View Full Version : Controlling Exposure on the Canon HV20
05-07-2007, 10:41 AM
Click Here to read the article (http://www.dvxuser.com/articles/article.php/8)
05-07-2007, 12:21 PM
Nice Barry :-)
1. I'll confirm that the XH-A1 does give you gain information if you play HV20 tapes in it, providing you've got the XH-A1's data display configured during playback.
2. Pressing the photo button halfway down (from Jenningsp's video tuturial) on the HV20 will show the aperture in use, and by varying, you can determine gain "real time".
So really, the exposure locking issue is pretty much a question of information and using the camera a bit differently...great news for HV20 owners.
05-07-2007, 03:01 PM
Excellent Barry. Once again saved me all the hard work. :beer:
05-07-2007, 05:56 PM
Great article, Barry! With my cell phone (Sony Ericsson T637) I set the wallpaper as a plain white image and am able to go from -11 all the way +8 before the shutter changes to 1/30 at +9.
This will be really helpful while I'm using my 35mm adapter, lenses and accessories... which cost several times what the HV20 cost... haha.
Great fun! :beer:
05-07-2007, 08:52 PM
that was an AWESOME article. many thanks for taking the time to put that together.
05-07-2007, 10:12 PM
Alright, so if I understand correctly, the basic workflow goes like this:
1. Set camera in Cine Mode with HDV 24p
2. Shine light or bright screen into the lens
3. Set Exposure bar according to chart
What about taking a white picture (maybe a Windows Paint blank white picture) and using a Sony PSP screen? Or what if you just shine a bright video light into it? I have a 20w Sima video light I bought a while back when I first got my GL1, would this be better for this process?
06-07-2007, 02:46 PM
I have a miniSD card. The only way I can check the shutter speed is if I have the camcorder switched to camera mode via the switch on the right side of the camcorder located below the auto/program switch. Only then can I press the photo button halfway to get the shutter speed and aperture. Pressing the photo button halfway while in camcorder mode, specifically 24p cinemode and with the exposure menu on after pressing the joystick and navigating to exposure than pressing the joystick upward, yields me no shutter information. Instead I get a red camera icon to the left of the screen denoting the camcorder is not in photo mode. What am I doing wrong here? Also, would it be more effective to try your cellphone trick rather than guessing the camcorder will stay at the same shutter speed after you've checked it with the photo button. How about if there's a subtle light change when you pan? Wouldn't this affect your shutter speed in cinemode. How would you check for that? Argh. So frustrating. I'm so close to getting ready to shoot a short but I don't know how to immediately get the settings I need from this camcorder. Your suggestions are very much appreciated.
06-07-2007, 03:07 PM
Once you lock the exposure, it's locked. If you don't lock the exposure then yes, during that pan it may very well change the iris or shutter on you. But if you lock it, nothing will change.
The switches on the side of my HV20 are set to the "P" and to the tape. Make sure yours are as well. Then, when you're in camera mode, if you have the miniSD card installed, a light press of the PHOTO button on top of the camera should show the aperture and shutter.
06-07-2007, 06:57 PM
Ok. I think I have it. So one does have to switch from tape to camera mode in order to access the aperture and shutter information.
The charts you mentioned work if you have the constant of the light(nokia phone in your case) present when you go to lock the exposure. The exposure range would show up as you described. But if I don't want to use that method but instead use the info from the camera mode coupled with the miniSD card, how do I reference the chart? For example, If the readings from pressing the photo button give me a 2.4f and 1/48 shutter, I should assume I'll have 0 gain if I then lock the exposure in the range of -9 to +6. Is this correct?
Thanks again. I am new to this and the technical side can be somewhat overwhelming yet I am absorbing as much as I can as quickly as I can and hope to continue to learn as I proceed with my upcoming project.
06-07-2007, 07:21 PM
No, if you are in tape mode the button works, but only if there's a miniSD card in the slot.
If you have the miniSD and are using the photo button, then you don't really need any chart. You just want to make sure that the iris is between 2.0 and 8.0 and you're assuring yourself there won't be any gain. If you lock the exposure and then go to the '+' side of the scale, you may be introducing gain if the iris goes more open than 2.0.
06-11-2007, 07:14 AM
Hi. I have a 1gig miniSD card in the camcorder. The card is in perfect working condition and records images swimmingly. When pressing the photo button halfway in camera mode(the switch below the program switch), shutter and aperture info are displayed. When the camcorder is switched from camera back to camcorder mode, and I press the photo button halfway, I do not get shutter and aperture info. What I do get is a red camera icon to the left and a beep sound. Do you have a prerelease model? Maybe this feature was left out of certain models in early production? I purchased the camcorder in mid May. Who knows.
Regardless, can I still obtain accurate information if I use the reading obtained from camera mode instead of camcorder mode?
06-11-2007, 09:43 AM
nycshooter. You must have still image turned off in the menu. The Camera will still take a picture when the card is selected wether still image mode is on or off but you need it on to take pictures (and see the required info) when in tape mode.
Sorry I am probably getting the terms wrong (No manual handy) but in tape mode hit the func. button and go to the second icon up (just above the menu icon) it should be a little camera and say OFF Change this to LW or SW and should should be fine.
06-28-2007, 08:14 AM
Over at HV20.com, I was alerted to a little application that can generate the HV20's settings information on a laptop. The application is called HDV Data Monitor and can be downloaded for free at http://hv20.info/yopu/HDVdataMon.zip
But having tried the little application with my HV20, it has raised a big question for me. The application purports to give a read-out of things like aperture, gain and shutter speed (things the HV20 doesn't readily give you data on by itself). However, when I use Barry Green's great technique for locking exposure so as to get a locked 1/48 shutter speed and no gain, and then plug it into the HV20 Data Monitor application, the application tells me my shutter speed is 1/60. Even when I half-press the HV20's camera button, which confirms that my shutter speed is locked at 1/48, the HV20 Data Monitor still tells me it's 1/60. It could be a bug in that application. I hope it's a bug in that application. Because as Barry points out, it's quite critical to have a locked and known shutter speed for the HV20 to be useful to filmmakers.
06-28-2007, 08:14 PM
I ran this thing several times and it seems to be a quirk in the software when it comes to shutter speeds. i purposely changed my shutter speeds up and down and it just displayed a "0" most of the time. When I had it in 1/48 it showed 1/60. It seemed to be unable to read certain shutter speeds. But...it showed the gain and the f stop perfectly.
06-28-2007, 08:31 PM
Well that's a relief. Thanks for checking on that Ian-T. It's a handy app for double-checking gain, but I'm glad to know that my HV20 has been at 1/48 as we all thought. Cheers.
That's a great article! Thanks so much for the explanations!
08-23-2008, 08:26 AM
In lieu of your phone, I use a Nintendo DS Lite on the main start up image, on the second brightness setting.
05-05-2009, 05:28 AM
by far the best that this has been explained! KUTOS to you for sure... :]
08-14-2009, 06:21 PM
I can't get this to work. I'm using a HV30, and when I'm in Video mode, I try to click the "PHOTO" button and I get nothing but a "Off" logo flashing in the bottom left corner. Can this only be checked in Photo mode?
EDIT: Nevermind, I just reread the article closer and I guess I need the SD card in to check it.