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PostPosted: Wed Dec 05, 2018 8:29 pm 
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OK, here are some better images.
Alanine 10x HMC
Image
Safranine 10x HMC
Image
OrangeG
Image
These look way more textured than Oblique and POL to me, but my peepers are early 1950s vintage.
Still learning.
Radazz

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Olympus IX70 HMC
Olympus BX40 Phase Contrast
Olympus SZ40 Stereoscope


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PostPosted: Wed Dec 05, 2018 8:41 pm 
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Location: Germany, Karlsruhe
Indeed great images Radazz!
Would be nice to have the comparison Oblique + Pol versus HMC.

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sincerely Jochen
My microscopes: Zeiss inverse IM35, Zeiss Standard (RA, WL, Universal, Junior), Stemi III
Youtube: https://www.youtube.com/channel/UCVio3U ... cg-Fm2su3w


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PostPosted: Wed Dec 05, 2018 10:23 pm 
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So jealous. Maybe I will take the time to make my own HMC slit plates.

mnmyco


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PostPosted: Thu Dec 06, 2018 2:09 am 
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ImperatorRex wrote:
Indeed great images Radazz!
Would be nice to have the comparison Oblique + Pol versus HMC.

Interesting, something for the next session.
Thanks, Dominus,
Radazz

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Olympus IX70 HMC
Olympus BX40 Phase Contrast
Olympus SZ40 Stereoscope


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PostPosted: Thu Dec 06, 2018 3:05 am 
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Location: Santa Cruz, CA
Gorgeous images.

If you get a chance to compare alternative methods -- would be very interested to see them.


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PostPosted: Thu Dec 06, 2018 1:32 pm 
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Hi Radazz,
thank you for showing these nice images! I too would like to see a comparison of this rare contrast system with pol + oblique combined with pol.

I would also like to see an image of a typical phase contrast-object in phase and Hoffman contrast if possible.

The Hoffman system works with assymetrical stops - is there preferred way to orient them to the object and it's structures?

This might be a system that is uncommon but might as well have had more success.

Bob


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PostPosted: Thu Dec 06, 2018 4:37 pm 
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Nice to see this thread! I just picked up a Nikon 40x 0.55 HMC LWD objective with correction collar pretty cheap on eBay. Got three Nikon CF objectives for a grand sum of £75: the 40x HMC objective, a plan achromat 20x 0.40 ph2 phase objective with correction collar, and a simple E achromat 10x 0.25 ph1 objective. Worth a shot, I thought. The only phase objective I had previously was a 40x CF N plan objective (and a Heine condenser) plus some WI Lomo's, so I got two more phase objectives that will be useful to me, plus a completely new illumination technique!

I don't have a HMC condenser and I don't plan to get one as I'm using my Nikon objectives on a Wild M20 stand, but based on what I've read it seems like it should be possible to make a DIY version by making a slit anullus and placing it in an empty slot in my phase condenser. Getting the slit to line up with the modular plate in the objective might be tricky without being able to rotate it easily, but should be doable.

I'll post some results when I have some (but it might take a while before I have time to do that).


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PostPosted: Thu Dec 06, 2018 5:59 pm 
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Hi viktor,
you might print a black disc with multiple slits with a laser printer on transparency film and get a better idea where the slit has to be.
I'm looking forward for your project updates.

Bob


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PostPosted: Thu Dec 06, 2018 6:16 pm 
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Hi Bob,
My idea was similar: to print a fine grid system on transparent film to see where the slit should be.

Looking at: https://micro.magnet.fsu.edu/primer/tec ... intro.html

The simplest design that could work is simply a single slit, as in figure 4. But I think it would be simple to add some polarizing film that covers half the slit and place a rotating polarizer below the condenser so as to manipulate the width of the slit, as in Figure 2.

Fun project, this.


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PostPosted: Fri Dec 07, 2018 12:51 am 
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MicroBob wrote:
Hi Radazz,
thank you for showing these nice images! I too would like to see a comparison of this rare contrast system with pol + oblique combined with pol.

