question about the difference background of phase contrast

[92111]

why my phase contrast background is so bright
but somebody's phase contrast background is so dark?
because Positive and Negative Phase Contrast ?
or Polarizing phase contrast and no polarizing light.
_____________________________________________
my phase contrast

somebody'phase contrast

[75RR]

Remind us of your setup and the steps you are taking to achieve Phase Contrast

[ImperatorRex]

I also would raise same question as 75RR, respectively if you have checked that the anular aperture ("light ring") of the condenser was centered to the objective phase ring?

[92111]

hi.i am not at home for few days

[apochronaut]

Phase contrast isn't one specific type of contrast enhancement. It is a group of similar effects on a continuum. Most companies that make only one type of phase, make what is referred to as a dark phase and usually with medium contrast.
The problem image shown here, seems to be shifted more towards a bright phase contrast but it also lacks definition. Knowing more about what the system is you are using and how you have set it up would help us to help you.

[92111]

This is my equipment.

i suspect my condenser has a problem.the diaphragm and the top lens are not in a line.1 and 2...
A and B centering phase ring____C and D centering diaphragm .

[92111]

i will write my step later

[92111]

don‘t wait my step, my step is wrong.i am reading leitz manual now.

SHOULD i buy Phase Contrast Centering Telescope Eyepiece?????
i have no that .

[Hobbyst46]

SHOULD i buy Phase Contrast Centering Telescope Eyepiece?????i have no that .

I highly recommend you get one. I find it difficult to impossible to align the phase ring and condenser phase annulus without a centering telescope.

[92111]

step 1
centering the condenser:
diaphragm 1 close.diaphragm 2 open. conderser at H(BF)

[Hobbyst46]

So far so good. Is the objective 10X phase contrast?

[92111]

STEP 2:
condenser at phaco one,objective 10
look from the eyepiece tube certering the phase ring.
or
open diaphragm 1，close diaphragm 2，move the blalck in the center.

[92111]

step 3
take photo

[Hobbyst46]

None.
Step 1 was OK. Step 2 needs to be this: Close diaphragm 1 as much as possible. Until the lit area is a small circle. Not what you did.

[92111]

detail of my condenser:
the phase ring ,one side is silver color,another side is black.

[Hobbyst46]

After step 1 as shown, I suggest that you proceed to step 2 - closing diaphragm 1 (this is the FIELD diaphragm on your inverted microscope) until you get a tiny circle.
Step 3 will be centering that circle, with the condenser centering thumb screws. While doing it, verify that the field diaphragm is at focus. If it is not, raise or lower the condenser ever so slightly until it is focused.
Step 4 will be OPEN the field diaphragm such that the field of view is illuminated, just to the rim, not beyond that.

[Hobbyst46]

After step 4 your illumination is in proper Kohler adjustment (assuming that the light source is compatible).
Step 5 - rotate the condenser turret until the PH1 (or Phaco 1 if this is the Leitz terminology) is in the light path.
Step 6 - remove the eyepiece and inspect the bright ring and dark ring that should be visible down the eyepiece tube (that is the back focal plane of the objective). Then, you can align them with the PHASE ALIGNMENT HANDLES/KNOBS of the condenser - NOT the centering thumbscrews!! This I suggest to do although I do not know where thses knobs are on the Leitz condenser.
Good luck!

Step 6 is where a phase telescope will facilitate the operation.

P.S. If, to give us a view of the phase element in the condenser, you temporarily removed the front lens of the condenser, return it! it should be fitted in place for the 10X objective!

[92111]

None.
Step 1 was OK. Step 2 needs to be this: Close diaphragm 1 as much as possible. Until the lit area is a small circle. Not what you did.

thanks .i need time to try

[apochronaut]

step 1
centering the condenser:
diaphragm 1 close.diaphragm 2 open. conderser at H(BF)

One small problem, not immense but worth attending to is that the condenser plane is not parallel with the objective plane. The image of your iris has yellow c.a. on one side and blue c.a. on the other. The iris is tipped slightly.....not good if the annulus is tipped likewise.

