DV cameras and exposure

[ZombieFan]

Hey guys. First time poster here but been a long time watcher and have finally plucked up the courage to make a post. Go me :lol:

I have just completed my first year at university on a film studies course and now have eight weeks off to do what I want. What I want to do is make films. When I was at uni I worked with the sony fx1 which I really liked and am saving up to get one.

Until then I am going to be using a mates canon xm2 to make some shorts whilst away from uni but have a few problems concerning exposure. when I work with the fx1 I had the ability to hook the camera up to a broadcast monitor and work out the contrast levels etc through the special black bars located on the colour bars in the camera which helped me get good exposure, sadly I don't have this with the canon xm2 and so am having to rely on the zebra stripes. I know the bars indicate which parts of the picture are overexposed but when I lower the lower the exposure to get rid of all the stripes the picture seems underexposed and too dark. As well as this, when I have been able to get hold of a tv monitor to hook the camera up to, I don't have the special bars like the fx1 has.

what I want to know is if there is anyway to adopt the same method of the fx1 special colour bars through the xm2 bars and if I can't get hold of a monitor for my shoots, how i will know if my camera is exposed correctly with the zebra stripes on without totally getting rid of the stripes and having it appear underexposed. Hope I dont sound too much like a newbie

[Fulcifan91]

Contact LD-50 on these forums if he does not reply to this, he knows alot about cinematography.

[LouCipherr]

I bet 10 to 1 when he sees this post, he'll reply. LD-50 loves talking camera tech - and most of the time, the information he spouts makes my head wanna explode! I have no idea how he can fit all that in his skull.

LD!? Where the hell ya at? :D

LC

[MinionZombie]

Damn straight, that dude knows his cameras, gave me some good advice and help in decided what to go for for my new camera ... now it's a matter of waiting for Panasonic to hurry up and ship some more damn DVX100BE's to Britain!!! :| (Apparently some are coming quite soon, I'm getting my ass a reserve on one of those beauties).

Anyway, LD is the man for camera tech...:thumbsup:

[LD-50]

Hey guys. First time poster here but been a long time watcher and have finally plucked up the courage to make a post. Go me :lol:

I have just completed my first year at university on a film studies course and now have eight weeks off to do what I want. What I want to do is make films. When I was at uni I worked with the sony fx1 which I really liked and am saving up to get one.

Until then I am going to be using a mates canon xm2 to make some shorts whilst away from uni but have a few problems concerning exposure. when I work with the fx1 I had the ability to hook the camera up to a broadcast monitor and work out the contrast levels etc through the special black bars located on the colour bars in the camera which helped me get good exposure, sadly I don't have this with the canon xm2 and so am having to rely on the zebra stripes. I know the bars indicate which parts of the picture are overexposed but when I lower the lower the exposure to get rid of all the stripes the picture seems underexposed and too dark. As well as this, when I have been able to get hold of a tv monitor to hook the camera up to, I don't have the special bars like the fx1 has.

what I want to know is if there is anyway to adopt the same method of the fx1 special colour bars through the xm2 bars and if I can't get hold of a monitor for my shoots, how i will know if my camera is exposed correctly with the zebra stripes on without totally getting rid of the stripes and having it appear underexposed. Hope I dont sound too much like a newbie


