Blowing out windows - suggested f-stop, zebra settings, gamma knee at DVinfo.net

Stephen van Vuuren · July 8th, 2005, 10:26 PM

I've got a shot tomorrow of women delivering a monalogue in front of a window that is getting afternoon sun at about a 45 degree angle. I want the window to blow out and her face somewhat silhouetted but want enough fill to see a few details, hot spots on her face.

The shots will be mostly max telephoto, fairly tight shots. I'm thinking of bouncing light for filll and using no lights other than sun.

I want to set zebras for highlights on face and window - also wondering best gamma and knee for blowing highlights.

Model would be "The Shining" although I realize DV just ain't film...

Bogdan Apetri · July 8th, 2005, 11:18 PM

My two cents although I am not a professional cinematographer...

Using the sun as a key coming throught the window is probably the worst nightmare - it changes all the time, intensity, direction etc. Hmmm... You have no real control over it if it's just the sun.

In THE SHINING as well as in BARRY LYNDON (another absolutely great example of blowing out windows and at the same time using them as the key) they used tracing paper on the windows (next to the windows in fact) and artificial lights outside. Great (although they had some trouble on a few occasions) as far as control is concerned.

But ok, you have a different scenario. If the sun is at a 45 degree angle (but for how long?...), this is the only good thing, you use it as the key and fill the shadows like you said. Be careful with blocking if you want the face to be silhouetted.

As far as the menus are concerned, I would decide right there on the set at what levels to set zebras and gamma. Theoretically, you should use between 90 and 100 for the zebra on the window (depending of how much you want them to blow out) and 80 or so on the face. BUT, my guess is that the window will go over 100 easily, easpecially with no control at all on the glass, so zebra becomes somehow pointless? It will show "clipped" anyhow, unless you fill like crazy to bring your window withing 90-100 range - and if you plan to bounce light, and keep the face silhouetted, that's impossible.

With gamma, just change between them after you set up and see what happens to the highlight detail. That's the best thing to do rather than choose the gamma that is theoretically best for extending or compressing the highlights range.

Anyway, just my humble opinion. Tough scenario!
Good luck!
Bogdan

Stephen van Vuuren · July 9th, 2005, 12:37 AM

Quote:

Originally Posted by Bogdan Apetri

Anyway, just my humble opinion. Tough scenario!
Good luck!
Bogdan

thanks for the thoughts - yes, the using sun rather than a huge set and buttloads of HMI's is a pain, but it's worth a shot (and it's for the DV challenge right here, so no time for tests etc.

Okay, here are some visuals using cheezy clipart:

Standard look:
http://www.stephenv2.com/before.jpg

What I'm going for:
http://www.stephenv2.com/after.jpg

Charles Papert · July 9th, 2005, 11:07 AM

Hi Stephen:

I would suggest shooting your footage so that it resembles the "before" footage and applying similar contrast curves in your NLE or After Effects as you did in your photo app to achieve the final results, rather than shooting the blown-out version in camera. The reason being that you will likely see more unpleasant artifacts from the camera if the background is completely blown-out than by goosing it in post.

Not sure which shot in "The Shining" you are referring to specifically. Remember that on film, a blown-out background will "bloom" naturally whereas on video, it creates a harsh separation to a foreground object exposed more normally. You could consider a Promist or similar filter that will "invite" the light to wrap the subject slightly, blurring that hard line.

Incidentally, the huge windows in the Overlook were indeed tracing paper as Bogdan described, backed by a huge array of photofloods. The results were stunning--most assume that the Overlook was a practical location (the interiors were 100% constructed on stage). Thus they were able to avoid any unpredictability issues with the sun.

Stephen van Vuuren · July 9th, 2005, 12:02 PM

Charles:

Thanks - Barry Green on dvxuser had similar suggestions to shoot more like the before shot and shooting with low gamma and lower detail to keep artifacts to a minimum. Thanks for confirming.

I have both Vegas 6 and AE Pro to post with, so I will aim for those results. So far, we have a sunny day here but clouds will pick up so we shall see.

