First Timer High Resolution Objective Recommendation

[DougKoebler]

I am starting to build the high resolution system, but need some help on selecting an objective. My goal is to measure the resolution, using a 1951 USAF target. I want to compare the system to my Nikon TE300 system. I would like to try a low cost and a ‘reasonable’ cost objective.

[WilliamW]

Hi @DougKoebler, it would be really nice to see some different resolution tests.

For objectives, you will want 45mm parfocal distance. You can use 160mm tube length or infinity corrected lenses, but you would need to print the correct optics modules. The standard part in the instructions is for 160mm tube length, the version for infinity corrected lenses is in customisations and alternatives. The infinity optics module is slightly longer, so you also need a taller base.

A Plan Achromatic objective is the base specification that would be appropriate. Non-plan lenses will have too little of the field of view in good focus.

There are so many different objective brands to choose from. Many people on the forum seem to be using Amscope. They have a range of low to mid cost objectives which have clear specifications. For mid-price I have used Motic lenses, but there are many others. You can probably use the lenses from the TE300, to show any differences in the rest of the optical system.

[DougKoebler]

I will look over the Amscope objectives, many to choose from? I see a Motic 40x B series, 160mm with a .45NA for $57. The 40x objective on my Nikon is .60NA, Plan Fluor, ELWD infinity. I think for now better to start with a low end Amscope. Can anyone recommend an Amscope?

[DougKoebler]

I am looking for a low cost 40x objective, plan 160mm tube length, 0.65 NA from AmScope.
AmScope 40X Plan Achromatic Compound Microscope Objective Lens, $56.99
Has anyone used this objective?

[WilliamW]

These two posts seem to reference the same lens:

40x Objective Can’t Focus

I just got my microscope camera working with the “High Resolution Optics”. I am trying to scan droplets of algae culture on slides, looking up from underneath with a 40x plan objective (link below). I have used many inverted scopes before for this without difficulty, but I am finding that when I try to get the objective close enough to focus on the algae in the droplet, even those sitting on the top surface of the slide, the objective bumps against the bottom of the slide before the image come…

Objective supplier

You can find affordable and decent enough objective lenses from North American suppliers. Here’s an example: Since you’re not totally sure what to look for, I can’t recommend either Aliexpress or eBay. You can get good deals on eBay but you really have to know what you’re doing.

I don’t know if they were actually used.

[DougKoebler]

William, I think my best first build is to use the 40x Mitotic lens. I did read and look over all the suggested objectives. My concern is working distance. I will probably look at dividing yeast cells in a liquid, then later look at some live cells. I will measure the resolution then compare it to my Nikon scope. Most of the work I do is at 10 and 20x, so I will test the resolution again. My plan is to image the USAF 1951 target and then measure the resolution using the image.
Thanks so much for the references. I will continue to look for any suggested objectives. Thanks again for your help.
Doug