New objective dusty inside... Amscope poor quality control

[Crater Eddie]

Looking at a newly received objective under the inspection scope, I see several specs of "dust and stuff" on the inside surface of the front (bottom) lens. Generally speaking, how much of this contamination does it take to be noticeable in the final image? I don't think I have seen any like this before.
This is a brand new 20x Chinese Plan Achromat, I thought I would try one out just for the heck of it. I won't be able to use it on the scope until tonight. I can easily return it if its too bad.

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Here we are looking down into the bottom lens through the inspection scope, focused on the inside lens surface. Photo taken with my el-cheapo cell phone, sorry.
CE

[wporter]

Generally, a contamination that is diffuse or hazy (like a film of dust) will manifest itself as less contrast in the image, which will appear to reduce resolution. The specks of dust you have will do the same, but in the amount of dust that your objective exhibits, not much at all. Much bigger specks, or relatively big globs of stuff, or areas of delamination, can cast shadows or disfocussed areas, that are visible to your eye as darker or blurry areas in an otherwise evenly-illuminated well-focussed field of view.

What is the ring with the oval white clump? Is that part of the problem, or an artifact of your photography?

You may be able to disassemble the objective just far enough to blast the pertinent surface with canned air, which might clean it up enough; if you ask for an exchange from the seller, the replacement might be just as bad, if their QC is that deficient. But disassembling objectives has its own pitfalls: there are often multiple and separate spacer rings, more than two lens holders, etc., which if you're not careful and slow, may all fall out of the housing in a rush, never to be replaced in the correct order (lacking a diagram). (Don't ask me how I know this).

[apochronaut]

I once saw a brand new eyepiece from India , that had a louse in it. Maybe you finally found out what the differences in the objective styles at Amscope are. $10.00 discount for each chunk of debris.
I don't think it will make much difference but I would be inclined to get a replacement. That's a huge faux pas for a microscope company to make. .....however : it just might be very clever : since you needed a microscope to look at your new microscope part. Oh the deviouisness and what a cheap way to try and sell another microscope! Omax would never stoop so low!

[einman]

I don't like Amscope..just another reason.

[Crater Eddie]

This objective is going back! The focus is very soft and contrast very poor. I tried it with all my various eyepieces and all my LOMO stands plus the BH-2, as well as with a variety of subjects. My LOMO shorty achromats are far better than this. I guess it would be ok to someone who didn't know any better, but yikes.
I haven't decided whether to ask for a replacement in case I just got a bad one, or to go straight for a refund. Its a shame, because it is a very pretty objective with a good solid feel to it. Its just not worth a darn.
And the color correction is terrible.
CE

[Hobbyst46]

Crater Eddie - I wonder, had you asked the seller of this brand new objective to post close-up photos of this objective before buying it, would these speckles or dust or scratches be visible in the photos? would they show apriori that it could be suspect of defects ?

[Micro-Bob]

Apart from the dirt - the ring around the lens looks very rough. Is this just an opticalillusion or is the surface that uneven? The barrel and the lens fitting of an objective is part of the performance. If it is that roughly made outside I would expect the worst on the inside.

[Crater Eddie]

Thanks for the comments everyone, my responses below:

...the ring around the lens looks very rough....

Yes, the un-polished part of the lens is pretty rough. It does make one wonder what the rest looks like inside. Here it is:

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had you asked the seller of this brand new objective to post close-up photos of this objective before buying it, would these speckles or dust or scratches be visible in the photos?

Possibly. But these folks are often less than helpful about going out of their way to do things like that. One reason I seldom buy from them.

I don't like Amscope..just another reason.

Agreed. It had been a while since I bought anything from them. it will be a long while before I give then another try.

I once saw a brand new eyepiece from India , that had a louse in it. Maybe you finally found out what the differences in the objective styles at Amscope are. $10.00 discount for each chunk of debris.
I don't think it will make much difference but I would be inclined to get a replacement. That's a huge faux pas for a microscope company to make. .....however : it just might be very clever : since you needed a microscope to look at your new microscope part. Oh the deviouisness and what a cheap way to try and sell another microscope! Omax would never stoop so low!

