Tom_W wrote:
I found also that my 7D would not AF when I had stacked teleconverters on the 400/2.8 (1.4X and 2X, equivalent 1120mm, f/8) despite a reported f/5.6. I hunted relentlessly, and managed to focus only 1 in 20 times on the moon. The 5D2 and 5D can do this with just the center AF point activated.
That was in a situation where I had only 1 AF point selected. When I selected a zone AF scheme, I sometimes got confirmation in manual focus. I may try the 19-point grid and see how it works with the stack.
Update - setting the AF to use all 19 points did the trick, as Mark pointed out. I autofocused on the moon with 1120 mm worth of f/8 lens, repeatedly and reliably. Good deal!
kirry007 wrote:
Manual focus is your friend in such a case. The moon ain't going anywhere.
Well, I had some difficulty getting exact focus the other night through the eyepiece or with live view. It was high overhead, so I was in an awkward position trying to adjust focus while crouched down looking up at the back of the camera. And it is going somewhere - in 2 minutes, it is out of the frame. Of course, once focus is set, it need not be moved since the moon certainly isn't going to drift out of acceptable DOF any time soon.
Tom_W wrote:
Update - setting the AF to use all 19 points did the trick, as Mark pointed out. I autofocused on the moon with 1120 mm worth of f/8 lens, repeatedly and reliably. Good deal!
This does indeed seem to work but, alas, I have overcast skies so no chance to photograph the moon tonight with my 400mm F5.6L + 1.4xTC combination.
Well, you obviously overlook the fact that some copies of the 7D show a minimal degree of artifacts already, even with the early after-market converters.
abqnmusa wrote:
Hi Jim,
Well the answer is obvious. Use DPP until the after-market RAW converters reach the point they do not produce artifacts. Same as your 50D analogy.
DPP rocks
Jim Victory said ...
No it is an aftermarket Raw converter that has had 5 years to get it right.
The after market Raw converters available for the 7D just haven't had enough time to get it right. The same has been true for just about every Canon DSLR made. The most recent glaring difference was the 50D. Try a 3rd party Raw converter with it now and they work great but for 6 month period after it was released thay all sucked except DPP. It took ACR two revisions before you could get decent results.
I'm liking mine. Fast focus, 8 fps, and amazing 6400 ISO images. But holy cow, could they have installed a cheesier-sounding shutter? Every shot, it sounds like the shutter box is low on oil.
PatrickSweeney wrote:
I'm liking mine. Fast focus, 8 fps, and amazing 6400 ISO images. But holy cow, could they have installed a cheesier-sounding shutter? Every shot, it sounds like the shutter box is low on oil.
initially i thought my shutter was busted because it sounded so odd
If you recall, Romy was one of the birders who had concerns with the AF on a preproduction body, he seems pretty happy with the performance of the production body.
