2x converter with a nikon 18-200

[earthgraham]

I would like to know if anyone has tried a 2x converter on a AF-S dx nikkor 18-200 f/3.5-5.56g ed vr11. if so I would like to know how you got on.

My camera is a nikon D5100.
Thanks in advance Graham

[The_Moaner]

Converters like 1.4/1.7/2x do NOT work on those lenses. FORGET it and save your cash to buy something else.
Converters only work on lenses up to f4. Forget about tapeing the contacts as you will only get frustrated and it don't work with most lenses.

Google it and you'll get plenty of info on it.
Good Luck.

[earthgraham]

Thanks for reply The-Moaner I will certainly take your advice.
thanks again Graham

[DOXHOPE]

18-200 is too slow for a conveter, you will not get good results

[Alan Hewitt]

Hi,

Been a little while since I posted here. I saw this post and thought I would try and help you by explaining a little.

Before you but a teleconverter you need to be mindful of which lenses you are intending to use it on.

I use the 1.4x on my 200-400 f/4 lens. With the t/c attached it becomes a f/5.6 lens.

There are a few hazards with using a teleconverter and the main stumbling block is autofocus. Regardless of the aperture you intend to take a photograph with a modern DSLR will use the largest available aperture to find focus / lock / track until you actually hit the shutter, it then steps down to the aperture you wish to use. This way the lens is getting as much light in as it can for the autofocus system to use.

Adding a teleconverter will lose you a stop of light, the 1.4x as I mention above is 1 stop, the 1.7 is 1.5 and the 2.0 is 2 stops.

By chucking a 2.0 on a f/2.8 it becomes a f/5.6, put a 1.4 on it becomes a f/4.

Really teleconverters are designed only for use on f/2.8 and f/4 lenses as if you put them on say a f/5.6 it will become a f/8 and your cameras autofocus will not be able to get enough light in. It will become very unpredictable in terms of being able to focus - it will hunt a lot and have difficulty locking on, slow and unpredictable. Some lenses may not focus at all. Generally a DSLR will not autofocus at f/8. That said, the new Nikon D4 will.

I've only used my 1.4 on the 200-400. The 200-400 focuses superbly on both the D700 and D300. Stick the t/c on the D700 an there is a slight difference. On the D300 it is fairly noticeable.

Hope this helps and makes sense!