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-   -   CSTM Presets (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/13419-cstm-presets.html)

Mark A. Foley August 18th, 2003 11:40 AM

CSTM Presets
 
Curious about what CSTM presets you maybe using to to tweek the XL1s...
Mark

Rob Lohman August 20th, 2003 08:39 AM

I have a custom preset to lower the SETUP LEVEL to its lowest
setting (IRE floor of 0 instead of 7.5). This produces much blacker
blacks but can be illegal for NTSC broadcast though. Keep in
mind you actually need to select a preset before it becomes active!

Some other people use it for changing the sharpness a bit etc.

Christopher Hughes August 21st, 2003 01:57 PM

What setting do you use or like using on set-up level? for:
1) Making Films
2) Run and Gun shooting

Or do you just the set up level in the centre at all times? Or what settings and when?

Just for PAL, I'm not bothered about being legal for NTSC broadcast standards.

Rob Lohman September 9th, 2003 08:07 AM

I always use a 0 IRE floor (slider to the left side)...

Josh Bass September 9th, 2003 12:43 PM

I thought someone else had posted the putting the slider two notches left of its central position was the equivalent of the 0 IRE. Anyway for NTSC broadcast, won't the transmitter push the level back up to 7.5 anyway?

Christopher Hughes September 9th, 2003 04:34 PM

I have been told that -2 notches is 7.5 IRE and so FULL MINUS notches is 0 IRE.

But in USA (NTSC) country having 0 IRE is illegal, so I guess that MINUS 2 in a way would/could be stated as your (NTSC) 0 IRE equivalent.

Rob Lohman September 9th, 2003 05:04 PM

I don't know too much about NTSC. But in theory that wouldn't
be broadcast safe indeed. I'm in PAL land and don't have to
worry about that. So my slider is all the way to the left. If you
are only doing web work (and perhaps DVD?) there is no worry
for NTSC either.

Josh Bass September 10th, 2003 12:26 AM

Well, wait. If -2 notches is 7.5 IRE, then what is the default setting? Am I being cheated out of extra contrast?

Rob Lohman September 10th, 2003 03:05 AM

I think this is best answered with a set of scopes to see what
happens to the output signal... I'll see if I can get a test done
with my PAL XL1s tonight

Jeff Donald September 10th, 2003 06:12 AM

It is illegal to broadcast NTSC video with a level below 7.5 IRE. Most people do not intend their video to be broadcast. So, in effect they are losing part of the signals bandwidth by leaving setup at 7.5 IRE.

Video without the proper setup is given the proper setup before broadcast by TV stations. This is done rather crudely and will not always provide the best image quality. If you think there is a chance your video will be broadcast, it is probably best to shoot with the proper setup. Before adjusting the setup you might want to refer to Adam Wilt's site for his discussion of setup.

Tony Hall November 7th, 2004 12:35 AM

<<<-- Originally posted by Rob Lohman : I think this is best answered with a set of scopes to see what
happens to the output signal... I'll see if I can get a test done
with my PAL XL1s tonight -->>>

I tested this myself in Vegas by importing video shot with the sider all the way to the left, the slider two notches to the left, and the slider at it's default position. The Vegas waveform monitor showed:

slider all the way to the left: 0IRE
slider two notches to the left: 4IRE
default position: about 7.5IRE

It's logical to assume that the slider all the way to the right is 15IRE.

I'd like to know what the point of having all these options is. Why not just offer 7.5 and 0.

I just did my test again because I suspected that I had made a mistake and it appears that there is no absolute answer. I get different results everytime I shoot something. I'm going to try it again using a grey card to set my exposure and then shoot a chart to see what happens.

Tony Hall November 7th, 2004 03:56 AM

It seems that the default setting probably has a floor of 0IRE and anything below that crushes blacks by clipping them below the 0IRE floor of DV and anything above the default position washes out the blacks and reduces contrast. The only sure-fire way I could find to test what the real floor is was to just leave the lens cap on and record.

Here's what the -6 setting looks like on the Vegas waveform monitor:
http://img106.exs.cx/img106/2741/_6.gif
I think this might be useful if you were to shooting something really low contrast.

Here's what the default setting looks like on the Vegas waveform:
http://img106.exs.cx/img106/7784/default.gif This one appears to be close enough to the 0IRE floor... just slightly above it probably for a reason.

Here's the +6 setting:
http://img106.exs.cx/img106/6513/142.gif
This plus settings seem to increase the brightness disproportionally high. It's very washed out and low contrast.

Rob Lohman November 7th, 2004 08:59 AM

Perhaps it would be better to make your footage broadcast safe
in your editing environment (I seem to recall that most NLE's have
a broadcast safe filter for this, not sure since I don't need to use
that here)?? Then you can just shoot with the maximum latitude
(ie, slider all the way to the left) and then conform it after you've
done editing, color correction etc. (which might introduce new
problems?).

Tony Hall November 7th, 2004 03:00 PM

That's the thing, the slider all the way to the left doesn't give maximum lattitude. It crushes the blacks and you actually loose information in the shadows. Maximum lattitude is actually the default position and maybe a notch to the left.

Since the DV format always has a floor of 0 IRE no matter what your camcorder setting is, if you put the slider all the way to the left, it makes the "virtual" floor below 0IRE thus causing much of your blacks to get clipped depending on what you're filming and your exposure.

I don't care about being broadcast safe for what I'm doing. If my footage is ever broadcast, then the network can convert it.

I was just playing around with it all last night and came to the above conclusions.

My advice is to leave the slider in the default position unless you are trying to specifically darken or lighten the blacks. I've got DV Rack on the way, so I'll be able to try it live when it arrives.

Josh Bass November 7th, 2004 03:17 PM

On my last short, I meant to lower the black two notches left, 'cause I thought it made it more "filmy". I'm glad I forgot to do it until near the end of the day, because after seeing it in the monitor, I went back to default again.

Pulling the blacks down, in my experience, makes caucasian skin tones (and therefore, I'm assuming things similar to that color range) go more orange. . .not pretty.


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