Sigma 500 IF and no IF

[Michael Hogan]

What is the difference between a Sigma 500mm f4.5 APO EX DG HSM and a Sigma 500mm f4.5 APO EX DG HSM IF - and don't say 'IF'

Thanks

Michael

[Ant]

IF stands for Inner focusing, in otherwords the focusing mechanism is inside the lens the front of the lens does not rotate, I'm pretty sure its the same lens though, that is, Wherever you saw the lens discribed with 'IF' could of been a mistake on the part of the person/s /retailer /website as there is no lens on the sigma website of that name

[Michael Hogan]

Ant - Yes but did they have one out 2 years ago? Somebody is selling one and they say it is non IF. I can find no mention anywhere about a non IF Sigma 500 though

[postcardcv]

I've not heard of a no IF version of this lens - I'm certain that none of the DG ones will lack this feature.

[sassan]

This is a giant lens for about $4000 when new and half the price if used.
The front lens looks to big to be non-IF. As said it is pretty much impossible to have AF non IF version.
Was there any price difference?

[nirofo]

The Sigma 500 f4.5 has always been internal focussing, they never made one where the front of the lens turned with the autofocus. Even the Sigma 500 f7.2 was internal focussing. Can you imagine the problems turning the huge front element in the 123mm dia barrel would cause, the motor and or gearing to turn this huge piece of glass would require a lot of power. Big drive motor, lots of batteries to power it!

nirofo.

[Andy]

I suspect the 'IF' designation was dropped by many retailers to make room for all the other designations in the title of it
With a modern lens of this type, 'IF' should go without saying.