Has anyone tried this USB scope? General macro chit chat appreciated.

A) 1x-500x and it does not specify if any or all of that zoom range is optical or digital.

http://www.ebay.com/itm/322126555630?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

B) Seems like an "almost" product and at 5MP, I might be inclined to spring for one if the range was say, 1X to a max of 60X with the zoom optical. Maybe I'm thinking wrong?

C) Most I have researched, even the Dino-lites specifically for coins, start at 10X or 20X with, like this one, the high magnification range being absurdly not required for coins. This spells compromise in performance in my book for such devices. Again, maybe I'm wrong.

D) It also appears from the limited pix v. tech specs, like here is a penny at 10X, that their 10X varies greatly from what my low power scopes, magnifiers, and triplets see at 10X or even 30-45X.

E) I was really shocked to see somebody offering 0.3 to 1.3 MP microphone cameras for 500 or even 1200+ dollars. Are these made with surplus flip phone optical cards? Nice they say five IR glass lenses are used as opposed to plastic.

F) It may be my lack of expertise with optical cards and camera v. camera/video cards that is tripping me up?

G) Some of the pix appear decent but, many I see posted sure make me scratch my head wondering if people really are of the belief anyone can actually make meaningful determinations from them.

H) I'd like to play with a couple good quality USB microscopes and phase them to view in stereo then couple there output to be viewed in 3D on a 3D display. Kinda thinking it may be easier to do using two smartphones from a stereo's eyepieces and wirelessly cast them to a 3D TV.

 

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Looks like one I got early January.. Hate it! Can't even get the entire coin in the image on the screen when the scope is attached to the stand. And whatever you do enlarge seems grainy and cheap.

 

Unfortunately, you analyzed the situation very well. Your "G" is the reason there are so many claims of errors, doubling, etc. due to artifacts of bad lens ( many are plastic), and soft ware zooming which has the effect of reducing the resolution ( due to adding averaged false data that doesn't really exist) to the point where a blur is the norm. Most of us have owned or used a similar one. The idea of a 1X-500X zoom is not realistic. And as said, you had better specialize in dimes and cents, as the larger coins will always be a section. I use a B&L stereozoom 7 optical scope with different eyepieces ( 2.5X- 20X) and objective supplement lens of ( 0.5X) and (0.7X), which gives me a continuous range for all coins, and jewels. Costs more, but I have been using it for over 30 years, and will probably a few more and my son will continue it . As a bonus, it doesn't need software considerations.

 

I have one of these also. The older Nikon SMZ-2 Stereo Zoom is very similar and less bulky so I prefer it to the B&L. Most coins are viewed at 7X the lowest power I use (too lazy to insert the .5X accessory). I have a trinocular scope on my desk for taking micrographs.

IMO, digital scopes suck but that's what I said in the early years of digital cameras.

Two recommendations: If you can get a zoom range of 3X - 40X that's all you'll need. When very rarely needed, you can change the 10X eye piece for a 15X or 20X for more magnification.

 

I have never liked close-up images produced by a digital zoom. I don't want to count pixels.

Chris

 

I do appreciate and have the fine Teutonic (B&L, Leica, Zeiss, Cambridge etc) optical stereos and have played with the Vision Engineering stuff as well. Nothing like the Lynx with stereo zoom for relaxed, comfortable and effortless inspections.

Errors or varieties that appear certain via mono inspection sometimes simply go away with realistic stereo inspections and photography!

People don't understand what your EYE sees is not the same as what your EYES see, magnified or not and capturing it with about 14 huge pixels doesn't help the situation.

The f125 to f250 surgical stuff is amazing although disconcerting until you revise your operating techniques to conform to the very long working distances. The depth of field however, is phenomenal.

 

Did you get one specifically having the 1(one not ten or twenty)-500X range?

