think is the same principle. It's a pity that I can't adjust the same effect after changing the device.

[rjlittlefield]

It's a pity that I can't adjust the same effect after changing the device.

Please explain in different words what you mean here.

Do you mean that you got the effect once but cannot reproduce it? Or do you mean that you cannot make adjustments while seeing the effect those adjustments will produce? Or something else -- and if so what?

--Rik

[ztfggi]

It's a pity that I can't adjust the same effect after changing the device.

Please explain in different words what you mean here.

Do you mean that you got the effect once but cannot reproduce it? Or do you mean that you cannot make adjustments while seeing the effect those adjustments will produce? Or something else -- and if so what?

--Rik

Yes, I changed the microscope and the lenses were not exactly the same as before, and then I couldn't adjust the same effect. It is not possible to reproduce, but the effect itself can be called up and down by the upper and lower positions of the condenser.

[ztfggi]

Homemade Kohler lighting discovers special lighting methods.

What surprised me the most was that this illumination would give a three-dimensional effect to the thicker details, and the lighter details would be optically tinted like phase contrast microscopy. And the color of the illumination light is blue-purple-red. This perfectly covers the chromatic aberration of the lens itself, improving the contrast to the limit. The shooting objective is a low-end planar objective, and the price of a 40x objective is 269 yuan, so this illumination can maximize the potential of the objective. But the only drawback is that the effective thickness of this illumination is low. If this thickness or false focus can be improved, its overall effect is better than DIC, after all, DIC has high requirements for objective lenses, and special prisms are also required, which is very expensive.

[rjlittlefield]

Thank you for the clarification.

I note your description that "the condenser position is adjusted to produce blue illumination, followed by purple-green mixed illumination". From those words, my guess is that the illumination was coming through the very edge of the condenser, so it was both very oblique and colored due to chromatic aberration in the condenser. Such situations can indeed produce nice results but they are often very difficult to reproduce.

To produce similar effects in a more controlled manner, I suggest taking a look at the various condenser filter designs that are discussed at viewtopic.php?t=15142 . If the gradient portion of the filter also contains a range of colors, then I expect that something like your results could be achieved routinely. (As I understand it, one of the main advantages of DIC is that its 3D effects are easy to reproduce, as opposed to oblique setups which are more fiddly and variable.)

--Rik

[ztfggi]

Thank you for the clarification.

I note your description that "the condenser position is adjusted to produce blue illumination, followed by purple-green mixed illumination". From those words, my guess is that the illumination was coming through the very edge of the condenser, so it was both very oblique and colored due to chromatic aberration in the condenser. Such situations can indeed produce nice results but they are often very difficult to reproduce.

To produce similar effects in a more controlled manner, I suggest taking a look at the various condenser filter designs that are discussed at viewtopic.php?t=15142 . If the gradient portion of the filter also contains a range of colors, then I expect that something like your results could be achieved routinely. (As I understand it, one of the main advantages of DIC is that its 3D effects are easy to reproduce, as opposed to oblique setups which are more fiddly and variable.)

--Rik

It's true that I've talked to others about this idea based on your recommended post, but it doesn't seem to produce a better oblique effect because of the gradient of the filter, and I've also tried oblique lighting but with the lens in the collector.

[Pau]

...
Your homemade Köhler is providing oblique illumination, quite nice in your two first images.

Instead of oblique lighting, darkfield sheets are used. Center and place in the concentrator instead of the condenser. Then the concentrator diaphragm is maximized, the condenser diaphragm is minimized, and the condenser position is adjusted to produce blue illumination, followed by purple-green mixed illumination. The three-dimensional sense is strong, and there are no disadvantages of oblique lighting, which I don't think is the same principle. It's a pity that I can't adjust the same effect after changing the device.

I must confess that I don't fully understand your description.
I think that what you're getting in the first images is (in an unconventional approach) Circular Oblique Illumination (also named Circular Oblique Lighting COL)
You can search in the forum for this terms like
search.php?keywords=Circular+Oblique+il ... mit=Search

[dolmadis]

...
Your homemade Köhler is providing oblique illumination, quite nice in your two first images.

Instead of oblique lighting, darkfield sheets are used. Center and place in the concentrator instead of the condenser. Then the concentrator diaphragm is maximized, the condenser diaphragm is minimized, and the condenser position is adjusted to produce blue illumination, followed by purple-green mixed illumination. The three-dimensional sense is strong, and there are no disadvantages of oblique lighting, which I don't think is the same principle. It's a pity that I can't adjust the same effect after changing the device.

I must confess that I don't fully understand your description.
I think that what you're getting in the first images is (in an unconventional approach) Circular Oblique Illumination (also named Circular Oblique Lighting COL)
You can search in the forum for this terms like
search.php?keywords=Circular+Oblique+il ... mit=Search

I am also interested in the methods you have used to create your images but I do not understand exactly how you have produced them from your written description.

Would it be possible for you to provide us with photos of the individual parts you have used and where and how placed together with a drawn diagram?

Thank you, John