Cheap objectives?

[TareqPhoto]

Hi again,

I ordered cheap affordable objectives that are Plan type, it says Infinity, i really don't know what does that means, but it says Apochromatic, is this even possible? cheap and it is Plan APO brand new, i can't believe. It is Chinese so maybe it is not as it should be, but because it is cheap i ordered it to give them a test, hope they aren't same or worse than what i already have [non Plan Achromatic standard objectives].

After all i can't afford high end quality microscope brand new if available anywhere and no plan for used available one, also didn't want to risk buying very expensive accessories too to use with my cheap cheap microscope, but slight improvements or upgrades is no harm for me, it is not a big deal, after all i won't try to compete with high performance best microscopes out there with DIC/Phase Contrast/Pol whatever, but that doesn't mean my cheap one i shouldn't change/modify anything at all, i ordered cheap darkfield filters and it worked nice, although i bought a darkfield condenser but it didn't work because the illumination light isn't strong enough, but the condenser is truly nice and definitely it is working if the light is designed for, so i wanted to try the objectives too.

So again, what is Infinity means for objectives? and what is the big or main advantage of APO over Achromatic? Because i do astro i read the word APO is related to corrected colors and slightly sharpness, is that also with microscope objectives? color and sharpness is my least priority, just want to know anything else there.

[MichaelG.]

... it says Infinity, i really don't know what does that means ...

This is a good place to start :
https://www.microscopyu.com/microscopy- ... al-systems

MichaelG.

[TareqPhoto]

Someone posted to me saying that if my microscope using that 160mm objectives then it means this Infinity won't work, is that true? now late to cancel my order maybe, i will try to cancel, but what kind of microscope i can get for this Infinity objectives then? or it might work?

I need answers as soon as possible so i can think about what i can do, otherwise this is gonna be waste or maybe i wait long to get another microscope to make it works.

[MichaelG.]

Someone posted to me saying that if my microscope using that 160mm objectives then it means this Infinity won't work, is that true?

Strictly : Yes that is true
... You will probably get an image of sorts, but the objective will not be performing at its best.

Look carefully at Fig. 2 in the link that I posted earlier ...

MichaelG.

[TareqPhoto]

Someone posted to me saying that if my microscope using that 160mm objectives then it means this Infinity won't work, is that true?

Strictly : Yes that is true
... You will probably get an image of sorts, but the objective will not be performing at its best.

Look carefully at Fig. 2 in the link that I posted earlier ...

MichaelG.

Ok, i canceled the order, i just wait until the process the cancellation and refund me, then my only option for cheap is Plan Achromatic [160] objectives, after all Plan is what i am after, while Achromatic i can deal with later, not a big deal for me now, and then later i will add a Phase Contrast kit, but i really want to try adding Polarizer filter as someone suggested me to do so [to place in 2 spots of the microscope], i will check out and see if possible and which Pol filter anyway.

I was thinking, if i should just ignore that Plan objectives now and better think to get a cheap Phase Contrast kit instead, will i have more better results with PC than Plan objectives for camera and imaging? viewing or observing by eyes is just fine for now under 4X and 10X, and i was thinking about oil immersion for 100X but i am not in rush.

[Hobbyst46]

To really understand the compatibility among the optical components and the advantage of certain components (for example, plan objectives) it helps to read the explanation in microscopy sites, for example, the ones by Nikon, Olympus or Zeiss.
Moreover, it helps to choose the upgrade according to what you want to see, not according to what might appear as more exotic or sophisticated or pricey or inexpensive.

For example
"Plan" and "phase contrast" are not meant to replace each other, each of them is not "better" than the other. It all depends on what you want to see.
If it is important that all the field of view is uniformly sharp in focus (provided that the specimen is absolutely flat), Plan is an advantage.
But if your specimen is not flat anyway, plan is not important. If your camera catches only the central portion of the field of view - same.
If it is important that a transparent object becomes visible, for example, a cheek cell in water on a slide, then phase contrast is important.

There are objectives that are phase contrast; others are planachromat; still others are planachromats and phase contrast; and still others are planapochromats with or without phase contrast. Yet the specimen of interest might be satisfactorily observed with simple achromat...

[TareqPhoto]

To really understand the compatibility among the optical components and the advantage of certain components (for example, plan objectives) it helps to read the explanation in microscopy sites, for example, the ones by Nikon, Olympus or Zeiss.
Moreover, it helps to choose the upgrade according to what you want to see, not according to what might appear as more exotic or sophisticated or pricey or inexpensive.

