Canon EF 1.4x III teleconverter + lenstas

This extender is great giving me nearly 600mm from my 400mm canon lens, actually 560mm, when used on my full frame camera, or 896mm when used on the Crop sensor, and a lot cheaper than buying the equivalent size lenses. Would recommend

I have just bought this and very disappointed! I wanted it for my 5D Mark III + EF 100–400mm f/4.5 – 5.6L IS II USM lens but the auto focus dosent work when I attached the extender. I cannot understand how the lens is listed as compatible if you cannot use autofocus....

Bought it to take pictures of the moon and stars and the quality derived from needing to use manual focus is terrible (used it in combination with a canon 70D and canon 400mm US II lens). Not worth the cost; a cheap 800mm Chinese lens does the job as well for a fraction of the cost.

The price for the product on some sites have gone up when you look early in the year but managed to get what I wanted to pay ..

Unfortunately this extender does not work with cannon 100 to 400 L series zoom. I returned it and got full refund.