Bogdan Apetri · July 9th, 2005, 12:41 PM

I completely agree with Charles and with Barry. Shoot more like the first picture, then temper in post. Low gamma is a very good suggestion but - depending on the actual conditions at the time of the shoot - I would still toggle between all the gamma settings first, just to make sure. Will you monitor? Low gamma is the theoretical approach, the conditions themselves will dictate what to use.

-----
yes, the using sun rather than a huge set and buttloads of HMI's is a pain
-----

Lol, I appreciate the irony! Good luck with the shoot Stephen.

Back to Kubrick, I have never seen windows so amazingly used in film, especially in The Shining but also Barry Lyndon (a personal favorite). In The Shining, they used 860 1000-watt, 110-volt Medium Flood PAR 64 lamps, mounted on 40-foot tubular scaffolding behind a large (80x30) custom backing made by Rosco (very similar to tracing paper) -- this only for the Colorado Lounge. This from American Cinematographer, Aug 1980. In Barry Lyndon they mainly used Mini-Brutes behind a special kind of plastic material, deemed better than tracing paper by John Alcott.

I am only mentioning this because you might use this approach, Stephen :-)

Stephen van Vuuren · July 10th, 2005, 12:09 AM

It went pretty well despite having lots of clouds and windows light levels changing 6 stops from beginning to end.

I ended up shooting exposing for shadows - leaving a little detail in the shadows, even though I was going to crush them back down somewhat in post, but if I needed the detail it was there. I tried to keep the window from being too hot using ND filters and iris, but sometimes the contrast was just too much, but changing clouds and setting sun meant window treatments etc. not practical.

So my raw footage looks somewhat like the before, except for no deep blacks - just muddy, but as you see, easily corrected in post without artifacts.

I did shoot low gamma, lower detail but as you can see when the window was very hot, edges did get rough, but for this piece, I can live with it. When window was very hot, I have some color fringing but should be able to minimize it in post.

Here on some quick samples - all I've done is just a 10 second Photoshop levels adjust:

http://www.stephenv2.com/pics/

thanks again for help and guidance

July 8th, 2005, 10:26 PM	#1
Stephen van Vuuren Space Hipster Join Date: Oct 2001 Location: Greensboro, NC Posts: 1,508	Blowing out windows - suggested f-stop, zebra settings, gamma knee I've got a shot tomorrow of women delivering a monalogue in front of a window that is getting afternoon sun at about a 45 degree angle. I want the window to blow out and her face somewhat silhouetted but want enough fill to see a few details, hot spots on her face. The shots will be mostly max telephoto, fairly tight shots. I'm thinking of bouncing light for filll and using no lights other than sun. I want to set zebras for highlights on face and window - also wondering best gamma and knee for blowing highlights. Model would be "The Shining" although I realize DV just ain't film... __________________ stephen v2 www.insaturnsrings.com Last edited by Stephen van Vuuren; July 8th, 2005 at 11:53 PM.

July 9th, 2005, 11:07 AM	#4
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Hi Stephen: I would suggest shooting your footage so that it resembles the "before" footage and applying similar contrast curves in your NLE or After Effects as you did in your photo app to achieve the final results, rather than shooting the blown-out version in camera. The reason being that you will likely see more unpleasant artifacts from the camera if the background is completely blown-out than by goosing it in post. Not sure which shot in "The Shining" you are referring to specifically. Remember that on film, a blown-out background will "bloom" naturally whereas on video, it creates a harsh separation to a foreground object exposed more normally. You could consider a Promist or similar filter that will "invite" the light to wrap the subject slightly, blurring that hard line. Incidentally, the huge windows in the Overlook were indeed tracing paper as Bogdan described, backed by a huge array of photofloods. The results were stunning--most assume that the Overlook was a practical location (the interiors were 100% constructed on stage). Thus they were able to avoid any unpredictability issues with the sun. __________________ Charles Papert www.charlespapert.com