For example
"Plan" and "phase contrast" are not meant to replace each other, each of them is not "better" than the other. It all depends on what you want to see.
If it is important that all the field of view is uniformly sharp in focus (provided that the specimen is absolutely flat), Plan is an advantage.
But if your specimen is not flat anyway, plan is not important. If your camera catches only the central portion of the field of view - same.
If it is important that a transparent object becomes visible, for example, a cheek cell in water on a slide, then phase contrast is important.

There are objectives that are phase contrast; others are planachromat; still others are planachromats and phase contrast; and still others are planapochromats with or without phase contrast. Yet the specimen of interest might be satisfactorily observed with simple achromat...

Difficult to explain for you, but i want the field of view to be uniformly sharp in focus to edges, so that i want Plan, and in addition, i want also to see/observe transparent objectives, so mainly like i want both at the same time, Plan objective and Phase Contrast, but it is like i have to decide on one now if i can order one item only as a kit and not both, just i don't know what will be more important for me, i do have 200 Specimen prepared i bought and also another one previously 10 prepared samples, i enjoy looking at them with my current microscope, but they are best viewed only with 4X and 10X, the specimens are prepared to be flat, so that i felt i see it sharp, but when i use camera then this sharpness is gone, it is either center is sharp or the edges, here where it comes about i want Plan objectives so i can have the sample all flat field to edges either by eyes or by camera.

I also want to have Phase Contrast for transparent cells or objects, but i feel for now that i don't have anything that needs to use Phase Contrast for, i mean those prepared are already stained or clear enough with brightfield and darkfield, i didn't make any samples yet that it contains something transparent, but i am sure there are objects there just i can't see, i can wait to buy that or the objectives until February with another budget, i just have to decide now with available budget what i should go with first, i really like taking photos, so amazing really more than viewing them by eyes.

[apochronaut]

You have to be carefull with prepared slides because there are many kits available that are less expensive with simply stained and prepared samples. When viewed with 4x or 10x objectives they are usually o.k. but due to the fact that the sample and coverslip combined are often quite thick, they can be difficult to view with the higher power objectives. 40x .65 is often the limit and even less with phase because in order to get good phase contrast , you must have a fairly thin sample, with the sample and coverslip combination not much exceeding the cover specification on the objective; approx. .17 mm. The sample/cover thickness on cheaper prepared slides is usually .20-.25 and as much as .40 A 40x phase objective will produce a poor image with such samples, so the purchase of phase objectives with the intent of viewing thick specimens, would be something I would not consider.

Plan objectives also become increasingly irrelevant with such sample thickness'.

Presumably with time, you will prepare thinner samples yourself, if only temporary. I would be inclined to use your microscope as is, learn the art of proper sample preparation, while putting your available funds away for the time when you can take advantage of better samples with better plan phase objectives. If you do decide to proceed with finer professionally made slides, then you will need the funds for them as well.

Don't get hung up on the term achromatic. Any objective worth putting in even a low cost student microscope is achromatic. It doesn't even need to be on the barrel but some manufacturers do any way.

[Hobbyst46]

... the specimens are prepared to be flat, so that i felt i see it sharp, but when i use camera then this sharpness is gone, it is either center is sharp or the edges, here where it comes about i want Plan objectives so i can have the sample all flat field to edges either by eyes or by camera...

You have explained it well, and IMHO, the issue is not with your the objectives. If the whole FOV is in focus as seen with the eyes, it should be so in the image captured by the camera, unless there are aberrations in the optics between the camera sensor and the objective. This can happen, for example, due to the camera lens and the projection eyepiece (depending on the details of the interface between camera and microscope).
Maybe, if you describe and post photos of the whole setup, the origin of the problem can be identified by some of the photomicrography experts.

BTW: I just discovered your previous post, where plant sections are shown, and could not find a serious problem of non-planarity of the FOV there.

[TareqPhoto]

You have to be carefull with prepared slides because there are many kits available that are less expensive with simply stained and prepared samples. When viewed with 4x or 10x objectives they are usually o.k. but due to the fact that the sample and coverslip combined are often quite thick, they can be difficult to view with the higher power objectives. 40x .65 is often the limit and even less with phase because in order to get good phase contrast , you must have a fairly thin sample, with the sample and coverslip combination not much exceeding the cover specification on the objective; approx. .17 mm. The sample/cover thickness on cheaper prepared slides is usually .20-.25 and as much as .40 A 40x phase objective will produce a poor image with such samples, so the purchase of phase objectives with the intent of viewing thick specimens, would be something I would not consider.

