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-   -   How do I get the right exposure ? (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/9011-how-do-i-get-right-exposure.html)

Robb Bradstock April 26th, 2003 12:00 PM

How do I get the right exposure ?
 
I have recently upgraded from a domestic Sony camcorder to a PD150. I have several rather basic questions which I need help with mainly to do with exposure.
While in Spain recently I was getting familiar with the camera and shooting in villages where there was often a huge difference between part of a shot in sunlight and the part in shade. I was using the 100% zebra pattern as guide but I found it hard to eliminate the zebra pattern without under exposing the part in shadow So is there some way to get a balance between the dark and light areas without using grad filters? does AE shift help?( I’m a bit unclear exactly what AE shift is) and what about using the ND filters in the manual mode?
Also I used to use a Sony ECM909A Stereo mic ( Hard wire) when making radio documentaries. Would I be able to get broadcastable quality sound with an adaptor for the XLR input.
I hope I haven't asked too many questions at once!!
Thanks for any advice on any or all of this.

Wayne Orr April 26th, 2003 02:02 PM

Robb, you have to understand that not every opportunity for a shot will yield good results. If there is too much contrast between sun and shade, something will suffer; either the sun area will be overexposed or the shade area will be underexposed. How to tell when you are in trouble? Here is a good trick to learn:
****
Here is my one word advice to you: KISS (Keep It Simple Stupid) The most important item for you is to make your picture look good, so turn off the zebras for now and learn to "squint." This trick was taught to me many years ago by a film DP and is probably the one best piece of advice I ever received.

Your eyes are marvelous instruments which are much more sensitive than your camera in handling a range of contast. What looks fine to you, can end up awful on tape. Here's an example: You stand where you want to place the camera. The talent is standing with a bright sky behind her. She looks OK, until you squint. Then you notice the sky cools down nicely (good), but her face goes into darkness (bad). Don't shoot here. Another example: Your reporter is standing on the sidewalk, behind her is an important sign on a window under an awning. Looks fine, till you squint. Then she still looks good, but the sign goes dark. Solution? Move her under the awning with the sign, or, light the sign up, or, knock off some of the light on her with a grip flag or umbrella. Another example: You are doing an interview indoors and there is sunlight coming through the window behind the talent. You squint and the outdoors looks fine, but the talent is dark. You need more light on the talent or less coming through the window.

In each of the above examples you can identify the problem the same way; by squinting. And you haven't even turned the camera on yet. Squinting will work with people, lanscapes, interiors; anywhere you shoot, you should squint.

Try this. Turn off all the light in the room where you are reading this, so the only light is the computer and whatever ambient light is left. Now let's assume you want to shoot the desktop with all the peripheral stuff around the computer. So you squint, and other than the computer screen, everything else disappears. Solution? Add ambient light to fill to the level of the computer screen. Now, just how you add the ambient light is where the art comes in. Hey, if this was easy, they'd get a relative to do it.

So now you have a shot where you won't get in trouble with too much contrast in the picture, which will take care of your levels. So how do you set exposure? KISS. Let the camera do it. What is important in the picture? The talent? Zoom into her face, press the "iris" button, and allow the camera to set the level.(Yes, in manual iris mode) One caveat; do not zoom full tite or close to it, if you have to move the camera a little closer to check the iris, do so. Then move back to where you want to do the shot.
****

OK? In your situation, Robb, you could look at the scene and squint and what you would see would be the sun area looks good, but the shade area goes to black. Unless you looked directly into the shade area, in which case it would look good, but your peripheral vision would see trouble in the sun area. In general, the camera will tell you when it needs an ND. The AE shift does not enter into this, unless you are doing a lot of shooting where you need to shift the exposure, such as bright sun on snow. In this situation the camera tends to underexpose faces, and using the AE shift can be a time saver, but I think you need to spend more time on the basics before you get into this.

