Coverglass thickness of 0

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microscopeboi
Posts: 28
Joined: Wed Apr 15, 2020 11:26 pm

Coverglass thickness of 0

#1 Post by microscopeboi » Mon Apr 27, 2020 4:32 pm

hey, im looking at some high mag (40-100x) nikon objectives and i noticed that some are very low priced and they all have a coverglass thickness of 0, would the resolution of these objectives be hindered if i used .13-.17mm coverglass? typically, they are the Nikon CF plan infinity corrected. Thanks

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c-krebs
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Joined: Sat Jun 18, 2016 7:22 pm

Re: Coverglass thickness of 0

#2 Post by c-krebs » Mon Apr 27, 2020 7:38 pm

It would be best to know what objectives you are referring to. But if they are higher magnifications (40-100X) truly designed for use without a coverslip ("0") then you need to be careful. As the numerical aperture of an objective gets higher, a deviation from the designed cover slip thickness can cause image deterioration. You'll often see an NA of about 0.40 as about the largest where this effect can be tolerated, within reason. Naturally it varies greatly with the thickness error. NA's above 0.40 can be very sensitive to these errors.

Look at the discussion (and especially the last two charts... Figure 3 and Table 1) on this page to get some sense of the amount of images degradation based on NA and the thickness error.
https://www.microscopyu.com/microscopy- ... correction

microscopeboi
Posts: 28
Joined: Wed Apr 15, 2020 11:26 pm

Re: Coverglass thickness of 0

#3 Post by microscopeboi » Mon Apr 27, 2020 9:33 pm

okay, thank you!

microscopeboi
Posts: 28
Joined: Wed Apr 15, 2020 11:26 pm

Re: Coverglass thickness of 0

#4 Post by microscopeboi » Mon Apr 27, 2020 9:42 pm


microscopeboi
Posts: 28
Joined: Wed Apr 15, 2020 11:26 pm

Re: Coverglass thickness of 0

#5 Post by microscopeboi » Mon Apr 27, 2020 9:54 pm

nevermind, i contacted the seller and it turns out this was a metallurgic objective lol my bad.

Scarodactyl
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Joined: Sat Mar 03, 2018 9:09 pm

Re: Coverglass thickness of 0

#6 Post by Scarodactyl » Tue Apr 28, 2020 4:28 am

Generally that is what a metallurgical objective is (though they'd also need to tolerate epi illumination).

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