With all the rage about the Canon 5DmII for video, and everyone all gaga over the shallow depth of field video for a pretty inexpensive price, you have to remember that with every silver lining, there is a cloud… or something like that.
A nice new music video demonstrates that it’s not just camera motion that CMOS chips distort from reality, even motion within the frame, like a drummer drumming (something drummers in bands simply insist on doing constantly, throughout the whole darn song.)
If you want to have your wet noodle video featured on America’s Funniest Home Videos, then shoot it with a DSLR. Giggle-inducing images after the break. Read more…
After seeing their corrected footage, I have to say, wow.
Not only does it seem to properly recognize the distortion and correct it, it lets you calibrate it for specific cameras, and it doesn’t correct the whole image, just what moves- so an object moving in the frame (like the bus) is fixed while the street poles are left alone (which a “global adjustment” would distort.)
Hey camera manufacturers… there’s code that solves the problem.
Now you can fix it in the camera and save us the headache of having to process all our footage after the fact.
Very convincing video demo after the break. Read more…
These days, with so many digital cameras sporting different sensor sizes and different lenses to zoom from here to there, the “mm” reference for that camera means zilch to the end user. Because of this, marketing departments have taken to converting most zoom measurements to 35mm equivalents, even though, aside for those few full-frame DSLRs, there is little true 35mm acquisition taking place any more- especially in the consumer realm.
B&H Photo Video posted a nice article comparing numerous sensor sizes and lens zoom measurements and put all that against an Angle of View (AoV) measurement which makes a lot of sense out of such disparate dumbers. Anyone can spread their arms out in a 90° Angle of View. This is the same for a sub-compact as it is for a DSLR- no matter the individual camera lens measurement in milimeters. A 20x lens is still a 20x lens. Its time we start thinking in new photography terms. Time to ditch the mm and move on to AoV so its easier to explain, and use any sensor and lens in real life.
FreshDV shot some interesting footage with the Sony PMW-EX1 and video of a police car with numerous strobes firing clearly demonstrated that Sony’s new flagship SxS camcorder, despite being knighted with the CineAlta badge, clearly has problems with capturing partial-second instances of time.
There is going to be trouble in Teaneck…
One of the easiest ways to f— with video is to use flashes and strobes while shooting.
With CCDs, you’ll likely end up with one field of interlaced video completely blown out and the other “half” of the image is normally exposed. Apparently, with CMOS imagers, including the soon to be replaced first 100 RED cameras, strobes and flashes can look like this, where only part of the frame is illuminated. Odd, isn’t it.
The video on the Fini Films Site has lots of strobes popping, and most are captured properly, but a good portion- more than you would expect- aren’t.
There’s been a bit of discussion about the image distortion caused by the scanning (rolling) shutter used by CMOS chips which are starting to proliferate in the prosumer and professional video camera world. The key problem, as I have mentioned previously, is that the scanning imaging device is no longer sending the image solely to scanning displays- i.e. tube televisions. Today’s displays include plasma, LCD, DLP, OLED, etc. Most are progressive, but some include circuitry to display the image as if it were a scanning device.
Mike Curtis, of HD For Indies, is very heavy into RED usage and promotion on his web site. RED is the video camera that I will agree is changing, or will change, the hardware business in the video industry. I checked in with Mike about the “rolling shutter” issue…
At DVXuser, there’s a detailed article called Sensor Artifacts and CMOS Rolling Shutter by Barry Green. He discusses, and does a very good job at showing a phenomenon whereby the image captured by a camcorder’s imaging chip is not gathered all at once (what I’ll call “progressive” like a frame of film behind a shutter) but may end up being collected across the chip like a farmer collecting corn from his field. This can create footage that has unique problems. He says:
While CMOS and CCD sensors do the same basic job (gathering light and turning it into a video image), they go about it in different ways, and the differences can have very significant impact on your footage… CMOS sensors (equipped with “rolling shutters”) can exhibit skew, wobble, and partial exposure; CCD sensors are immune to those effects. And a CMOS sensor with a “global shutter” would also be immune to them, but since no current CMOS camcorders are equipped with global shutters, a camcorder buyer needs to be aware of what the implications of a rolling shutter would be.