teleconverter ?? RE: Brand and Auto Focus

[MichelleK]

Hi guys.

I have the EF 70-200 f/2.8 IS USM...couple questions....

1. I want the teleconverter...I am seeing some off brand ones (like tamron)...is this one a "buy Canon" type of product???

2. I thought I read somewhere when I was looking it up that if I go with the 2x then I can not use auto focus anymore. Did I not read that right?

Thanks :-)

Michelle K

[Lani Kai]

With the 70-200 f/2.8 IS you can AF even with a 2x TC. It'll just be slower and hunt more.

[SaSi]

All Canon cameras can AF with lenses having max apperture f/5.6 or larger, and the /2.8 will become /4 with a 1.4xTC or /5.6 with a 2xTC.

The lower the light, the slower the AF will become with most Canon lenses. This is because the AF evaluates contrast changes while focusing and the lower light creates low contrast situations.

The Canon Tele converters seem to force the camera to show down AF and many users complain that AF becomes slow with the Canon TCs, but not with most third party TCs.

The issue is, in bright light conditions, almost any TC will not cause issues with AF accuracy, so, perhaps, the lower speed of the Canon TCs is just bothering.

In all other situations, though, trying to have fast AF and a dark lens in dark environment will cause fast and innacurate (i.e. useless) AF.

I don't have a genuine Canon AF, but have only used one for a few minutes at a store. I remember that the camera tried to focus slowly while aiming towards darker areas of the store and was (I think) faster while aiming at the lights.

Perhaps an owner of a Canon TC can be more precice here.

[Uhland]

The two most popular seem to be the Kenko and Canon brands.
Although I hear the main complaint of the less costly kenko is that it doesnt feel as secure and there are rumors that peoples lenses have fallen off! owch!

[Jman13]

For the record, my Kenko 1.4x is very secure, as are the two I tried prior to purchasing.

[SunTsu]

Since you guys have the lenses, I'll ask in this thread too. :) Just wondering if you have full AF functionality with a 1.4x attached to a 70-200 IS 2.8. i.e. Can you still use all the focus points with the multi-direction controller?

[Pete]

Since you guys have the lenses, I'll ask in this thread too. :) Just wondering if you have full AF functionality with a 1.4x attached to a 70-200 IS 2.8. i.e. Can you still use all the focus points with the multi-direction controller?

Yes, you will. And AI Servo mode works with it as well.

70-200 f/2.8 + Kenko 2xTC in AI Servo AF mode.

http://www.the-aperture.com/EE/photos/normal/IMG_1854.jpg

[runninmann]

The two most popular seem to be the Kenko and Canon brands.
Although I hear the main complaint of the less costly kenko is that it doesnt feel as secure and there are rumors that peoples lenses have fallen off! owch!Rumors, huh? Can anyone cite any actual occurences? While I can't AF with it, my Kenko and Sigma 170-500 feel very securely attached in my opinion.

[gasrocks]

(My opioion, of course) The single best TC to get that will work with any Canon lens is the Tamron SP. It is off white, cheaper than Canons TC, great quality and works on any lens.

[SaSi]

(My opioion, of course) The single best TC to get that will work with any Canon lens is the Tamron SP. It is off white, cheaper than Canons TC, great quality and works on any lens.
And how about the 2xTC? Is the Tamron 2x better or worse than the Canon?

[LightRules]

(My opioion, of course) The single best TC to get that will work with any Canon lens is the Tamron SP. It is off white, cheaper than Canons TC, great quality and works on any lens.

FWIW, the Kenko Pro (non-DG = off white color) is identical to the Tamron SP in every way, shape, and form.

[the.digital.guy]

Just bought the Kenko Pro 300 DG 1.4x TC for my Canon 70-200mm 2.8 L IS.
I am absolutely suprised how well this Kenko works...........FANTASTIC !!!

Believe me..... I'm a Canon PURIST.....but I knew I would not be using the 1.4x TC that much and could not see spending the extra $$$. I was not really looking forward to the "Black" TC either.But once I put it on my camera; it looks like it's part of the body.It works way better than I could imagine.

The AF is Very Fast.In my opinion; faster than the Canon 1.4 TC that I had tried.

Bought it Brand New for $105.00 plus $20.00 shipping.

