Bug Wings On 55 Year Old Slides

Mitch640 · Post by **Mitch640** » Sat Jan 21, 2012 7:53 pm

Awhile back, I bought some old slides on E-bay. There are some prepared slides well into the 130 year mark that are better than some prepared slides made today. You just have to marvel at the knowledge and care given to mounting microscopic insect parts and the mountants those guys used to preserve them for a hundred years or more to the extent that such things as bronchial tubes inside the bodies of fleas can not only be seen, but seen in detail with modern scopes not even dreamed of in the day they were mounted.

However, these are not even in the same same class as the what the old masters made. These were made in Japan in the mid 50's by people in a country less than a decade out of total war. The quality suffered and the cleanliness of the factories can be seen in the fungus and bacteria that now infest the slides and slowly destroy what was mounted on them.

Still, some of them can be seen with modern equipment and the beauty that must have been there at one time still shows through. All of them were shot with a 20x Phase Contrast Objective at roughly 200x magnification. Lighting was flash.

1. A Mosquito wing with fungus that has entered under the coverslip into the mounting medium.

2. The edge of the same wing.

3. Dragonfly wing.

4. Butterfly wing with scales.

5. Bee wing.

6. Beetle wing.

NikonUser · Post by **NikonUser** » Sun Jan 22, 2012 7:49 am

You are getting good resolution with that 20x.
Are you using it as a 'regular' objective or with a phase condenser? if the latter, how are you lining up the phase rings?

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 8:05 am

Both the 20x PH2 and 40x PH3 seem to work best with the Phase Condenser. And since getting these two lenses, I have not taken the phase condenser off the scope.

I did test them with a regular brightfield condenser, and they are not as sharp as regular 20x and 40x lenses.

I have a no name centering telescope that works amazing well to center the rings. My original Fluophot phase condenser does not have adjusting cranks or keyed screws as some more modern condensers have. You have to reach with the thumb and first fingers of both hands, under the condenser saucer and to the back, and grasp the knurled knob with all 4 fingers and slide it around till the rings line up. Amazingly, this works perfect and takes seconds. I do wish I could find a Nikon Manual for this condenser though.

There are also two thumbscrews for centering the complete condenser, independent of the individual phase rings.

NikonUser · Post by **NikonUser** » Sun Jan 22, 2012 8:44 am

My Oly BH2 phase condenser is real fiddly to adjust the phase rings; I believe it has the keyed screws but there seems to be sufficient play in the alignment that I don't always engage the head of the screw.
Olympus recommend a green (looks yellow) IF550 filter for phase work; I eventually found one on ebay. Does Nikon have a similar filter?

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 9:01 am

You might remember, I bought a Nikon Phase Contrast Condenser II, thinking I could make it work, but as usual, it would have taken machine work I did not want to do to my scope.

Within a week, I found an original, scarce as hens teeth Nikon Fluophot phase condenser. It was up for bid by a guy in China, with a "Send best offer" button. I did that and within 8 minutes, I got a return reply and he had accepted. Within a week, I had the condenser. It took another several weeks and these two phase objectives came up for bid extremely cheap. I got lucky to win both of those.

I had to muddle through how to do the adjustments, and then I got a telescope. I was very skeptical at first, cause I had seen the Nikon Phase II condenser and now, the original Fluophot phase condenser. The older original condenser "seems" to be primitive by comparison. But it's really not. The 1970's build quality makes up for the more complicated and newer phase II condenser.

Anyway, I am very happy with both the condenser and the new lenses.

Filters. Built into the base of the Fluophot, and in line with the Halogen light path. A green, light blue and 3 ND filters. I have tried them all with phase and did not like the effect. I never understood what the advantage would be.

NikonUser · Post by **NikonUser** » Sun Jan 22, 2012 9:45 am

Nice to have the filters built into the base of the scope. With the BH2 I have to actually place each filter in the light path.

At very low power objectives I have to to use ND filters to reduce the amount of light from the flash. Even with the flash set at its lowest 1/128 power too much light gets through - need the ND filters.

I believe the blue filter converts the halogen light closer to daylight.

