Tamron 'Big T' 200-500 and Kenko 1.4tc. pic wanted please. (1 Viewer)

I have the Tamron 200-500 and when on holiday last year I borrowed a Kenko 1.4X converter. It seemed to work OK so eventual I took the plunge and bought one. But then I did a more scientific trial and it didn't seem to give good results being a lot less sharp. Taking a shot without a converter and enlarging it 1.4X in Photoshop gave better results.

However, I was mostly using the lens at f6.3 at 500mm and recently I have decided not to use the lens itself below f8 if I can avoid it as it does seem much sharper at f8 or above. So I repeated the test at f8 and it seems to work a lot better, the quality is now better I would say than just enlarging the original.

Using the converter the AF is impossibly slow at times. No good at all for birds in flight. Loosing another stop makes it harder to get to f8 in the UK. So unless you are using it on a tripod and manually focusing it doesn't help much.

On the lens itself I think I have gotten some good results with it, but the slow AF and lack of IS can be a pain. I have been considering swapping for th Sigma which seems better in these regards but then a lot of reports on that lens claim the IQ is not so great. A dilema!

I don't like to lug a tripod around so I mostly use a monopod or more likely hand hold it. It gives better results when I am in Portugal and the sun is shining than it does on a grey day in the UK.

Most of the bird photos in my Flickr pages are with this lens. There are some examples with the converter if you search for them.

See here
http://www.flickr.com/photos/alan-photos/

An amazing shot in the Gallery this evening taken by Donald Talbot using the Tammy lens(Red-Crested Pochards)-I think!!.
But re using an ext,I prefer to take a sharper smaller shot,which I can crop ,to using an ext.My technique ,perhaps lacks expertise in this field,but I now only use the 1x4 if the subject is perfectly still,and the light is average.I would much rather have a smaller cropped shot,with clear detail,than one slightly larger,and somewhat fuzzy.But having said this,if I was an expert,then yes,I would use a 1x4 whenever.