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Old Mar 7, 2004, 12:28 PM   #11
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Wow, thanks Frank for going out of the way to make the visual.
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Old Mar 8, 2004, 9:36 PM   #12
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Update: I ordered the lens today! I cant wait until it comes in!
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Old Mar 9, 2004, 9:03 PM   #13
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Quote:
I ordered the lens today!
Congrats Gandalf, I hope you like it! It'll be interesting to see what your conclusions are on that one.

I received my 50-500 and need to do some testing before I make any decisions about just how great it is. It's heavy but not as bad as I thought and it even sits nicely on my cheap little monopod.
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Old Mar 12, 2004, 12:03 AM   #14
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Update: The lens arrived today! Its too bad i had to work this evening, or I would have had something to show for sure!
So far, my thoughts are:
-Lens is larger than I expected (my poor Nova 3 AW, the lens strains it)
-AF is a tad slow, but workable.
-I managed to take a fairly stable shot at 1/30 and 400mm!!!
The lens is a beast, but a sweet beast. Weather permitting, I will run the gauntlet with it tomorrow.
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Old Mar 12, 2004, 10:17 PM   #15
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Frank...

I received the 2x converter and tried the tape trick on both the Bigma and my 70-200 F4. I got the same response from both:
- camera registered the "non-conversion" aperture, good
- camera seemed to seek for focus in AF mode, good
- neither lens had much luck actually focusing; a couple of times focus locked in but most of the time the sensor jittered about like it was doing a dance.

My conclusion: surely if this was an advisable thing to do then both Sigma and Canon would do this little fix themselves and offer more money for the converter since it would now be able to AF these lenses. Since they don't offer this I am very suspect about this sort of thing so I'm going to manual focus with the converter when using these lenses.

Thanks for the trick, though. It was extremely interesting to try!
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Old Mar 13, 2004, 1:42 AM   #16
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Strange focus is dead on on both my 70-210 f2.8 and my 80-400OS.

I low light it hunts indeed, but it also does without the tape.
2 weeks ago I used the 1.4x on my 70-210 and shot a whole soccermatch with continues focus and it worked like a charm, also some shots I made with the 80-400OS (but the weather was to bad) turned out good.

Very strange, but I'm happy it works here .

However the 80-400OS is offcourse a bit lightstarker than the 50-500, maybe that pushes it over the edge ?

Greetings,
Frank
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Old Mar 13, 2004, 6:14 AM   #17
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Guys

... It's not just how much light!
Think about this: if it's just about more light an f/5.6 lens alone would have problem in dark areas (indoor/gym..etc) correct? Well no, the 50-500mm f/6.3 has no problem focusing in the dark without a TC.

It's the lens diameter or it's opening. Remember the split-screen prism in older film camera when you close the lens down or mount a slower lens on the camera? The split-screen is 1/2 dark and even you have problem focusing manually regardless of how much light was available! This is because the difference in focusing info was not available for you or the camera to compare or focus on... Try to look through the viewfinder with the stop-down lever on the camera even with a 50mm f/1.8 with its aperture close down!

My bet is a 1.4xTC on an f/4-5.6 would be pushing the limit at the max zoom. A 2xTC will definetly not be kosher (unless the lens is wide diameter f/2.8 or faster)! 8)
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Old Mar 13, 2004, 12:06 PM   #18
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I think that NHL is saying that F8 is not giving the camera a lot of light to use to AF. Right? I've read posts in the past from people that calim the 1Ds manages to AF ok at F8, but that camera has a much better AF system than the 10D or 300D.

Barthold
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Old Mar 13, 2004, 1:34 PM   #19
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The 1Ds can AF at F8 by design, so it had better work and work reasonably well (as good as the 10D at f5.6 is what I'd accept. Not the 10D at F8... which huts like mad and occiliates but eventually gets there.)

I would not expect much from a 2xTC on the 50-500 @ 500. Since the aperture is really f6.3 (not the f5.6 that it reports) the fstop is a half stop beyond f11 (I believe.) Way beyond spec of the 10D or DRebel.

Eric
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Old Mar 13, 2004, 11:38 PM   #20
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I think you guys miss the point...

It's not about light! But strictly an aperture limitation, take the 50-500 at 500mm f/6.3 for example and use it somewhere where there's two stop less light, the camera/lens would still autofocus fine so it's not about light... (more light/contrast help of course). Give it a lens with an f/8 and doubling up the light will not get it to work even though the EV measured by the camera could be higher than an f/6.3 in a darker environment!

With the 50mm f/1.8 which everyone has, this lens can even focus in almost total darkness, ie EV close to 0! It has to do with the tiny prisms in front of the AF phase detector array, and as the aperture/diameter of the lens get smaller to a pinhole there's less and less of a difference in info where the AF sensors can use (and not about how bright this info is!).

The 1Ds just has a better micro-prism or more sensitive autofocus module. :P
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