2x Tele-Photo Lens

[tyonghen]

Recently ordered 1 67mm Tele-Photo Len and thot it will increase my current zoom by factor of 2. To my surprised, it did not perform as it should and worst the image came out very burl and look like those fish-eye type that is circular at the circumference. Attached is the photo from ebay:-

Can another advise whether it is true that this type of method is not working.

Thanks....
:cry:

 

[voldisinarta]

First, don't add this to a wide angle lens. Heavy vignetting will be seen. in this case, the "circular at the circumference" that happened to your photo.

Based on my experience, this kind of tele attachment works better in a telephoto lens. However, don't expect the quality to be good. The shortest the lens, more blurry it will be.

It's better to use a teleconverter if you want a cheaper alternative to extend your lens.

My two cents.

 

[tyonghen]

Thanks for the advise. Now, looking at kenko converter

 

[dark72]

I think the f -stop will increase by 2, am i right??

 

[voldisinarta]

I think the f -stop will increase by 2, am i right??

Yes, a 2x teleconverter would reduce 2 stop, and the 1.4x will reduce 1 stop. For example, if your lens max apperture is f/2.8, it will become f/5.6 with 2x teleconverter, or f/4 with 1.4x teleconverter.

Remember that autofocus won't be possible if the max apperture > 5.6.

My two cents.