Settings for dynamic range

TimurCivan

TimurCivan

Director of Photography
Staff member
What can you do to extend the dynamic range as far as possible? Like i have a theory, if yo ushoot cinegamma, then increase the Master Ped, to like +5 - +10
and you stop down till nothing over exposes, i think, it should preserve tons of detail everywhere? What you think? then you can add some contrast in post, and hope full reduce the milky look while keeping detail all over the place.


I am gonna try it and post some grabs so you can see if there is any difference..... cause now im just curious.
 
ok herewe go. Heres the setup. I have three lights, 2 X 250 watt halogens evenspaced apart on both sides of me at about 8 feet away. they light everything in thescene that you can see. I then took a 200W spot lamp and held it close to my face, so my face would overexpose. I then shot a couple seconds of footage, with the followingsettings. 24P Cinegamma, MAsterped -5 and F2.8. I then stoppeddown to F11 until my over exposed face wasnt reading over exposed anymore, using the 100% zebra. I then rpeated the process using the settings, 24P Cinegamma, Masterped +8 and F2.8 => F11 with the same exact lighting conditions. I then, imported to vegas, and have baseline grabs of each setting. I then added the exact same amount of contrast to both video streams, and then added contrast to the MAsterped +8 until it matched the masterped -5 grab.

Ok these two are the Baselines.






This is the comparison of the same image with the intense face light, overexposure.
Still F2.8



This is a comparison of the face properly exposed. with the two MAster ped settings.
F11



Ok now i added the same amount of contrast to both images. +.2 contrast in Vegas.



Now what i did was, i added contrat to the MP +8 grab until it matched as close as i could get it to the MP+5 with +.2 contrast.
It actually looks like there is a tiny difference in the picture. look at the base of the flower pot, and the leaves in the plant, where the arrows point. Now i was thnking there seems to be a littel bit of over exposure in my face, but i think it comes from boosting the contrast higher to match the black level of the side table in the back. Now this wasnt perfect, but it actually seems to have spread the Range a Tinytiny bit further. then again maybe i fuc*ed up. i dunno? Barry what you think?

 
by the way anyone know of a better free image hosting program, this stupi d thing wont let you post images directly.... its realllllly pissing me off.
 
damn it, the site isnt bringing me to the pics, I really want t see them too...

check your links and see if it is just me, which I am sure it is
 
umm... i opened an account on myspace, free hosting of photos, and trust me, I dont use it for the stupid popularity contest reason little teenagers use it for, give that a try
 
Did you test getting the same contrast in camera, because im almost certain that you will get the same contrast result by bringing the MP to about -7, and possibly adding the ND, with adjusted iris, for the shots with the light blow out.
 
if you reduce the MP to -7 you lose the detail inthe dark areas, i am trying to figure out if by using a higher MP, if we can retain the data, instead of crushing to black. Hopefully keeping some information inthe area that would be black, if yo uused a low MP number. Then add the contrast later, whereit wont destroy as much on the data. so it will remain contrasty, but still have image information in the darker areas.

Idunno it was a test. Let Barry look at it, see what he thinks.imma send him a message asking him to look at it. see what he thinks.

But it will try that, actually see what ahppens. cant do it now though too tired.
 
I did this sort of same thing on a short. I cranked the master ped all the way to + 15 adjusted for the high lights and brought contrast back to the scene in post. Treated it like film. Over rated the film to it's max and timed it in the telecine. Same principle here but with less results. I kept the highlights under control and the shadow area from going to dark rather quickly. It was a great thing to do in a pinch but would of like to of had some more control in the first place
 
Intriguing, but I think it's kind of six-of-one, half-dozen-of-another. The best thing to do for increasing dynamic range is to use CineGamma and keep your highlights from blowing out. The Master Pedestal seems to give the full range of shadow detail while not crushing shadows when set to about -6. Raising it up washes out the shadows, but doesn't necessarily produce more detail in the shadow areas.

Remember that video has a lot better tolerance for underexposure than it does for overexposure. Don't let your highlights clip, and then spray some light into the shadows. Raising the master pedestal will turn your blacks to gray, but won't necessarily add any detail that isn't already there (unless you have your master ped set artificially low, such as -10 or so).
 
hmm soo it was just an optical illusioon... damn i thought i was onto something.... so much for a poor kid with hopes of becoming a moderator.... I kid i kid. That will never happen, lol

thanks for lookin though!!!
 
x2,

I like your experiment. I like the theory of shooting video like color reversal film also. keep going, try it with a "chip chart" too. This may give you easier-to-judge results. I made a chart using compressed charcol and white paper.

-ab
 
you know i just realised the only benefit this offers. It only increases the DR if youre tweaking in post. Out ofthe camera, barry is totally right. it does nothing. but its whne you drop MB or Celluloid or some other film look on it, that it helps. beacuse thoes add somuch contrast, if the darker parts are nearing black, they are gonna blow out black. here is an example. Now keep in mind i pushed the master ped up unnaturally high. but i think a ped of +2 or +3 would be great for using a plug in like magic bullet, and preserving deatail all over.

the first two are master ped -5
thesecond two are the +8

This is a -5 with standard Vegas version of MB, Color reversal


This is -5 with a custom MB look


This is a +8 with color reversal


and the +8 wit hthe other MB look


i dunno its an experiemnt
 
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