July 9th, 2005, 12:02 PM	#5
Stephen van Vuuren Space Hipster Join Date: Oct 2001 Location: Greensboro, NC Posts: 1,508	Charles: Thanks - Barry Green on dvxuser had similar suggestions to shoot more like the before shot and shooting with low gamma and lower detail to keep artifacts to a minimum. Thanks for confirming. I have both Vegas 6 and AE Pro to post with, so I will aim for those results. So far, we have a sunny day here but clouds will pick up so we shall see. __________________ stephen v2 www.insaturnsrings.com

July 10th, 2005, 12:09 AM	#7
Stephen van Vuuren Space Hipster Join Date: Oct 2001 Location: Greensboro, NC Posts: 1,508	It went pretty well despite having lots of clouds and windows light levels changing 6 stops from beginning to end. I ended up shooting exposing for shadows - leaving a little detail in the shadows, even though I was going to crush them back down somewhat in post, but if I needed the detail it was there. I tried to keep the window from being too hot using ND filters and iris, but sometimes the contrast was just too much, but changing clouds and setting sun meant window treatments etc. not practical. So my raw footage looks somewhat like the before, except for no deep blacks - just muddy, but as you see, easily corrected in post without artifacts. I did shoot low gamma, lower detail but as you can see when the window was very hot, edges did get rough, but for this piece, I can live with it. When window was very hot, I have some color fringing but should be able to minimize it in post. Here on some quick samples - all I've done is just a 10 second Photoshop levels adjust: http://www.stephenv2.com/pics/ thanks again for help and guidance __________________ stephen v2 www.insaturnsrings.com

July 8th, 2005, 11:18 PM	#2
Bogdan Apetri Regular Crew Join Date: Oct 2003 Location: New York, USA Posts: 117	My two cents although I am not a professional cinematographer... Using the sun as a key coming throught the window is probably the worst nightmare - it changes all the time, intensity, direction etc. Hmmm... You have no real control over it if it's just the sun. In THE SHINING as well as in BARRY LYNDON (another absolutely great example of blowing out windows and at the same time using them as the key) they used tracing paper on the windows (next to the windows in fact) and artificial lights outside. Great (although they had some trouble on a few occasions) as far as control is concerned. But ok, you have a different scenario. If the sun is at a 45 degree angle (but for how long?...), this is the only good thing, you use it as the key and fill the shadows like you said. Be careful with blocking if you want the face to be silhouetted. As far as the menus are concerned, I would decide right there on the set at what levels to set zebras and gamma. Theoretically, you should use between 90 and 100 for the zebra on the window (depending of how much you want them to blow out) and 80 or so on the face. BUT, my guess is that the window will go over 100 easily, easpecially with no control at all on the glass, so zebra becomes somehow pointless? It will show "clipped" anyhow, unless you fill like crazy to bring your window withing 90-100 range - and if you plan to bounce light, and keep the face silhouetted, that's impossible. With gamma, just change between them after you set up and see what happens to the highlight detail. That's the best thing to do rather than choose the gamma that is theoretically best for extending or compressing the highlights range. Anyway, just my humble opinion. Tough scenario! Good luck! Bogdan

July 9th, 2005, 12:41 PM	#6
Bogdan Apetri Regular Crew Join Date: Oct 2003 Location: New York, USA Posts: 117	I completely agree with Charles and with Barry. Shoot more like the first picture, then temper in post. Low gamma is a very good suggestion but - depending on the actual conditions at the time of the shoot - I would still toggle between all the gamma settings first, just to make sure. Will you monitor? Low gamma is the theoretical approach, the conditions themselves will dictate what to use. ----- yes, the using sun rather than a huge set and buttloads of HMI's is a pain ----- Lol, I appreciate the irony! Good luck with the shoot Stephen. Back to Kubrick, I have never seen windows so amazingly used in film, especially in The Shining but also Barry Lyndon (a personal favorite). In The Shining, they used 860 1000-watt, 110-volt Medium Flood PAR 64 lamps, mounted on 40-foot tubular scaffolding behind a large (80x30) custom backing made by Rosco (very similar to tracing paper) -- this only for the Colorado Lounge. This from American Cinematographer, Aug 1980. In Barry Lyndon they mainly used Mini-Brutes behind a special kind of plastic material, deemed better than tracing paper by John Alcott. I am only mentioning this because you might use this approach, Stephen :-)