OK - so we know we're supposed to auto black balance when changing temperatures and major ISO changes, but do we really need to remove the lens and attach the body cap, or is it enough to attached the lens cap and leave the lens on?

Oops, C100 was supposed to be in the title too ;)

i don't bother with the body, and it's likely they're just saying what's more foolproof, but if the screen is black, it should be good

I just put a lens cap on, although I try to find a dark place if I can.... Seems to work.

No problem with doing ABB with the lens cap on as long as there is no light leakage around the cap. I also close the aperture down all the way as a little extra light leakage insurance when I run ABB with the lens cap on.

Does anyone here subscribe to CML? There's been an interesting debate about nomenclature regarding the 'get the camera to do something geeky with the body cap on'. Bottom line is that it isn't quite as simple as a an Auto Black Balance.

Some cameras are looking for stuck pixels, others are trying to look at 'Fixed Pattern Noise' and I think this is what the C100 is doing, hence the official need for an 'ABB' née 'FPN' routine. Other things that are taken into consideration are the temperature of the system (versus the temperature at which the previous FPN measurement was taken), and (apparently) gamma radiation.

As for doing an ABB on every ISO change, does that equate to the same thing every time we kick in more gain? Some of us don't 'do' ISO. This might be one step beyond for most people - just do an ABB before each setup or after a location change. Lens cap with the microfiber cloth or a bit of black-wrap over it.

I´m thinking about getting this camera for filming weddings, corporate events, music videos etc. What is all this about setting the ABB every time you change the ISo or gain? That sounds really impractical when filming events. How does that work in reality?

You can get away with it, but you should get into the habit of ABBing at the start of any shoot, when you move from one temperature zone to another, and perhaps when you significantly change your setup (moving from one location to another). Changing Gain/ISO is one step beyond for event videographers (I count myself in that group).

If you don't, you may find that you get vertical streaks of noise pattern in your images. In such situations, a good denoise filter will fix this - but takes ages to render.

This blog post may help: http://mattdavis.wordpress.com/2014/01/12/c100-noise/

Thanks for the replies / feedback.

I've certainly seen some better quality / lower noise when doing regular ABB on the C100, something I've got away without doing very often on other cameras.

For corporate work it's not really a problem and it really doesn't take that long, but for live events I often have to skip it, which is a shame given what the camera is capable of when done right.

How long does it take? How does it affect the images apart from noise? I mean, is it alright to film the entrance into an interior, e.g. a church, without doing the ABB and once things have settled down do a quick ABB. Does it create a big difference between images? Does only affect noise or colors as well?

Basically, if you don't BB... THE WORLD WILL END

i hope you get my sarcastic point, the world will not end if you don't BB, nor will your image look destroyed, think of BB as a way to get the best image, but even without it, the image is already outstanding, so if you have time, do it, if you risk missing a shot by doing it, DON"T.

it does take a painful number of seconds for it to complete the process, and in many cases you probably won't even notice the difference, it's basically image insurance.

Basically, if you don't BB... THE WORLD WILL END

lol,
Got to add it to the list of world ending phenomena!
Thanks,
that´s what I wanted to know. I suppose it´s best practice but not always possible.