Remember its OK to overexpose the sky if what you are interested in are the buildings and street scene. But if you are really anal about overexposure, you better have a grip and lighting truck with you.

Have fun.

Robb Bradstock April 26th, 2003 03:26 PM

Thanks a lot for your lengthy reply Wayne. I'll start squinting right now.

Guest April 26th, 2003 05:58 PM

Ok I squinted, in my room with nothing else but monitor light but things didn't go away as expected. How do I squint propery?

Wayne Orr April 26th, 2003 06:44 PM

<<<-- Originally posted by RagadyAnne : Ok I squinted, in my room with nothing else but monitor light but things didn't go away as expected. How do I squint propery? -->>>

Don't know where you are located, but right now on the West Coast, the late afternoon sunlight coming through the window and illuminating my desk and my monitor show no differerence when I squint, which means a well balanced scene that will photograph quite well. If I come back after dark in about three hours, with only the monitor on, the rest of my desktop will go black when I squint, indicating I need more fill on my desktop. Make sense? Hope so. Keep asking questions as this is a great tip and I promise if you are into lighting you will really appreciate it. I did a shoot recently where I did everything myself, light and shoot. There was a tech along who monitored my work from a truck, and I told him to leave the camera set a f/2.8, and I lit everything by eye, using the squint technique. He was amazed at how fast and accurate I could light a scene without looking in the camera. Rough it in by eye, and then refer to the monitor to fine tune.

Robb Bradstock April 27th, 2003 01:05 PM

Hi Wayne. could you explain what you meant in your relpy
"Zoom into her face, press the "iris" button,
and allow the camera to set the level.(Yes, in manual iris mode)"
Thanks, Robb

Wayne Orr April 27th, 2003 02:02 PM

<<<-- Originally posted by Robb Bradstock : Hi Wayne. could you explain what you meant in your relpy
"Zoom into her face, press the "iris" button,
and allow the camera to set the level.(Yes, in manual iris mode)"
Thanks, Robb -->>>

Sure, Robb. In normal situations, what you are most interested in is making the people look good, and obviously this means proper exposure on flesh tones. So, with the camera in manual setting (that means you can see the iris setting in the viewfinder/lcd), zoom into the face of your subject, and press the iris button. The camera will now go into auto iris mode, and set the proper exposure for the lighting situation. Press the button again, and it will hold that setting, again, as indicated by the read out in the viewfinder/lcd.

This procedure assumes average causasion skin tones under normal lighting situations. If you were to do this with a dark skin tone, the camera may overcompensate and overexpose the picture. If you were to do this in a low light scene, such as a bar interior, it may again overcompensate for the situation, and you would want to stop down a bit, less the bar and the subject end up looking too bright for the scene.

This technique works well for most situations, including landscapes, if you will adhere to the logic behind the camera's actions. Let's say you want to shoot a beautiful landscape with a bright sky. If you leave the camera on auto exposure, it will probably underexpose the landscape in favor of the bright sky. But if you tilt down and exclude the sky from the shot, set the exposure, then tilt up to your original framing, you will hold the correct exposure for the landscape. Your sky will be burned out to degree, but you will have good exposure on what are interested in, the landscape. How far can you go before the picture starts looking bad? ?That is partially a matter of personal taste, but if there is a 1 stop difference between the picture with the sky versus the picture without the sky, you are probably alright. If there is a three stop difference, you are treading on thin ice, but there are things you can do in post to correct some of this difference, or by shooting with a graduated ND filter which will knock down the sky while leaving the landscape unaffected.

It bit of logic goes a long way in working with these cameras, and of course, a lot of practice. Let me know if there are any other questions.

Mike Rehmus April 27th, 2003 02:08 PM

I frequently have to shoot in just such a situation as you described. The quick solution when you cannot change the lights is to reflect some of the sunlight onto the subject with a reflector. I almost always use reflectors whenever I'm doing fixed-camera work and I have a reflector holder.

