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-   Canon XL and GL Series DV Camcorders (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/)
-   -   background lighter than subject (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/91689-background-lighter-than-subject.html)

Jonathan Kirsch April 30th, 2007 01:03 PM

Hi Nic,

Using Safari, I clicked on your link (is that all I have to do?) and it gave me this message:

Not Found

The requested URL /canon/DemoMovie/XL2_demo_tour.mov was not found on this server.
---------------
Apache/2.2.0 (Unix) mod_jk/1.2.15 mod_ssl/2.2.0 OpenSSL/0.9.8d Server at syndicate.tentoe.com Port 80


Any ideas? I don't want to add a download manager to my apps, but I will if necessary.

Jonathan

Jonathan Kirsch May 1st, 2007 09:48 AM

Never mind. The link FINALLY worked. I had to use Firefox to actually download it, because it kept freezing Safari.

Thanks for the link, Nic.

Jonathan

Jonathan Kirsch May 10th, 2007 09:43 AM

Just bumping this up to the top since my question has not been answered. After you apply the preset in the camera (according to the demo movie), how do you know what f-stop to use to make it come out correct in post? Do you just set it where the meter in the top left corner is in the middle? I tried it a few times and then tried to correct it in post (with the contrast), but it didn't work. Anyone using FCP tried this and want to tell me how to correct it in post?

Thanks.

Jonathan

Cole McDonald May 10th, 2007 12:16 PM

I would use the iris for exposure (rather than shutter speed), zoom in, expose correctly for the subject. Zoom back out, click the iris wheel 1-2 clicks darker to help with the background, then adjust the levels in post back up to normal. In DV, underexposing slightly will help deal with the lattitude problems. You can then adjust the levels in post to correct. I always underexpose slightly.

Jonathan Kirsch May 10th, 2007 12:33 PM

Thanks, Cole. Yeah, I meant using the iris, not the shutter. I was shooting 30p and kept it at 1/60. Problem I've found is that the picture gets a LOT darker after zooming in...like the iris is closing up (even in manual mode). How close you talking about zooming in to expose for the subject? Cuz it's tough for me to predict what the right exposure is when zoomed in (since it's a lot darker than it should be). Does that make sense?

Jonathan

Matt Newcomb May 10th, 2007 12:40 PM

Quote:

Originally Posted by Cole McDonald (Post 676693)
I would use the iris for exposure (rather than shutter speed), zoom in, expose correctly for the subject. Zoom back out, click the iris wheel 1-2 clicks darker to help with the background, then adjust the levels in post back up to normal. In DV, underexposing slightly will help deal with the lattitude problems. You can then adjust the levels in post to correct. I always underexpose slightly.

How do you adjust the levels in post? I know of the brightness/contrast but that doesn't seem to give very clean results.

Cole McDonald May 10th, 2007 01:04 PM

Jon...depending on the camera, the iris will change as you zoom, so just enough to set exposure automatically, or don't zoom in and eyeball it (eeks). Keep an eye on the f-stop numbers as you zoom in, if they change, then that's too far ;)

Matt...depending on the editing software you use, there's probably a filter called Levels you can apply to the clip.

Cole McDonald May 10th, 2007 01:07 PM

may also be called gamma.

Jarrod Whaley May 10th, 2007 01:27 PM

I just thought I'd add a few things here.

First of all--and this might sound somewhat counterintuitive--you want to set your exposure to the bright background rather than your subject. You'll never in 1,000 years be able to pull detail out of an overexposed shot, but you can usually dredge up a bit of picture information from an underexposed area (at the expense of added grain: see below).

Also when you're shooting, it will really help you out later if you bump up the color gain a bit--the gamma corrections you'll be doing later will tend to wash out the color, and any extra color information you can get while shooting will help you compensate for this.

When you adjust the gamma in post, don't expect a completely clean image. Since you'll basically be bringing up the gain on the darker areas of the shot, you're going to be adding some grain--in many cases, quite a bit.

Good shooting technique and a little practice will help you minimize the need to bump up the gain quite as much, but you're going to end up with kind of a grainy image no matter what you do. There just isn't enough dynamic range available to get a completely clean image.

One thing that helps somewhat in post is to play around with masks and luminance keys so that you can separate the subject from the background, but it can be a very tricky thing to pull off, it can take a lot of time, and you're still not going to find perfection.

The best tip of all in regard to these kinds of high-contrast situations--which I realize is that obvious thing that no one wants to hear--is to properly light the dark parts of the image. You don't necessarily need a huge or expensive lighting kit, just a little resourcefulness and creativity. The suggestion to start with a reflector in these types of situations is a good one. If that doesn't work, start lighting up daylight-gelled 300w incandescent bulbs from Ace Hardware or something.

