I havw a Nikon Coolpix,L840. the lens shows threads for screwing in another lens. How do I know what size to buy?

[ch7437]

Grading from "top" largest to smallest "closer to actual lens".

 

[getochkn]

If there is threads, it could be for screwing in a filter and not a nother lens. You normally don't put a lens on a lens with camera. You remove a lens and put a different one on, they don't work like that.

 

[USAFRet]

Those threads are for filters. 62mm.

While there are accessory "lenses" that may screw into that, don't.
I have a similar level Fuji HS-10. Along the way, I acquired (was gifted) a couple of "lenses" that screw into the threads.
1.4 telephoto, and something.something macro.
Uniformly bad, when compared to the actual camera lens.

Just use the camera with the lens it has.


If I wasn't busy with yard work, I'd create and post a few pics as a comparison.

 

[ch7437]

If there is threads, it could be for screwing in a filter and not a nother lens. You normally don't put a lens on a lens with camera. You remove a lens and put a different one on, they don't work like that.

 

[bjornl]

There are in fact lenses you can screw in to the front of a camera. They are typically low quality.
The most popular is a diopter which increases your macro magnification. The ones from Raynox tend to be decent quality.
The second most popular are tele-converters which increase the effective focal length of your lens (more zoom). There are a FEW good ones here. Olympus and Nikon are about it.

The "fun" part is you can ignore the thread size for both tele-converters and macro diopters. This is because in both of them you will be using only the center portion of your exit lens size. Meaning that the amount of vignetting (darkening of the outer portion of the image) is minimal or zero. You will need a step up or step down adapter. For example the Oly tcon17 is a 55mm thread so you will need to adapt that to your 62mm filter thread.

If you opt to get some screw in lenses, make sure you use them sparingly. Leaving them in permanently will eventually damage your built in lens due to the added weight.

 

[ch7437]

There are in fact lenses you can screw in to the front of a camera. They are typically low quality.
The most popular is a diopter which increases your macro magnification. The ones from Raynox tend to be decent quality.
The second most popular are tele-converters which increase the effective focal length of your lens (more zoom). There are a FEW good ones here. Olympus and Nikon are about it.

The "fun" part is you can ignore the thread size for both tele-converters and macro diopters. This is because in both of them you will be using only the center portion of your exit lens size. Meaning that the amount of vignetting (darkening of the outer portion of the image) is minimal or zero. You will need a step up or step down adapter. For example the Oly tcon17 is a 55mm thread so you will need to adapt that to your 62mm filter thread.

If you opt to get some screw in lenses, make sure you use them sparingly. Leaving them in permanently will eventually damage your built in lens due to the added weight.

 

[ch7437]

Thank you, I think I will not do the "lens" thing.
Hopefully, this is my last camera.
All in all, it does a good job.
The "extra lens" was a whim and I shall return it.
Carol