MicrobeHunter.com Microscopy Forum

dolmadis wrote: ↑

Mon Feb 27, 2023 7:13 am

Thanks for this very interesting thread.

I would welcome a thingiverse link please.

John

Please see whether you can access this link

https://www.thingiverse.com/thing:5881647

It doesn't matter where the modulator is located though, as long as it's location is matched by the slit location relative to the condenser. A similar principle is used in locating the phase annulus outside the objective in some phase systems, such as Reichert did also around 1972 and for all contr...

That's starting to look right! Nice job. The analyzer slit needs to be at the back focal plane of the objective. For low power objectives, your insert is probably at close to the right place - the back of the objective. For higher power objectives the back focal plane seems to be in the barrel - ha...

dolmadis wrote: ↑

Mon Feb 27, 2023 7:13 am

Thanks for this very interesting thread.

I would welcome a thingiverse link please.

John

Hi John,

I recreated my account today and uploaded the files. Looks like I have to wait for 24 hours before I can publish it. Will post the final link around this time tomorrow.

Sure. Will post it later today.

Got hold of ND Filter (12.5% light transmission, close to 15% mentioned everywhere). Changed my approach a bit. Instead of creating a slider as I tried before, I created an insert that goes into the objective backside. It gives better control. Tried it with various combinations ( 10% or 15% dark and...

Verified with phase telescope to make sure only the transparent area is covered by nose polarizer. It goes full extinction and create dark background at the highest turn. So it seems 3rd polarizer will not work. I will look for a gray/ND film. BTW, even though it didn't provide desired result(whatev...

Ldflan, probably I didnt explain it clear. I didn't change the condenser slit after I set it. I am rotating the light source polarizer after everything is set. What I am moving is the 2 sheets in the nose to adjust the position to put them in place. I followed the information in the user guide below...

Improvised something to do the diy HMC quickly. Here is the first version. All the videos were unprocessed and taken quickly. The photos were from the videos a d unprocessed 1. Top one - goes on top of light source. 2. Middle one - filter holder. Slit is for 40x 3. 2x poster board papers in the nose...

zzffnn wrote: ↑

Mon Feb 13, 2023 1:43 pm

How does it look at higher NA of 0.65 or more, please?

Hi zzffnn,

Here it is. It is based on the original design in the link. The darkfield area is 18mm so I used the same path for both 10x and 40x(.75NA).

Please watch it at higher resolution if you can.

That is the information I was looking for. Thanks.

Thanks ldflan for taking time to post the images. It gives me some ideas. I am trying various lighting methods just for fun as I like the challenge. Gives me satisfaction at the end. I thought HMS seems simple enough to diy. :) . Posting sample videos help others make a decision to do diy ( just lik...

Perfect. Thanks. Appreciate the response.

I doubt that 15% transmission rating for the polarizing film is an absolute must. I would give it a try with whatever linear polarization film you can get. The 1% transmission area of the Hoffman slit (marked on the website you reference as "D") can be omitted, at least at the objective rear. I kno...

One more video on the original VAC. Just to avoid confusion, I used one linear polarizer at the light source and the VAC patch mentioned in the link in the first post. The patch goes to filter tray. Then the polarizer at the light source is turned to produce variable effects. Camera couldn't keep up...

I see! You are combining circular and linear polarization... at one edge fairly high up in the optical train. I have no clear idea what that is doing... I am getting the gray and blue hue with just 2 proper linear polarizer( when I rotate the bottom one) without the nose filter. It only comes if th...

I think you must be mistaken about the 3/4 perimeter not varying. Just rotate the condenser and light source filters against one another and you will see what I mean. The area that is cut out of the condenser filter cannot vary in intensity because only one polarizer affects the light that goes thr...

This is a cool thread, and thanks for uploading your video tests; that's a lot of work. Sansub, are you using an inverted microscope? What's your set-up look like for those videos? Thanks :) . Nothing much to do outside in the weekend, so trying things that I kept thinking of doing for sometime now...

Thanks for posting the videos. To my eye, the VAC2 setup seems to be giving a much better result than the modified system; the modified system's results seem very similar to normal oblique lighting. When you rotate the light source polarizer on the modified system, it pretty much seems to dim acros...

No, the cut out area of the main filter is not the variable area of light transmission. The area of variable light transmission is the 3/4 disk polarizing filter. The 3/4 perimeter can be tuned to extinction using the light source polarizer. Neither of these are Hoffman interference contrast. To ge...

As I understand it, the Strange VAC system creates a horizon of variable intensity illumination along 270 degrees of the circumference of the field of view, the result being similar to darkfield (or near darkfield) perimeter lighting condition, but with an oblique lighting effect in which the brigh...

Ldflan, Thanks for the detailed response. As you mentioned, yes, VAC seems to be fancy oblique. Atleast that is what I am getting as results. It varies the background light intensity uniformly to get better obliqueness. I didn't have better sample to demo it and make it "uuhh-wow" :D . That is why I...

While searching on the forum, I found VAC setup mentioned and how it is good on certain conditions. While doing further searching, found one earlier thread talking about how to create diy for VAC (link below). Even though you can get that done with a bit of tinkering, I thought I can make it simpler...

Pretty nice video. It is more impressive when I saw your spec. I agree with the phone recording. My microscopes are trinocular. I did setup entry level sony mirrorless camera ( bought it for 250$ used) and spent another 50$ for other accessories but at the end I found out that my phone camera takes ...

Looks nice. Combine them together or alone in oblique manner produces nice effect. I have multi color films as well and playing with it :). They produce nice image up to 20x. 40x is not good in my experiments. https://live.staticflickr.com/65535/52613147071_96d5d0a0b1.jpg 20230107_134545 by San Sub ...

Legion air, I took your idea a bit further. I realized that this can be expanded to produce the dic effect mentioned in the below link. http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov02/diydic.html Here is the normal oblique slider. https://live.staticfli...

Thanks for sharing it. Simple and functional.

Thanks for the response Pete. Sorry, forgot to mention earlier that I do have a generic 20 plan acro objective. I compared the image quality of the phase objectives to the acromat plain from Amscope. The normal acromat image and videos are more crisp. The different is noticeable. Please see the com...

Hi VCR, I just noticed your message. Yes I did took videos. I didn't use the photo port though. I use my phone camera ( Samsung s21 ultra) which has better quality camera than the cheapo Usb cameras out in the market. It is easier to use as well. I have a 3d printer. So made the "sleeve" for the pho...

I liked the edited video. If edited video brings more details, more power to it. This is one of the to-do item in my list. Thanks for posting the video. I am going to try it this weekend.