[Ian964]

I occassionally need a longer lens than my 70-200 f4/L IS, but not enough to justify buying one. So considering one of the Canon Extenders (1.4 or 2). Looking at the specs, the 1.4 inceases the effective maximum aperture by one stop, and the 2x by two stops, so to 5.6 and 8 respectively on the f4 lens. Also says that autofocus won't work if the max aperture is more than f5.6 - therefore I assume that with the 2x extender I'd lose autofocus, but be OK with the 1.4. Is that right?

Does the extender affect IS at all?

Also, does the EXIF data reflect the fact that an extender was used? i.e if a shot was taken at 200mm with the 1.4 extender, giving an effective focal length of 280mm, does the EXIF say 200 or 280 (body is an EOS 30D)?

Thanks
Ian

[T0MAT01]

You're right about losing AF with the 2x on the 70-200 f/4 but I'm afraid I don't have one so I can't help with the IS or EXIF questions.

[Tobers]

Hi - you'll be v.pleased with the 1.4x extender. I've got a 70-200 F4L non-IS. I tried the 2x but the autofocus does indeed crap out. The 1.4 though is great, sharp and adds really useful length.

Yes, the exif does show the "proper" focal length. I'll chuck a couple of pics up in a mo of my son's cricket match this morning taken with the 70-200 + 1.4 combo, and the exif shows the lens as 98-280 and the focal length is 280 at max zoom. Multiply by your 1.6x crop factor and you've got a 392mm lens.

Also, the extender is nice & small so tucks away v.neatly in your bag.

[Tobers]

Here's 3 with the extender on. ISO at 400, 1/1000th shutter speed, exposure compensation -2/3rds to stop blowing out highlights on the white clothes. Exif shows 98-280mm lens and focal length @ 280mm. Aperture f11.

#1 thwack!

#2 doh!!

#3 double-doh!!

[Ian964]

Thanks for those - excellent pics! Looks like the 1.4 is what I'll go for.
Cheers
Ian

[BananaTiger]

Very interesting post. Not that I have a telephoto but interesting to know about the right exif info, and the lack of autofocus above f5.6. Makes me think more about my telephoto lens purchases in the future.

[h4rri]

Yeah good to know about the exif info etc A 1.4x TC is definately on my shopping list