CMOS vs CCD

[Steve Burrows]

I'm looking at upgrading / buy a new Video camera. Currently I have the Sony HDR-XR150 which I plan to keep as a back up Video Camera.

The problem I have with CMOS video cameras is when lightning strikes and is visible for less than the amount of time the sensor can create the image the lightning is blown out due to the rolling shutter effect.

Example above from a chase a few days ago. Top half has been over exposed then corrected half way down. Doesn't make for a good screen capture or video for that matter!!!

I know CMOS cameras are cheaper to make and use less power making the battery life longer but as a consumer why are we putting up with it? We are buying a cheaper and less quality product but as long as it has HD on the box people don't seem to care. This inst the only problem with CMOS cameras, jello-cam (worst on cheap cameras) and the skew effect are both deal breakers to me. I had a quick browse at B & H online and it would seem that about 80% of the market now is CMOS and any good CCD Cameras are now over $2000.00 and climbing very quickly.

I guess I may have to just suck it up, live with a lesser quality Camera or look at mortgaging a small country to buy a decent CCD video camera!

 

[Bill Hark]

You may be able to find a Sony Z or FX1 that shoots HDV video with CCD. Just remember that you will still be dealing with tapes.

Bill Hark

 

[STexan]

I've decided the next opportunity, I'd shoot video with my Canon 5D mII (or my 7D) and see how it dealt with lightning strikes in comparison to my little Sony Camcorder. Anyone have any input regarding shooting storm video with high-end cameras? My main issue is dealing with maintaining precise focus. (and I may be missing something as I've not done much video work with my camera). I have a wide variety of quality lenses, both primes and zoom, if lens selection makes a difference .

 

[scott r currens]

Unfortunately the SLRs have the same rolling shutter issues when shooting video.

 

[STexan]

After doing some more reading about shooting video with DSLR, there are mixed reviews and opinions, and quality video seems to be possible perhaps in good lighting, otherwise it can be hit and miss. Also, having the mirror locked up in very windy conditions may make for many additional costly trips to the camera guy for sensor cleaning. But, as one who is more interested in capturing full frame stills than video, and who rarely shoots with a camcorder ... I may still end up pressing the video record button on occasion just to see what happens but I just don't care much for video still captures, just the same but I realize they are better than nothing in applicable circumstances.

All that said and back to the original point of the OP, it does appear that one will have to spend upwards of $2k to get the great light capturing, rapid exposure compensation, and focusing requirements sought.

 

[Skip Talbot]

With the DSLR's, you can drop the recording framerate, the Canon Magic Lantern mod allowing you to go down to 1 fps or less. The chances of the strike occurring between frames is significantly lower with a low frame rate (but of course it can still happen). This doesn't help much if you're trying to shoot real time video as you wind up with a sped up timelapse, but if you have your camera tripodded for structure, you'll probably see a lot less frame tearing with a lower framerate, as well as benefit from other advantages such as better low light performance and smoother motion.

 

[Michael Thompson]

The last of the consumer grade HD video cameras with CCDs and Global shutter were the JVC HD 7, 6 and 5. Used, they can be got on E bay for $200-$400.

There have been some very negative reviews about these cameras however - poor low light, unusual HD video format, poor resolution for HD.

I have a Sony PJ760 ( same as the CX760) and love everything about it except the rolling shutter. Its stabilisation is a dream, and stills straight from video frames rival some of my past digital cameras (at smaller sizes). It has a nice wide lens as well and 96GB of flash memory. I used to buy Panasonic back in the SD days, but found that Sony had more accessible options for manual focus. I always leave my video cameras locked into landscape mode.

Here are examples from the Sony 760 - straight from a video frame.

 

[STexan]

those are some nice frame captures. What video mode do you shoot in where those were taken from?

 

[Michael Thompson]

those are some nice frame captures. What video mode do you shoot in where those were taken from?

I shoot in 1080 / 50P, the only other setting is landscape - for the infinity focus, nothing else. I will however experiment with dropping the shutter speed to get better lightning stills.

Like all supplied software , the supplied Sony software (PMB) is pretty useless except for one thing, it seems to extract the best from still frames.

 

[Mark Ellinwood]

I did a lot of research while looking for a new camcorder this past fall, and while I did have my heart set on getting CCD I ended up going with CMOS instead. Once you get into the next higher price bracket (approx $1000-3000), the rolling-shutter effect is fairly minimized. When I was deciding on a new camcorder, I was split between getting the Panasonic AG-HMC150 and the AG-HMC40... the 150 has 3 CCD 1/3" sensors and the 40 has 3 CMOS 1/4" sensors, so the 150 has the larger sensors that are better in low light, but it doesn't shoot full frame (it upscales to 1920 from 1440) and it was heavier and more expensive. I looked at a bunch of test footage from the 40, and you really can't see much of a rolling shutter issue. Big plus with both of these camcorders is they record straight to SD in the AVCHD format, so there's no tapes and the format works great on Premiere.

If you really want those lightning stills to come out, grab a CCD camera, but be willing to shell out the extra cash. Personally, I want to focus more on getting the sharpest, clearest day shots as possible, which is why I decided that a solid CMOS camcorder was "good enough" for me.

 

[Olivier Staiger]

using a Canon EOS 600D ( T3i ), yes the CMOS has rolling shutter issues on lightning, but sometimes I still get lucky, even if I have to cut / crop some of the full image.

the full videostill image is visible here : http://www.wetter-foto.de/images/upload/orig/D6mRPc.jpg and you can see the rollingshutter mishap at bottom near the pinetree.

 

[Skip Talbot]

Shooting in 24p if your camcorder supports it instead of 30p or 60i/p may help reduce frame tearing from the rolling shutter a bit too.

 

[STexan]

Shooting in 24p if your camcorder supports it instead of 30p or 60i/p may help reduce frame tearing from the rolling shutter a bit too.

That makes sense ... 20% fewer frame separations per second. Does that not affect the perceived video performance or the viability of being "true HD" insofar as the video output possibilities?

 

[Skip Talbot]

Does that not affect the perceived video performance or the viability of being "true HD" insofar as the video output possibilities?

Your motion will be blurred a bit more because of the lower framerate, but many videographers like that format because it's the same as film and can produce an image that's more film like than what you get with video at higher or interlaced framerates. You also benefit from better low light performance from having the shutter open longer. 24p is a "true HD" framerate. In fact it's the highest progressive framerate a 1080 Blu-ray disc can support. There is no 1080-30p or higher Blu-ray. You'd need another format to get higher progressive framerates (like using your computer and an HDMI cable). Sorry for diverging from the main topic.

 

[Robert Edmonds]

From what I remember from my instrument class. CMOS will always have a higher read noise, but the amount of time it takes to read the chip is shorter and you use less power. Thus, CCD has the benifit of lower read noise, but longer read time and a greater drain on the battery. I know this is a video thread, but for photography I would always pick CCD since I like lower noise. Unfortunatly, every camera maker pretty much produces CMOS DSLRs (so they can put in a 'bigger' sensor [ie more megapixes], but still have the comsumer use a small battery and not complain about the batter life of the camera). Unless you can pay lots of $$$ for some fancy digital back to a medium format camera.