Also see here:
http://photography-on-the.net/forum/showthread.php?t=304070&highlight=kenko+1.4

[Ricko of Fla]

All Canon cameras can AF with lenses having max apperture f/5.6 or larger, and the /2.8 will become /4 with a 1.4xTC or /5.6 with a 2xTC.

The lower the light, the slower the AF will become with most Canon lenses. This is because the AF evaluates contrast changes while focusing and the lower light creates low contrast situations.

The Canon Tele converters seem to force the camera to show down AF and many users complain that AF becomes slow with the Canon TCs, but not with most third party TCs.

The issue is, in bright light conditions, almost any TC will not cause issues with AF accuracy, so, perhaps, the lower speed of the Canon TCs is just bothering.

In all other situations, though, trying to have fast AF and a dark lens in dark environment will cause fast and innacurate (i.e. useless) AF.

I don't have a genuine Canon AF, but have only used one for a few minutes at a store. I remember that the camera tried to focus slowly while aiming towards darker areas of the store and was (I think) faster while aiming at the lights.

Perhaps an owner of a Canon TC can be more precice here.
SORRY BUT YOU CAN NOT AUTO FOCUS WITH A TC 2X ON A 20D 30D OR 5D. ONLY ON A MARK SERIES CAMERA CAN US AUTO FOCUS

[MichelleK]

SORRY BUT YOU CAN NOT AUTO FOCUS WITH A TC 2X ON A 20D 30D OR 5D. ONLY ON A MARK SERIES CAMERA CAN US AUTO FOCUS

Really??

So if I got a TC 2x on for my 30D + 70-200 2.8 IS USM I would not have AF???

Michelle K

[formula4speed]

Ricko is mistaken, the 2x TC will allow autofocus with your camera provided the lens is natively f/2.8 or faster. The autofocus speed and image quality will suffer, but it will work.

[runninmann]

SORRY BUT YOU CAN NOT AUTO FOCUS WITH A TC 2X ON A 20D 30D OR 5D. ONLY ON A MARK SERIES CAMERA CAN US AUTO FOCUS20D/30D will AF with lenses down to f/5.6; D series with lenses down to f/8. So, if you had an f/2.8 lens and a 2X tcon on a 20D/30D, you would have an effective aperture of f/5.6 and it would autofocus; not as quickly, probably.

[plewfran]

I'm using a 70-200mm f/2.8 +1.4x on a 20D. I cant' tell if the autofocus is working because the focus confirmation light doesn't turn on nor the beeper. Any thoughts?

[LightRules]

I'm using a 70-200mm f/2.8 +1.4x on a 20D. I cant' tell if the autofocus is working because the focus confirmation light doesn't turn on nor the beeper. Any thoughts?

There should be no problem with AF with your set up. Use ctrpt AF set to one-shot mode. You should hear a beep. You won't hear a beep in AI servo.

[plewfran]

Thanks LightRules! I had the setting on AI servo. So does that mean AF doesn't work in AI servo, only in one-shot mode? Thanks again.

[LightRules]

Thanks LightRules! I had the setting on AI servo. So does that mean AF doesn't work in AI servo, only in one-shot mode? Thanks again.

AF works in servo, but it's mostly used for action and movement. So it will continue to "track" your subject. Generally, you should use one-shot (for non-action).

[plewfran]

Thanks again!

[wimg]

The two most popular seem to be the Kenko and Canon brands.
Although I hear the main complaint of the less costly kenko is that it doesnt feel as secure and there are rumors that peoples lenses have fallen off! owch!
That was with (broken) extension tubes, not the converter itself, as far as I can remember.

I have a Soligor tcon, which is a rebadged Kenko, and it is just as secure as my Canon extenders.

Kind regards, Wim

[Wilt]

Really??

So if I got a TC 2x on for my 30D + 70-200 2.8 IS USM I would not have AF???

Michelle K

I'll corroborate that Canon has its amateur and prosumer dSLR's (Rebel, 30D) programmed to try to AF as long as the effective max aperture of the lens is f/5.6 and faster. The 1Ds Pro bodies can AF to effective aperture of f/8. So if the native lens is f/4, the 30D can AF with a 1.4x convertor (effective aperture f/5.6) but will not try a 2x convertor (effective aperture f/8 ). So your 7-200 f/2.8 lens would have effective f/5.6 max aperture with a 2x convertor, and your camera will happily AF