60X objective

[p3aul]

Well I don't think either of us will convince the other. I know for a fact there are members that think as I and others that think as you. In fact reading a few posts here by one gentleman who is even more adamant than you that Chinese Scopes are cheap junk. I don't think I would change his mind either!

My focus is on getting the best I can afford and I don't think used microscopes(the so-called "big four") are in my future. I would someday like to get Amscope Plan optics but they aren't really a necessity I can just move slide to the middle of an interesting field.

In any case I'd rather discuss objectives. I have cancelled my order for the 60x. and thinking of getting a pair of 15 or 16X to use with the 40X. With an NA of .65 that would allow me to go up to 650X and that would be 600-640X. I believe Wally mentioned something about the high NA of the 60X being a minus.

[billbillt]

Hi Paul,
I use Chinese oculars from 5x to 20x all the time... I use them on all of my stands regardless of "brand"... They perform well for me... This way I can come up with many different combinations of magnification...

BillT

[p3aul]

Yes the 20x came with the scope. Bt I get much clearer views with the 10X and now that I understand how to figure the maximum usable power I will stick to the formula of 1000 * N,A. That will limit me to 650X if I go no higher than the 40X. I think that's alright though, probably for everything but bacteria. I'm looking through the scope right now at 400X I can see the nucleus of an epithelial cell. I can just make out something in the nucleus but that's all. At 800X , using the 20X EP I can see two somethings but it is too blurry to see any thing else, so that's why I want the 16's

[billbillt]

Yep, experimenting is part of the fun... The variables are endless!..
BillT

[billbillt]

Hi Paul,
I was looking on Ebay and found this:

http://www.ebay.com/itm/1-PCs-WF16X-13m ... SwpdpVVZkl

The 16x is the ones I do not have... I think I might buy two on my nest purchasing cycle...

BillT

[p3aul]

you know i think that looks like the ones amscope sells. They are unbranded so I think they must be pretty common. I am ordering that one, actually two, from Amazon. I choose Amazon for ordering instead of Amscope, because of a no-hassle return policy and things seem to arrive quicker. I don't know what the difference is, but on Amscope and Amazon, a pair of these same EP's cost $25. Maybe they are a matched pair, I dunno? I guess Ebay is safe, but some articles they have a high shipping price. Amazon has free shipping for anything over $35 and here's a chance to get some oil for the 100X to add up to the $35.

[einman]

One method to using oil is to set up a nose piece equipped with only oil objectives. Three of my Leitz stands have removable turrets. The turret slides in and out in seconds. I have several of them. They go for less than $50 if you are patient on E-bay. I have one equipped with low mag objectives. One is equipped with Higher mag and the other has all oil objectives. That way you only clean-up when you are finished and not between objectives.

eiman,
What is lowest magnification oil objective that you have and what is its fair market value? I considered a Leitz oil (IIRC a NPL 25x 0.75) before, but gave up due to its high cost (cheapest on eBay at the time was over $220). Most 10x dry objective can look through a thick layer of oil without problem. And a Leitz oil NPL 10x 0.45 is also very expensive at over $200.

Sorry for the late reply. I have been traveling. My oil objectives start at 40X and go to 100X. The idea of an oil objective is to get greater resolution correct? The idea of a dedicated turret is to prevent cross contaminating a dry objective with an oil objective. At 20X you can get dry NA's of 0.75 with a working distance sufficient to eliminate cross contaminating with oil. I have a 40X/1.3, 63X/1.3 and a 100X/1.4 oil objectives mounted with a 20X/0.65 and a 10X/0.30 dry objective. I am not sure what using a 10X or 20X higher na would buy me unless I go to a higher magnification eyepiece. I generally only have a need for higher resolution at 40X or above.

recall the LOMO WI 30X has an na of 0.90!! I love that objective.

[zzffnn]

eiman,

For me, that Leitz 25x oil provides more convenience and scanning ability rather than resolution/NA. A dry 20x NA 0.65 or 0.75, theoretically, won't be able to image through oil (left by immersion) without quality degradation. Yes, WD is sufficient, but image quality through oil won't be that much better than a regular 20x NA 0.4. And low oil can maintain image quality through oil and scan (say, for a protist escpaed under high power oil) at the same time. Benefit is no clean-up and great image.