This goes a long way towards solving the problem.

To properly use the Zebra pattern, you want a 70 percent pattern on some of the face. Usually the side or forehead. Green Grass and blue sky are also 70% situations.

Experience helps and it takes a bit of shooting to figure it all out. Fortunately the 150 does a little bit of image processing and this helps make othewise poor lighting a little bit more acceptable.

Bryan Beasleigh April 28th, 2003 12:20 AM

http://www.urbanfox.tv/workbooks/sonypd150/pd150exposure.htm

Robb Bradstock April 28th, 2003 11:14 AM

Hi Wayne, Mike,Alex and Bryan. Thanks a lot for your advice. If it would just stop raining here I could get out and try your out your tips.Then I'll probably have some more questions. All this help is wonderful by the way. Regards Robb

Mike Rehmus April 28th, 2003 12:40 PM

You are welcome.

Now, as for camera rain jackets . . .

Dennis Hull April 28th, 2003 04:31 PM

HIGH CONTRAST AND NEUTRAL DENSITY
 
Robb, at least I think the PD150 will do about the best you could hope for at that price point in high contrast shots. I am very much the novice, but while doing a side by side shoot of similar priced camcorders at camera store, the sun came out on cloudy day--part of scenery in shadow, part in bright sun. The VX 2000 in full auto but with neutral density filter switched in (as prompted by camera), did the best job in that situation--bright colors in both sun and shade and no washed out colors in bright sun. I have since read articles which mention high contrast light shooting (as well as low light shooting) as standout features of PD150 and VX2000 due to slightly larger CCD's vs other similar price camcorders. More controversial is role of neutral density filter in high contrast lighting situation--some say no impact, others say they help.

Wayne Orr April 28th, 2003 05:47 PM

Re: HIGH CONTRAST AND NEUTRAL DENSITY
 
<<< More controversial is role of neutral density filter in high contrast lighting situation--some say no impact, others say they help. -->>>

Actually, the nuetral density filters will do nothing to impact on high contrast lighting. As indicated by the name, they are "nuetral." They only lower the levels overall to bring the picture to a more manageable f/stop. There are filters designed to mess with conrast, such as "lo cons," but these should be used with caution and tests done to determine if they are creating the desired effect. They will tend to flatten out the picture, as the name implies.

BTW, I hope Robb gets out there and shoots some footage in those rainy conditions. You can get some rather spectacular footage in heavy overcast as the colors really pop, and faces look great from every angle.

Andrew Plona April 28th, 2003 06:01 PM

Polarizer
 
When shooting outdoors an easy way to increase your latitude is to use a polarizing filter. It will allow you to expose "darker" areas correctly and then tune some of the brightness out of the over exposed areas. On my old VX3 what I do is put the polarizer on, lock the shutter speed and gain then let camera choose aperture. Then I turn the filter ring until I see minimum polarization. Then choose the aperture to correctly expose your subject and then lock. Now turn the polar filter to maximum polarization and magically watch the over exposed areas darken up nicely while keeping your other areas the same. A trade off is that colors get very saturated (Kodachromeesque) so depending on the look you want you may have to turn the color down in the custom preset.

Oh you probably want a circular polarizer due to the cameras light splitting prism.

Bryan Beasleigh April 28th, 2003 06:27 PM

A linear work just fine. Try it and see. This issue crops up every few months. I'll leave it up to someone else this time.

Rick Spilman April 28th, 2003 06:37 PM

"I found it hard to eliminate the zebra pattern without under exposing the part in shadow."

I think the one clear problem you have is getting use to the zebra pattern. In a nutshell, it is fine to slightly overexpose the parts of the shot that do not matter to you as long as you get the portion of the shot that you need.

As Mike pointed out at a 70% zebra there should be some striping on faces. A light colored shirt, flowers or a sunlit wall will show zebra stripes. Zebra stripes aren't bad.

