[Aboe]

Hi can anyone point out a good site or make comments about the 2x converter?
I understand it doubles the zoom length . that's the plus side. is there a down side?

[Soupdragon]

The downside is a loss of two stops of light getting to your sensor!

[Dave]

This may be useful :- How much does a 2x convertor impact final image quality

If you do a search on convertor you should get lots to read on this site

[Gary Bagshawe]

On certain models you also lose auto focus.

[Boofers]

I have 1.4,,,2,,,and a 3x converter. I have them to shoot at the moon, have used them for long distance landscape. The 1.4 does really well, the 2x real well, the 3x kinda well. I have stacked them, kissed them and talked to them. I end up with detail noise with poor focus with the 3x and slight to very low noise and less problem with focus on the 2x. No noticable problem with the 1.4. I lose autofocus with them all. I use a 20D and should have autofocus with the 1.4,,,this info for 100-400 zoom. When used on a prime lens they all seem to work alot better with very little problem if any. My primes are fast and I don't lose autofocus. The converters do get you closer to the moon.

[Aboe]

Thanks for the input, everyone. Much appreciated

[Dave]

Originally Posted by Boofers

I have 1.4,,,2,,,and a 3x converter. I have them to shoot at the moon, have used them for long distance landscape. The 1.4 does really well, the 2x real well, the 3x kinda well. I have stacked them, kissed them and talked to them. I end up with detail noise with poor focus with the 3x and slight to very low noise and less problem with focus on the 2x. No noticable problem with the 1.4. I lose autofocus with them all. I use a 20D and should have autofocus with the 1.4,,,this info for 100-400 zoom. When used on a prime lens they all seem to work alot better with very little problem if any. My primes are fast and I don't lose autofocus. The converters do get you closer to the moon.

Now that explains the avatar