I would also like to see an image of a typical phase contrast-object in phase and Hoffman contrast if possible.

The Hoffman system works with assymetrical stops - is there preferred way to orient them to the object and it's structures?

This might be a system that is uncommon but might as well have had more success.

Bob

Not enough room to set up both the HMC and Phase contrast scopes so I can't do a side by side of Ph and HMC, but I've got some PH shots to compare.
The HMC, POL, oblique set will be easy, its on the list.
Radazz

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Arnold, Missouri
Olympus IX70 HMC
Olympus BX40 Phase Contrast
Olympus SZ40 Stereoscope


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PostPosted: Thu Dec 27, 2018 2:41 am 
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Hi Radazz.

Can I ask you for a favour? Could you take a photo of the back focal plane of the HMC objective through your phase telescope/bertrand lens when you have set your scope up for HMC? I'd love to compare the look to my own DIY version.

best,
Viktor


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PostPosted: Fri Dec 28, 2018 1:14 pm 
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Hi, Victor
Shot with my cell phone, so best of several tries.
The coils of the halogen illuminator filament are actually much more clear in the mark one eyeball.
Image

Hope this is useful,
Radazz

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Arnold, Missouri
Olympus IX70 HMC
Olympus BX40 Phase Contrast
Olympus SZ40 Stereoscope


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PostPosted: Sat Dec 29, 2018 5:11 pm 
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Check out :

http://micro.magnet.fsu.edu/primer/tech ... intro.html

You can safely ignore the central modulator. You're not likely to find one.

Scroll down and take the Interactive Tutorial. You'll need Java installed. The tutorial is
not necessary but I've found it helpful.

Edmund Optics sells polarizing material for too much of course ($20 ?), but it's
probably the thinnest material you'll find and that's good.

Have fun.

Brad


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PostPosted: Sat Dec 29, 2018 7:12 pm 
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Posts: 42
Brad_ wrote:
Check out :

http://micro.magnet.fsu.edu/primer/tech ... intro.html

You can safely ignore the central modulator. You're not likely to find one.

Scroll down and take the Interactive Tutorial. You'll need Java installed. The tutorial is
not necessary but I've found it helpful.

Edmund Optics sells polarizing material for too much of course ($20 ?), but it's
probably the thinnest material you'll find and that's good.

Have fun.

Brad


Many thanks, Radazz and Brad.
I've read that link many times. However, because it says that "Drawings of the modulator plates shown in Figure 2 are exaggerated and increased in size for the purposes of this discussion", I wanted to see how it looks like in a real-life example.
It's not perfectly clear from Radazz picture, but it helps.

This is what my DIY solution looks like: Image
Wild achr.apl. condenser with a slit cut from an old library card slid into the filter holder beneath the condenser.

I think the back focal plane looks similar to Radazz's. However, I think that your slit is a little longer? I'm going to try a couple of different lengths and widths to see how it impacts image quality.

I already have some polarizing film and tried to mask half of the slit as described in the link above, but I didn't really feel that it changed the effect as much as I'd hoped when I rotated another polarizer over the field lens. Will keep experimenting, though. Now that I have it working it's easy to make slight variations.

Radazz, have you tried the slit condenser with some other non-phase objectives? Mine gives really nice 3-dimensional oblique illumination with my other 20x and 40x objectives, and something similar to oblique dark field with my 10x. Very nice, actually! Much easier to switch between brightfield and HMC for me


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PostPosted: Sat Dec 29, 2018 8:46 pm 
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Location: Arnold, Missouri USA
“Radazz, have you tried the slit condenser with some other non-phase objectives? Mine gives really nice 3-dimensional oblique illumination with my other 20x and 40x objectives, and something similar to oblique dark field with my 10x. Very nice, actually! Much easier to switch between brightfield and HMC for me”

I have, and I agree.

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Arnold, Missouri
Olympus IX70 HMC
Olympus BX40 Phase Contrast
Olympus SZ40 Stereoscope


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