Help needed with S-LOG exposure at DVinfo.net

Mark McCarthy · March 20th, 2012, 05:59 AM

Hello all. I think I am getting to grips with exposing for S-LOG gradually but would appreciate some guidance.
My indoor trials seem to be better than my out doors trials at the moment.

My main unknown is what levels I should allow the hottest part of the image to go on the waveform monitor when shooting outdoors. If I was shooting a scene with a bright sunny sky, should I keep the sky (hottest part of the image) at around 90ise, to keep all the highlight under control? Or should I limit the ISE to 80ISE whatever I am shooting? Is there a maxium ISE you should keep the camera under to retain all the information?

I think my indoor tests look better as there isn't so much of a contrast between in the scenes to control.

One more thing! Any tips on exposing with S-log for night time shooting?

Thanks in advance. Sparky

Peter G. Johnson · March 20th, 2012, 09:07 PM

Hello, Mark,

I recorded Christmas Lights in December around the house using s-log. The results were so good that I didn't worry about color grading it afterwards. I set the F3 on 5600K and 0dB with a clear filter. The greens and reds were particularly strong.

PMW-F3 Christmas Lights 2011 - YouTube The most impressive aspect of s-log is how well it handles 'noise.' The image is just so clear.

I also wanted to know if s-log was acceptable to be used without color grading, hence my earlier request:
http://www.dvinfo.net/forum/sony-xdc...-all-time.html

Alister Chapman · March 21st, 2012, 02:15 AM

The main concern is to get your mid ranges correctly exposed as generally these are the parts of the image that will be most noticed by the end viewer. Mid grey should be around 38% and white should be about 68-70%. That then gives you plenty of headroom for direct light sources such as the sky and reflections. That equates to about one stop under where you would expose your mid range compared to a conventional gamma.

S-Log goes up to 109% and there is no reason why you should not use the full range but as you get towards the high end of the S-Log curve there is an ever increasing loss of linearity so you need to keep the really important stuff as low down the curve as practical, preferably below 75%. But highlights, bright clouds etc can be allowed to go all the way to 109. Obviously, if you go over 109 then the image will be clipped, but I am happy to have bright clouds etc at 100%.

Mark McCarthy · March 21st, 2012, 01:55 PM

Thanks for taking the time out to advise. I have a three stop European shoot lined up next week so I'm really looking forward to using S-log out there along with a COOKEOPTICS COOKE S4 16MM lens to go alongside my 50mm and 85mm cp2. Will post results when edit's finished. All the best..

March 20th, 2012, 05:59 AM	#1
Mark McCarthy Regular Crew Join Date: Mar 2003 Location: Westcliff-On-Sea, Essex, England Posts: 154	Help needed with S-LOG exposure Hello all. I think I am getting to grips with exposing for S-LOG gradually but would appreciate some guidance. My indoor trials seem to be better than my out doors trials at the moment. My main unknown is what levels I should allow the hottest part of the image to go on the waveform monitor when shooting outdoors. If I was shooting a scene with a bright sunny sky, should I keep the sky (hottest part of the image) at around 90ise, to keep all the highlight under control? Or should I limit the ISE to 80ISE whatever I am shooting? Is there a maxium ISE you should keep the camera under to retain all the information? I think my indoor tests look better as there isn't so much of a contrast between in the scenes to control. One more thing! Any tips on exposing with S-log for night time shooting? Thanks in advance. Sparky

March 20th, 2012, 09:07 PM	#2
Peter G. Johnson Regular Crew Join Date: Jul 2009 Location: Melbourne Australia Posts: 87	Re: Help needed with S-LOG exposure Hello, Mark, I recorded Christmas Lights in December around the house using s-log. The results were so good that I didn't worry about color grading it afterwards. I set the F3 on 5600K and 0dB with a clear filter. The greens and reds were particularly strong. PMW-F3 Christmas Lights 2011 - YouTube The most impressive aspect of s-log is how well it handles 'noise.' The image is just so clear. I also wanted to know if s-log was acceptable to be used without color grading, hence my earlier request: http://www.dvinfo.net/forum/sony-xdc...-all-time.html __________________ youtube.com/petejohn4 (Moving Imagery = Ultimate Expression) Last edited by Peter G. Johnson; March 20th, 2012 at 10:43 PM.

March 21st, 2012, 02:15 AM	#3
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Re: Help needed with S-LOG exposure The main concern is to get your mid ranges correctly exposed as generally these are the parts of the image that will be most noticed by the end viewer. Mid grey should be around 38% and white should be about 68-70%. That then gives you plenty of headroom for direct light sources such as the sky and reflections. That equates to about one stop under where you would expose your mid range compared to a conventional gamma. S-Log goes up to 109% and there is no reason why you should not use the full range but as you get towards the high end of the S-Log curve there is an ever increasing loss of linearity so you need to keep the really important stuff as low down the curve as practical, preferably below 75%. But highlights, bright clouds etc can be allowed to go all the way to 109. Obviously, if you go over 109 then the image will be clipped, but I am happy to have bright clouds etc at 100%. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

March 21st, 2012, 01:55 PM	#4
Mark McCarthy Regular Crew Join Date: Mar 2003 Location: Westcliff-On-Sea, Essex, England Posts: 154	Re: Help needed with S-LOG exposure Thanks for taking the time out to advise. I have a three stop European shoot lined up next week so I'm really looking forward to using S-log out there along with a COOKEOPTICS COOKE S4 16MM lens to go alongside my 50mm and 85mm cp2. Will post results when edit's finished. All the best..