MicrobeHunter.com Microscopy Forum

'Why the flare out' .. 'why the black ring' ? My guess; the light that is entering the cone and going less than the critical angle will exit the cone and other light (heading straighter) will bounce down the inside of the cone (?) I think that the cone ought to concentrate light. Conrad Beck in 'The...

Just pop out the BF condenser and pop in the DF condenser. No It would be nice wouldn't it be? ......Tooo nice, the manufactures might say. (and if you really want the freedom to use a standardised condenser you are going to have to purchase a special mount ). Of course they each maintained other d...

The inability to get the correct height for the DF oil condenser is strange, especially given the fact that I have found no such difficulty. Would I be right in thinking that when you used the darkfield condenser on the No.5 that it came pre-mounted on a push-in disc similar to the disc with the RM...

Maybe the first thing to do is to try out the DF condenser head? ... You could attach the DF head directly to the RMS condenser mount disc with some hot melt glue if the RMS disc is flat enough in the right area and the threading on the head is long enough to raise the darkfield condenser head to to...

It seems that Spencer had to put a darkfield condenser onto an extension tube at some point: Spencer darkfield long.jpg I have a Leitz ' helldunkenfield' (whose head has pretty much the same thread measurements as you measure on your condenser) and fitted that into a Watson centering mount with a pu...

I think more likely, use a 70 to .75 objective. with your dry DF condenser. Maybe even less The dry darkfield condenser made a good annular illuminator for the 1.25 oil objective. The yeast cells dont seem to be the right target for darkfield. Quite a nice set of three photographs in the middle of ...

There seems to be a general and ongoing problem uploading images :
viewtopic.php?f=8&t=19281

29 December;
'The image file you tried to attach is invalid'

What about the movement of the organelles inside the yeast cells? Is that brownian movement as well or rather a result of cellular function and metabolism? Or both? Here is a timelapse video, taken in light-grey darkfield; a dry darkfield condenser under a 1.25 oil Lomo objective (it covers about 1...

My 40x images of yeast are not any better (slightly worse in fact ) however the Cooke Troughton & Simms phase kit I used is not new (cough). The 95x 1.3 does rather better at showing interior detail. If you look at DIC images of yeast they are maybe the best you could dream for: https://www.youtube....

Is it possible that the wedge-shaped ring is mounted the wrong way up? ....I only say this because R&J Beck condensers have the flanged face of the wedge-ring turned towards the bottom.
(I guess it helps to keep the condenser body aligned)

Something rather soothing about it;
https://streamable.com/gen0xp

(It's a timelapse).

It says that the link will expire in a couple of days.

A lot of interesting things live on or around duckweed (lemna) so it is easy to drop a plant or two under a coverslip ..however this sort of deep/thick mounting makes a 'dangerous' combination with an x40 objective.
So I would go for (with a triple nose piece) 4x 10x 20x .

I've just took my two first pictures Quite a special moment :-) I think it is good to consider what you have got rather than what you havent ! ..and they are nice If there is one thing ; I notice that the large bristles on the back of the fly seem to have a slight "softness" to them .. do check tha...

Do you know of a good "Cone" that fits M4/3 (Olympus OM-1)? Is there a good brand I should look for that has the light baffles you spoke of? I have only one cone adapter (M42:RMS) so I cant really say too much, however looking on the internet they all appear to have the same shiny black-anodised fi...

Very nice, I had my first go too a couple of months ago (not as nice as some of the growth shown in your video ).
Out of curiosity; How do you get the zooming out effect... Is it an Iphone App or was it done in something else?

Do consider a cone-shaped adapter* ...they are very lightweight (~100grams) and ergonomic. They can be purchased for around 25$ (some cost nearly double that, for some reason). As far as objective quality goes; most bottom end 4x 5x finite objectives work pretty reasonably. * This sort of thing: htt...

As Alexander says .. the oil ones do not cover much of the field when using, say, an x4 objective with a 6x eyepiece. You might be better off trying Rolf Vossen's method/modification of an Abbe condenser, for general use : https://microscopyofnature.com/low-budget-condenser-darkfield-phase-contrast-...

And the Watson RMS mount Holoscopic condenser:

Here are the Cooke Troughton & Simms condensers, RMS threaded are on the bottom row:
April 1946 prices:
M1382: £1 14s
M1383: £4 14s
M1386: £7 6s
M1391: £8 12s

Where are the BF condensers , though? I only ever see DF condensers. I am a bit puzzled you dont have them too...... most English microscope manufactures seemed to offer them. Maybe they just grew bigger? : The Watson Holoscopic condenser (a 6 element thing) that was initially available only in an ...

Phill Brown; Isn't it simpler to imagine that a bit of Cedarwood oil has leaked in through the top (??)

I am always re-inventing the wheel, every day, in every way :-( Indeed, I have just come across Simon Gage's '"Modern Dark-field Microscopy" .. it's all in there (nearly) ..a good read..even a nice sounding way to size darkfield patch stops : https://archive.org/details/jstor-3221838/page/n1/mode/2u...

I dont know if the optical part of your condenser unscrews from the top of it's mounting tube, but if it does (and I am guessing that it should do) then a small pea-sized blob that strange aimed-at-children silicone putty can be squashed onto the back lens of the condenser: Black silicone putty blob...

The Watson zonal DF oil condenser has a small refractive indent in the centre of the top lens. It can be seen in the 4x image as a ring around the central square of illumination. It's oil filled,not user serviceable. Realistically the na is still limited to .95. Considering it's 1950's RMS it's sti...

Yes, the long modern sort. I tried it with an older 3.75mm 0.95 Beck too ...both the the same.
I have just scuttled off and got my micrometer; the slide thickness is ~1.1mm.

Superglue is not a good mount! ..but it was deadly quick ; the refractive index seems quite different where it starts to set... the slides show a curious ripple effect. The 'screen' does help if things arent going as they should ..I had a slightly twisted mount with a CTS , one DF patched abbe conde...

Messing about with various darkfield condensers with some success and some failures, I wanted to see what was going on with the failures. I used a white 'water-based liquid chalk' marker pen, but the particles were a bit too dense, dipping the tip of the pen in a few drops of water 3 times seemed to...

In some cases could it also be that the 1.2 or 1.25 number sometimes refers to thickness of the slide (aka slip) that the condenser is optimised to use ? (Maybe more so when the numbers cannot be read as an ascending sequence). The AO oil DF on this site has 'SL 1.25' on the slide. https://microscop...

Ange20, you might be getting 'totally black with 40x' if the condenser isn't getting close enough to the underneath of the slide. It has to be very close ( I am guessing , but I am think the thickness of a coverslip or less). It is very hard to estimate this gap by eye. So ; put a drop of immersion ...