Extension Tubes

I want a longer zoom lens for taking bird/wildlife shots, and keep looking at this one http://www.adorama.com/NK80400AFVRU.html. But, I really need to sort out more lighting etc, and I want an 85mm, and a macro.

So.... I am getting there do any of you use extension tubes to give your existing zooms more reach???

From what I can remember, Extension tubes give more of a Macro function.

Do you mean the 2x adapter you can buy?

Alan.

Extension tubes are more for macro and enable you to get closer for more magnification. They contain no glass and come in sets which allow you to add more and get nearer to your subject.Some extension tubes are just plastic tubes whilst some have the electrical contacts. The ones without electrical contacts stop 'lens-to-camera' communication so you have to do everything manually. Focusing is okay (manual focus is the way to go anyway with macro) and exposure control isn't too tricky, but setting the aperture is a right pain as you have to do it all before removing the lens and adding the tubes. You can quickly run out of light too, especially as you generally need a high f/number to get any workable depth of field at all. That's why ring flash is popular, which also helps with camera shake which is a big problem at high magnifications.

Teleconverters or extenders are a different thing all together and tend to be used to make a long lens longer. Like tubes they fit between the lens and the camera but contain glass and electrical contacts. They come in 2X and 1.4X and are used to make (for example) a 100mm lens a 200mm or 140mm lens. The big downside is that they also multiply the aperture.
What you will find is that you will reach a point (depending on the lens) that it can't autofocus.

The basic sums for knowing if your lens will be able to autofocus.......

A 2x teleconverter can be used on lenses with aperture at least f2.8 (becoming f.5.6)
A 1.4X teleconverter (and usually a 1.7X) can be used on a lens with an aperture of at least f4, (becoming f5.6 or f6.8)
lenses with maximum aperture of f5.6 might not autofocus with teleconverters much more than 1.4X

A popular lens is 200mm f2.8 as they perform well as 400mm f5.6 when a 2X converter is fitted.

Yes ,sorry used the wrong words I want something to extend the reach of my zoom.

After doing some reading this afternoon, not sure I will go down this route, not going to be much good with the lens I own. Seems the quality can drop too. The Nikon ones are not recommended to be used, with my lens anyway

Thanks for your help guys,appreciated Did not know anything about them, so thanks x


If I buy this lens ,as it is 80- 400mm on a FF, it is going to be roughly 120-600mm on my D300?

Yep - You're d300 has a 1.5X crop so just had half again.

In reality cropped sensors capture a portion from the middle and enlarge it so it appears more zoomed in.

Lol had me confused then too for a mo

Think Stanokella has one for his 70-200 - results were pretty good from what I remb

Make sure the lens will take a tele converter, some don't.

Bazza

Thanks bazza, I discovered mine won't ,so will have to either put up with the one I have, or by a new one.

Have a look at the Sigma 120-400 this will take the Sigma tele converters. I have this combo using the 1.4 Sigma converter

Bazza

Ta, will have a look.