Plan objectives also become increasingly irrelevant with such sample thickness'.

Presumably with time, you will prepare thinner samples yourself, if only temporary. I would be inclined to use your microscope as is, learn the art of proper sample preparation, while putting your available funds away for the time when you can take advantage of better samples with better plan phase objectives. If you do decide to proceed with finer professionally made slides, then you will need the funds for them as well.

Don't get hung up on the term achromatic. Any objective worth putting in even a low cost student microscope is achromatic. It doesn't even need to be on the barrel but some manufacturers do any way.

I don't understand your post, i can see the samples from 4X up to 40X, just with 40x it is less sharpness or less flatness let's say, and less or dim light, less contrast, so i assume it is either the objective isn't good enough or it is too much for 40X, but i can see anyway, and that is why i was thinking about Plan objectives mainly for 40X so maybe it can give me better improvement maybe as flat field or field of view overall, i doubt it will be worse than the one i already have.

Maybe you are right about thickness of the slide with coverslip, for now i am happy watching it under 4X and 10X, i won't ask more about 40X for now, i tried to prepare few samples too with thin coverslip, i was able to see moving germs or living, was nice, but i want to skip that for now and working with dead or steady objects for now to do imaging then later i will try to start having my own slides and living objects and doing pictures and also videos to show, in fact maybe i can try to do that soon and show you, i remember once i saw kind of small creatures fighting for one source [food] in the sample, i saw that clearly with 40X, while with 4X even with darkfield it was like impossible or let's say i felt like only very tiny dots that i can't see any shape or form.

Still, i like to have Plan Objective, at least for one day if i have perfect samples, so i can get that flat view to edges, who knows.

[TareqPhoto]

... the specimens are prepared to be flat, so that i felt i see it sharp, but when i use camera then this sharpness is gone, it is either center is sharp or the edges, here where it comes about i want Plan objectives so i can have the sample all flat field to edges either by eyes or by camera...

You have explained it well, and IMHO, the issue is not with your the objectives. If the whole FOV is in focus as seen with the eyes, it should be so in the image captured by the camera, unless there are aberrations in the optics between the camera sensor and the objective. This can happen, for example, due to the camera lens and the projection eyepiece (depending on the details of the interface between camera and microscope).
Maybe, if you describe and post photos of the whole setup, the origin of the problem can be identified by some of the photomicrography experts.

BTW: I just discovered your previous post, where plant sections are shown, and could not find a serious problem of non-planarity of the FOV there.

Maybe you are right, i have better images i will post later of samples, this was my first, wasn't bad, but this was taken with 4X, so it won't show much of the issue, you will see the issue more with 40X, 10X shows slightly or it is there but i can ignore it, but 40X is definitely has issues of focus, only very very tiny field of view is in focus, either center or edges [either one side or all sides], so that i was thinking maybe a Plan 40X can reduce this issue, if it is not flat enough with 40X then why not with 10X and 4X too, i don't know how to fix this problem between the camera sensor and the tube and the sample/slide.

Good you saw my plant section, not a great example, i like the sample by eyes, but as i said, with 4X it won't show much of the problem, another example even with 10X it was still nice though, so i won't depend or judge mainly for 4X/10X. but i don't know if 40x or even 60X up to 100X [with oil immersion] can show any good results with camera, or maybe i am expecting too much, just i want to be sure that it is either normal with 40X and more, or there is a problem i need to solve or reduce, and that is why i asked, i still feel Plan objectives may give me kind of better views and maybe also images, i found cheap ones i can order and try, i know if the slide isn't flat then it won't help, but it will be very basic simple innocent question then, if Plan won't help much then who need to use Plan objectives if there is no much/big difference? and if very slight difference is enough or important for some then i want to g with that too.

[Hobbyst46]

Do you have images taken with your 40X objective that show the problem? preferably a brightfield image, not darkfield.

Also, it might be useful to validate the planarity of the FOV with a simple high-contrast monochrome pattern, possibly black on white or any other combination of a dark color and bright color. I would buy a stage micrometer for that. They are relatively cheap, for example:
https://www.ebay.com/p/Corss-Dot-0-01mm ... 1672406640
and are convenient to use.

