How To Pick An Extension Tube For Macro Photography

By | 19/09/2022

What are the benefits of an extension tube? We lay out the details on how they work, how to use them, and a few pop extension tube models.

If y’all’re simply starting out with macro photography, you can get a dedicated macro lens for your camera. Or you can pair a macro extension tube with a lens to produce infrequent results! To become even closer to your subject, pair extension tubes with macro lenses for greater-than-macro magnification.

What is an Extension Tube?

An extension tube is a hollow tube that fits between your lens and the torso of your photographic camera. They allow you to focus on subjects that are closer to the camera and reach greater magnification. Every bit a outcome, they’re also sometimes called macro tubes because they can allow you to create macro images without a dedicated macro lens.

Because extension tubes don’t contain any actual eyes, they can exist very inexpensive. They don’t innovate new distortions the way some add-ons (such as filters and teleconverters) can. They are too very flexible, allowing y’all to stack multiple extension tubes and tin be used with any lens y’all own.

How Extension Tubes Piece of work

stack of extension tubes

Lenses focus low-cal a specific distance to the sensor backside it. Every lens has a minimum focus altitude where it’southward able to project the focused paradigm onto the sensor. If an object is too close to the lens, that distance falls behind the sensor.

Past moving the lens away from the torso, an extension tube adjusts the focal point. This allows you lot to focus on objects closer to the lens than you could otherwise.

One trade off, though, is that it also moves your farthest focus distance closer to the lens besides. When using an extension tube, you’re going to lose the ability to focus at infinity. With some lens and extension tube combinations, you may only be able to focus a few feet away. Extension tubes should only exist used when you want to focus as close as possible to achieve the most magnification.

close up of a kiwi

How much boosted magnification you lot tin get depends on the combination of lens and extension tube you choose. You can make up one’s mind how much additional magnification you want by dividing the extension tube length by the original focal length.

For example, the incredibly popular Canon EF 50mm f/1.viii STM has a native maximum magnification of .21x. Using a 25mm extension tube, you lot can add .5x magnification, bringing the full magnification to .71x. Using both a 12mm and a 25mm extension tube volition add .74x magnification, bringing the total to .95x, very shut to a true macro lens.

This also ways that an extension tube has a larger event on shorter lenses. A 25mm extension tube will add .5x magnification to a 50mm lens. But it volition only add .25x magnification to a 100mm lens and .125x to a 200mm lens.

How to Use an Extension Tube

Three extension tubes 36mm 20mm and 12mm

Using an extension tube is as unproblematic as connecting the extension tube in betwixt the photographic camera body and lens. Once the extension tube and lens are in identify, there are no boosted controls or mechanics you need to worry well-nigh.

The more you magnify the image, the more likely camera milk shake may affect your image. Just as with using a longer focal length, you need to apply a faster shutter speed, secure your photographic camera to a tripod, or use a flash to freeze any motion and ensure a abrupt shot.

Extension tubes will change the effective aperture of your lens. Your f-stop is the measurement of the focal length divided by the bore of the student of the aperture. For example, if you’re using a 100mm lens whose aperture is 25mm in diameter, the f-stop is f/4.0 (100mm/25mm). If an extension tube combination gives you an constructive focal length of 150mm, the aforementioned aperture setting (25mm diameter) will give you an constructive f-cease of f/6.0. Less light volition exist hitting the sensor, so you’ll need to compensate for that.

You also need to brand the same adjustments when shooting with an extension tube as when using a macro lens. Nearly chiefly, when you lot focus on an object that’s so close to your lens, your surface area of focus is going to be incredibly small. At these focusing distances, the depth of focus volition be measured in millimeters. You lot will need to use smaller apertures, focus extremely advisedly (manual focus volition likely exist more than reliable than autofocus hither), and potentially use tricks such as focus stacking to become exactly what y’all want in focus.

photo of small frog

Pros and Cons to Using an Extension Tube

An advantage to using extension tubes is that they can be very cheap. You lot become macro capabilities for far less than a defended lens. Also, considering they don’t contain any bodily optics, they don’t innovate new distortions the way some add-ons (such as filters and teleconverters) can. They are very flexible, allowing you to stack multiple extension tubes, and can be used with any lens you ain.

