MicrobeHunter.com Microscopy Forum

Thank you for posting the images! I too like the second, monochrome, picture best. It shows lots of fine detail combined with good contrast and just looks pleasing. The other images look overall a bit dark in the background, but this is probably not VAC2 specific but just a question of personal pref...

These precise multi-start threads often need a lot of patience to get them started. It might have been forced in the past and might not thread at all without a slight touch-up with a file. I would clean both components really thoroughly and inspect them for minor damages at the ends of the thread. T...

Hi rmb,

I can very well believe, that you have shot better pictures than these!

Bob

from what I can see the VAC disc combined with an adjustable second polariser allows for a gradual change between dark ground or circular oblique lighting and quarter segment oblique lighting. It might be an idea to put a small center into this disc that adds a pleasant background color like blue. P...

Hi rmb,

this is very interesting, I have never heard of it. Could you describe the system in more detail, perhaps with a couple of pictures?

Bob

For phase contrast you also need a phase contrast condensor. Phase contrast shows certain details very well, but the image is not especially nice to look at. It shows details that are transparent but have a different refractive index from the surrounding medium.

In this thread you find an image describing the possible Leitz combinations: http://www.mikroskopie-forum.de/index.php?topic=16145.0 With the Periplan eyepieces, the ones marked 10x 18 are for 160mm and pick up the image 10mm down the tube. A Periplan 10x is for 170mm and picks up the image 18mm dow...

PL on a leitz objective means planar to a certain image diameter (18mm?) It's not quite the same as Pl. on a Leitz objective though :mrgreen: EF on a leitz objective means "semi-planar" up to 18mm image diameter, probably as planar as an older plan objective Pol doesn't mean polarised: It means its ...

About mixing components I could only give you some sources in german - are you interested? Oel is Öl when your typewriter has no "Ö"-key. It means Oil immersion objective. Mixing components is in some cases possible. But you need considerable knowledge to get it right without a long and costly trial...

From my experience ethanol is quite critical as a cleaning medium. Try e.g wiping a red Victorinox swiss officers knife - the tissue will be red afterwards. I think I read that at least some german makers explicitly said not to use ethanol, but surgical spirit. Lighter fluid should be usually good e...

The mentioned real microscope makers of the more recent past all made quite good instruments. Each maker had it's own advantages or disadvantages, like the quality of the grease, mechanical simplicity to make overhauls easier, good availability of trinocular tubes and plan objectives.... Most had mo...

Hi John,

it is interesting to see this comparison, but it would be nice to know the precise type of objective. Especially Leitz had a big variety of objectives and small details like "PL" or "Pl" make a difference.

Bob

Probably you will be able to get the part from a zeiss dealer. Have you already removed all damaged parts? It might be a left hand thread. Zeiss liked non-standard metric threads.

Bob

I try to save optics to some extent from sudden temperature changes by covering microscopes with a hood when not in use. I try not to have optical parts on the desk when not in use. My microscopes live in a big closed cupboard apart from the one that is in use. I swear to become a tidy person and be...

As far as I know the overall image information is much higher in a low power objective than in a high power objective. For an objective like this here you would probably need a 50 mp camera to record all information. So it doesn't hurt much if you sacrifice 50% for a better depth of field. Apart fro...

Hi zzffnn, the max. height is 103mm. On the NF the pancreatic condenser is looking at a field diaphragm about 30mm below the bottom of the condenser. https://picload.org/image/droiaccw/pank1.jpg https://picload.org/image/droiacir/pank2.jpg Which of the condenser heads would you use for COL? The dark...

@zzffnn: The Biolam is a copy of the Zeiss Jena LG, made from 1934 on which must have been a revolution at this point of time. Early Biolams until about 1970 (not quite shure if this name was actually used) were close copies and not much worse than the original. Later the Biolam was simplyfied with ...

Hi Charlie, the NF dates from the mid-sixties and the objectives then still had the old length of about 33mm (what Lomo copied with a slight varation). As research grade stand it is also able to cope with whatever else objective you have, e.g. 45mm. The interchangeable revolver allows to use differe...

Unfortunately the work of Antonie von Leeuwenhoek was a dead end. In the decades after his death very little progress was made. I think that the reason for this was not only his secretiveness but also the ergonomics of his single lens instruments. You have to have great dexterity and patience to set...

Hi Ian, I use a Zeiss Jena NF as my favourite microscope too. It really is a multi-knob-microscope where you can adjust everything, but also can spend some time get get everything right. The very high stage controls are a real disadvantage over the lowly LG model. As far as I know there was no stage...

The SONY A6000 and probably other models offers tethered shooting via Android app. I haven't tested it for microscopy applications yet, but for general use it works very well. For proper function it is necessary to update the app in the camera via internet, and this was quite difficult. I don't know...

A sealant for motor casings might work also, it should resist oil.
Shellac is used by artists, and craftsmen, e.g. for veneering and for gold-plating.
Where in the world do you live?

The usual microscope objectives are calculated to find the object directly below the 0,17mm cover glass. Even when you manage to focus much deeper the image quality is not up to specification due to this additional layer of mountant. You can just dilute your diatom-water-mix further to get a strew w...

Hi John,

thank you for showing your work in this detail! It is very interesting to see which steps you take and what the results are.

Bob

Hi Hobbyst46, thank you for posting the results of your work! If you find a nice and simple diatom mounting medium, many people will be very happy about it. I don't think that you have to buy diatom material at this point to test the properties of your new mounting medium. From my experience diatoms...

Your objectives probably are made by Seibert. Seibert used to make high quality microscopes with apochromatic objectives and high class stands. They started to make microscopes somewhen it the 19th century but stopped probably between 1915 and 1930. From then on they specialized in supplying microsc...

Hi John B,

thank you for showing this project!
How do these wax-ribbons come to exist? I would expect an untidy pile of slices. Does the top of one slice make contact to the bottom of the previous one after the cutting is done?

Bob

Hi Peytr, the high refractive index of these mountants comes from the chemical properties of some of the ingredients. Such stuff is not found in household materials. Its mostly harmful and difficult and dangerous to make. Whether you really need a high r.i. also depends on the diatoms you have. For ...

Hi Rudi, from what I know it is useful to put the material through different sieves before sedimentation. Big diatoms and small sand particles sink down at the same speed, so sedimentation of the whole sample doesn't really work. Here in Germany you can buy stainless steel sieve material with mesh o...

Hi John B, your images are really great! So the work you have put into it is was very much worth it. Would it be ok for you if we would use some of your clear images to improve the protocol of our last meeting? We just sqashed the onion tips and our images would only be understood by someone who alr...