EDIT: I have just noticed the brightfield 4X and 40X images. They look quite good to me! In my humblest opinion, I think that the whole field across the image is in the same focus, uniform. This holds for both 4X and 40X images. What I see is non-uniform illumination, the right side is brighter than the left side, and this is an issue with the illumination, not the objective. Also, the whole 40X view is slightly out of focus. I might be wrong...

[TareqPhoto]

Do you have images taken with your 40X objective that show the problem? preferably a brightfield image, not darkfield.

Also, it might be useful to validate the planarity of the FOV with a simple high-contrast monochrome pattern, possibly black on white or any other combination of a dark color and bright color. I would buy a stage micrometer for that. They are relatively cheap, for example:
https://www.ebay.com/p/Corss-Dot-0-01mm ... 1672406640
and are convenient to use.

EDIT: I have just noticed the brightfield 4X and 40X images. They look quite good to me! In my humblest opinion, I think that the whole field across the image is in the same focus, uniform. This holds for both 4X and 40X images. What I see is non-uniform illumination, the right side is brighter than the left side, and this is an issue with the illumination, not the objective. Also, the whole 40X view is slightly out of focus. I might be wrong...

I posted another sample, using 4X and 40X, in brightfield, so that is done.

Nice link, i will get that one day too, sounds a handy item for microscopy.

[Hobbyst46]

Sorry, small mistake: Uniform focus for the 40X, slightly less so for 4X image.

About the 40X image: do you have a condenser, a condenser aperture iris, a field aperture iris? perhaps the image suffers from flare, too bright light over parts or most of the FOV. To remedy that, one has to create Kohler illumination if available, or at least close the condenser iris.

[TareqPhoto]

Sorry, small mistake: Uniform focus for the 40X, slightly less so for 4X image.

About the 40X image: do you have a condenser, a condenser aperture iris, a field aperture iris? perhaps the image suffers from flare, too bright light over parts or most of the FOV. To remedy that, one has to create Kohler illumination if available, or at least close the condenser iris.

Yes, i have a condenser, and a condenser aperture iris, but i don't know what is a field aperture iris?

Flare is the main problem, i think it is the reflection from the objective itself, i really don't know how to avoid that, it ruin everything really.

I can close the condenser iris, but when i do that then suddenly i can see all the dust spots or black dots there, i don't know where is that came from, is it within the objective glass, or the condenser itself, or the slide, so i end up opening the iris to keep those hidden dust spots hidden.

I don't know about Kohler illumination, sounds there are many or different method for microscopy that can improve the experience, hope i can get to that sooner or later.

[apochronaut]

You have to be carefull with prepared slides because there are many kits available that are less expensive with simply stained and prepared samples. When viewed with 4x or 10x objectives they are usually o.k. but due to the fact that the sample and coverslip combined are often quite thick, they can be difficult to view with the higher power objectives. 40x .65 is often the limit and even less with phase because in order to get good phase contrast , you must have a fairly thin sample, with the sample and coverslip combination not much exceeding the cover specification on the objective; approx. .17 mm. The sample/cover thickness on cheaper prepared slides is usually .20-.25 and as much as .40 A 40x phase objective will produce a poor image with such samples, so the purchase of phase objectives with the intent of viewing thick specimens, would be something I would not consider.

Plan objectives also become increasingly irrelevant with such sample thickness'.

Presumably with time, you will prepare thinner samples yourself, if only temporary. I would be inclined to use your microscope as is, learn the art of proper sample preparation, while putting your available funds away for the time when you can take advantage of better samples with better plan phase objectives. If you do decide to proceed with finer professionally made slides, then you will need the funds for them as well.

Don't get hung up on the term achromatic. Any objective worth putting in even a low cost student microscope is achromatic. It doesn't even need to be on the barrel but some manufacturers do any way.

I don't understand your post, i can see the samples from 4X up to 40X, just with 40x it is less sharpness or less flatness let's say, and less or dim light, less contrast, so i assume it is either the objective isn't good enough or it is too much for 40X, but i can see anyway, and that is why i was thinking about Plan objectives mainly for 40X so maybe it can give me better improvement maybe as flat field or field of view overall, i doubt it will be worse than the one i already have.

