EF12 extension tube and 1.4 teleconvertor ?

have a canon 40d am looking at a cheaper alternative to a 100mm i was told of a Canon 60mm, EF12 extension tube and 1.4 teleconvertor is there anyone who has them and if so what are there benefits and drawbacks and is there anyone who has this setup with ikelite housing?any help would be greatly appreciated

Steve:-)

Hi Steve,

The extension tube won't alter the focal length. It will allow you to focus even closer but with an already very short focus distance that is not much use. It will also prevent you from focusing beyond a certain distance, which may be short enough to be a drawback.

The 1.4x TC will make the lens behave like a 84mm F4 which is the better option. If you can get very close it will even let you go up to 1.4 times life size magnification. I doubt it is a satisfactory replacement for a real 100mm F2.8 macro but it could be a useful compromise.

Bart

Hi Steve,

 

The extension tube won't alter the focal length. It will allow you to focus even closer but with an already very short focus distance that is not much use. It will also prevent you from focusing beyond a certain distance, which may be short enough to be a drawback.

 

The 1.4x TC will make the lens behave like a 84mm F4 which is the better option. If you can get very close it will even let you go up to 1.4 times life size magnification. I doubt it is a satisfactory replacement for a real 100mm F2.8 macro but it could be a useful compromise.

 

Bart

The tube is needed because the TC and 60mm cant be linked directly due to the shape of Canon EF-S lenses. Thats why all 3 elements are needed, making it useful for very close supermacro but not so useful for the increased standoff that a 100mm can offer.

have a canon 40d am looking at a cheaper alternative to a 100mm i was told of a Canon 60mm, EF12 extension tube and 1.4 teleconvertor is there anyone who has them and if so what are there benefits and drawbacks and is there anyone who has this setup with ikelite housing?any help would be greatly appreciated

Steve:-)

Steve: Which aspect of the 100 mm do you want to emulate? There is no difference in magnification between the 60 and the 100, both shoot 1:1 meaning that you can fill the frame with a 23 mm or so subject with either lens. The 100 has more working distance behind a flat port. Putting on the extension tube will not increase the working distance and putting the 1.4 teleextender on either lens will let you shoot 1.4:1 so some super macro. If you want to go that route, think about the Tamron 60 mm macro lens, you can put it on the teleextender without the need for the extension tube.

Bill

you need to make sure of compatibility of extension tubes and the efs lens - i think the latest models work. the problem is you will lose the ability to focus at infinity/far distance which probably won't be a problem underwater

i think you're better off looking for a used 100 macro. i bought a 60 hoping it would autofocus better than the 100 which it didn't. then found that the working distance at high magnification was too close to the front of the port (focal length of internal focusing macro lenses decreases at close focus) and recently sold the 60. i then bought the new 100 L IS (which is superb on land) with the anticipation of better autofocus (which won't be tested UW until next month) and found that the price offered for my old 100 macro was severely depressed by lots of other people switching. the 100 macro remains an exellent lens with a very useful working distance for full or crop frame cameras (and i was offered as much money from a dealer for the 60 as the 100).