Amscope: Focusable eyepieces (SM-4NTP) or integrated diopters (SM-4TP)?

[Bob_McBob]

I'm finally ordering a decent soldering microscope. The Amscope trinocular simul-focal double boom arm models seem very popular, but they come in two variants. The SM-4NTP has focusable eyepieces and a locking zoom setting, and the SM-4TP has integrated dual diopters. They are priced similarly and have nearly identical specifications, with no distinction made between them in discussions, so I'm having a hard time figuring out which one I should get.

I seem to recall reading that integrated diopters can be a point of failure with zoom optic microscopes, while focusable eyepieces are more expensive to replace, but beyond that I have no idea how the two compare.

[thm_w]

You'll basically only be using the WF10x/20 eyepieces for electronics, so it doesn't matter if those stay in there. You can get WF10x/23 adjustable eyepieces for $40-60 on aliexpress, so I wouldn't worry about breaking them.. I've never heard of that being a problem.

I would choose whichever position you prefer the zoom knob in, one has it at the front and one is more toward the back. Either way after that green20 coupon code its only $420 which is quite cheap.

[Bob_McBob]

You'll basically only be using the WF10x/20 eyepieces for electronics, so it doesn't matter if those stay in there. You can get WF10x/23 adjustable eyepieces for $40-60 on aliexpress, so I wouldn't worry about breaking them.. I've never heard of that being a problem.

I would choose whichever position you prefer the zoom knob in, one has it at the front and one is more toward the back. Either way after that green20 coupon code its only $420 which is quite cheap.

I agree, the eyepieces somehow breaking isn't a realistic concern; it was literally all I could come up with as a point of comparison in a day searching around discussions. And I only found a single mention of the distinction between the two models, in a random watch forum post that didn't really answer anything.

I did get a reply from Amscope. First they state the obvious, that the NTP model has the zoom lock (which is accessed by tool and doesn't seem all that useful). About the difference in optics: "The focusable eyepieces are more forgiving as they can compensate for any defects in the prism and stereo head objective optics. Otherwise, they will operate very similarly." I'm not really sure why they continue to sell both models, but it sounds like they're saying the NTP version is more tolerant of manufacturing defects, which I suppose is worth consideration with these budget microscopes.

On the other hand, I did notice that both models come with WF10x/20 eyepieces. Is that something I should consider upgrading to a wider FOV? Seems like the AE eyepieces from e.g. Eakins are a mix of focusable and non-focusable, with 10x often being focusable. Not sure I will ever want to try a 5x or 20x eyepiece on this particular microscope, but it is more limited without the integrated diopters.

Kind of wish I didn't have the choice to make in the first place 

[jfiresto]

I did get a reply from Amscope...: "The focusable eyepieces are more forgiving as they can compensate for any defects in the prism and stereo head objective optics. Otherwise, they will operate very similarly."

That is a curious answer as eyepiece diopter adjustments or eyepiece tube diopter adjustments usually just effectively shorten or lengthen the tubes to focus the whole eyepiece optical train on the intermediate images that nominally, typically form ca. 10mm down from the tube ends. AFAIK, the microscope makers migrated the diopter adjustments to one or both eyepieces to cut the system cost. Different makers have chosen different depths. Having diopter adjustments on the eyepiece tubes may let you use nicer, non-adjustable eyepieces, or adjustable eyepieces with a reticle – that were designed for a different microscope.

I did notice that both models come with WF10x/20 eyepieces. Is that something I should consider upgrading to a wider FOV?

10X/20 or even 10X/21 are generally not considered wide field for 30mm diameter eyepieces. I have not yet read or heard of anyone who has been unhappy with a wider field of view. Will Amscope let you modify the order to get that? If I were ordering, I would ask.

[Bob_McBob]

That is a curious answer as eyepiece diopter adjustments or eyepiece tube diopter adjustments usually just effectively shorten or lengthen the tubes to focus the whole eyepiece optical train on the intermediate images that nominally, typically form ca. 10mm down from the tube ends. AFAIK, the microscope makers migrated the diopter adjustments to one or both eyepieces to cut the system cost. Different makers have chosen different depths. Having diopter adjustments on the eyepiece tubes may let you use nicer, non-adjustable eyepieces, or adjustable eyepieces with a reticle – that were designed for a different microscope.

It is a curious answer for sure. It's also my understanding that all they do is shifting the position of the eyepiece optics, one way or another. Seems like whatever OEM makes most of these microscopes has been moving towards focusable eyepieces. It's certainly easier to find focusable WF10x/22 and WF10x/23 on AE.

10X/20 or even 10X/21 are generally not considered wide field for 30mm diameter eyepieces. I have not yet read or heard of anyone who has been unhappy with a wider field of view. Will Amscope let you modify the order to get that? If I were ordering, I would ask.

I found it pretty hard to get in touch with Amscope. I actually got those replies from them on Amazon. May be worth inquiring about swapping the eyepieces I suppose.

[Bob_McBob]

I had a good chat with a very helpful Amscope rep on Facebook. They basically said there is no meaningful performance difference between the two versions. The best reason they could offer for choosing the TP version is that future eyepiece upgrades may be cheaper, and there's more selection at other magnifications. So it mostly comes down to what you plan to do in that respect, as well as really basic stuff like where you prefer the knob position as well as whether the zoom lock is useful to you.

Since I was frustrated not finding some of this info, here are a few extrapoints for future readers:

• Both the TP and NTP now have the mounting groove for the LED ring light on the shroud (the TP originally didn't).
• They can't substitute the eyepieces in the kit. You'll probably want to upgrade to WF10x/22 or WF10x/23.
• The double boom mount unfortunately now has the larger base shown on the actual product page, regardless of which version you order. Previously it had a much smaller base that took up less desk space, but was unstable at maximum extension.

Oh, and the GREEN20 coupon is available until Thursday.

[thm_w]

On the other hand, I did notice that both models come with WF10x/20 eyepieces. Is that something I should consider upgrading to a wider FOV? Seems like the AE eyepieces from e.g. Eakins are a mix of focusable and non-focusable, with 10x often being focusable. Not sure I will ever want to try a 5x or 20x eyepiece on this particular microscope, but it is more limited without the integrated diopters.

Buy it with the WF10x/20, then once you've tried it out consider WF10x/23 from AE. I doubt amscope sells them for a reasonable price. 
I would say many people don't really care about FOV, so you could be happy with it as is. But if you are using the microscope for long hours it can help for comfort.

There is no point in using 5x or 20x eyepieces on this type of microscope. But you may want a 0.3x, 0.75x, or some other barlow than the included 0.5x to play with working distance. Again, just buy them from AE not amscope.

[jfiresto]

I had a good chat with a very helpful Amscope rep on Facebook. They basically said there is no meaningful performance difference between the two versions. The best reason they could offer for choosing the TP version is that future eyepiece upgrades may be cheaper, and there's more selection at other magnifications....

For $14 more, less coupon and plus tax, I would get the -TP version because of that, and in case you want to use an adjustable eyepiece with a reticle. Having two cascaded diopter adjustments (in the eyepiece tube and in the eyepiece) will let you superimpose the reticle in sharp focus on the sample image, and then bring the combined image in sharp eye focus on that eye.