50D autofocus with Kenko 1.4 + 400 Lf5.6 (1 Viewer)

S

Schulz-Benick

Member

• Oct 16, 2008

• #1

has anybody of the 50D owners tried autofocus capability with kenko 1.4 and 400 mm Lf5.6 or 100-400mm with special regard to central autofocus point ?? Is it the same as with the 40D ?

Regards,
Andreas

 

JohnZ

Well-known member

• Oct 17, 2008

• #2

I believe quite a few folks are waiting for that question to be answered.

 

H

hampers

Hampers

• Oct 17, 2008

• #3

I collect my 50D this weekend will post a response when I have tried it.

Phil

 

gmax

Sontium Dweller

• Oct 17, 2008

• #4

JohnZ said:

I believe quite a few folks are waiting for that question to be answered.

Click to expand...

Here I am, perhaps top of the list o

 

Saphire

Christine

• Oct 17, 2008

• #5

I will also be able to test it out next week when mine arrives on Tuesday.o

 

Roy C

Occasional bird snapper

• Oct 17, 2008

• #6

Looking forward to the results. My guess is that it will be similar to the 40D as they both have the same AF system.

 

Last edited: Oct 17, 2008

Saphire

Christine

• Oct 21, 2008

• #7

The 50D came this morning and I just couldn't wait for the battery to charge so popped in one of my older oneso.

My findings with the taped kenko 1.4 is, it still won't focus consistently with the center focus point, it does snap in quickly with all the other points.

I also tried the cheaper kenko non reporting 1.5 converter. That works better but occasionaly loses it with low contrast subjects but a lot more promising.
The photo below was taken with the 1.5 and 400 f5.6. The IQ is brilliant considering the crow must have been a 100yds or more and only filled a 10th of the frame..

 

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H

hampers

Hampers

• Oct 21, 2008

• #8

I have now tried my set up, 400 f5.5 and Kenko 1.4. Found exactly the same. No good on centre point at all, but is ok on others. I don't have a 40D so cannot say if it is the same or not. It was particularly good on the far left and right sensors, so its use them and shift slightly I think. Weather hasn't been good enough to go out here, intend trying on Friday. Will update again after this.

Phil

 

Roy C

Occasional bird snapper

• Oct 21, 2008

• #9

hampers said:

I have now tried my set up, 400 f5.5 and Kenko 1.4. Found exactly the same. No good on centre point at all, but is ok on others. I don't have a 40D so cannot say if it is the same or not. It was particularly good on the far left and right sensors, so its use them and shift slightly I think. Weather hasn't been good enough to go out here, intend trying on Friday. Will update again after this.

Phil

Click to expand...

Sounds exactly the same as the 40D.

 

tdodd

Just call me Tim

• Oct 21, 2008

• #10

When my 50D arrives I'll try it with my 100-400 and Kenko 1.4X with taped pins.

I find that with my 40D the AF is hopeless on the centre point but really quite acceptable on the upper diagonals. I haven't given the other focus points a good work out so I can't comment on how well they perform.

 

websurfer

Well-known member

• Oct 21, 2008

• #11

When do we get cameras with proper AF - I think an used 1D Mk II would be better than new 40D / 50D?

 

hollis_f

Well-known member

• Oct 23, 2008

• #12

websurfer said:

When do we get cameras with proper AF

Click to expand...

The 40D and 50D do have proper AF. They're not designed to work with a f5.6 lens attached to a 1.4x converter.

I can't believe how many people seem to consider the fact that these cameras don't work out of specification as some sort of major fault.

 

gmax

Sontium Dweller

• Oct 23, 2008

• #13

hollis_f said:

I can't believe how many people seem to consider the fact that these cameras don't work out of specification as some sort of major fault.

Click to expand...

C'mon, if that was true they would not work at all!!! Why the centre focus point only and not one on the right or at the top?
It's a major fault, considering the fact that the new more sensitive centre focus point is made to work properly on f/2.8 (or better) lenses - excluding in this way the vast majority of amateur(ish) photographer who can't afford those sweet toys.

Moreover, this trick is made on a prosumer camera which in my opinion is mainly used with f/4 (or worse) lenses - I reckon it's more fit on a 1D mk xxx.

I don't think many of the 40d and now 50D users will appreciate it fully (how many bird photographers may consistently enjoy birds at 2 metres with a naked 300mm f/2.8 lens?), whilst the 20D/30D+TC's AF performance (even with stacked TCs) - albeit not perfect - was good enough, allowing many of us to exploit a range which would have been otherwise reserved to those who can afford one of those jewels out there ...:-C
Just my rambling thoughts :-O

 

Tim Taylor

work in progress

• Oct 23, 2008

• #14

Max, I'm with you on this. Sure it's not a 'fault' when you look at its paper specification but I'm not intending to 'upgrade' my 30D until I can get something that will AF on centre spot with my current lens selection. Whilst I would no doubt be genuinely upgrading all sorts of camera function I would lose or at least degrade a feature that matters a lot to me.