Achieving oblique illumination with motic ba310e

[JM Cano]

Hello,

Is someone in the forum imaging with motic ba310e an using oblique illumination? I would greatly appreciate some guidance about how to achieve it, either with diy approaches or manufacturer's solutions. Tried some diy filters without success. Any examples and/or photos of setups would be greatly appreciated.

Best,

Cano

[apochronaut]

As far as manufacturers are concerned, obliique is a forgotten technique. In former times manufacturers produced specialized oblique condenser carriers, which allowed for the iris diaphragm to be precisely moved laterally , relative to the condenser. Some even had two iris diaphragms that could be moved relative to each other.
Oblique condensers have gone the way of the Dodo.
Lomo continued to make an offset condenser carrier up until the dissollution of the Soviet Union. They are sold on ebay fairly frequently and probably not that difficult to adapt to your Motic. That's the route I would pursue, in lieu of getting some input from someone doing oblique on a Motic.

[Charles]

It should be easy if there is a filter holder. Make an opaque filter (black) and start sliding it into the filer holder until you get the desired effect in your eyepiece. You can see some design changes you can make for different effects here: https://www.ebay.com/itm/31-MM-Dark-Fie ... d%3APL_CLK

[JM Cano]

Thank you Apochronaut and Charles!

I'll keep in mind the lomo option in case there is no way to get it to work with DIY filters/masks or playing around with other gear from the manufacturer (phase or dark field sliders/turrets).
I tried with DIY filters copying patterns as these showed in the link provided by Charles. I tried both on the filter holder (in the BA 310e is on top of the diafragm ring) and in the slot for the filter slider (under condenser aperture diafragm ring).
I did not get the desired effect. I'll try more with different sizes and positions. I've seen nice examples of this technique both at Motic Europe Instagram account (contacted them but not explanation of setup yet) and Journey to the Microcosmos youtube channel (also with BA310e, left inquiry but not answer yet).

I'll keep trying but if someone have it sorted out with the same model and can speed up my learning (trial error) curve it would be great.

best,

Cano

[DonSchaeffer]

How about a movable light source like an led light sitting over the original light source. It can serve as a movable block filter when turned off and can be a supplement or a replacement when turned on.

[JM Cano]

How about a movable light source like an led light sitting over the original light source. It can serve as a movable block filter when turned off and can be a supplement or a replacement when turned on.

Thanks, I'll give it a try if I have a suitable light

[JM Cano]

Update, in this Facebook thread https://www.facebook.com/10000071424675 ... 834496821/ there is one way to go about it with the BA 310E, I guess it may work with other microscopes as well.

[Charles]

Update, in this Facebook thread https://www.facebook.com/10000071424675 ... 834496821/ there is one way to go about it with the BA 310E, I guess it may work with other microscopes as well.

If my memory serves me right, I think he uses darkfield with tissue paper to get a DIC effect.

Edit: Reading the above post, he is using scotch tape on a coverslip over the condenser in darkfield. I remember when he first started, he was using lens tissue.

[apochronaut]

Thank you Apochronaut and Charles!

I'll keep in mind the lomo option in case there is no way to get it to work with DIY filters/masks or playing around with other gear from the manufacturer (phase or dark field sliders/turrets).
I tried with DIY filters copying patterns as these showed in the link provided by Charles. I tried both on the filter holder (in the BA 310e is on top of the diafragm ring) and in the slot for the filter slider (under condenser aperture diafragm ring).
I did not get the desired effect. I'll try more with different sizes and positions. I've seen nice examples of this technique both at Motic Europe Instagram account (contacted them but not explanation of setup yet) and Journey to the Microcosmos youtube channel (also with BA310e, left inquiry but not answer yet).

I'll keep trying but if someone have it sorted out with the same model and can speed up my learning (trial error) curve it would be great.

best,

Cano

One of the reasons that filters and masks used in a filter slot have become popular is that they are inexpensive if purchased, very inexpensive if d.i.y.'d and very currently there is a lot of buzz about Rheinberg etc.
One of the reasons that manufacturers made complex mechanisms to do a similar job is that with the precision built into those mechanisms, you can get better results and they can be combined with passive filtering too. My guess is that you are looking for maximum physical relief? Such an effect requires a high degree of precision. It doesn't necessarily happen at Koehler and only a smàll + or- in the location or orientation of the components can make the difference between hey, that's o.k. and wow, that's great.

[JM Cano]

Update, in this Facebook thread https://www.facebook.com/10000071424675 ... 834496821/ there is one way to go about it with the BA 310E, I guess it may work with other microscopes as well.

If my memory serves me right, I think he uses darkfield with tissue paper to get a DIC effect.

Edit: Reading the above post, he is using scotch tape on a coverslip over the condenser in darkfield. I remember when he first started, he was using lens tissue.

Yes, that's exactly what he is doing.

[JM Cano]

...My guess is that you are looking for maximum physical relief? Such an effect requires a high degree of precision. It doesn't necessarily happen at Koehler and only a smàll + or- in the location or orientation of the components can make the difference between hey, that's o.k. and wow, that's great.

