A teleconverter, also known as an extender, is a camera accessory that attaches between the lens and body of an interchangeable lens camera. They were made for 35mm and medium format cameras and are hard, if not impossible, to find for micro 4/3rd. That said this article is using one on a micro 4/3rds fitted with a Pentax K adaptor.

Whats does a teleconverter do?
A teleconverter increases the focal length of a lens by the number of x. The most common is 2x but models have also been made in 1.4x, 1.5x and 3x. With a 2x teleconverter your 300mm telephoto lens becomes 600mm.

What are the advantages of a teleconverter?
The main advantage is size and cost. A teleconverter and one lens takes up much less space than two lenses And it’s much cheaper to buy a teleconverter than a second lens.
Another advantage is the closest focusing distance of the lens doesn’t change when a teleconverter is attached so the magnification is doubled with a 2x from the same distance.

What are the disadvantages of a teleconverter?
The teleconverter adds a few more layers of glass for the light to travel through so there’s chance the image quality will be degraded. This is more noticeable on cheaper models where contrast can suffer as well as added distortion and reduced sharpness.

The teleconverter reduces the amount of light reaching the film/sensor by the same factor as the magnification. So a 2x converter loses two stops of light and a 3x converter loses three stops of light.

Can you use more than one teleconverter?
Its possible to add several teleconverters in a stack. Sharpness decreasing and light loss increasing with each one added. In this article Stacking five 2x teleconverters Petapixel stacked five teleconverters onto a 300mm lens to get a huge 9600mm telephoto.

A couple of test photos with a teleconverter
Below are examples of two subjects taken with the illustrated combination above – an Olympus OMD EM5 MkII with a 50mm f/1.4 Pentax lens and a budget priced Ozeck 2x teleconverter. The left photos are without the 2x teleconverter and the right hand ones are with the teleconverter. The map is taken at the closest setting of the lens, and the city view is with the lens at infinity. The bottom pair are highly cropped pics from the city scene. You can click on the four top pics to see the full size version.

For those viewing on a mobile device 1, 3 and 5 are without teleconverter and 2, 4, 6 are with teleconverter

As you can see the converter loses contrast, but sharpness is not as bad as many people have made out over the years, and a converter is certainly a good idea if your budget is tight.

We have a selection of second-hand teleconverters here at PhotographyAttic – used teleconverters 

There’s a video doing the rounds at the moment titled Leon The Professional. It’s being shared by photographers who’re impressed by the featured photographer’s home made “shooting” accessory.  The gent in question has adapted a wooden rifle stock to the bottom of his camera to create a comfortable hand holding gadget for long lens shooting …in this case bird photography.

Photographers who’ve been around before the digital age will remember this type of gadget is not new.

Back in the 70s they appeared in a kit from Russia called the PhotoSniper.

This was a Zenit camera with a chunky 300mm telephoto and a very realistic rifle grip below. Supplied in a metal box style case, at a very good bargain subsided price. But was seen as specialist gear as heavy and cumbersome for the majority of photographers.
Way before this in the 1950s-60s Novoflex had added a handle grip to the base of their long lenses in a gadget called the Pistol Grip Follow Focus. Available in 400mm, 600mm and 640mm with a 560mm joining the range in the 70s.  This gadget focused the lens when the trigger was squeezed…later models had a push pull action to focus. Lots of imnformation about the Novoflex system here NOVOFLEX accessory system for Exakta Varex at Photo but More

In the 70s-80s thanks to the popularity of the SLR and rise of camera accessory brands several budget Japanese/German products appeared from the likes of Rowi, Hama and Kaiser that could be attached to the base of your 35mm SLR to convert into a rifle grip. The Kaiser Kamera – Schulterstativ 6005 Rifle Grip was one such example.

These were light weight and had a cable release attached to the trigger to make rifle shooting simple. Camera Retailers Jessops and Dixons also sold rifle triggers for under £20.

And throughout the history of the 35mm camera, manufacturers have produced trigger grips that attach to the base of the camera to provide alternative and more comfortable ways of holding and firing the shutter.  These are just a simple hand grip shaped handle which are much lighter and far less bulky than the rifle grip.