Extender Question

Ok, I got my 70-200 f4.0 L lens and want to know if using the Canon Extenders will still yield good prints. I have never used an extender so am completely unfarmilure with them. Can someone shed some light on this for me?

Alot has been written about the 1.4x and 2x extenders on these boards. You will not be able to use Autofocus with the f/4 lens unless you do the "Tape Trick". Most people including myself feel that the images produced with the 1.4x are of better quality then those produced with the 2x. You lose 1 stop with the 1.4 and 2 stops with the 2x. That makes for a much darker viewfinder.
If you do a search above on Canon Extenders you will find alot of pictures shot with both.
Here's one shot with the 100-400 IS L and 2x extender:

HTTP response: NOT FOUND | MIME changed to 'image/gif'

Denny: I did a comparative test of the 400 f/5.6L prime, the 100-400 L zoom, the 70-200 f/2.8L IS with the 2X extender, and the 70-200 f/4.0L with the 2X extender. (see https://photography-on-the.net …e6c7ad4201fe813​f4c47fa020)

The results with the 70-200 f/4 using the extender were very, very good. My only complaint is that you will lose two full f-stops with the extender, so the largest effective aperture you'll be able to shoot with is f/8. If you're outdoors in bright sun, this won't be a problem, but as light falls off, the utility of the lens will suffer accordingly.

Good luck with your new lens. It's a goodie.

Tom

It will autofocus with the 1.4X Teleconverter.. which will give you an effective max aperture of f/5.6 The 1.4X lloks great on the f/2.8 version of this lens... I bet it will work well with the f/4 as well.

But when you say "extender" I don't think Teleconverter,. (I can't really remember what Canon calls them)

..I think "extension tube" EI: what we use to turn or normal lenses into macro lenses.

Could you clarify which you are looking at?

That's what Canon call them - extenders. Dunno why, just about everyone else calls them teleconverters.

KRs
Chris

An f/4 lens with a 1.4x tele-converter has a maximum aperture of f/5.6.

An f/4 lens with a 2x tele-converter has a maximum aperture of f/8.

The "prosumer/consumer" DSLRs (e.g. the 10D, 300D, D60, D30) will AF with f/5.6 lenses, but will disable auto-focus when the lens' maximum aperture is "worse" than that (i.e. smaller apertures with larger f-numbers, like f/8). The "tape trick" fools the camera into trying to AF, though it might not do so reliably.

The "pro" DSLRs (e.g. the 1Ds and 1D) will auto-focus with f/8 lenses, but no worse than that.
-harry

Bit the bullet...

Okay... so after reading all this about TC's ... decided to try out the 2x on my Sigma f/2.8 70-200mm lens...

While I was at it.. figured a 25mm extension tube would be cool to play with... so got that also...

Now for figuring out what to use these for...

A teleconverter (or extender, as Canon calls it) has lenses in it and effectively makes the focal length of your lens 1.4x or 2x as long.

An extension tube has no lenses in it and is just a hollow tube that fits between the lens and camera body. An extension tube is for close-up photography. Lenses have a minimum focusing distance: they cannot focus on anything closer than this distance. With an extension tube, you make the minimum focusing distance shorter, which enables you to use a normal lens for close-up, macro-like things. Note that with an extension tube, you will loose infinity focus: you cannot focus on things that are far away when you're using an extension tube.

So, the teleconverter is for things that are far away, the extension tube is for close-up.

I use the 1,4x extender on my f4 lens a lot and the results look great.

re: tape trick...

note that either using the tape trick on canon (or using the tamron sp teleconverter, which doesn't have the pins to tape) results in most lenses (that i've tried) doing this scary 'hunt' for focus. so scary in that i've physically heard the lens (the generally silent usm) going back and forth past the point where it needs to stop to get focus. it's much better on the mk ii, but it still happens. i've found that i can zoom in (where the aperture is wider), get a lock, and then slowly zoom out - re-aquiring the lock.

i get the feeling that the 'hunting' *can't* be good for the lens, therefore the 2x is only used on my really fast lenses. i've even seen it on both my canon and tamron 1.4x @ 5.6

anyone else see the same thing?