Extension tubes help

[Zoundz]

I'm thinking about buying some extension tubes, but am curious, as they're not something i've used before, how exactly do they work? And what exactly am I looking for?!

found these - but they look awfully cheap - is that something to avoid, or are they suitable?

eBay.ie: Macro Extension Tubes 4 NIKON D40 D60 D70 D80 D90 D300 (item 350125235445 end time 13-Mar-09 16:58:24 GMT)

xx

[Words]

Extension tubes are just hollow rings that fit between the lens and the camera body to alter the focusing point (basically they shorten it so that you can get closer). There's no glass. With them on the camera you lose 'infinity' or indeed anything more than a few feet away. You may also lose autofocus (depnds in the pins in the tubes , if any). But that said, they are really useful to shorten the minimum focusing distance. I've got some cheapos (not as cheap as these). The main drawback with cheap ones is that as they tend to be made of plastic you might not feel too confident with an expensive/heavy lens hanging off the end of them.

They commonly come as a set of three (at different lengths) which you can combine. At that price you can't really go wrong.

[Zoundz]

very helpful thanks! I need to be careful though, as the nikon macro lens i have is very heavy really for its size, and i would be worried that the plastic may not work so well... but now i have a rough idea what i'm looking for i can go for some! Price isn't much of an issue, but you get what you pay for, and it may be better to aim a little higher

xx

[wildlifesnapper]

Hi

extension tubes are great when you need that bit of extra magnification. I use them on my macro lenses.

I would avoid the ones you have found on ebay, to me they don't look as if they have the connections to keep the cameras auto-exposure.
You really need the cameras auto-exposure as it makes life a doddle, you can work out the math for manual exposure/effective apperture but it's a pain up the ass!

Look for a set of kenko or jessops "auto" tubes.

neil

[glsammy]

I've got the Jessops ones and I can recommend them. They have the pin connectors so you keep the auto functions of your lens. As they don't have glass they don't directly degrade an image.
Here's an image I took using the three together, added onto my Sigma 150mm.
The interesting point with these is that the shorter the focal length of your lens, the higher the magnification you get so the 150mm isn't the best macro lens to use with them, but it all helps get that bit closer.

[Geoff F]

As you say, £3.50 for 3 tubes just doesn't sound correct. Genuine Canon tubes are around £50 for one 12mm and upto £100 for a 25mm. I assume genuine Nikon parts would be about the same. Recognised third party brands are slightly cheaper but not that much.

The ad does say they are new and made of aluminium but I can't see any electrical contacts and there is no mention of any manufacturer.

Maybe somebody is casting fake copies. But, as it has already been mentioned, you would probably only be able to use your lenses in full manual mode.

To some extent, it would be interesting, at that price, to get a set just to see how badly they have been manufactured. But being a cynical old so and so, I would be wary of giving that seller any personal details.

ps. If you are new to tubes there are a couple of other points to consider. They do cause a bit of light loss so you really need to increase ISO a bit and you have a restricted focus length, ie can't focus on infinity. I find that exposure readings can vary considerably and while auto focus is possible with compatable equipment I find that manual focus works better.

But the main use of tubes is for macro work and I prefer manual operation here anyway.

[Andy Warne]

Originally Posted by Geoff F

To some extent, it would be interesting, at that price, to get a set just to see how badly they have been manufactured.

That's what I thought, so I did.
They are well manufactured considering their price. However, no auto-focusing, no metering, and unfortunately the three tubes do not each have their own camera and lens mounts. You have to decide which tube you want to use and screw the two mounts onto it.
If you can live with the shortcomings then they are a bargain and a good introduction if you are unsure about splashing out on a full auto set.

[BillyPilgrim]

Originally Posted by glsammy

I've got the Jessops ones and I can recommend them. They have the pin connectors so you keep the auto functions of your lens.

Do Jessops still do their own brand?

I've been after a set for a while and have checked their site a few times but cannot find the Jessops own brand.

The others, such as Kenko, seem to be overpriced at the moment which is why I had a look at Jessops but I can't seem to find them. If anyone else can then a link would be very much appreciated.

[cyber_spud]

I have looked for the Jessops ones too and I don't think they do them anymore. I have a cheap set that I bought off ebay and they seem to work ok. They are aluminium rather than plastic but don't have the pins so you lose AF but I work in MF anyway.

Originally Posted by wildlifesnapper

I would avoid the ones you have found on ebay, to me they don't look as if they have the connections to keep the cameras auto-exposure.
You really need the cameras auto-exposure as it makes life a doddle, you can work out the math for manual exposure/effective apperture but it's a pain up the ass!

Re exposure, you put the camera into AV mode and it should adjust the shutter speed using the max aperture. I think this means that auto-exposure does work but I'm not sure - perhaps someone else could confirm this one way or the other?