Microscope woes

[leon.1980]

Purchased the following scope. Having issues finding my samples at the 2000x zoom. Keep hitting the slide before things can focus. Tried using my phone to zoom 3x at the 500 for 1500 but it’s super fuzzy. Do I need a different scope?

 

[DaJMasta]

Very high magnifications are effectively useless, don't even bother beyond 1000x, it's just a marketing trick (general rule for all microscopes, but especially so for cheap ones). It also makes it harder to locate because the field of view is narrower and the focal plane is thinner, but it's also no better resolved - your top magnification objective is a 40x, and while more magnification makes the image physically larger, it makes it dimmer and no more clear.

The longer reason for it is that mathematically, the optics are limited by the angle of the light the objective can capture, which is conventionally noted as Numerical Aperture (or NA, yours seems to max out at 0.65, likely on your 40x objective.), and while additional magnification does make it look larger, the NA limits the resolving power and clarity of the image - with your setup you can probably resolve about half a micron wide features as being distinct from each other, so further magnification just narrows the field of view, making any movement adjustments more touchy, and showing you a more zoomed, no higher detail image.

So to more answer your question, a microscope with an objective with a higher numerical aperture objective (and the appropriate condenser to match) could give you more detail, but it's likely a 40x objective with 25x eyepieces is already plenty, even without the doubler, but for the clearest looking images, I probably would be using 10x or 15x eyepieces (not advocating buying more, but since the maximum resolving power is fixed, having a wider field of view also makes the image look sharper.)

 

[TangerineSpeedo]

That lens usually is used with a "wet slide" submerged. So they say. With my Nikon I asked my friend who uses a the same scope in his lab. He laughed and said it needs a special slide and fluid.
So you’re fine.

 

[leon.1980]

The 500x video

Very high magnifications are effectively useless, don't even bother beyond 1000x, it's just a marketing trick (general rule for all microscopes, but especially so for cheap ones). It also makes it harder to locate because the field of view is narrower and the focal plane is thinner, but it's also no better resolved - your top magnification objective is a 40x, and while more magnification makes the image physically larger, it makes it dimmer and no more clear.

The longer reason for it is that mathematically, the optics are limited by the angle of the light the objective can capture, which is conventionally noted as Numerical Aperture (or NA, yours seems to max out at 0.65, likely on your 40x objective.), and while additional magnification does make it look larger, the NA limits the resolving power and clarity of the image - with your setup you can probably resolve about half a micron wide features as being distinct from each other, so further magnification just narrows the field of view, making any movement adjustments more touchy, and showing you a more zoomed, no higher detail image.

So to more answer your question, a microscope with an objective with a higher numerical aperture objective (and the appropriate condenser to match) could give you more detail, but it's likely a 40x objective with 25x eyepieces is already plenty, even without the doubler, but for the clearest looking images, I probably would be using 10x or 15x eyepieces (not advocating buying more, but since the maximum resolving power is fixed, having a wider field of view also makes the image look sharper.)

the problem is I can’t use my phones magnification my phone just makes the image blurry. And the 40x won’t focus on anything before it hits the slide.

 

[The_Paradox]

How are you mounting and how thick is your slide/cover glass?

 

[leon.1980]

sorry this is all new to me.
If by mounting you mean placing the slide on the deck I just put it on the microscope base.
I don’t know the thickness I just use the slides and covers that came with the scope.

 

[The_Paradox]

Not ideal, but on hobby scopes it is what it is, have you tried putting your sample between two covers? They are quit a bit thinner. If you do try that, make sure you don’t crash the objective lens as covers will break very easy.

 

[DaJMasta]

Does the 40x objective say oil or water or something similar on it? My guess would be not, but if it does, a drop of that on the coverglass and touching the objective would significantly help image quality (they are designed for a specific medium and don't perform as well if not using it, though the same goes if the medium is air). Using supplied cover glasses should be no issue, they should be supplying the right thickness, but some objectives are designed around using a nonstandard thickness - the standard is 0.17 mm thick.

The 40x focusing may just be due to the focuser mechanism, especially if there isn't a fine mode, only very small vertical movements are required to find focus when zoomed in very far, and the working depth of field of what will appear in focus at any one time is something like 100 times thinner than your cover glass with a 0.65 NA objective. It could also be that the focuser is a little loose - there is often an adjustment to make it feel a bit tighter which could help add some resistance to the mechanism - at least some of the adjustments in the video appear to set a focus and have it gradually move out of focus. While this could be the mechanism just not holding where it should and needing that adjustment, it could also be the depth of the water under the cover glass (I like to use a bit of paper towel on the corner of the cover glass once in place to pull out excess water and thin the sample), and it could even be thermal expansion/contraction of the stage mount, since the actual amount of movement is extremely small.

To the blurriness issue, though, again this may be a limitation of the objective and eyepiece combination used. This isn't a great analogy, but you could think of the NA of the objective as setting the detail level of what can be seen (higher is better). So if your 40x, 0.65NA objective can give you the equivalent detail of a nice and sharp looking 800x600 image of your subject, just blowing it up with eyepiece magnification or phone magnification is like taking that 800x600 image and putting it on a 4k tv. Sure, the image is bigger, but there's no more detail or sharpness.

This limitation is present due to the physics of the optics, so while there are observing and mounting techniques that can improve an image in general terms, there's also just a hard limit to how much light an objective can gather (and thus the size of the details it can resolve) and because it's an analog optical system, instead of being pixel size as the analogy above, this limitation manifests as blur.

Making sure you use a coverslip, that there isn't too much fluid under it, that your setup is clean, that your focuser is tight enough to hold its position, that your lighting is optimized to show contrast on your sample, that there's an appropriate mounting medium between the objective and the coverslip (if it's needed), and other things can help make sure you get the most out of your microscope, but with a 0.65NA objective as your best in terms of resolving power, any features below about half a micron are going to be blurred no matter how well you use the microscope or how far you zoom in because the optical information simply isn't being captured. Every microscope objective will have this, though especially nice ones often have much higher NAs.

 

[taricha]

The 500x video

the problem is I can’t use my phones magnification my phone just makes the image blurry. And the 40x won’t focus on anything before it hits the slide.

this is a decent shot of spirulina cyano and some pennate diatoms.

 

[The_Paradox]

this is a decent shot of spirulina cyano and some pennate diatoms.

Agreed. I think a lot of people expect SEM caliber shots off student microscopes. This is about as good as it gets in a hundred dollar scope.

 

[taricha]

I think a lot of people expect SEM caliber shots off student microscopes. This is about as good as it gets in a hundred dollar scope.

yes, just avoid any that have the "toy microscope" description. Those things are useless - unable to resolve even the most basic of cell shapes. "student microscopes" - I can do most anything I want with them.