Cole McDonald May 10th, 2007 01:41 PM

lighting the foreground better is the best way of doing this...either with bounce or lights.

Be careful exposing for the background that you don't push the forground to straight silhouette, that'd be worse than blowing out the background a bit...unless you want a silhouette, which doesn't sound like what you're asking for...so splitting the difference is the best bit...stay toward the subject for exposure as raising exposure on dark stuff past a stop or two will start to produce tons of video noise...which just looks icky.

Jonathan Kirsch May 10th, 2007 02:08 PM

Thanks for the continuing tips...

Jarrod...I am not gunning for perfection in post. I know that if I wanted it perfect, I'd shoot it perfect (in a perfect world...wow, that's a lot of perfects, eh? HA! ). Anyway, I'll try bumping up the color gain and the other tips you suggest. Unfortunately, the productions I shoot do not afford me the luxury of setting up lights...I don't even have a PA that can hold a reflector! I'm constantly on the move and can't carry everything by myself. So I am relegated to moving someone into the sun (or turning so they face the sun), near a light, by a window, or (ugh) using my camera mounted light. I'm just trying to make chicken salad outta chicken sh!t. :)

Also, I noticed that in the demo movie, when they show the original shot, then the post shot, the background NEVER CHANGES (that I can tell...the video is pretty compressed). Makes me wonder if it was actually shot with lights. I mean, if the contrast was increased, wouldn't the background in the post shot change at all?? Did they use masks? I'm sure there's an explanation and I'm just frustrated cuz I can't replicate it.

As for the debate between exposing for the background or the subject, I'm all for exposing for the subject, since that's the most important part of my pieces. BUT, to play devil's advocate, in the demo movie it looks like the background is exposed better than the foreground. Anyone else notice that?

Jonathan

Jarrod Whaley May 10th, 2007 02:36 PM

Quote:

Originally Posted by Jonathan Kirsch (Post 676769)
Unfortunately, the productions I shoot do not afford me the luxury of setting up lights...I don't even have a PA that can hold a reflector! I'm constantly on the move and can't carry everything by myself. So I am relegated to moving someone into the sun (or turning so they face the sun), near a light, by a window, or (ugh) using my camera mounted light. I'm just trying to make chicken salad outta chicken sh!t. :)

I often find myself shooting without help, like you, and also like you (from what I gather) I rarely have more than a few bucks to my name. You can put together some very basic lighting stuff for almost no money, though, and while you're right about it being harder to carry around and deal with on set and so on, it's definitely worth any extra trouble. No one to hold a reflector? Buy some cheap A clamps and gaff tape and stick your reflector to whatever's handy. Buy up a bunch of scoop lights and the highest wattage of bulbs you can fit in them. Make temporary flags and barndoors out of tinfoil if you can't afford true flags and barndoors (or even cinefoil, for that matter). Get some daylight gels and gaff tape them to coat hangers which are in turn gaff-taped to your lights. Whatever makes sense for whatever it is you're shooting. I'm telling you, if you just get a little creative you can jury-rig just about anything. Sure, you'll have more control and much less setup time with an expensive kit, but you can often get passable-to-great results with the cheapest stuff imaginable.

Quote:

Originally Posted by Jonathan Kirsch (Post 676769)
Also, I noticed that in the demo movie, when they show the original shot, then the post shot, the background NEVER CHANGES (that I can tell...the video is pretty compressed). Makes me wonder if it was actually shot with lights. I mean, if the contrast was increased, wouldn't the background in the post shot change at all?? Did they use masks? I'm sure there's an explanation and I'm just frustrated cuz I can't replicate it.

What they're doing there, like a previous poster suggested, is adjusting the gamma using a "levels" (which is what you'd use in Vegas) or similar plug-in rather than straight brightness/contrast adjustment. Vegas' Levels, for example, allow you to adjust gamma to small parts of the overall gamma curve--like only the dark part of the image, for example.

Quote:

Originally Posted by Jonathan Kirsch (Post 676769)
As for the debate between exposing for the background or the subject, I'm all for exposing for the subject, since that's the most important part of my pieces. BUT, to play devil's advocate, in the demo movie it looks like the background is exposed better than the foreground. Anyone else notice that?

Like I said, you actually want to expose for the background in this situation, even though it seems counterintuitive to do so. If you blow out your background, you're screwed--there's no saving it. But if you stretch your blacks and lower your master pedestal and setup level, you'll be able to bring out a pretty fair amount of detail in your shadows.

Jonathan Kirsch May 10th, 2007 02:49 PM

Thanks, Jerrod for the quick replies. I don't use Vegas, so I'll see what I can do in my app (Final Cut Pro).

Jonathan


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