Thanks I'm looking for at least "some" physical relief, the so called poor's man DIC. I'm starting on microscope imaging and the Koehler brightfield yields quite "flat" imaging. I was filming tardigrades over the weekend, and I was pretty happy, but I saw footage obtained with the same microscope, but using some modification for oblique illumination, and, in my opinion, captures better the morphology of the critters. I'll post updates if I progress on this.

[Saul]

...My guess is that you are looking for maximum physical relief? Such an effect requires a high degree of precision. It doesn't necessarily happen at Koehler and only a smàll + or- in the location or orientation of the components can make the difference between hey, that's o.k. and wow, that's great.

Thanks I'm looking for at least "some" physical relief, the so called poor's man DIC. I'm starting on microscope imaging and the Koehler brightfield yields quite "flat" imaging. I was filming tardigrades over the weekend, and I was pretty happy, but I saw footage obtained with the same microscope, but using some modification for oblique illumination, and, in my opinion, captures better the morphology of the critters. I'll post updates if I progress on this.

if you are really interested in this, please PM me, I can try to help you with something similar https://www.ebay.com/itm/264308894870 for your condenser

[apochronaut]

...My guess is that you are looking for maximum physical relief? Such an effect requires a high degree of precision. It doesn't necessarily happen at Koehler and only a smàll + or- in the location or orientation of the components can make the difference between hey, that's o.k. and wow, that's great.

Thanks I'm looking for at least "some" physical relief, the so called poor's man DIC. I'm starting on microscope imaging and the Koehler brightfield yields quite "flat" imaging. I was filming tardigrades over the weekend, and I was pretty happy, but I saw footage obtained with the same microscope, but using some modification for oblique illumination, and, in my opinion, captures better the morphology of the critters. I'll post updates if I progress on this.

if you are really interested in this, please PM me, I can try to help you with something similar https://www.ebay.com/itm/264308894870 for your condenser

beware.
the condenser isn't included in that listing, just 3-D printed masks. i think there are mask sets available much cheaper.

[BrianBurnes]

I would also add that 3D printed dark field/oblique filter sets do come with limitations. Even "black" plastics will transmit significant amounts of light, especially at low thicknesses (such as a thin field stop) and under intense lighting (such as in a microscope).

They will work (mostly at lower magnifications), but the contrast can be limited due to light bleeding through.

[Saul]

Thanks I'm looking for at least "some" physical relief, the so called poor's man DIC. I'm starting on microscope imaging and the Koehler brightfield yields quite "flat" imaging. I was filming tardigrades over the weekend, and I was pretty happy, but I saw footage obtained with the same microscope, but using some modification for oblique illumination, and, in my opinion, captures better the morphology of the critters. I'll post updates if I progress on this.

if you are really interested in this, please PM me, I can try to help you with something similar https://www.ebay.com/itm/264308894870 for your condenser

beware.
the condenser isn't included in that listing, just 3-D printed masks. i think there are mask sets available much cheaper.

I'm talking about designing insert set for Motic, not masks
And this listing is not for masks but for insert set with masks with no condenser

[BramHuntingNematodes]

There is a solid aluminum foil tape used for duct work, no not "duct tape" foil tape, that can be put over masks plastic or cardboard to great effect. I used it once on a iris diaphragm I made out of paper and it worked a charm.

[JM Cano]

Such an effect requires a high degree of precision. It doesn't necessarily happen at Koehler and only a smàll + or- in the location or orientation of the components can make the difference between hey, that's o.k. and wow, that's great.

Thanks once more for the good insight. It is great all the information you are providing. Since I'm a beginner I'll approach this incrementally. At this stage I am trying to get some improvements (=relief) by playing around with dark field and oblique masks. I ordered Motic's dark field filter slider and I'll play with the DIY light diffusors and masks there. When I recover financially, and feel more confident with the gear and techniques (= know better what I really need), I might consider installing a de-centrable condenser in my scope. As you mention it may be the most sound approach, it just feels a bit daunting so early in my investment and learning stage.

[JM Cano]

if you are really interested in this, please PM me, I can try to help you with something similar https://www.ebay.com/itm/264308894870 for your condenser

Thanks a lot for the kind offer. I just ordered Motic's dark field slider, which is quite inexpensive, to start with. At the very least I expect to get a better feel about the suitable placement and size of masks for the BA310E.

[Saul]

https://www.ebay.com/itm/264952447009

[Challenger007]

Hello,

Is someone in the forum imaging with motic ba310e an using oblique illumination? I would greatly appreciate some guidance about how to achieve it, either with diy approaches or manufacturer's solutions. Tried some diy filters without success. Any examples and/or photos of setups would be greatly appreciated.

Best,

Cano

Look at similar equipment on different trading platforms. I think that in an ordinary store of laboratory equipment you will not find instruments that are out of production. Or ask around in some laboratories, maybe they will rent it.

[rudnicki]

I believe that in case of oblique lighting it is essential to use a mat filter. One should put the mat filter in the filter holder under the condenser and place the stop patch on the filter and not on the illuminator. I also noticed that it helps to raise the condenser as high as possible.
2 examples of oblique lighting with the same stop patch.