Macro advice..Tubes on the way.

[Jonny]

Yesterday, after looking into getting a close up filter for my 70-200 F2.8, i decided to buy a set of extension tubes instead. i did this because i believe £80 for a canon filter that i will only be able to use on 77mm lenses was a bit steep!

Anyway i ordered a set of Kenko tubes from Japan and i am looking forward to having a play with them when they arrive.
For now i am looking for advice on how to use them correctly, IE: How to decide which size tubes to use, when to stack them, what to expect with focusing and DOF, using the 1.4x extender with them and any other info.

Also does anyone have any sample shots with the 70-200 f2.8 L IS, kenko tubes and the 1.4x in any combination.

I am really looking forward to getting these tubes! DID I MAKE THE RIGHT CHOICE? Whats the difference between brands considering there is no optics?

Thanks all

[mdr]

You could have gone for the filter. It would have fitted your 17-40mm as well, and with a step up ring for a couple of quid, it can be fitted to any lens with a smaller thread, including your 50mm.

Which tubes to use/stack depends on the magnification you want to achieve. The longer the distance between your body and lens, the higher the magnification. Also, magnification at the 70mm end is higher than at the 200mm end. The tubes come with a chart showing you magnification at different focal lengths.

You'll probably get more use out of them with the 17-40mm lens.

Drawback of extension tubes are the distance between lens and subject becomes smaller with increased magnification. Stacking all three would require you to push the front of the lens against the insect to get it in focus.

Difference between makes of extension tubes is built quality and compatibility. Cheap ones have a plastic mount, which I would not recommend with a large lens such as the 70-200mm. A friend tried the Kenko tubes on her 300D, which didn't work. The work on my 20D though.

[wolf]

To give you a rough idea a honeybee shot at a 70mm setting with all 3 Kenko tubes attached and approx 5" from the subject will fill 3/4 of the frame with a 300D.

[Jonny]

Which tubes to use/stack depends on the magnification you want to achieve. The longer the distance between your body and lens, the higher the magnification. Also, magnification at the 70mm end is higher than at the 200mm end.
You'll probably get more use out of them with the 17-40mm lens.


Thanks but why do you think i would be using them more with 17-40mm?

[jterlecki]

I've only used extension tubes with prime lenses, never with zooms. That's not to say that it won't work, it is just that I've never tried it. I've never been a big fan of close-up lenses, always opting for tubes or bellows when I wanted extreme magnification. As far as a combination - you'll have to experiment. The magnification range for any given subject is more of a subjective issue than an objective one. Run with it. Just remember, the farther you take the lens from the "film" plane, the greater the magnification, the longer the exposure and the shorter the depth of field. Stopping the lens down obviously helps but remember that difraction through too small of an aperture will blur more than it will sharpen.

[Persian-Rice]

my only suggestion is to use a tripod...no really, you are going to need one.

[billsh]

I've used kenko tubes with my 70-200 2.8 L with satisfaction. A tripod is a must. The loss of light and the awkwardness rule out hand held shots for me. One advantage with the zoom is you can focus using the zoom instead of moving the tripod sometimes. Play with it, you will have lots of fun.

[Jonny]

I've used kenko tubes with my 70-200 2.8 L with satisfaction. A tripod is a must. The loss of light and the awkwardness rule out hand held shots for me. One advantage with the zoom is you can focus using the zoom instead of moving the tripod sometimes. Play with it, you will have lots of fun.

Excellent, do u have any shots to show?

thanks

[blackviolet]

i've found it's actually a little bit hard on the 17-40, especially with moving bugs. yes, the magnification is great and you will find that you can use more combinations of tubes (and potentially less light loss by not using all 3 tubes). you'll also find the dof is really shallow and you have to get quite close. that said, a nice small apeture and maybe a helping flash (and a slow or non-moving bug) can produce great shots. personally i've found the 85mm 1.8 to be a great lens with the tubes. i've also achieved some good results with the 135 f/2 L, although not at as high a magnification factor.

oh yeah, you can also use the 1.4x extender as well...