Auto focus/metering macro extention tubes on ebay any good?

[thefonz78]

http://cgi.ebay.co.uk/Auto-Focus-Mac...item2eb67e7db4

I noticed the macro extension tubes on ebay. They have the electronics conections so you can meter and auto focus. I was going to get some cheap manual ones for a tenner but for £60 it just as well go for them. Has anyone got a set from ebay? Are they any good? Am i right in thinking there is no glass in the tubes? so how bad could they be?

[MattUK]

Personally, I wouldn't touch anything other than the Kenko tubes with a bargepole...

You're right - there's no glass in extension tubes. They just move the lens away from the body, allowing the camera to focus at very small distances

[thefonz78]

I have a 50mm 1.4 lens so this on a kenko do a decent enough job? I've never taken any macro shots before and will not be taken that many but would like to have the option there in my camera bag.

[amk1977]

Like Matt, I'd recommend the Kenko extension tubes, which I've used on the 50mm f/1.8D, although I normally just stick to using the Tamron SP90. It works very well and is very sharp. If you require any more powerful magnification, then simply get a 52mm reverse adapter and put the lens on back to front. Just be careful of the rear element, as there is no lens hood or anything to protect it.

I recently used a reverse adapter with this with my Nikkor 28mm f/2.8 Ai-s and used the extension tubes too. I was pretty stunned by the magnification. Here's a couple of images straight out of the camera for comparison. The 28mm shot has a little blur as I didn't allow time for the thing to stabilize but, you get the gist.

Tamron SP90 + 3 kenko tubes



Reversed 28mm + 3 kenko tubes



Obviously, you aren't going to require magnification this strong (think its 9:1 if memory serves) all that often but, the option is there for the price of a reverse adapter ring.

[thefonz78]

Thank you, i think i might get myself one. I've seen them for £80 so won't break the bank. A new tripod is first on the list at the moment.

[littlebro]

I have a set of Kenko, I'm not so sure about reversing rings though, light being the problem there you can still use a ring flash with the Kenko's but not the ar 'er backend of a lens.

[jet_kit]

Weighing up the pros & cons of auto extension rings. First, how good is the auto focus at 9:1? I normally end up doing manual focus on macro anyway. OK you lose the metering and have to remember to stop down manually, but how bad is all that when your camera is nailed to a tripod?
I use the BR2 reversing ring with a 24mm f2.8 - the only things from my Nikon F kit that have survided the transition to digital, except for the bubble level!

[Cathus]

you can use extension tubes on other lenses also, they're not just for macro stuff.

I use mine on my 600mm which allows me to focus closer than the 5m minimum on my 600mm lens, good for sitting in the garden & watching the bird feeders.

I also have Kenko auto tubes

[amk1977]

I normally shoot macro in MF mode too. The main benefit for me of the auto extension tubes is that it allows me to maintain aperture control, metering information and can still use I-TTL flash with my Tamron SP 90mm whilst increasing the magnification. As most modern lenses have no aperture ring and the f-stop controlled via the camera body, you require the auto extension tubes in order to be able to stop the lens down.

For still life, the loss of metering, I-TTL and AF is no big whoop as you can just fire off another shot and adjust the flash power accordingly, but for subjects like flying insects where you're probably only going to have 1 or 2 cracks at it before it gets startled and flies off, it can be important to maintain those metering features.

The 9:1 ratio is only achieved on the reversed 28mm f/2.8 Ai-S and extension tubes. As its reversed you lose the AF and metering anyway (unless your camera body will meter - my Nikon D90 doesn't).