Best Telephoto lens 8x or more

[daimv]

Hello.
I am looking into buying a telephoto lens to take pictures from a distance.
I have seen some expensive lenses that apparently are good quality (brand is Moment) for $100 USD but they only have a 2x "telephoto" lens. (they have other lenses though)

I'm looking for something 8x or more. And looking around in the internet, ebay and amazon are filled with cheap chinese lenses. There are different ones and the prices vary but they all look very similar. I've been considering one of these but I'm afraid of it being terrible lol. I have read some reviews say that they are terrible, some say they are ok, etc.

The question is, is there a brand/provider that has a lens that is better than others? Even if only a little and of course it doesn't beat a $2,000 USD lens from a DSLR camera, but it might compete with cheap cameras with optical zoom.

Here are some examples https://flipboard.com/@topreviews/b...iphone-and-android-smartphones-2016-6c56jjq2z

Also some are only focused on iphone and Galaxy S phones only which sucks.

 

[gpobernardo]

It seems that your only choices are those "cheap" lenses from China at that magnification. Even if there were "better" lenses out there, getting consistently "good" images from them would be challenging for several reasons:
- they most probably are "universal", which means mounting it onto your phone camera will not be consistent - just a minor misalignment will distort your image;
- given the aperture/opening of the phone camera, these telephoto lenses will only work best under bright lighting conditions*;
- at that magnification, you would most of the time need to mount your phone onto a tripod given the amount of motion blurring that will occur;
- at that magnification, aberration, distortion, and flaring will all be enhanced unless the glass is made of special material (i.e. extra low dispersion, high refractive index), has special coatings on them (anti-reflection, electron-beam coating), and/or has special lens elements in them (i.e. aspherical elements) - all of which result in higher "cost";
- given the "popularity" of Windows Phones, chances of finding such a good lens (in combination to the previous item) is close to impossible.

* Most phones have an effective aperture near f/2.2. Attaching an "8x telephoto" lens will effectively increase the f-stop to around f/16, which can be really dark. The phone will compensate by decreasing the shutter speed which will make your images blurry, or increase the ISO which will make your images grainy.

Conclusion: A 2x multiplier may work; at 8x, probably not. Go get one of those "cheap" lenses and hope you get a good one. Most of the time it is not the lens that will be the problem, anyway - it will be the photographer (i.e. he/she was the one who attached the mount improperly, moved while taking the photo, chose a poorly-lit subject, etc.).