60x 0.17 or 63x 0 objective

[cd13]

Hi guys,
I have a question: I have a plan achro 60x .85 0.17 objective and was looking at a plan achro 63x .85 0 objective.... my question is: Should I buy the 63x? Is there a sustancial benefit to justify the purchase? I should be able to return the 60x if I decide to go for the 63x (which is going to cost me an additional $40).

Thanks in advance!

[Scarodactyl]

0 means it is corrected for no coverslip, which is best in a pretty drastically different set of applications (mostly for reflected light work).

[cd13]

I have a regular cheap chinese microscope.... should I keep the 60x 0.17 or go for the 63x 0?

[Scarodactyl]

You probably don't want the 63x.

[cd13]

The kind of response I was looking for. Thanks!

[DrPhoxinus]

I bought a 60 x and regretted it. You have to ask yourself what do you want it for.
In terms of resolution the rule of thumb is don't exceed 500 times the numerical aperture, otherwise it is empty resolution
500 *.85 =425 so stuff is not so good with a 10x eyepiece for 600x.

So many people are preoccupied with 4x 10x 40x 100x

If you look at pond life a 20 x objective is the sweet spot Goldilox objective- more power than a 10x, bigger field than a 40x

I bought a cheap Plan one for $40 and it is good enough

Gerard

[cd13]

Thanks Dr.
I already bought the 60x so I assume I’m stuck with it, but thanks to you guys, I’m not making the same mistake with the 63x

[BramHuntingNematodes]

In terms of resolution the rule of thumb is don't exceed 500 times the numerical aperture,

Dr. Peter Gray has it at 1000 times NA, which would put a 60x .85 objective coupled with a 10x or 12.5x objective within reach, and he was not afraid at all to tell off students using microscopes incorrectly.

He also points out that in fact, the applicable NA is not the NA of the objective, but the lowest NA of the entire optical system.

[Scarodactyl]

Yeah, 1000x is the typical rule of thumb, though it is of course not absolute.