Amscope Turret Phase-Contrast Kit SKU: PCT

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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Red_Green
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Amscope Turret Phase-Contrast Kit SKU: PCT

#1 Post by Red_Green » Sat Mar 13, 2021 2:07 am

Hi, there. I was just wondering if anybody has used this kit that could answer a question or two for me?

With the condenser, is the filter holder the typical flip out kind? And... Can I pop in whatever filter I want? Like darkfield and rheinberg filters? And... Can phase contrast be used with darkfield at the same time to have phase on a black background?

Also, with the condenser, does it have an adjustable iris to control how much light goes through?

In the meantime, here's a totally awesome tardigrade.
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BramHuntingNematodes
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#2 Post by BramHuntingNematodes » Sat Mar 13, 2021 2:16 am

Phase contrast.cannot be used at the same time as darkfield. Frequently, a phase stop can act like a darkfield stop in certain situations, but then you won't be able to align the phase ring and th phase stop. Zeiss had some double phase contrast setups, and I never played with those, bit definitely not with the AmScope kit.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Greg Howald
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#3 Post by Greg Howald » Sat Mar 13, 2021 9:45 pm

The Amscope phase contrast kits have no filter holder beneath the condenser in phase mode, only in brightfield. You can not dark or Rheinberg field and phase contrast simultaneously as either of those will kill phase contrast effects using any microscope. The only filtering you can do with phase contrast is to put a solid color over the illuminator. The popular color is green.
Greg

BramHuntingNematodes
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#4 Post by BramHuntingNematodes » Sun Mar 14, 2021 1:07 am

As I understand it phase contrast is most useful for transparent, phase change inducing subjects i.e. colorless. The introduction of say a Kodak no. 58 that has peak transmission around about 520-530 nm will obviate the need to address chromatic aberration induced by the typical achromat phase objective without the loss of information since the subjects are already colorless.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Red_Green
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#5 Post by Red_Green » Mon Mar 15, 2021 1:23 am

Okay thanks.

How come phase can only be used in 10x 20x 40x and 100x but not 4x or 60x?

PeteM
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#6 Post by PeteM » Mon Mar 15, 2021 1:45 am

Red_Green wrote:
Mon Mar 15, 2021 1:23 am
. . .

How come phase can only be used in 10x 20x 40x and 100x but not 4x or 60x?
It's not an optical constraint. Other makers have 4x and 60x phase contrast objectives and annuli. One assumes Amscope thought 10x,20x,40x, and 100x covered the need for phase contrast well enough (and I'd be inclined to agree, if there wasn't sufficiently sales volume to warrant adding the others).

apochronaut
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#7 Post by apochronaut » Mon Mar 15, 2021 11:29 am

Since the diameter of phase diaphragms and phase annuli in the objectives are based on a group of optical considerations, all of them are unique. The diaphragm and it's corresponding annulus must overlap in a conjugate plane but sometimes a partial overlap will give a phase effect too.
It is possible that a 60X objective from another mfg.( as long as it is the same tube length and parfocal length) could work quite well.
It is an experiment though, and there are no guarantees.

Red_Green
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#8 Post by Red_Green » Mon Mar 15, 2021 2:36 pm

Understood.

I looked on ebay for a 60x phase objective and all I could find was used Olympus 60x phase and that was like $1,600 (ish). So that won't be happening in this life time for me lol.
A 4x phase was around $500 - $600. So I didn't really see it as being worth it.

I reckon I could just get the phase kit and get an extra 60x plan objective for those times when the 20x just doesn't get er' done.
Like with this Oscillatoria redekei. It's so thin that a 60x would be of use.

I could just swap out the 100x and either use the 4x or 60x depending on use.
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Rossf
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Re: Amscope Turret Phase-Contrast Kit SKU: PCT

#9 Post by Rossf » Tue Mar 23, 2021 7:41 am

I’ve got a couple of 4x phase and they can be good for certain (large) microbes but just using a 20x (or maybe 40x) annulus on the 4x gives pretty good dark field which makes scanning a slide easier cos of better contrast compared to bright field.Rather than getting a 4x phase I reckon a nice sharp 4x (n/a .12 or higher) is way better value-I can often see bacterial swarms with a sharp 4x in DF-tiny shimmering dots...I’ve got a Nikon 60x phase for inverted and I must admit it is pretty cool but hardly see them for uprights-but a 60x or 63x with an iris could give you dark field with the 100x annulus. I think a good 60x can make the 100x superfluous-just my opinion...
Regards

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