You may want to turn off the zebra stripes for a while. Shoot what looks right then turn the stripes back on and see what is striping and what isn't. Then play back the footage preferably through a monitor but even the LCD will work if you aren't in the sun. Video gives you instant feed back. See what looks good then shoot some more until you get a clear idea of how to make the zebra stripes work for you.

Dennis Hull April 28th, 2003 06:58 PM

Neutral on Neutral Density
 
Wayne, I agree with you based on most of what I have read about ND filters and what they are supposed to do (I have mostly reading at this stage with little practical experience) , but page 33 of March 2003 "Camcorder and Computer Video" magazine article on use of filters says "The ND filter adds more intensity and deeper colors to images that are washed out from excessive light present in the scene." I thought this might help account for why I saw much better results from VX2000 in high contrast (sun/shadow) scene vs competitive camera ( the VX2000 had ND filter switched in and I don't think the competitive camera had its one ND filter switched in). On the other hand, might be semantics of magazine article.

Jeff Donald April 28th, 2003 07:11 PM

A good neutral density filter is just that, neutral. It neither adds or subtracts color to any scene (more the job of a polarizer). The washed out look would be more the result of over exposure. By using a ND filter, the scene is prevented from over exposing. This results in improved color and better contrast.

Dennis Hull April 28th, 2003 07:32 PM

Convinced
 
Wayne and Jeff, Right you are and it all now begins to make sense--neutral but helps with exposure resulting in better colors and contrast without washouts. Thanks for patience in explaining this.

Wayne Orr April 28th, 2003 08:45 PM

More pearls
 
You people are so lucky that my series has wrapped and I have the time to "pig out" on the web and pass along these pearls of wisdom. Here are the latest.

I second Bryan's endorsement of the linear polarizer. The circular will work fine, but you will pay extra for it. BTW, remember when using a polarizer, if you pan 45 degrees you may totally eliminate the effect of the polarizer, which will result in overexposure if you do not compensate by changing the iris. The best thing to do is preview your planned shot just by eyeballing through the filter. You will be able to see the change, and know that you will have to compensate.

Rick's response to the original post from Robb is on the mark, but there is a caveat here about using lcd's to check exposure. My experience is that the little screens tend to make everything look good, and that coupled with the different results from a slightly different viewing angle make them unreliable for real critical judgment, IMHO. Another thing that is buggy about the zebras, is they will show up in areas beyond 70%, and this can be decieving. In betacams and other professional Sony cameras, the 70% bars appear only in the area of 70 to 80%. Anything higher, and they go away. But on my PD150 they first appear at 70% and stay on ad infinitum. Let's say there is a face we are shooting, and a 70% highlight should appear on the cheek bones, nose and forehead at f/4. That would be proper exposure. However, when we first set the exposure, if we start from wide open, and begin to iris down, we see the zebra first appear at f/2/4, possibly leading us to believe that is the correct exposure. What you may be seeing coming from wide open, is the high end of the range. So, what I suggest is, look for the zebras coming from a closed iris setting, such as f/11 or f/8. Then you will be increasing the exposure, coming from 10% to 20% etc, till you come to 70%, where you first see the zebras. I hope this makes sense, because it is pretty important, and you won't find this in any of the literature.

Please read my response to Robb about learning to "squint." I promise one day you will thank me for this advice, along with the DP who passed it on to me. Do I sound like your father?

"The ND filter adds more intensity and deeper colors to images that are washed out from excessive light present in the scene." This is about what I would expect from something called "Camcorder and Computer Video," Dennis. OK, everybody, what's the purpose of a magazine? Altogether now: "To sell advertising!!!" Thank you. The best way to compare two cameras is to look at their output on the same scene through a professional monitor, or at least a quality television. Certainly do not depend on the lcd's.

Excuse me now. I have to return to the "help wanted" section of the Times.

Jeff Donald April 29th, 2003 11:33 AM

The Saran Wrap question was off topic and moved to here.


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