extension tubes

[hopecount]

hi guys
just got my sigma 70-300mm apo dg macro recently and have been using it for macro shots
however i cant get close enough for a fuller frame
i have heard that things such as extension tubes will help
if so, in what way and by how much
what kinds of extension tubes are there
and how much do they roughly cause

thanks!
oh btw canon user here

[giantcanopy]

They are a hollow tube ( yes just a tube ) with no optical elements within.

It moves the lens further away from the sensor / film.
The magnification depends on the length of the extension tube and the focal length of the lens. A shorter focal length lens will gain more magnification from a longer focal length lens with the same amount of extension.

You will however lose infinity focus of the original lens.
The working distance will be reduced as well.

Some tubes have electrical contacts allowing AF and metering to work. Kenko, Triplus are some makers ( they have canon mount as well )
They are usually not too pricey, and can get them used at cheaper rates ( since no optical elements, a used one will not
be too bad an idea )

Some however are fully manual.

Ryan

[giantcanopy]

Here is a set of three (Kenko) extension tubes.



and Triplus ( they are the same actually. . )



compare these hollow extension tubes to say .. a teleconverter. no glass, and much cheaper!



Ryan

[BUZ_BUZ]

Teleplus ( aka Kenko ) has a set of 3 in 12mm, 20mm and 36mm,
with auto focus capabilities, available in both Canon and Nikon mount.

NOT cheap though, it cost about $190 per set. Bargain for this price, don't let the salesman take you for a ride.
( The Ah Lao salesman in Cathay Photo trying to sell me for $220 )

There is another Teleplus single tube of 25mm AF capable ,cost about $95.

[giantcanopy]

Originally Posted by BUZ_BUZ NOT cheap though, it cost about $190 per set. Bargain for this price, don't let the salesman take you for a ride. ( The Ah Lao salesman in Cathay Photo trying to sell me for $220 )

The Cathay fellas quote me 230 lor ...
The Camera Workshop gives u a better rate new and I got one of my sets there. The best rate u can get is our B&S.

Originally Posted by BUZ_BUZ There is another Teleplus single tube of 25mm AF capable ,cost about $95.

I got that for 30 bucks used :P

Ryan

[BUZ_BUZ]

Originally Posted by giantcanopy The Cathay fellas quote me 230 lor ... The Camera Workshop gives u a better rate new and I got one of my sets there. The best rate u can get is our B&S. Ryan

Thanks Ryan.

Originally Posted by giantcanopy I got that for 30 bucks used :P Ryan

Now that's a real bargain.

[alternatve]

Originally Posted by giantcanopy Here is a set of three (Kenko) extension tubes. and Triplus ( they are the same actually. . ) compare these hollow extension tubes to say .. a teleconverter. no glass, and much cheaper! Ryan

Don't confuse extension tubes with teleconverters. They are two different types of equipment.

Samuel

[giantcanopy]

Originally Posted by alternatve Don't confuse extension tubes with teleconverters. They are two different types of equipment. Samuel

The teleconverter was shown to make sure there is no confusion between the two

Ryan