I hadn't seen this earlier, so sorry for the late reply. The first thing I would tell you is that it is usually better to underxpose video by up to a stop. It is possible to gain up in post if absolutely neccesary, although not much, but once highlight detail is gone, its gone. So depending on how they are set, if you are seeing zebras in the shot, that means no detail is being recorded in that area. higher end cameras have Zebras that can be set to various levels, as a warning to back off rather than an indication of highlights that are already over. But the xm2 probably just has zebras that are set for 100 ire.If you have to stop down and the rest of the scene is underexposed, that means you have to add more light to those parts of the scene. You have to light to the stop rather than the other way around. What that means is, you have to choose the fstop you want to shoot at, and light the scene so that it exposed correctly when set at that fstop. However, I realize your budget may be limited, and since you are seeking advice on a horror forum, I think it is safe to assume you will want to shoot a number of scenes at night. It is difficult to balance out scenes like this with a very limited light kit. In order to get enough light on players to see them they have to be lit, but it's hard to do in a way that doesn't look "lit" if you are wide, or outdoors. If your stylistic vision permits, try to shoot high contrast scenes such as this tight, with light motivated by street lights, car headlights, even cigarettes in their mouths. These concepts may have been communicated to you in school, but if yours is like many american film programs, your instruction is long on theory and critical appreciation, and very short on technical how to, especially with regards to lighting and electricity. My other reccomendation, especially if you know how to read a waveform monitor, (and if you don't, learn how to if you plan on shooting a lot of video) is to use DVrack. It is a software package made by Serious Magic.

http://www.seriousmagic.com/

It provide a broadcast monitor, hard disk recorder, vectorscope, audio spectrum analyzer, waveform monitor, shotclock and more, all from your laptop. It's basically a flypack on your laptop, for a couple of hundred dollars. I wouldn't shoot dv without it, and the newer updates have support for dvcpro and dvcpro hd. The drawbacks are that it is pc only and you will need a laptop with at least higher midrange speed and graphics capabilities. There is also this

http://vidscopepro.com/

This is software that provides just scopes. I haven't used this software so I can't really comment on it too much. Once again, PC only. If these solutions cannot work for you, because of expense, or because you are a Mac diehard, you could try to get a used exposure meter for film, and learn to use that to set lighting ratios. Of course this is a tool for film, and it's use does not translate directly to video. Some believe it is pointless to meter for video, because a video camera could be viewed as the worlds most expensive lightmeter. But you could use it just to give you an empirical understanding of light levels within a scene, especially if you get one that reads out in lux. The last thing I will say, and you may have already realized this, is that you can never properly judge exposure, color, or sometimes even focus, from the viewfinder of flip out screen on any prosumer camera, at least not without many hours shoting with it and comparing it to a properly calibrated monitor. Being LCD's, the color reproduction is poor, color and apparent brightness is dependent on viewing axis, and being tiny and low in resolution makes it difficult to judge focus. when shooting dv, you really need some sort of external monitoring solution. I hope that my reply has given you information you can use, and I'll be happy to answer any other questions to the best of my ability

[LouCipherr]

The first thing I would tell you is that it is usually better to underxpose video by up to a stop. It is possible to gain up in post if absolutely neccesary, although not much, but once highlight detail is gone, its gone.

Ok, STOP THE FRIGGIN PRESS!

Dj - are you reading this? Am I seeing this correctly? Did I just see LD-50 say to 'fix' something 'in post'?! Now i've seen it all!! :lol:


To those wondering "WTF is Lou talking about?!" allow me to explain:

This was a horrible (albeit it, funny from our perspective) joke we played on LD-50 during the filming of Deadlands. We always used to say "that lightning is good enough, we'll fix it in post if there's a problem" which would drive LD-50 nuts i'm sure. He never said anything and he kept his cool throughout, but I know in the back of his mind he had to be thinking "f*ck you ya bunch of dickweeds! get it right first, don't mess with it in post production - more work up front equals less work on the back end and will make post-production easier" Actually, he probably just ignored us as he went about his business. Smart man, 'cause we certainly weren't helping him while messin' with him. :lol: Being the bastards Dj and I are, we still used the "we'll fix it in post" line on him waaaay more than we should've. Sorry, LD. We had to have some kinda fun on the set, didn't we? I mean other than letting zombies eat people...? :lol: :p

Even though we messed with him a lot, we tried to let LD do his thing as much as possible on the set...and as you can see from his posts, there's a reason why we did - the man knows his sh*t. If there's anything cinematography-wise that's redeeming in Deadlands, he is the reason for it. ;)