oblique illumination

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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PeteM
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Re: oblique illumination

#31 Post by PeteM » Wed Jun 01, 2022 2:45 am

Of course, oblique and HMC are different. The purpose was to show an alternative method of mounting that could work for your condenser should you find fitting it in is a problem.

With respect to the second point, there isn't enough room between the condenser fork mount and the bottom of the stage mount to easily insert the HMC condenser directly in. So, it's inserted in its shorter incarnation and then extended to the needed height. That design probably also helped Hoffman more easily adapt its condenser to a variety of dovetails.

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woyjwjl
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Re: oblique illumination

#32 Post by woyjwjl » Thu Jun 02, 2022 1:05 am

I'm afraid I need to use this passage to reiterate the significance of designing this device, so as not to deviate from the direction of discussion.

"the entire diaphragm was rotatable around the axis of the microscope so that oblique light could be directed toward the specimen from any azimuth to achieve the best desired effect for a given specimen."

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woyjwjl
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Re: oblique illumination

#33 Post by woyjwjl » Mon Jun 20, 2022 1:35 am

Update it. There are still some small problems. I hope we can have preliminary results next week
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viktor j nilsson
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Re: oblique illumination

#34 Post by viktor j nilsson » Thu Jun 23, 2022 8:13 am

Looking really good!

Macro_Cosmos
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Re: oblique illumination

#35 Post by Macro_Cosmos » Sat Jun 25, 2022 6:46 am

woyjwjl wrote:
Thu May 19, 2022 7:15 am
Curious, why did the resolution doubling technology that was commercialized 50 years ago disappear?
Phill Brown wrote:
Thu May 19, 2022 7:56 pm
Cost.
Greg Howald wrote:
Thu May 19, 2022 8:41 pm
Agreed. Not cost effective to continue when easier ways to obtain oblique lighting were developed. But the condenser seems to have adjustment to control the degree of obliqueness or to change the light path.
Olympus still offers a specialised oblique condenser for the modern BX line. Such a condenser is incredibly niche, but it solves an annoying issue where DIC is inadequate for plastic bottom observation/petri dishes.

The part ID is WI-OBCD, around $1700. It offers very precise oblique capabilities, the crescent-moon-like aperture can be adjusted and rotated. A 32mm rotatable polariser is installed at the light port in a filter wheel, IR versions exist for deeper penetration at the cost of overall resolution ($800+ filter).

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woyjwjl
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Re: oblique illumination

#36 Post by woyjwjl » Mon Jun 27, 2022 1:59 am

Thanks for the information
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Judging from the picture, this condenser is designed for low Na, without adjustable grating, and the baffle size is fixed (switchable).

According to my understanding, this design cannot be achieved: "the entire diagram was rotatable around the axis of the microscope so that obvious light could be directed towards the specialty from any ambition to achieve the best desired effect for a given specialty"

If I am wrong, please correct me.

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woyjwjl
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Re: oblique illumination

#37 Post by woyjwjl » Mon Jun 27, 2022 2:34 am

Update it
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Next, we need to trim the dovetail of the stage to solve the travel problem

Macro_Cosmos
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Re: oblique illumination

#38 Post by Macro_Cosmos » Mon Jun 27, 2022 5:08 am

woyjwjl wrote:
Mon Jun 27, 2022 1:59 am
Judging from the picture, this condenser is designed for low Na, without adjustable grating, and the baffle size is fixed (switchable).

According to my understanding, this design cannot be achieved: "the entire diagram was rotatable around the axis of the microscope so that obvious light could be directed towards the specialty from any ambition to achieve the best desired effect for a given specialty"
What do you mean by grating? The internal annulus? The diagram is not clear enough, Olympus' marketing material is quite lacklustre...
This condenser is designed for the water immersion system for electrophysiology, patch clamp systems. Long working distance is needed to accommodate micromanipulators.

There is an aperture lever. Do you see the silver dial? That dial can be rotated to change the shape of the internal crescent-moon-like annulus, that is why the diagram says "可調整", though it would have helped if they elaborated on what is being adjusted... Evident.

The entire slider can be pulled in and out, so you are even able to get very good phase-like effects with phase contrast objectives. The top lens with an NA of 0.8 can be (forcibly) removed, I believe it is possible to modify this with an oil immersion condenser like the U-AAC, force (cut!) the top lens off. I just need to bite the bullet on the price -- not cheap.
If you want another similar condenser, the Heine condenser gives very good oblique effects and it offers high NA, it can also be used with phase objectives (Ph2 and Ph3, it struggles with Ph1). I designed a BX adaptor for the Heine condenser.

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woyjwjl
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Re: oblique illumination

#39 Post by woyjwjl » Mon Jun 27, 2022 7:08 am

"Aperture iris" forgive my English

Well, if you've seen it in person, I can accept that it supports iris adjustment.However, the design of the aperture iris mid-axis to remain aligned with the optical axis makes it impossible to do "simultaneous adjustment: blocking range and blocking angle". Switching correctly between different stopper sizes will be a challenge.

If possible, could you show the "Heine condenser oblique effects"?

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woyjwjl
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Re: oblique illumination

#40 Post by woyjwjl » Wed Jun 29, 2022 6:13 am

更新一下

最后一步
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viktor j nilsson
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Re: oblique illumination

#41 Post by viktor j nilsson » Wed Jun 29, 2022 6:29 am

Macro_cosmos has posted a couple of nice videos showing different illumination settings with the Heine:

https://youtu.be/_tecNY-yJNY

https://youtu.be/zRAHPIoL7tI

MichaelG.
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Re: oblique illumination

#42 Post by MichaelG. » Wed Jun 29, 2022 6:55 am

Very useful links, thank you Viktor

They nicely show the versatility of the Heine

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woyjwjl
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Re: oblique illumination

#43 Post by woyjwjl » Sun Jul 03, 2022 1:49 pm

If you think about it, it will come back to you.
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viktor j nilsson
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Re: oblique illumination

#44 Post by viktor j nilsson » Sun Jul 03, 2022 2:15 pm

Video doesn't work for me

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woyjwjl
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Re: oblique illumination

#45 Post by woyjwjl » Sun Jul 03, 2022 2:33 pm

Corrected :D

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