PZO PhZ question(s)

[Smokedaddy]

I feel for you!
The following comes from having had a similar experience to yours:
While the PZO Biolar with standard lighting is a serviceable microscope for routine lighting applications, I found that it was very poor for more critical techniques like DIC and Phase.
I believe the problem you are experiencing lies with the lighting system – basically, I found that (in my microscope at least) it was not possible to place the light filament at the perfect position within the optical train to allow even lighting across the entire field of view (I use a full frame camera) – results were much like yours. It was also very difficult to center the filament, and of course the light level is very low.
My solution (after trying, and failing, with other lighting systems), was to buy the PZO LH100, 12V 100W halogen lamphouse – unfortunately it is difficult to find, but they do turn up (I had to buy a complete microscope simply to get the lamphouse!). It should be easier today to get hold an LH100 because there are now many more people selling PZO items than a few years ago.
The LH100 has fixed all my lighting problems and I believe, and hope, that it should fix the uneven light coverage issues you have experienced. The main advantages with the LH100 are the increased light output, and the fact that you can precisely center the light. I also found that it was possible to set up correct khoeler lighting whereas before it was less than perfect.
Your PHZ system looks to be in good working order – I actually found it more difficult to find a good PHZ than I did the lamp house!........so perhaps do not give up just now........
Best wishes

I've known for a long time that the PZO illumination accessory I have is inadequate but I have taken some decent DIC images with it. I did purchased an aftermarket LED illuminator from someone on eBay which I discussed in another thread but it wasn't any better operationally. It mimicked the stock PZO slide in illuminator but was LED based instead of a bulb. As I mentioned in my original posting in this thread the PZO LH100, 12V 100W halogen lamphouse would be my choice IF I was able to find one.

Anyway besides the illumination issue with my PZO I think there are other culprits involved which I also mentioned because of my inconsistent results. I also think the field lens aperture blades are an issue and the adjustment centering screws on the K3PhZ condenser.

BTW IF you have the time, would you unscrew the Abbe lens on your K3PhZ condenser and look at the TOP 20x phase ring filter, then post a picture of it? It comes off easily. Just make sure you're careful not to bugger up the threads when reinstalling it.

https://squattingdog.smugmug.com/Diatoms/i-N5fZ6vj/A

https://squattingdog.smugmug.com/Diatoms/i-CJfSwSC

https://squattingdog.smugmug.com/Diatoms/i-dm55GCD/A

https://squattingdog.smugmug.com/Diatoms/i-27cXtZd/A

Cheers,
-JW:

[dolmadis]

James

I remembered an old post from JohnyM.

http://www.photomacrography.net/forum/v ... ec50e699c0

One other possibility to get more light, is to use / modify 50w UFL HBO dia illuminator that is much more common than 100W tungsten illuminator, and have much better FN coverage. I use to keep one of those modified for 100W halogen / flashlamp.

HTH


John

[Smokedaddy]

James

I remembered an old post from JohnyM.

Thanks John. I sort of remember that when I reached out for help before. I never understood how to physically modify the LED in the aftermarket LED that I purchased on eBay. I still have that too. I still wouldn't be able to center the LED since there isn't any adjustment.

-JW:

[David Maitland]

You take wonderful Diatom pictures and I can imagine how frustrating this problem is proving to be.
I have had a close look at my system. For my microscope, the uneven lighting with a “black central spot” results from a combination of two factors:

1. Uneven lighting across the frame is exacerbated if the lamp filament is not placed optimally as close as possible to the first lens which sits inside the microscope base and functions to relay the light through the microscope. The lens has a concave surface which the light bulb pushes up against (in my experience, the low wattage lighting system fitted as standard does not sit optimally – it does not get close enough to the lens).

2. The centering and fine adjustment of the phase rings is less forgiving than with normal phase contrast . I found that I had to center each ring separately after switching from positive to negative phase contrast by turning the polarizer (probably because each ring is not perfectly aligned since it is difficult to stop the condenser wobbling slightly as the polarizer is turned). This fine adjustment centering is best done by looking at the resulting image through the other eyepiece, or better still, on live-view at the camera, while adjusting the centering screws. When you do this, you will be able to move the black spot around the image.

I attach two diatom photographs taken with a Biolar with PZO LH100, 12V 100W halogen lamphouse. The diatoms are a full frame view taken on a sony A7r MkII – you can see that there is still a central dark patch but at least this extends across most of the frame with only a slight peripheral vignette – It is not ideal, but the Image can be fixed with a slight crop.

I also show an image taken through the Bertrand lens of the x40 with the inner phase ring blacked out by the polarizer. And, the top of the x20 condenser phase disc as requested – the black marks are touch-up paint brush strokes made at the time of manufacture – the discs concentric rings are sharp and clear when viewed against a white background.
Hope this helps.

[Smokedaddy]

Thanks David,

I think the PZO Biolar is a outstanding scope considering the cost IF you can find one with all of its accessories and IF everything is working properly. Especially the DIC head (MPI-5) with no issues or dlamination. The only drawback is the illumination system I have. If I understood how the internal components of the PZO LH100 100w lamphouse worked and what they are I could probably make one since I have fabrications skills. I feel I can fabricate just about anything but I'm super slow at understanding certain working principles of the part I have to mimic.

I started to get frustrated with the PhZ because I wasn't able to achieve consistent results with the same magnification. Even when the setup 'seemed' to be the same. As far as I recall my setup procedure was the same. Sometimes I was able to align the phase rings and sometimes not. Once I couldn't get them aligned horizontally and had to rotate the condenser slightly to make that happen BUT then I couldn't get them aligned vertically with the adjusting screws. That's when I gave up.

I love to have the knowledge to use the PZO's ability to measure refractive index and thicknesses and optical path differences. Unfortunately that's way beyond my knowledge base.

I was wondering if the 'top' of the phase rings were defective and the reason for asking you to remove the Abbe lens. Here are a few pics of my K3PhZ condenser. I wish I could disassemble the condenser and see what's exactly going on inside and remove all the super old grease. I wasn't able to get the top two screws loose without buggering them up, so I didn't force it.



Below is a close up of the 'top'.




Below is the setup I used photograph the top and bottom of the phase rings.



Then I backlit it with the flashlight.



Below is my second setup to photograph the 'bottom' phase ring.



I then backlit it.



-JW:

[dolmadis]

JW knows about this find but the power unit has no adjustment to US 110v.

A dealer in Poland has a PZO OH1 – 12V 100W Halogen illuminator (Lamphouse) with PZO ZM100E – 220V 100W Power Supply with light intensity regulation.

BR


John

[dolmadis]

No direct interest in this sale. (just a customer).

https://www.ebay.com/itm/223616601454