| It looks very cheap and "tacky". The polymer moldings are poor and you can see the "flshings" (dags of plastic that oozed between the mold halves). None of the pictures actually show you anything useful....like a view directly into the apparatuses at each end or, even better, a view of it disassembled.
I have looked at this listing before, it was the cheapest listing I looked at..about a year ago.
But what do you expect for under five dollars?
I believe that if you are careful, you could disassemble this unit, clean it up, trim all the flashings off put some thick grease in to help it hold its focus etc.
If you read the comments under the original listing...they all seem to be in German..but are easily translated into something semi-meaningful.
I will "dump" them here..
The Thai guy says...
"Although it is not build perfectly .. It does give some ideas to improve the build, it works well with some adjustments .. It uses a rough cut prism and an adjustable lens in the middle .. Not just the lens you have to adjust Also the piece with the slit where you point it towards the light have to be set in reference with the prism .. I also put aluminum tape around the blue tube because bright light goes through it .. if you want better results."
The Dutch guy says...
"Nice spectroscope, not very precise but with enough definition to see if a lighsource has a line or band spectrum or has a full spectrum. Defining the sodium D line does not work, so for analysis purposes it will fail. But it's more than just a toy. For this price however .... Nice to buy and able to show the difference between sunlight and fluorescent. It proves what color is and how the influence of light works in awareness of colors."
And he adds..
"Got to update my first impression. This spectroscope is able to show clear lines. The cause was not a misalignment between the grating and the prism. If aligned correctly (by turning the target (small black end) and focus correctly, the sodium D lines and other distinctive lines are well visual and noticeable !!"
The German guy says..
"Arrived in perfect condition within less than a month (China-Germany)."
The Russian guy says...
"All of the: and assembly, and picture quality, and instructions in Chinese-hell will deal with a hand watch and why it is a screw." (Translation is not perfect but he seems unhappy that the instructions were in Chinese.)
The Belgian guy says...
"Device does not work and is of poor quality, it is not even a toy. Don't throw your money away with that seller, he sells me ..."
The Lithuanian and US guys seem happy but don't say why.
Here's my summing up based on what was said on the original site and here on Lighting Gallery...
Treat this unit as an unfinished, maladjusted unit.
If you expect a perfectly working and adjusted unit out of the box with instructions in your language for less than five dollars you are deluded. However if you treat this unit as something that is already 80% of the way to the goal you wish to achieve and you are prepared to apply yourself to supplying the remaining 20%....than as others have said it is possible to get its resolution to approx 1nm and its contrast into a workable range.
So, for less than five dollars the Chinese do 80% of the work for you, but you must supply the remaining 20% of the effort yourself.
Looks like it has a fixed slit, set narrow to give you resolution at the expense of image (spectrum) brightness. Fir bright H.I.D. or fluorescent sources this probably won't be an issue, but for dim sources like neon lamps it mught give too dim a spectrum to see clearly or photograph.
Also bear in mind it uses a prisim as a monochromator, so your spectrum win't have a linear scale, (your red end will be all compressed and your violet end all stretched out)....this may be disconcerting if you are usede to using a grating (like a DVD or CD) as a monochromator which gives a nice linear spectrum.
Summing up, for less than five bucks and a bit of effort on your behalf to get something than can resolve the sodium D line..looks like quite a good deal to me.
IMPORTANT: It does have a slit in the optics path, so its resolution will far exceed that of a bare monochromator.
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