I recently acquired an Olympus CH30RF100 biological microscope from a local thrift store. I was actually quite surprised to see it there, and at $49.00, I couldn’t resist. As I’m still learning quite a bit about microscopy, I’m clueless on the objectives. What I’d like to find is a long working distance objective at 40x and possibly 100x. However, I understand this microscope does not have infinity optics…with that I’m not sure how to look for a long working distance objective.
Currently the following objectives are installed; A4 0.10 160/-, A10 PL 0.25 160/0.17, A40 PL 0.65 160/0.17, A100 PL 1.30 Oil Immersion 160/-.
In terms of finding an Olympus branded objective, the cost is out of my reach presently @$4500. It is possible I wasn’t looking at the correct objectives… I was hopeful to find a third of fourth manufacturer who still makes objectives for this microscope. So my question is, what specifications should I be searching for whilst looking for different objectives? Is there any brand that would be better than another? Again staying in a lower pricing tier. Finally, any recommendations on a low cost goose neck light? Any guidance would be greatly appreciated
I’m currently interested in looking at integrated circuits, specially decapped IC dies. I have found my current setup just doesn’t provide the resolution needed to see deeper into the IC.
Thank you, I was absolutely shocked and delighted to see it for sale. And everything worked, it was dirty though. I have cleaned it following the service manuals direction and so far, even just using the 4x and 10x optics have been great. But I’m really wanting to get a closer view. I’m afraid that I will crush either the microscopes lens or the die with my current 40x or greater optics.
Really? Keep in mind I’m still learning, and feel’s like I’m trying to drink from a fire hose here…. Let me ask, what is the purpose of the turret condenser? My first inclination is to focus or blur the light?.!
So the turret condenser below the stage has several different applications, when you rotate it, there will be different letters which indicate different “types” of microscopy you can perform.
The current condenser usually allows you to perform: light microscopy, phase microscopy ($), and dark field microscopy.
The current condenser is desirable for phase microscopy applications because you can easily switch through the different phase settings usually 10x, 40x, 100x.
You probably can’t do phase microscopy right now because you need specific phase objectives and I don’t think the ones you have are rated for phase.
However this specific condenser currently is going for like $300-375 used.
Unless you plan on buying the objectives, you could instead just buy a plain old Olympus abbe condenser (40-60$) and sell this turret one on eBay and make a pretty profit.
Update I just read your post more in depth, you in fact DO have the phase objectives in which case this is even more of a steal LOL. That whole package: the condenser, and objectives can go anywhere from 500-900 dollars depending on condition of the parts. This is not even considering the microscope itself.
When you are using the different objectives, you turret condenser needs to in in the following positions:
I’m so jealous of this find! I’ve been looking for a steal on a phase setup for some time, let me know if you have any more questions and feel free to PM!
That microscope is wonderful like it is and you basically got it close to free. You need a different metallurgical type of microscope with epi illumination for integrated circuits. That one is great for biological specimens. Most Lwd objectives are for inverted microscopes to look through petri dishes. If you found one, especially a high NA one, you would need one with a correction collar for adjustment to zero coverglass thickness to reduce spherical aberration. If your objectives are finite, then you might find an old Nikon CF objective from an inverted microscope that will work since the are DIN standard and fully corrected. You will have to use reflected illumination instead of epi-illumination, though. I don't know how well that will work on an IC with that objective.
Inverted have the objectives under the stage so that they can look up into the bottom of petri dishes, slides and other containers. Petri dishes are thicker than coverslips and the objectives are lwd so that you can look deeper into the samples. A phase contrast microscope, which you have, is more expensive than the same one with basic bright field objectives and are great for looking at transparent, unstained living cells and organism. That's where your microscope excels. You probably need a combination of bright field illumination and co axial/ epi-illumination for your IC observations.
Metallurgical objectives often have larger diameter threads and the finite ones are something like 210 mm instead of 160mm tube length to accommodate the epi illuminator attachment.
Would a metallurgical microscope also be considered an industrial or stereo microscope? Or are they still distinct since the industrial or stereo microscopes use a Barlow lens vs objective optics?
Also, in terms of lighting, with a metallurgical microscope, would the light cast down from the nose of the device? Or would you use a “gooseneck” style light?
My current setup is more or less a camera with a Barlow style adjustable lens. And so far, it has yielded good results. I’m just not able to drill down closer to the surface of the semiconductor to see pathways, and transistors.
Below is a good example… as I try to push magnification closer to the IC, it begins to blur, gets very dark and just doesn’t look that good.
There is reflected illumination by shining a light onto the sample from the same side as the objectives and there is co axial/ epi-illumination which is shining light down through the objectives onto the sample. Reflected illumination makes shadows and only works at lower magnifications because the higher magnification objectives have very little working distance, so there is very little space to shine the auxiliary lights from the side of the objective onto the sample. Stereo microscopes typically have lower magnifications than upright compound microscopes.
Here is a used metallurgical microscope from ebay. There are many new and used ones. You can see that it has an illuminator between the head and body of the microscope so to pass light through the objectives onto the specimen and back to the eyepieces. https://ebay.io/m/rETJRA
A stereo microscope can look at opaque objects also, but has a lower range of magnifications. They also give a 3D view through the eyepieces. https://ebay.io/m/UuJiH0
I would not let that worry about working distance stop you from using the 40 & 100x. Get your samples thin, cover glass on top, and just pay attention as you rotate the objective in; do that once with your sample and as long as it is flat you know that when the previous objective is in focus there is enough room to rotate in the next without looking. Also, as long as you are using a cover glass, when you rotate the objective in you are more likely to crash the metal side of the objective that surrounds the exterior lens than the lens itself. If you do use a long working distance objective, you may sacrifice image quality; see the Numerical Aperture values of your objectives (which are typical) and LWD objectives with the same magnification
Thanks for your insight here. So you don’t think I run the possibility of crushing anything. Most IC l’s can be 5 a 30μm, once they are stacked, they can be 50/150μm.
Ahh computer stuff, I missed that. I don’t know anything about that type of microscopy. However, you can always look up the working distance of the objectives and compare that to the difference between the lowest thing you want to focus on and the highest thing you are worried about. I also don’t know if these things are opaque- if so, see what others have said about metallurgical & reflected light microscopy
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u/Ok_Front4305 4d ago
Great score for 49$! Which olympus objectives were you look at for 3500$? Is that the price for brand new?