 

The highest optical magnification you need for variety searches is 10x at the image plane. Most USB microscopes actually have only 1x-2x optical magnification, though a few with bigger sensors have perhaps 3x-5x. The remaining "magnification" is all mechanical, ie the sensor pixels are mapped to monitor pixels, and since sensor pixels are very small compared with monitor pixels, the multiplier is very large. Once you are viewing at 1:1 sensor vs screen pixel, you are at the highest magnification you can get with real information. Zooming farther gives no more information, so is "empty" magnification.

The situation in a StereoZoom-7 (or any other compound microscope) isn't much different. The maximum pod magnification is 7x, though you can add an auxiliary lens to go higher. You can choose 10x, 15x, 20x, or even high magnification eyepieces. The eyepieces act to zoom-in on the image at the objective image plane, and give a similar effect to the mechanical magnification of the USB scopes. At some point, diffraction limits the resolution, and if you zoom further you will see no more information.

So take the USB "magnification" numbers with several grains of marketing salt. When they say 500x, what they probably are actually giving you is 5x. Hard to believe they could be so disingenuous, but it's true.

 

Again, what I see in what people post and what is shown in the advertisements, is that people truly do buy digital scopes touted to be perfect for coins/steps etc that appear to be much more suitable for examining blood cells than coins. More in line with the ranges found on scientific compound scopes than low power dissection stereos.

The pix shown in many places, with some of the previously mentioned Dino-lite scopes at specified magnification, compared to others and what I know to be there or that magnification, only clouds things further. However, those 0.3 to 1.3 MP (and even 5MP+) photographs do, as you point out, go all to hades on any type of large monitor, or even tiny and good modern screen, and appear best to be kept at post card or smaller sizes.

 

I think I was not clear. I was speaking USB scopes, not stereoscopes, but a similar statement goes for the objective magnification in a stereoscope. Indeed you don't need much more than 3-5x in a stereoscope objective. Coupled with 10x eyepieces, this yields from 30-50x, which is I think where you were going.

I'm still talking optical magnification of the USB scopes. They really are as low as I'm saying, with the additional magnification happening mechanically and digitally, but NOT optically.

The "pod" is the main body of the scope, not including stand, eyepieces, etc. The SZ7 pod magnification is 1x-7x.

Interestingly though, a few USB scopes can focus nearly to infinity, so it is possible that a USB scope that is touted as having mag range from 1x...500x may really have that capability. The "mechanical magnification" from a 2.6um pixel pitch sensor to a 260um pixel pitch monitor is 100x. If indeed the marketing folks were targeting such a monitor, then the scope would have maximum optical magnification of 5x, and minimum magnification of 0.01x, ie close to infinity. This is indeed possible, though I expect a good portion of the magnification quoted is actually digital. Let's say the digital zoom is 5x. This means the actual mag range is .01x to 1x, which is easily achieved.

 

Define:

Mechanical magnification

Digital Magnification

Optical Magnification

For me to hang onto what you are saying has me getting thrown off on these hanging points for starters.

 

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I have an older (2 years) version of this USB microscope. It's extraordinarily difficult to set and keep the focus. The optical zoom is to 40x and the rest will be software-driven. I rarely use mine for coins, however, there are other less demanding uses for it. I'd advise you to save your money!

 

Sure...

Mechanical magnification = the physical size ratio between the pixels in the display vs the sensor array.

Digital Magnification = using more than one display pixel to show 1 sensor pixel, usually accompanied by DSP interpolation of some sort

Optical Magnification = the ratio between the size of the image projected onto the sensor array vs the actual object size.

Hmm, I was only figuring on 5x digital magnification, but you're saying it's more like 12.5x. That doesn't sound too good.

 

I bought a much cheaper one. I liked the price and the picture is nice when looking at my cents. It did have a cheap plastic holder that broke and when I get the money to upgrade, I would like to get one that has a heated drive like yours for up and down. Thanks for all the discussion. I think this is a topic that needs covered more.

 

Your definitions are electronic specific but, I believe using them freely when comparing the electronic devices and the display devices TO glass optics and the human eye results in making the conveyances seem conflicted and on some points, impossible to reconcile.