I'm guessing the green filter allows only a very narrow band of wavelength to pass, perhaps allows for sharper images as it reduces (eliminates?) chromatic aberration as only one wavelength of light has to be focused.

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 10:04 am

I have noticed a slight bit of the green fringing, but none of the purple fringe I really get in heavy doses with my nice Nikon 40x Plan Achromat BF lens. I admit, I did expect better from it.

Here is a bottom picture of the original Fluophot phase condenser and one of the phase ring centering adjusters. You grab that with the fingers and slide it forward or back, left or right to center the ring. Looks crude, works beautifully with the telescope.

I use the light blue filter all the time for BF. It seems to take the harshness out of the light and is supposed to make colors more accurate with digital sensor cameras.

RogelioMoreno · Post by **RogelioMoreno** » Sun Jan 22, 2012 11:15 am

Mitch,

You are getting good results with that phase set.

Rogelio

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 11:27 am

Thanks Rogelio, I am learning fast.

And thanks again for pointing me to the E-bay seller with those wonderful lenses, and, in a roundabout way, to the Chinese seller of the original Fluophot condenser.

Pau · Post by **Pau** » Sun Jan 22, 2012 11:47 am

Mitch, congrats for your new equipment.
Your second picture shows well ,IMO, both the utility and the limitations of phase contrast: the details in the wing border are beautifully rendered with good resolution and contrast while in the wing itself and in the out of focus mountant medium the image is more busy due to the main phase contrast artifact: the halos.

Phase is usually recommended for thin and transparent specimens

I think you are going to get better results with thin specimens like amoebae in clean water. The buccal mucose cells (just gently scratch the mucose skin of your mouth to obtain them) are a good test material for phase.

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 12:06 pm

Thanks Pau. I have been meaning to try the buccal cells, but just haven't gotten around to it. I am trying anything and everything now, just to get the feel for what works and what doesn't.

What would I expect from a thin plant slice?

Walter Piorkowski · Post by **Walter Piorkowski** » Sun Jan 22, 2012 12:27 pm

Mitch, that second mosquito wing is really nice and interesting. I am going to have to mount one myself someday and check out the details you have shown. I mounted some Japanese beetle wings years ago when they were present in the tens of thousands. I was facinated by the strands of muscle fibers in them. Do you see similar features?
Walt

Pau · Post by **Pau** » Sun Jan 22, 2012 12:29 pm

It's very easy, all my 12-17 yrs old students do it: just scratch genltly few times the inner skin of the mouth with a spoon, and place the small quantity of saliva wich contain the detached cells in a clean slide with a drop of water, mix them and put the coverslip.

A thin plant slice would work but usually it is difficult to cut enough thin. Another easy scholar slide is to tear off a bit of the internal skin of the onion cataphyl (the modified leaves that form the bulb).

Mitch640 · Post by **Mitch640** » Sun Jan 22, 2012 12:38 pm

Walter, I don't recognize anything in any of these except the hairs and scales. Not sure what the straight and snake shaped bundles are, although they may be muscle fibers. Everything in these specimens is mummified.

Pau, I will try it. I think, looking at these shots, while the lens is a Plan lens, it does seem the center is in focus while the edges are not. I also noticed it when panning around with the stage knobs. The center looked in focus, while either side looked out of focus. My other Plan lenses show nice and flat, side to side.

Pau · Post by **Pau** » Mon Jan 23, 2012 2:05 am

Mitch640 wrote:...And since getting these two lenses, I have not taken the phase condenser off the scope.

Hi Mitch,
I remember commentaries in some others of your posts about your inability to use darkfield and oblique illumination stops with your brightfield condenser.
Now, with a phase turret condenser it will be much easier:
Mount BF objectives
- with the Ph3 stop you likely are going to get darkfield with the 10X and perhaps the 20X objectives
- For simple oblique illumination, set the BF position of the condenser and while viewing through the eyepieces turn slowly the condenser turret to decenter it until you have oblique. Try with different condenser diaphragm apertures and objectives
- For circular oblique, test the BF objectives with the phase rings designed for higher magnifications (for ex. the 10X with the Ph2 stop) and play with the condenser height. This is more difficult but sometimes it works.
- If your condenser has empty positions you can use them to put self made stops for DF, oblique or Reinberg