[HMC40] Question regarding 60p Footage at DVinfo.net

Chris McMahon · December 27th, 2009, 11:03 PM

I'm looking into getting a HMC40 (possibly a pair of them) to replace my FX7, mainly because of the 60p feature (and, of course, the built-in XLR jacks and tapeless workflow).

What I'd like to know is if the following:

If you shoot a fast pan (let's say that you're tracking a bicycle traveling at 20mph past a fence made up of vertical bars, with the shot zoomed in close enough to make out the logo on the guy's shoe) at 60p (1/120 shutter) with the stock lens, is CMOS skewing more or less apparent than shooting the same pan at 60i (1/120 shutter) with the stock lens? Or is there no skewing? I'd love to hear that there's none at all, but I doubt that that's the case.

Paulo Teixeira · December 28th, 2009, 10:23 PM

You have to buy the XLR adapter separately for around $260 but the good news is that the camcorder has been reduced to $1850 in both B&H and Amazon.

Barry Green · December 29th, 2009, 02:46 AM

Shutter speed has no effect whatsoever on the amount of skew that's present.

Things that affect skew are the frame rate you're shooting at (faster frame rate = less skew) and the amount of motion in the frame. If you're at full telephoto, the amount of relative motion in a pan is much more than it would be if you're at full wide angle, so telephoto does increase the appearance of skew (assuming constant motion at both focal lengths).

If you're worried about picket fence skewing, you can try one of the tricks from Panasonic's "how to control skew" video, which would be to tilt the camera slightly in the opposite direction. Add a little "dutch angle" to your shot and the skewing will straighten out. Won't work for everything, of course, but for this particular shot you're describing, it might be enough.

Chris McMahon · December 29th, 2009, 05:54 PM

Quote:

Originally Posted by Barry Green

Things that affect skew are the frame rate you're shooting at (faster frame rate = less skew) and the amount of motion in the frame.

That's all I needed to know (the extra information was just to answer any questions that may crop up regarding how I'd be filming and the situation). Thanks!

December 27th, 2009, 11:03 PM	#1
Chris McMahon Regular Crew Join Date: Jul 2009 Location: San Jose, CA,, USA Posts: 144	[HMC40] Question regarding 60p Footage I'm looking into getting a HMC40 (possibly a pair of them) to replace my FX7, mainly because of the 60p feature (and, of course, the built-in XLR jacks and tapeless workflow). What I'd like to know is if the following: If you shoot a fast pan (let's say that you're tracking a bicycle traveling at 20mph past a fence made up of vertical bars, with the shot zoomed in close enough to make out the logo on the guy's shoe) at 60p (1/120 shutter) with the stock lens, is CMOS skewing more or less apparent than shooting the same pan at 60i (1/120 shutter) with the stock lens? Or is there no skewing? I'd love to hear that there's none at all, but I doubt that that's the case.

December 28th, 2009, 10:23 PM	#2
Paulo Teixeira Trustee Join Date: Dec 2005 Location: Massachusetts Posts: 1,773	You have to buy the XLR adapter separately for around $260 but the good news is that the camcorder has been reduced to $1850 in both B&H and Amazon. __________________ https://www.youtube.com/user/PhotoVi...esEtc/featured https://www.pond5.com/artist/paulot

December 29th, 2009, 02:46 AM	#3
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Shutter speed has no effect whatsoever on the amount of skew that's present. Things that affect skew are the frame rate you're shooting at (faster frame rate = less skew) and the amount of motion in the frame. If you're at full telephoto, the amount of relative motion in a pan is much more than it would be if you're at full wide angle, so telephoto does increase the appearance of skew (assuming constant motion at both focal lengths). If you're worried about picket fence skewing, you can try one of the tricks from Panasonic's "how to control skew" video, which would be to tilt the camera slightly in the opposite direction. Add a little "dutch angle" to your shot and the skewing will straighten out. Won't work for everything, of course, but for this particular shot you're describing, it might be enough.