[Brad_]

You seem to have one too many condensers on your microscope. The
402a condenser is a "normal" working distance condenser, made to
work on a 170 mm upright scope...not at all useful on an inverted
scope. The tube that has "diaphram 1" is likely the proper
condenser for the scope.

There's problems with the objectives. The 10x will work well
but must be used with 170 TL eyepieces. Same with the 20x. The
40x LWD is a spiffy objective for your scope, but must be used
with 160 TL eyepieces The other two flutars, while fine lenses,
have little, if any, value on an inverted scope.

[92111]

You seem to have one too many condensers on your microscope. The
402a condenser is a "normal" working distance condenser, made to
work on a 170 mm upright scope...not at all useful on an inverted
scope. The tube that has "diaphram 1" is likely the proper
condenser for the scope.

There's problems with the objectives. The 10x will work well
but must be used with 170 TL eyepieces. Same with the 20x. The
40x LWD is a spiffy objective for your scope, but must be used
with 160 TL eyepieces The other two flutars, while fine lenses,
have little, if any, value on an inverted scope.

Hi, I am sleeping .Yes two condensers . read leitz divert mannual.there are two condensers in it.5 objectives are all phases contrast .All working with 0.17mm slider.

[Hobbyst46]

Hi 92111,

Limiting my comment to the illumination and phase setting issues only:

Indeed, the Diavert Manual tells that one can do phase contrast with both condensers, No 91 and series 400, installed on the microscope. Together they provide phase contrast with objectives 6.3X and up, and Kohler illumination as detailed in the steps suggested in my previous response above. And the instructions for phase rings alignment are also the same as in the response above - with one small difference:

The manual tells you to set Kohler illumination directly with the phase contrast condenser position Phaco 1, instead of the brightfield position (that you had started in Step 1, and I suggested to proceed with it). My previous experience with Zeiss and Olympus microscopes is that initial Kohler setting, when done on the brightfield position, is convenient and sufficient as preliminary to the phase ring alignment. Perhaps on other condensers it is better to set Kohler directly on the condenser in the Phaco 1 position.

[92111]

thanks everyone.i found there are many place need i adjust.such as i should adjust 4 Screws in the red circle to make the condenser vertical .i even need adjust the objective turret. i have ever disassemble this microscope to clean the lens inside so many position changed.

[92111]

bought a chinese CT CENTERING TELESCOPE MICROSCOPE EYEPIECE .

[92111]

You seem to have one too many condensers on your microscope. .

HI ,i found you are right ,i read leitz diavert Manual again,i found i can't use two condenser at same time,that will make me fail in Hobbyst46's step 2.
i am busy in my camera system,so reply late.

[TareqPhoto]

Reply wit your new finding out, let us know, and show examples please, i was planning to buy a Phase Contrast kit, but if it won't help much then i won't bother to buy one.

[92111]

Reply wit your new finding out, let us know, and show examples please, i was planning to buy a Phase Contrast kit, but if it won't help much then i won't bother to buy one.

Big Sorry TareqPhoto.
my microscope can't work now.i never test that kit after I bought it.
if you can buy it anytime.don't buy.
I need 7-----30days to repair my microscope.

[92111]

Reply wit your new finding out, let us know, and show examples please, i was planning to buy a Phase Contrast kit, but if it won't help much then i won't bother to buy one.

Hi TareqPhoto!!!!
without telescope,you can't fully centre the phase ring.but can't tell the difference between fully centred and not fully centred.show you two vedio.
not fully centredhttps://youtu.be/C9_nn6FbF7E
fully centredhttps://youtu.be/m8VR32FeKTs

i baught this chinese telescope for 120/7 Dollar。it works well on my leitz diavert.show you some picture

[92111]

finally,i find my leitz diavert can use two condenser at same time

[Hobbyst46]

finally,i find my leitz diavert can use two condenser at same time

Sure, this is what the manual states! Now that you have a phase telescope all phase settings will be easier. Moreover, you can now experiment and see what the iris and field condensers do.