MicrobeHunter.com Microscopy Forum

It helps to not just skim the last page of a thread - I see now that all of my previous points have already been made. At least it's good that we all arrived at the same conclusion :) On a second read of the patent I also noticed the last paragraph of section 1 which states "the spatial filter for g...

I happen to be a native German speaker and have read the patent for a bit, and I think you are mostly correct in your investigations hans. The Thorlabs and the patent diagrams specify the same optical system, and simply show complementary planes. Patentspeak is rather dense, but some salient parts t...

I would also add that 3D printed dark field/oblique filter sets do come with limitations. Even "black" plastics will transmit significant amounts of light, especially at low thicknesses (such as a thin field stop) and under intense lighting (such as in a microscope). They will work (mostly at lower ...

Thanks for the info on the pump, looks good, is it a vibrating type or some sort of clever rotary type to be so quiet ? It appears to be rotary but it doesn't look like I can take it apart without some destruction. As for my water tank, it seems to have suffered from sudden mass extinction - everyt...

Very nice, I have not tried darkfield on the Microstar IV yet, how are you doing it? I designed a 3D printed filter holder that fits onto the Microstar condenser and a number of 3D printed filter inserts. It works relatively okay and lets me experiment with different filter shapes quickly. The main...

A few videos from a piece of forest pond transplanted into a microbe aquarium and left to grow for a week. Microstar IV, Canon EOS 7D, 10x Plan Fluor and 40x Plan.

Hi Microbob, The pump I bought is this one , but the same pump seems to be sold under many names and from many vendors (it can also be had directly from china for a bit cheaper, if you are willing to wait). I was very impressed with how quiet it is - the sound of the bubbles themselves is louder tha...

With winter upon us I decided to set up an indoor aquarium to get access to microbes during the cold season. A 2 gallon glass storage jar from Home Goods and a cheap USB bubbler pump seem to do the trick, for a total cost of $15. I don't have a grow light, and I will have to see if that will be my u...

I've often seen camera lens repair folks use suction cup tools to remove stubborn lenses held in by friction or vacuum. They are gentle on the optics but can apply a lot of force. There are tools made for the purpose such as this one , but even household suction cups from the hardware store (e.g. fo...

That's a good summary. It is true that we shouldn't lose the practical goal out of sight (to get good images out of a Microstar), but at the same time I found a lot of these investigations fascinating from a more academic standpoint, just to satisfy my own curiosity about how this system worked. I t...

What size Phillips bit are you using for those set screws in the outer part of the eye tubes? I never found a size that worked well and they drove me crazy until I eventually bought a bag of hex set screws and threw out all the original Phillips ones. From what I can tell they are hex grub screws, ...

For the low price of $79 I picked up (among others) this assortment of eyepieces and Reichert objectives. 6.5x/10x/20x/40x RMS plan epi objectives, and 10x plan epi/20x plan epi/50x plan fluor epi/100x plan fluor objectives with a much larger thread, likely from the Polyvar line of microscopes. The ...

I should also mention that I did some physical experiments as well, and found that I could not get enough correction with the doublet in a direct projection setup - I just could not get the doublet close enough to the tube lens. In an afocal setup the results are better (I posted pictures of the ada...

To breathe some life back into this thread: I spent quite some time reconstructing the Microstar IV microscope body and objectives from Reichert/Cambridge patents in order to perform a full spectral optical simulation of the whole system. What follows is a fully virtual reconstruction, based on real...

I'm looking for an iris diaphragm similar to the one below, ideally from a Microstar IV but others will do as well. A diaphragm diameter in the neighborhood of 35mm/1.5" would be ideal. https://i.imgur.com/Dks6Jmd.jpg If you have a broken stand you don't know what to do with and would be willing to ...

I wonder how well that standard formula could approximate two relatively distinct regions of curvature? Would obviously require using the radial power series terms, I think, but if curvature as a function of r looks somewhat like a step function, then a power series is not a very efficient way to a...

Apo is correct. If you have a frosted glass, you are using 'critical illumination', which is what the 410 uses: the frosted glass, making an evenly-lit field, is right before the field iris which is to be conjugate with the specimen. I would have to disagree with this - the presence of a field lens...

Another thing I forgot to mention in my previous post... have you looked at the two elements of the collector lens assembly individually? I have a broken Microstar IV that I have been stripping for parts, and from what I recall that lens did look aspheric. According to the patent it is intended to ...

Having dug through most of Reichert's and Camridge's patents, I have not found any other ones so far that describe a diascopic illumination system similar to the one found in the Microstar (though there is one describing the fluorescence attachment). It may be that subsequent iterations were deemed ...

Hi all, I'm in the process of building some custom optics for my Microstar IV and I've been going through old Reichert and Cambridge patents to understand the intent of the original illuminating optics. However, a problem I've run into is that few of their patents actually seem to work. As a simple ...

The original analyzer box for the Microstar IV seems hard to come by, and I've been using a simple PVA polarizing disk inside the head for a while to get a poor man's polarizing microscope. I've been looking for a more convenient way to house the analyzer which would allow me to rotate it and remove...

Following on the discovery of the chromatic aberration correcting doublet by hans, I've decided to make a more permanent afocal camera adapter for my Microstar IV that incorporates the correcting optics, eyepiece and a firmly mounted camera lens. It consists of a combination of 3D printed parts, met...

I also noticed in the photos you and Brian posted of your LED retrofits, both originally had circular lamp holders, while all mine are a different rectangular design with a little door that swings out for lamp replacement. I have two bodies, and there is some variation between the two. One has the ...

Phenomenal work hans! That explains a lot about the optical issues I have been seeing in my setup. I've looked into the heads before but did not think to check the base of the eyepiece tube, and sure enough, both tubes contain a correcting glass plate. I am quite interested in a direct projection se...

Happy to see so many LED conversions! The CRI of my LED is rated only at 70+, and I will have to do more testing to see if color accuracy becomes an issue. A higher CRI LED should be easy to swap in. hans, sadly I don't have any new updates to report since my last post. I'm waiting to regain access ...

The 20W tungsten bulb of my Microstar IV started to feel a bit underpowered for darkfield/phase constrast and photography, and I've been working on a high-power LED illuminator to replace it. I wanted to preserve as much of the original scope as possible, so I picked components that would fit into t...

Thank you for taking the time to write such a detailed response apochronaut, this is very useful information. I've been able to realign the nosepiece and the quality seems improved. In your setup, are you using a camera lens at all, or does the eyepiece project directly onto the sensor? If it is the...

Thank you all for your replies! I'm very much aware of the ad hoc-ness of my setup, and for sure would prefer to do without cardstock or 3D printing. With no access to a machine shop they sadly happen to be what can be easily accessed at the moment (and within budget!). I have been on the lookout fo...

Hi all, I've been trying to build a decent quality DSLR setup for my trinocular Reichert Microstar IV, and I could use some advice from the resident microscope experts on how to fix the problems I'm seeing (or - maybe these issues are expected with this microscope). I'm at a point now where I can ca...

LCDs need a final polarizing filter to modulate transparency, but that filter doesn't have to sit on the display itself - it can be in the microscope head instead (i.e. the analyzer), in which case light passes through the sample first. The LCD then serves as a (programmable) bottom polarizer in a p...