Extension tubes themselves are very light and meaty. When packing your photographic camera bag, if you can use extension tubes with another lens, you will save space and weight versus adding an extra dedicated macro lens.

While extension tubes don’t innovate distortions, they tin magnify existing problems. Some lenses are not very sharp at their closest focus distances. If y’all use an extension tube to one of those lenses, yous can magnify those problems.

A downside to extension tubes is, aside from moving your minimum focusing distance, they also motion your uttermost focus distance. When using an extension tube, you’re going to lose the power to focus at infinity. With some lens and extension tube combinations, you may not exist able to focus more than a few feet away. Extension tubes should only be used when you want to focus as close as possible to achieve the most magnification.

Finally, adding an extension tube changes both your effective focal length and aperture. Past substantially making your lens a little scrap longer, you make it more than prone to camera shake. Your f-stop, which is your focal length divided by the bore of the discontinuity’southward student, also becomes smaller, so less low-cal will end up hitting your sensor.

For instance, if you’re using a 100mm lens whose aperture is 25mm in bore, the f-terminate is f/4.0 (100mm/25mm). If an extension tube combination gives you an effective focal length of 150mm, the same aperture setting (25mm diameter) will requite y’all an effective f-stop of f/6.0. You lot will need to brand certain y’all compensate for both of these effects.

Types of Extension Tubes

Because of how simple extension tubes are, y’all can find incredibly inexpensive ones. Simply not all extension tubes are equal and you lot should consider a few things when choosing them.

Extension tubes may or may not be compatible with your photographic camera. If they aren’t, you will lose the ability to electronically suit the aperture and use autofocus. Because almost no mod lenses have transmission aperture controls, non-electronic extension tubes volition leave your lenses wide open up, which may be extremely hard to use, due to the tiny depth of focus you lot’ll have.

Both Canon and Nikon make extension tubes in a couple of dissimilar sizes:

Model Length
Canon EF 12 Ii 12mm
EF 25 II 25mm
Nikon PK-12 14mm
PK-13 27.5mm

Other major lens manufacturers aren’t currently making extension tubes, but there are a number of other third parties such as Kenko, Vello, and Neewer.

When choosing an extension tube, consider electronic aperture control and autofocus. Because there’due south no optical performance difference between extension tubes (due to in that location being no glass elements to interfere with light transmission), lower upkeep extension tubes might be all-time for your needs.

One factor in choosing a more expensive extension tube is if you demand more than robust build quality. Cheaper extension tubes need to exist treated more carefully to avoid dissentious them. In particular, some cheap extension tubes have reputations for having weak threads that can cause them to become stuck to your lenses. If you’re unable to remove the extension tube, that lens will not exist usable for anything other than macro photography.

Choosing an Extension Tube

Extension tubes can be used with almost any photographic camera mount. Proceed in listen not to use an extension tube if you’re using a lens with a unlike mountain from your photographic camera trunk. Y’all might not have whatever trouble using extension tubes and an adaptor at the same fourth dimension, but it does increase potential points of failure.

Because you will likely be using an extension tube with a smaller aperture, y’all may desire to pair it with a camera that take ameliorate low lite performance. If your photographic camera struggles at higher ISOs, you might struggle to properly expose your images.

Because the entire signal of using an extension tube is to increase magnification, y’all can benefit from using a camera with an APS-C sensor that volition give you a native crop (and additional magnification).

While any photographic camera can pair very well with an extension tube, crop sensor cameras with very good low light functioning volition piece of work all-time. The Nikon D500, for example, is a peachy pick if y’all want great magnification.

Extension tubes tin can exist an easy way to add macro capabilities to non-macro lenses or even to increase the amount of magnification that you become from your dedicated macro lenses. Because of the uncomplicated nature of an extension tube, at that place is little operation difference between different brands and models. Pairing an extension tube with the right lens can open up many possibilities for your photography.

Tags: Canon Lenses, macro
Last modified: July vii, 2022


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Originally posted 2022-02-12 16:53:21.