100mm macro + extension tubes

[tdigi]

I have the 100mm macro and I was told that its best to use it with extension tubes to shoot insects. Is this true? any suggestions on which

extension tubes to purchase?

 

thanks

[JohnMWright]

It depends on whether or not you can get close enough with your existing lens, but I would think you could get close enough for most insects with the lens alone. You might find you need more distance than 100mm offers however. Particularly if they move fast to get away from you. In that case I'd look at the 180mm macro.

[awindsor]

How small are your insects? For butterflies I prefer to use my 70-200/4L plus extension tubes. The extra focal length is very useful. A 100mm macro plus extension tubes gives you high magnification but very little working room. In particular some serious effort to light the subject is required.

[tdigi]

That is really my question what extension tubes are best? I do have a 70-200 2.8. Would I be able to use the same

extension tubes on both lenses?

 

Allistair, I am looking for more magnification and I have a ring light so stopping down is no problem.

[zml]

The use of extension tubes (and magnification with/without tubes) is described in the lens manual.<br>Extension tube is extension tube (a spacer with air inside...) so as long as the tube controls the lens attached to it, the manufacturer doesn't matter. I use Canon tubes.

[JohnMWright]

You can use tubes on any lens.

 

You will be awfully close to the subject going more than life-size. I'm glad you have the ring light.

 

I'd just stick with Canon tubes but there are cheaper sets available to try, like Kenko. I can't speak about the quality but I've never read of any complaints with Kenkos either.

 

Which size tube depends on the magnification you need but they are cheap enough you can buy a set and mix and match.

[tdigi]

Thanks, I have no experience with ex. tubes. but I want to get as close as possible. I assume they all are the same size

as to mounting them?

[mark u]

Take a look at Photonet member Lester Wareham's excellent page on macro here:

 

http://www.zen20934.zen.co.uk/photography/Macro_Equipment.htm

 

You will find a lot of useful data about working distances and magnifications with various lens and tube combinations.

[awindsor]

I have the Kenko tubes and have had no problems but at least one PN member has had problems with his lens detaching accidentally. His problem was the weak springs on the retaining pin make it easy to bump the lens lock switch and detach the lens.

[geoff_foale]

I have frequently used my Canon 70-300 IS with a 25mm extension tube for macro shots of insects. The things to remember are: You need to manually focus. Your shutter speed will be considerably reduced when using a tube, but this can be overcome by increasing ISO. The magnification factor of a tube is very little but it enables you to get closer which results in a larger image.

 

I can't see much advantage in using a tube with a close focusing macro lens. Occasionally worth it with a longer macro lens like the 180. Can you use a 1.4x converter with the 100 lens? I don't know about the Canon converter; but a third party unit such as Kenko would work, although you are bound to lose a bit of sharpness. Also, when using a converter or tube you will lose a bit of depth of field as well as light fall off.

 

When using tubes with a larger zoom, it all depends on how close is your minimum focusing distance. With my 70-300 which focuses down to 5 ft I can gain an extra 1 ft of distance with a 25mm tube which is similar to using a 180 macro at 3 ft. It really depends on what you want to photograph and how large you want to print. If you are after flighty insects then a working distance of 3 or 4 ft is about right but if your subjects are flowers or other inanimate objects you might as well stick with the standard 100 mm. I can't remember what is the minimum distance with your zoom but if you are working at 4 ft with a 200 mm lens you aren't much better than a 100 mm at 2 ft. The only advantage is greater working distance.

 

All you can do is think carefully about how you would use your zoom with a tube and try to decide if it is going to be worth while spending around £100 for a 25 mm tube (probably a bit cheaper in the US). I wouldn't recommend getting a smaller tube, the 25mm is a good comprimise.

 

I can take reasonable quality images with the 70-300 plus 25mm tube including objects as small as 1/2 inch. But I have just purchased a Sigma 180 macro for closer work and slightly finer detail.