Kenko Extension Tube Set + EF 100-400 ?

[billabong5]

I have an EF 100-400 and spent almost all my money with it, but I really like to take macro but I can't afford anymore lens :(.

I search everywhere and I found this Kenko Extension Tube Set which is really cheap comparing to the other macrography stuff.

Can the Kenko Extension Tube Set make the 100-400 a macro lens ?

If it does, will there be any loss of light or image quality ?

:rolleyes:

[olz]

I have the kenko extension tubes and theyre great. I think they will work with your 100-400 but I don't think it will be the "ideal" setup for macro. I use mine almost entirely with my 50mm f/1.4 and this makes it very easy to handhold. Even though the rings are said to mantain autofocus, my find is that it hunts too much so I always use manual focus (moving the camera in and out - not using the focus ring).

There wont be any loss of quality because extension tubes are just hollow rings without any glass. There just extending the distance from your sensor to the front element.

[Lester Wareham]

I have an EF 100-400 and spent almost all my money with it, but I really like to take macro but I can't afford anymore lens :(.

I search everywhere and I found this Kenko Extension Tube Set which is really cheap comparing to the other macrography stuff.

Can the Kenko Extension Tube Set make the 100-400 a macro lens ?

If it does, will there be any loss of light or image quality ?

:rolleyes:

There is more to a macro lens than close focus, they are very well corrected for aberations from infinity to life size.

The Kenko tubes should work but a sharp prime lens would be better. I guess you might just get to life size at the wide end.

You might be better of teaming it with a sharp prime, even the 50/1.8 would be a lot better I would suspect.

BTW I did hve a Kenko set but changed to Canon after they kept unlocking and letting the lens drop. So I can't recommend them myself. Others seem to be happy.

[billabong5]

Can anyone tell me how close can I take with the Kenko Extension Tube Set+100-400 ?

[billabong5]

What about a 50/1.4 + the kenko set ???

[Lester Wareham]

Can anyone tell me how close can I take with the Kenko Extension Tube Set+100-400 ?

As I said in my earlier post at the wide end you might get to life size (1.0X), it is difficult to say with internal focus lenses.

With the lens zoomed to 100mm and focused to infinity I can say the magnification will be 68/100=0.68X.

With the lens zoomed to 400mm and focused to infinity I can say the magnification will be 68/400=0.17X.

Focusing in using the focus ring on the lens will increase this magnification but it is difficult to say by how much.

The Canon 25mm tubes specify a magnification range of 0.27-0.35/0.31-0.07 for wide/tele on that lens.

[Larry Weinman]

I use my 100-400mm lens for macro only when I am dealing with a very skitish subject like a dragonfly or butterfly. I have used it in various combinations of tubes to reduce the focusing distance. Finding the subject and stabilizing it in the viewfinder with a lens like this is very difficult. The slightest lens motion and your subject is no longer in the viewfinder. Because of the motion magnification a tripod is semi-helpful and I say semi because your subject is usually moving. Focusing also becomes challenging with tubes on. To sum it up, if you are thinking of small insect photography with this lens and tubes you will be constantly frustrated. I think a better solution for small subject photgraphy with this lens would be the addition of a Canon 500D closeup lens. At least you will not suffer light loss with this lens and focusing will be near normal but if you really want to do macro I think you should save your money and get a dedicated macro lens

[billabong5]

There will be light loss using the tubes ?

[olz]

There will be light loss using the tubes ?

Yes. A lens is like a tunnel. The longer the tunnel the greater the light loss. For this very reason i usually use my external flash and a off camera cord. If youre on the budget road a torch pointed at your subject will do also.

[Jon]

The Kenko tubes will only get you somewhere between 1:2 and 1:1 at 100 mm; they'll give you much less magnification at the longer focal lengths. For that reason, I'd say they'll let you use the 100-400 for close-focussing, not macro, work.

[jrsforums]

http://ca.geocities.com/lokejul/jlcalc.htm

A great calculator for finding the effect of close-ups, extention tubes, and TCs (or combinations) on any focal length.

[Lester Wareham]

http://ca.geocities.com/lokejul/jlcalc.htm

A great calculator for finding the effect of close-ups, extention tubes, and TCs (or combinations) on any focal length.

These will calculations will only work at infinity focus on internal focus lenses. Focus changes the focal length and moves the rear node of the lens so without knowing the details of the design it is difficult to predict.