setup level
 

i'm a xm2 owner and i wonder if any of you can tell me about the setup level: what is it exactly? does it have anything to do with shadows? how do you preset it?
thanks
pietro

The subject has been discussed a number of times, so please
use the search function in the upper right corner (or follow the
link in my signature).

Setup level basically tells the camera to shift the light with the
amount you set. Normally this is used to get a NTSC broadcast
safe picture (IRE floor). If you lower the setting you will get
blacker blacks indeed, but your image will not longer be broadcast
safe.

Consult your manual on how to change the setting.

Re: setup level
 

<<<-- Originally posted by Pietro Jona : i'm a xm2 owner and i wonder if any of you can tell me about the setup level: what is it exactly? does it have anything to do with shadows? how do you preset it?
thanks
pietro -->>>

Pietro as you are using an XM2 this is a PAL video standard camera as distinct to a NTSC American standard and as such the setup is not really relevent to you as it relates to a function of the NTSC signal that does not happen in Pal.

Regards, Cliff Elliott

Indeed, I missed that you are from Italy. With a PAL camera you
can move the setup slider all the way to the left (as I have done
with my XL1S). I don't know if this feature is under custom presets
(as it is on my XL1S), if so, remember to actually ACTIVATE/CHOOSE
that preset when shooting! Otherwise it will do nothing.

actually the setup level is one of the possible custom presettings in my XM2.
i read some of the previous posts about this topic but still don't get the point. to the left the image is darker and to the right it is brighter, but i've found it a bit noisy, like a kind of gain. i wonder why canon nearly doesn't mention it in the owner's manual...
how do you preset it, by the way, and why?

It should not be noisy, unless you are shooting perhaps in an
automatic mode or automatic gain. I'm not sure that I can explain
it better than I already have. If you understand RGB values then
you know complete black is 0,0,0. If you raise the setup level
then black will become 16,16,16 for example thus making it a bit
of gray. Just turn the setup level all the way to the left for an
increased exposure range and nice rich blacks (for PAl camera's).

This is in preset because you can have multiple presets to choose
from (for different shooting conditions or different persons using
the camera for example). Since I'm only using my camera and it
is used for the same kind of work I only have one preset.

I don't know how you choose and enable your preset on the GL2.
On my XL1S I have buttons to do it and it will show in the
viewfinder that a certain preset is selected.

thanks rob
i have no problems in choosing and enabling preset on the XM2.
i'm shure i found the setup level to be noisy when raised (full right-brighter image) using no gain (manual). anyway what you say is interesting. like: using a low setup for deep darks and still having a bright image by overexposing if needed... is it possible, does it make sense?
i'll do more shots...

Well, you should never actually over-expose. But if you lower the
setup level you will gain a larger exposure range and thus your
hightlight will blow a little bit less.

exposing again, not overexposing. i used the wrong word.
my fault, it's a language problem...
i mean: starting from a correctly exposed image, lowering the setup level will make the blacks more black and the whole picture a bit darker. by exposing a bit more (not overexposing!) i can get the same whites i had before and keep the blacks black?!?
thanks again

That's the idea indeed.

As I understand it, and I don't know much about PAL, but in NTSC, the IRE range is from 0-100. This numerical range is mapped to RGB signal in a number of ways, but, in broadcast NTSC it is 16-235 instead of the conventional RGB of 0-255. So, the difference comes in the mapping of 0-100IRE into 16-235 or 0-255. Obviously, 100/(235-16)=.46 vs. 100/255=.39. The number of discrete steps is 18% smaller for conventional RGB mapping than for the NTSC mapping. The end result is a possibility for more banding and reduced continuous looking color variation with the reduced bandwidth of NTSC.

What this all means is that setup level doesn't really affect the highlights of an image. What it does do is affect the shadow depth and the total bandwidth available to work with. If you intend NTSC broadcast, you'll just have to accept the lower bandwidth and degraded image by setting a moderate setup level....I set -2 as equivalent to RGB16. If you never intend NTSC broadcast, then set the minimum, I think it's -4. If you set -4 then display on an NTSC monitor, you'll find the blacks are muddy looking because the NTSC circuitry has clipped the true blacks at RGB 16.

Some NLE's will allow a remapping of a true 0-255 RGB signal to 16-235. If this is the case, you can always shoot with minimum setup and re-map in your NLE.

So -2 on the XL1s custom presets will yield you the deepest blacks that you can still have in an NTSC broadcastable environment?

that's how it is on my Xl1s

Thanks.