Sony a57 and teleconverters

[scarter]

I have a Sony A57 with the 18-55mm and 75-300mm lenses. Will the Sony teleconverters work with these lenses and will they auto focus. I borrowed a Vivitar 1.4 teleconverter from a friend but it won't always auto focus even in a bright light condition. I am looking at purchasing the Sony teleconverters but want to make sure they will auto focus at least most of the time. Also, can anyone suggest a good all in one lens so I don't have to be changing lenses all the time. I do mainly landscapes and wildlife photography. Thanks!

 

[Kolia]

When you add a teleconverter, you reduce the amount of light reaching the sensor. Combined with the lenses you have, you will probably have that problem when zoomed in regardless of the type of converter you use.

The Sony are built for the G series lenses and a bit pricey. I'm not sure it is worth the investment in your case.

 

[dxqcanada]

Higher quality teleconverters are matched to lenses. I don't think either of your lenses would be a good match for one.
Faster lenses will work better with them.
The Sony teleconverters will only work with certain lenses ... Teleconverters for Sony / Minolta a-mount lenses

All-in-one lens ? I have never found one worth using that covers extra wide to extra long.