Phil, there is so much gold in everything you said here I just can't add anything.

What is the ring with the oval white clump? Is that part of the problem, or an artifact of your photography?
You may be able to disassemble the objective just far enough to blast the pertinent surface with canned air, which might clean it up enough...

That bright ring is just the reflection of the LED ring light on the inspection scope. So yes, its just an artifact of my photography.
It might be possible to blow out at least some of the contamination as you suggest, but as the overall performance of the objective is so poor I don't think its worth the trouble. I'm just going to send it back. This reminds me, as a kid I took apart all the objectives from a scope that my dad brought home, no idea where he found it. Of course I never got them put back together properly, the whole thing disappeared very mysteriously one night. I'm sure dad was less than pleased at this, but I was only 5 or 6 at the time best I can recall. (edit: My brother says I was about 10)

I'm going to contact the seller today and see what they say, might try a replacement, might just go for a refund, depending on how they respond. I had hoped to use this to fill out the turret on my latest LOMO scope, as I haven't found any LOMO Plan 20x D.I.N. objectives that I liked the looks of. Oh well.

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CE

[billbillt]

Hi CE,

I disassembled an objective once and can testify it is a real touchy project....

BillT

[apochronaut]

This objective is going back! The focus is very soft and contrast very poor. I tried it with all my various eyepieces and all my LOMO stands plus the BH-2, as well as with a variety of subjects. My LOMO shorty achromats are far better than this. I guess it would be ok to someone who didn't know any better, but yikes.
I haven't decided whether to ask for a replacement in case I just got a bad one, or to go straight for a refund. Its a shame, because it is a very pretty objective with a good solid feel to it. Its just not worth a darn.
And the color correction is terrible.
CE

I forgot to previously suggest to you, Vickers or Baker( the same) as a possible option. The later ones( post 1970 approx.) are also DIN. They sold mostly achromats, and microplan achromats but there were some plans too, as well as fluorite and apos. The catch is, that as time went on , more and more of their market became the electronics industry, and metallurgy, so there are a lot of met objectives around. The cover slip corrected and no-cover objectives are hard to tell apart, so you must look for the word met on the barrel and the cover slip correction data, in order not to buy the wrong type. 20X are a little thin in the market too but I have seen nice cover slip corrected microplans, because I previously went looking to make a set but then changed my mind. They can be very cheap and the optical quality is absolutely stellar. Worth waiting for.

[Crater Eddie]

I just got an email back from Amscope, they are shipping me a "tested replacement" along with a prepaid return label. If I don't like the replacement I can send them both back for refund.
That seems like pretty good service. Stay tuned.
CE


Oh, and thanks Phil for the mention of the other objectives to watch for. Will keep a look out.

[Crater Eddie]

Update:
The replacement objective arrived today, and it is at least much cleaner than the first one, but it still delivers a very poor image in all my scopes. I guess it just isn't optically compatible with my scopes. It says 160/0.17, so it isn't a finite / infinity mismatch. Oh well. Back they both go come Monday.
CE

[einman]

There are some good objectives on E-bay by the way. I don't know how much you paid for that objective. What's your budget?

[Crater Eddie]

This was around $45 shipped. I just thought since it was so cheap I would see if it was any good. Now I know.
CE

[coominya]

Update:
The replacement objective arrived today, and it is at least much cleaner than the first one, but it still delivers a very poor image in all my scopes. I guess it just isn't optically compatible with my scopes.
CE

The variance in quality from Chinese manufacturers is enormous but on average the gear is below par IMO. I just wont risk it anymore for expensive stuff that needs to last for years. I was chatting with a friend yesterday, a CEO of a small auto-electrics distribution company who is off to Taiwan for a trade show in a week. I knew they sourced product from places like Europe and Mexico and I asked him if they dealt with Chinese manufacturers. He gave me the oddest look, like what planet are you from, and said simply "no way".

[Crater Eddie]

The objective was cheap so I thought I would give it a fair trial. It didn't work out so I got a refund. Nothing lost, but experience gained.
CE