Do you have different definitions for Mechanical Magnification and Optical Magnification for non-electronic devices, ie..... the stereo or monocular microscopes relevant to the discussion? If not, perhaps for camera lenses of any focal length that are zoom capable or otherwise?

Do you agree what the human eyes see thru glass optics and the brain translates, without any electronic intermediary devices, is not pixel related?

On the B&L SZ7, 4 or whatever. I believe it is correct to state that the bare pod itself has a 7:1 mechanical zoom ratio as opposed to 7 power magnification. The SZ4's have a 4.3:1 zoom ratio.

The bare pod does nothing the human eye can use without selective and variable eye pieces.

 

If you're not involving a digital sensor, mechanical and digital magnification aren't happening. Optical magnification only.

Mechanical magnification is why even the "small" 10MP sensor on my Rebel XT requires me to downsize my images by half before I post them here - they're too huge onscreen to post full size. It's also why I've never brought more than 4x optical magnification to bear on a coin - I don't need a stereoscope, my camera does all those roles on my monitor. 2500 pixels on the sensor of my camera is only 15mm high, but on my display those pixels are physically something close to 20" tall. That's mechanical magnification in action.

Digital magnification is all in software, the code is literally inserting extra pixels where it thinks they should be, and code doesn't collect coins.

To achieve the same level of "apparent" detail presented to your eye, you'd probably (I'm guesstimating) need something around 20-30x optical on a stereo microscope to achieve the same combination of optical/mechanical magnification I get from my camera/monitor combination. And the physical size and resolution of the monitor - as you might imagine - form a direct part of the total mechanical magnification number.

A zoom lens on a camera is an optical magnifier. It increases the size of the image (reduces the total field of view) given to the sensor, and although modern zoom lenses can be very sharp indeed, they are pitiful compromises when used in a "macro" role. Or, they would be, but the price of that zoom is inability to focus close enough to make "macro" useful.

The smaller the megapixel count on a "digital" USB scope, the more it leans on digital and optical magnification to achieve a "big" picture. And make no mistake about it, strict optical magnification in excess of 5x which offers sufficient quality for our purposes is expensive. It ain't gonna be found in a cheap USB scope, so they're achieving those ridiculous "magnification" claims some other way.

 

The lenses inside glass optics were mechanically moved to change their effective magnification long before an optical card ever existed.

So the nomenclature, without the distinction that I am now reading is not possible, is confusing and frightening to my simple caveman mind.

 

Consider "optical magnification" to be anything involving solely the lens(es), be that moving lens elements within a group inside the lens, or moving the whole assembly viz-a-viz your eyeballs, to manufacture magnification.

"Mechanical magnification" is the photographic equivalent of "mechanical advantage" offered by pulleys and levers, in this niche due to the fact that pixels are microns apart on the sensor, and a mere hundred or two per inch on a computer monitor. My camera sensor has 4448 pixels per inch, and my monitor has 109 pixels per inch. That's a helluva mechanical advantage. Mechanical magnification involves solely a digital image sensor and a monitor.

 

me·chan·i·cal
məˈkanək(ə)l/
adjective

1. 1.
   working or produced by machines or machinery.
   "a mechanical device"

I'll confess, when I got my electrical degree, computer work was done in DOS because OS's as we now know them did not exist.

I appreciate your patience in explaining the details. Thank you.

I missed the newer generation seemingly slipping in changes to the meaning of words as I knew them.

My thinking is that the magnification you are describing might be more accurate and clearer with subtext clarification. Perhaps using another word other than mechanical as well. Amplification seems more appropriate. I'll revisit this after some sleep.

I mean since there truly is nothing mechanical about the concept other than in somewhat abstract analogous terms.

Has the cheese slid off my cracker or do I simply need to get with the times?

I've never regarded solid state or discrete electronics as mechanical devices in any form or fashion. I had no idea anyone did until now!

Thank you again.

 

Do any of you own an Aven stereo scope? The internal working design is interesting although the plastic gears don't impress me much regardless of how precise, long wearing and smooth they claim they are.

Whose optical glass do they use?