extension tubes on a 100macro
/forum/topic/101609/0

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dan hillis
Registered: Apr 04, 2004
Total Posts: 731
Country: United States

What will the efect be on a 100mm macro using extension tubes? im planning on get a set of kenko's (12,20 and 36mm). Will this greatly enhance the magnifaction?
If so what will be the greatest magnifaction that I will get using the set.

As allways thanks for the needed info.......dan



dan hillis
Registered: Apr 04, 2004
Total Posts: 731
Country: United States

uh



jmcfadden
Registered: Oct 30, 2002
Total Posts: 30061
Country: United States

It will make the distance to subject Very , Very small indeed , basically if you understand what a macro lens is actually doing , it is *adding* extension tubes to *itself* this is why if you put the camera in aperutre priority at the maximum aperture ie f3.5 and then turn the focus ring to 1:1 the aperture value will have increased somewhat because you are losing light as you gain extension

J



dan hillis
Registered: Apr 04, 2004
Total Posts: 731
Country: United States

jmcfadden wrote:
It will make the distance to subject Very , Very small indeed , basically if you understand what a macro lens is actually doing , it is *adding* extension tubes to *itself* this is why if you put the camera in aperutre priority at the maximum aperture ie f3.5 and then turn the focus ring to 1:1 the aperture value will have increased somewhat because you are losing light as you gain extension

J


Thanks John! so other than making the distance to subject very small (short ?) it will not change the magnifaction? BTW how do you like that new D70. thanks again dan



jmcfadden
Registered: Oct 30, 2002
Total Posts: 30061
Country: United States

Dan

I love the d70

of course as minimum distance to subject is lessened the mag factor will of course follow !

There is some math to this , but I could care less about the numbers

but if you gotta know , ask Tom , he knows how to do the math

J



troglo
Registered: Oct 06, 2003
Total Posts: 150
Country: France

Hello dan

Magnification will be "nearly" 1,7:1
Witha 50 macro(1:1) and same set of extension it will be nearly 2.5:1.
Denis



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