Maybe you are right about thickness of the slide with coverslip, for now i am happy watching it under 4X and 10X, i won't ask more about 40X for now, i tried to prepare few samples too with thin coverslip, i was able to see moving germs or living, was nice, but i want to skip that for now and working with dead or steady objects for now to do imaging then later i will try to start having my own slides and living objects and doing pictures and also videos to show, in fact maybe i can try to do that soon and show you, i remember once i saw kind of small creatures fighting for one source [food] in the sample, i saw that clearly with 40X, while with 4X even with darkfield it was like impossible or let's say i felt like only very tiny dots that i can't see any shape or form.

My caution was, to not jump to phase contrast too early ; before you become good at sample preparation. It would be a waste of money because phase is more demanding of sample preparation. If you are getting a fairly dramatic falloff in the quality of your image when you jump to 40x, that could be caused by the quality of the sample prep. or the thickness of the prepared slides, because spherical aberration will increase , once the specimen/cover thickness exceeds a certain threshold and 40x objectives are much more sensitive to it, than an average grade 10x.
If you are trying to put your limited funds to best use. Spend it on tools to make good slides, or on better quality prepared ones.

[TareqPhoto]

You have to be carefull with prepared slides because there are many kits available that are less expensive with simply stained and prepared samples. When viewed with 4x or 10x objectives they are usually o.k. but due to the fact that the sample and coverslip combined are often quite thick, they can be difficult to view with the higher power objectives. 40x .65 is often the limit and even less with phase because in order to get good phase contrast , you must have a fairly thin sample, with the sample and coverslip combination not much exceeding the cover specification on the objective; approx. .17 mm. The sample/cover thickness on cheaper prepared slides is usually .20-.25 and as much as .40 A 40x phase objective will produce a poor image with such samples, so the purchase of phase objectives with the intent of viewing thick specimens, would be something I would not consider.

Plan objectives also become increasingly irrelevant with such sample thickness'.

Presumably with time, you will prepare thinner samples yourself, if only temporary. I would be inclined to use your microscope as is, learn the art of proper sample preparation, while putting your available funds away for the time when you can take advantage of better samples with better plan phase objectives. If you do decide to proceed with finer professionally made slides, then you will need the funds for them as well.

Don't get hung up on the term achromatic. Any objective worth putting in even a low cost student microscope is achromatic. It doesn't even need to be on the barrel but some manufacturers do any way.

I don't understand your post, i can see the samples from 4X up to 40X, just with 40x it is less sharpness or less flatness let's say, and less or dim light, less contrast, so i assume it is either the objective isn't good enough or it is too much for 40X, but i can see anyway, and that is why i was thinking about Plan objectives mainly for 40X so maybe it can give me better improvement maybe as flat field or field of view overall, i doubt it will be worse than the one i already have.

Maybe you are right about thickness of the slide with coverslip, for now i am happy watching it under 4X and 10X, i won't ask more about 40X for now, i tried to prepare few samples too with thin coverslip, i was able to see moving germs or living, was nice, but i want to skip that for now and working with dead or steady objects for now to do imaging then later i will try to start having my own slides and living objects and doing pictures and also videos to show, in fact maybe i can try to do that soon and show you, i remember once i saw kind of small creatures fighting for one source [food] in the sample, i saw that clearly with 40X, while with 4X even with darkfield it was like impossible or let's say i felt like only very tiny dots that i can't see any shape or form.

My caution was, to not jump to phase contrast too early ; before you become good at sample preparation. It would be a waste of money because phase is more demanding of sample preparation. If you are getting a fairly dramatic falloff in the quality of your image when you jump to 40x, that could be caused by the quality of the sample prep. or the thickness of the prepared slides, because spherical aberration will increase , once the specimen/cover thickness exceeds a certain threshold and 40x objectives are much more sensitive to it, than an average grade 10x.
If you are trying to put your limited funds to best use. Spend it on tools to make good slides, or on better quality prepared ones.

I see, i will remember that, i thought that Phase Contrast is good for anything even for blood or non transparent specimen, just hear or read it is better to show details of transparent objects, but your post showing me that i better wait this idea then.

In this case i should just go with Plan objectives then, and by the time passing i will try to learn making my own specimen with proper thickness, hope this will work to give me nice experience then about microscopy in general.

[apochronaut]

I sent you a p.m. There is a set of very high quality plan objectives in Asia, that should work on your microscope. Very good deal, since they were over $1000.00 when new.

[TareqPhoto]

I sent you a p.m. There is a set of very high quality plan objectives in Asia, that should work on your microscope. Very good deal, since they were over $1000.00 when new.

Thank you very much for your P.M., i already replied to you, i will see what i can decide.