How to Use Teleconverters for Macro Photography

Teleconverters are valuable lens accessories that extend the focal length of the lens they are attached to. Positioned between the camera body and the lens—typically a telephoto lens—they enhance magnification without requiring you to move closer to your subject.

The degree of magnification depends on the teleconverter’s power, which is indicated as a factor. For example, a 1.4x teleconverter increases a lens’s focal length by 1.4 times. This means a 100mm lens effectively becomes a 140mm lens, while a 200mm lens extends to 280mm. The most commonly used teleconverters are 1.4x and 2x, though 3x converters are also available.

Why is this relevant to macro photography? The advantage of teleconverters is that their magnification effect applies not only to focal length but also to the magnification ratio of macro lenses. This allows photographers to capture extreme close-ups with even greater detail, making teleconverters a powerful tool for macro photography enthusiasts.

Teleconverters can be incredibly useful tools for high-level magnification, such as                                                                          snowflakes, for example.

“Attaching a 1x macro lens to a 1.4x teleconverter increases its magnification to 1.4x, allowing for enhanced close-up detail.”

**”However, using a teleconverter also affects the effective aperture, leading to light loss and increased diffraction softening. A 1.4x teleconverter reduces light by one stop, while a 2x teleconverter results in a two-stop loss.

This happens because teleconverters magnify the aerial image projected by the lens. Since only the central portion of this enlarged projection reaches the sensor, a significant amount of incoming light is lost. The illustrations below demonstrate this effect.”**

Without teleconverter

With teleconverter

“On the bright side, since a teleconverter simply enlarges an existing image, it does not affect depth of field or working distance. This can be particularly beneficial when shooting in the field or dealing with reflective subjects.

Teleconverters vs. Extension Tubes

Teleconverters aren’t the only way to achieve macro magnification, so why invest in an expensive optical accessory when extension tubes offer a more budget-friendly alternative?

Extension tubes are a popular choice among macro photographers due to their affordability, making them a go-to solution for increasing magnification. However, their effectiveness diminishes with each additional tube, offering progressively smaller gains. In contrast, teleconverters provide consistent magnification without significantly altering lens performance.”

“When maximizing magnification, teleconverters become an invaluable tool, allowing photographers to significantly increase the magnification ratio while maintaining a practical working distance.

For instance, they are especially useful when capturing intricate details of tiny subjects like snowflakes or when a high magnification ratio is needed without compromising distance. To push magnification even further, a teleconverter can be combined with extension tubes. When doing so, it’s essential to mount the teleconverter first, followed by the extension tubes—this setup helps preserve image quality.

However, since teleconverters introduce additional optics to an existing lens, they can degrade image quality more than extension tubes. The extra glass elements create additional barriers in the light path, and while high-quality teleconverters are designed to minimize this effect, some loss in sharpness and contrast is inevitable.

Additionally, both teleconverters and extension tubes can amplify chromatic aberration and reduce sharpness as they expand the image circle, making it essential to balance magnification needs with image quality considerations.”**

For this set-up I needed a large working distance to maintain proper alignment without catching a reflection of the lens in my footage.

Stacking Teleconverters Is Not Recommended

Due to the inevitable loss of image quality, stacking multiple teleconverters is generally discouraged. The extent of this degradation depends on several factors, including the specific converters used, their individual optical quality, and how well they function together. In most cases, using multiple teleconverters in sequence significantly reduces image sharpness, either through optical degradation or increased diffraction.

However, there are rare exceptions. For instance, in the images below, I successfully combined two 2x teleconverters to achieve an impressive 16x magnification ratio. To make this work, I had to shoot with my lens wide open at f/3.5 and accept some level of diffraction softening. While this approach can yield extreme magnification, it requires careful technique and an understanding of the trade-offs involved.

Just in case you haven’t guessed it, this is the eye of a bumblebee

Summary of Pros and Cons

To summarize, here’s a breakdown of the advantages and disadvantages of using teleconverters for macro photography:

Benefits:

✔ Can be combined with extension tubes for even greater magnification. (Always mount the teleconverter first, closest to the camera.)
✔ Provides increased working distance compared to a lens with the same magnification and focal length without a teleconverter. (Working distance remains unchanged when adding a teleconverter.)
✔ No loss of depth of field. (Typically, increasing magnification reduces depth of field, but teleconverters maintain it.)
✔ Compact, lightweight, and highly versatile. Works with a wide range of lenses, including nearly all macro lenses, except for a few specialty models.
✔ Even without a dedicated macro lens, a 2x teleconverter can bring you into true macro territory. Many zoom lenses with close-up functionality can reach 1:2 lifesize magnification—doubling that with a 2x converter effectively turns them into macro lenses.

Downsides:

✘ Reduced image quality—though the extent varies, acceptable results can still be achieved.
✘ Can be expensive, depending on the brand and model. (Third-party options from brands like Tamron, Soligor, Kenko, and Yongnuo can offer good value and are often available on platforms like eBay.)
✘ Light loss—1.4x teleconverters reduce light by one stop, while 2x teleconverters reduce it by two stops.