Using Extension Tubes

auto extension tube set

Extension tubes or extension rings are hollow tubes designed for use in macro photography.

The tubes are usually supplied in a set of three lengths (eg 12mm, 20/25mm and 36mm) and fit between the camera and lens to offer a choice of macro magnifications.

Some manufacturers produce them singly too for those who have a specific requirement, but a set of three offers more versatility because you can use the tubes in any combination to give six magnifications.

auto extension tube set

As there are no elements inside the tubes, quality is as good as the original lens and the size and versatility is perfect for the nature photographer who may be humping a load of kit around.

12mm Extension tube + Pentax 50mm

12mm Extension tube + Pentax 50mm.

25mm Extension tube + Pentax 50mm

25mm Extension tube + Pentax 50mm.

36mm Extension tube + Pentax 50mm

36mm Extension tube + Pentax 50mm.

Their only real drawback with tubes is that there is a loss of light and this increases the more extension you add. Fortunately modern cameras with through-the-lens metering automatically compensate, even when using flash (providing it is dedicated). If you are using an older manual camera or a non TTL flash system you will have to make adjustments manually.

Using extension tubes is easy. Select the tube or tubes you want to use, remove the lens from the camera body, attach the tube or tubes to the body and reattach the lens. The tubes have markers on them to show where the lens aligns to the body.

Once in place adjust the lens focusing as normal. If you cannot fill the frame with the subject add another tube or when the magnification is too high, remove a tube.

When used in conjunction with a 50mm lens, a 25mm tube gives you half-life-size image, and a full set 1:1 reproduction. If you want incredible magnification you could combine more than three tubes. Two sets would give around 140mm of extension which is similar to a standard set of bellows.

If your camera has TTL metering use the suggested exposure, compensating as normal when the subject is predominantly light or dark. If the camera has manual exposure you need to calculate the extension used and increase the exposure to compensate.

Check out this exposure table.

Macro Photography Techniques

You will find everything you need to know about macro photography in our easy to follow technique guides to help you take great close ups.

BPM camera bellows for sale

BPM Bellows

We have limited stocks of used BPM camera bellows including customised sets for the Bowens Illumitran professional slide copier.

BPM camera bellows mounts for sale

BPM Camera and Lens Mounts

We have the worlds largest collection of original camera and lens mounts for the BPM bellows.

BPM camera bellows spares for sale

BPM Bellows Spares

We can supply spare parts for BPM Bellows. Every item in stock from the bellow material to tiny screws that hold them together.

BPM camera bellows accessories for sale

BPM Bellows Accessories

Accessories for the BPM Bellows to expand their versatility, including the Repotran slide copying add-ons.