I posted earlier on the 'Wildlife Gardening ' thread by mistake (see ISO800)
These are a few of my latest shots using Canon 400D + Kenco 2XTC + Sigma 175-500mm. In some of these shots I used a flash to try to improve them.
1: ISO800 , EC-1, No flash, 425mm, 1/60

2: ISO400, EC 0, 425mm, 1/200, Flash

3: ISO 400, EC -1, F8, 425mm, Flash

4: ISO800, F8, 425mm, Flash, EC 0
Sigma 175-500mm plus Kenco 2X TC (on a Canon 400D)
My original tests were to see whether the TC was going back on ebay (where it came from).
ADVANTAGES – If you need to get into long lenses on a budget, this is certainly a cheap way to go.
I eventually discarded the Camo netting across the doorway and moved further inside to photograph in comfort, ( chair, sandwich, glass of beer !) .
If you are keeping an album of 6 x 4 prints you’ll get some decent results.
The TC + Lens + the bucket of a lens hood will make people think you’re Simon King when you’re out .
DISADVANTAGES – Relies heavily on post processing, due to having to use a high ISO.
Manual focusing.
Probably wouldn’t stand an A4 printout.
CONCLUSION – When all conditions are favourable you may get a near ‘pin sharp’ image.
The 175-500 on it’s own is the way forwards. It’s a decent lens (from the same stable as the 50-500 ‘Bigma’ ).
WILL THE 2XTC BE GOING BACK ON EBAY ? - No way !!!
Keith