Canon Extender EF 2X III

The purpose of this article is to compare photographs taken with a Canon 100 – 400mm 4.5-5.6 L IS II lens with and without the Canon Extender EF 2X III. The goal is to help people decide if the Canon Extender EF 2X III will prove a useful tool in your camera bag.  

 

Methodology:

• The same Canon 5DSr body was used for all the photographs.
• All photographs were taken with a tripod.
• All photographs were taken at 400mm or 800mm with 2X extender.
• At least five photographs were taken of each subject. Autofocusing was performed for every shot. The best photograph from each sequence was selected for this article.
• No retouching / sharpening were performed except where indicated.
• Photographs taken at 400mm were doubled in size for comparison.

 

Test 1 – Full Moon 99% illumination:

Below: as captured, 800mm on left – 400mm on right

Left 1/80sec., f11, ISO 100  – Right 1/100sec., f8, ISO 100

Below: 800mm on left – 400mm on right. The 800mm photograph, left, had its contrast and exposure adjusted to match the 400mm photograph.

Below: an enlargement, made after the contrast and exposure adjustments above. While very close the 800 mm photograph, left, appears to have slightly more detail and sharpness.

Test 2 – Half Moon:

Below: an enlargement, made after slight contrast and exposure adjustments. While very close the 400 mm photograph, right, appears to have slightly more detail and sharpness in the mountainous regions.

Left 1/20sec., f11, ISO 100  – Right 1/80sec., f5.6, ISO 100

Test 3 – Daylight a Church at 436 yards:

Below: as captured, 800mm on left – 400mm on right

Left 1/80sec., f18, ISO 100  – Right 1/250sec., f5.6, ISO 100

Below: enlargement as captured, 800mm on left – 400mm on right

Below: contrast and exposure adjusted, 800mm on left – 400mm on right

In this test the reduction in contrast due to the 2X extender is clearly visible even with adjustments.

Test 4 – Gas Station Sign at Night – 400 yards:

Below: enlargement as captured, 800mm on left – 400mm on right

Left 1/6sec., f11, ISO 100  – Right 1/15sec., f5.6, ISO 100

In this example the 800mm is has much better edge sharpness which is best seen in the large “A”.

 

Analysis: In most of the conditions shown above the Canon Extender EF 2X III can produce excellent images when compared to a 2x enlargement created without the extender.

Conclusion: For those who often shoot with a telephoto lens, the Canon Extender EF 2X III is an excellent tool worthy of a place in your camera bag. Keep in mind that the 2X will introduce a two f-stop lost in light you’ll most likely need a sturdy tripod, and your best photographs will be produced utilizing f-stops in the mid-range of the lens. If you cannot safely get close to the subject the Canon Extender EF 2X III is the tool for the job.

Take care, and keep experimenting.