[Freako]

Sorry Guy's if this is a bit basic for you, but what are the issues useing a Extender EF 1.4x on my 100-400 L ? Mick.

[Martin Thomas]

You will lose one f stop and potentially some image quality. At the end of the day it's a compromise but compared to the price jump between a 100-400mm and a 500mm lens its reasonable in my eyes (and pocket).

I have one which I use with my 100-400 and am delighted with it. I decided against the 2x because of the loss of two f stops.

Search the previous posts elsewhere as the question of telecoverters comes up quite often. There are also plenty of far better qualified photographers than me here who I'm sure will provide you with further comment.

Best wishes.

[JohnZ]

If I remember correctly you have a 20D in which case there should not be any problems providing you tape the necessary pins. Or you could get the non-reporting Kenko 1.5x TC that IanF has recently said that he uses. I believe that this particular TC does not have the pins that are normally taped.
The TC is available from Bristol Cameras and I am seriously thinking of getting one for myself. I believe it costs £66.00 plus P&P.

[Martin Thomas]

Perhaps worth mentioning that there are two similar Kenko converters. The 1.4x Pro 300 (5 element) around £100 and the 1.5x Teleplus (4 element) at £60ish as mentioned. The former should be provide a better image quality than the latter.

[stu78]

I have read about people having problems with a 1.4 tc and a 400mm prime lens on a 40D, when this combo works well on a 30D. I however have a 400D and was wondering how it performs with a 1.4 tc (taped pins). Does anyone use this combination? Does the camera have difficulty focusing?

[Words]

I use a 400D, 100-400 pump and the 1.4 TC. Issues? To allow AF you need to tape the pins. I also find that the IS fouls up with the combination so I always switch that off. You need decent light and a stable hand. Given the right conditions (and you quickly learn which are the wrong conditions) it works well. I'm currently taking a series of herring gull chicks with it. Here's a sample shot.