MicrobeHunter.com Microscopy Forum

Today is good day, let's enjoy it! I wish everyone here has got a great 1st day in 2024!

Then I dip a drop of oil onto the condenser, the image is much improved. looks like NA 0.75 should pair with higher NA condenser:
1. You can see a lot more details in the yeast cell
2. every yeast cell somes with darker core inside and some light dark area surrounded.

An iris on a 40X is not uncommon but usually it is on objectives with higher N.A.s. Reducing from .65 will quickly result in a loss of resolution. This brand that you reference , Leichert. I have not seen it and a 40X with an iris is unusual. I know Reichert had a 40X with iris. It is very difficul...

That certainly shows more detail. I am wondering how thick your sample is? Yes. Higher N.A. reduces the depth of field but increases the resolution but only if your sample/ coverslip sandwich is within the parameter of thickness that the objective is suited to. The lower N.A. objective can tolerate...

Unfortunately osterport, your phase contrast contribution above isn't the best and somewhat atypical of what phase is capable of. Some simple phase systems tend to exacerbate the defects associated with achromats, thus using a green filter and photographing in black and white has been employed to o...

Hi, osterport, and group. Visual observations with Nikon dl phase finite (circa 1980's?) optics: 10X, 20X, 40X, 60X, and 100X-oil objective..are terrific. My crude image-capture/ camera setup never records what visually I enjoy with dl-phase contrast methods. And the variety of Nikon phase condense...

You can also make DIY circular oblique light (using different circular mask sizes) and cover up 1/3 to 2/3 of the light circle. That would produce similar effect as what Macro_Cosmos does with his Heine condenser. I'll try it. whether it's 1/3 or 2/3, depends on objective's magnification? how much ...

If we adjust the curve of oblique field image in PS, it looks much better.

I did a test to compare brightfield, phase contrast, and oblique field. Obviously Oblique field gives much more details, phase contrast only brings some dark area where we do not see anything. ( is it Shade-off artifact?

Whatever trick is welcome: I see Zeiss has a technique called Varel, but very little information on the internet, have you seen anyone using it? This is something you can absolutely DIY. Get an abbe condenser which allows inserts to be placed at the back focal plane of the objective, and make yours...

Yes, pictures help . Those active tutorials provided by those Florida State guys for various mfg., can be useful. https://www.microscopyu.com/techniques/phase-contrast Thanks, a lot of information that I need to digest. I'll try something this weekend to see if I can improve the image quality. What...

Scoper wrote: ↑

Mon Dec 18, 2023 1:27 am

How about some representative phase photos of the different systems and types of phase?

that'd be also helpful to figure out some tricks we can make to improve the image quality. I've seen pictures as above, but those are theoretical, do not help us understand the actual results.

Thanks for the reply. Have you seen anyone with good phase contrast pictures? I took a look at Nikon website, looks quite ok.

https://www.microscopyu.com/techniques/ ... e-contrast

Has anyone here ever used such objective?

It is not very easy to see the little dots inside the cell actively moving ( pls watch in 1080p ) r57YZkvB04A https://youtu.be/r57YZkvB04A?si=U2B-u4NyPISNxBMT But if I use a normal 40x motic PLAN objective in darkfield, you can easily see the dots are swimming in the yeast cell.( pls watch in 1080p ...

Hi, all I have a 40x phase contrast objective from Leichter, and I tried quite many times, but the highest resolution picture I got ( no photoshoping ) is like this: 1. There is always a halo around each Yeast cell, which makes the yeast look blur. 2. Due to the fact that the phase contrast stop cre...

Just Beautiful! No other words.

ADi wrote: ↑

Sat Dec 02, 2023 6:11 pm

Hello everyone,
One eye taken with a Nikon Plan Apo 20x/0.75 :

Best, ADi

This is the best picture of Fly I've ever seen, and it's the first time I can see the individual eye of it.

Thanks for reply! What I'm wondering is, if a DF condenser N.A. is 1.4-1.2, does it mean in most cases 1.2 is the NA that the condenser performs and only in some special cases NA 1.4 is possible? I got the knowledge from this forum that objective NA should be 0.2 NA less than the condenser NA in cas...

Olympus


Nikon

I noticed that some condensers labeled as 1.4-1.2, especially darkfield, some just labeled as 1.4. I've seen condensers like Leica condenser 0.90/1.25oil, then I know its NA is up to 0.90 without oil, 1.25 with oil. Why is it 1.4-1.2? sometimes 1.2? Just do not know the condition to get the best per...

This is how it looks like under Motic 100x oil 1.25, this is not darkfield.
To make, high NA darkfield, Iris objective is a must.

It's hard to measure the size of Iris NA with this picture, definitely not 1.32, far from that.

My dream is, someday I just use a normal objective 100x oil NA 1.25 in Darkfield, looks like it's hard.

Then I tried the oil immersion objective Reichert 100x 1.30 with this set up.

It's much improved, but still not comparable with Oblique condenser in terms of details.

One thing I've been wondering: is this achromat condenser? I see blue, yellow, red colors.

One more change is, I only dipped very little Yeast water, which forms a very thin layer under the coverslips. Evenly position the condenser is very important, see picture 1, By adjusting the PVC board direction, we can see the circle of Yeast is replenished ( see picture . One more trick, the high ...

Now the condenser underneath is fully contacting the slide, it's a dark circle.

Let me try to solve 40x NA 0.75 first. I found the DCW condenser is not contacting the slide bottom evenly.
Then I inserted a PVC board of 1mm at the edge of the condenser mounting area.

Yes, if you want to take a look at small insects, or flower, it gives you an overview. Not like 4x, 5x, where you only see a small portion of it.
[youtube]https://youtu.be/dtIyunkmYH4?si=dvtt-Cgv-iuUTdhu[/youtube]

Thanks for the detailed suggestion. 30W LED really surprised me. One question: is your LED a ring form factor like mine? Is it very big? For such darkfield stop, probably only the outer circle light would make sense, right? Most of light is blocked anyway. osterport, Your LED light may be too small ...

Actually I got the NA down by adjusting the Iris. However no matter how I adjust it, it is either completely dark or bright&messy. As the last step, I swap to 100x Reichert 100x NA1.30+DCW+LED Ring, it's a mess. We can see some details, but very poor quality If the 100X Reichert has a fixed NA of 1....

As the last step, I swap to 100x Reichert 100x NA1.30+DCW+LED Ring, it's a mess.

We can see some details, but very poor quality