Aliasing/Moire Workaround

shoqman said:
Ok, so there's a lot of freaking out going on about deep focus, ultra sharp shots and the resulting aliasing etc.

First of all, the whole point of this camera is that your shots don't end up with super deep focus. That's why we all bought it and that's fine- it does phenomenally for creating a very organic cinema feel.

If you must have super deep focus shots with loads of horizontal detail, then frankly, you're better off buying a super cheap HV20 or whatever. They will beat it hands down for those kinds of shots, and that's fine too. Use the right tool for the kinds of shots you're getting.

If, however, you must use the 7D for a shot such as that, do the following:

Focus the shot so it's razor sharp.
Look at the LCD and if there is moire showing up, or aliasing (and yes you can see it on the LCD) then pull the focus SLIGHTLY off until it goes away.
Sharpen in post.

Looks great, almost indistinguishable. Except for the lack of moire/aliasing.

See pictures below.

Also, view at full size- you can't see it as well otherwise.
Click to expand...

Hey shoqman

Your technique works great.

Quick question: is it always possible to tell when you're going to hit moire troubles on the LCD while shooting, or is it something you only really notice in post.

Most of the time I can spot it while framing the shot in live view. But not 100% of the time.

For me, the live view magnify function seems not to suffer from as much moire so it's sometimes hard to tell when a focus adjustment is required.
 
I don't know about 100% of the time, but the more serious problems are super obvious on the LCD. I have been able to see it pretty well in my tests.

And you're right, the magnify button seems to show actual resolution from the full 5k frame, so it's not helpful for it.

Really, an external monitor would be super helpful- in my tests you can always spot it on an external monitor, or even a laptop using the EOS utility.
 
shoqman said:
I don't know about 100% of the time, but the more serious problems are super obvious on the LCD. I have been able to see it pretty well in my tests.

And you're right, the magnify button seems to show actual resolution from the full 5k frame, so it's not helpful for it.

Really, an external monitor would be super helpful- in my tests you can always spot it on an external monitor, or even a laptop using the EOS utility.
Click to expand...

I've often wondered how the sensor can do that, outputing the full 5k at 30p to the LCD without moire. I'd suggest that the camera (5D and 7D) support sensor windowing. If that's the case you'd have thought they would have a crop mode feature (like GH1) - maybe that's a possible Magic Lantern edition for the future?
 
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