Canon 500 mm f:4 Vs 500 mm f:4,5

[FrenchAmateur]

Stupid debate but some personal experiences would help.

I have got the 4,5 500 mm and uses it during the last 10 years. In addition, I have, among various lenses, the excellent 100-400.
I use now an Eos D Mark II.

Since the 500 mm f:4 IS has been commercialized, I am hesitating to sell my 4,5 for the new one. It is a lot of money to add, even if my shop is very flexible for accepting 3 or 4 montly payments...

I am doing only amateur wildlife photography and travelling for that.

Reasons to change : the stabiliser, the f:4 that allows the use of the 1,4 converter with autofocus, and possibly an increase in image quality(according to some tests, the quality of the new F:4 is slightly better...).

Reasons to keep my 4,5 : the difference in price, 700 g of additional weight (and this is important when travelling...).

Any of you has the experience of changing from one to the other ?

Thank you for your advice.

[FrenchAmateur]

I know that these are not very common lenses, but just a last try...

[EXA1a]

I guess you're in the wrong Forum here for such a question.
Have you tried the dpreview lens forum?

--Jens--

[CyberDyneSystems]

The 500mm f/4.5L will AF on the 1D MkII with the 1.4X T-con..

It adds up to f/6.3 and so long as you have the center AF point only in use it will AF up to f/8

If you get the 500mm f/4 youy will have AF with the 2X!

The weight difference is signoficant.. the image quality I'd say is so close that it will not be noticeable... so the deciding factors are more likely, weight, cost, IS and f/4 Vs. f/4.5

Hope this helps.