video tutorial on how to control the shutter/aperture/gain

[seider]

this thread has helped me out soo much (even thou i dont own a hv20 yet) but i would like to know a few things and if its not the right place to ask them could you just tell me and i will re post elce-ware. ok...
1. for filming snow should i use polerized filter
2. filing snow and filming fast moving objects (skiiers) should i keep my shutter speed at 1/50th.
3. in the tutorial, after he pointed camera to the light and locked exposure the image was soo dark, is that how he was meant to leave it, what was he ment to do next, pump up exposure
4. does EXP stand for exposure

thanks to all the previous questions and answers because they helped me out soo much, i hope the answers to my questions help others out.

and its nice to see a forum with such nice people out there willing to help out others.

[Rumpelgeist]

This article discusses the same topic, that is, manually controlling exposure of a Canon camcorder.

http://www.elurauser.com/articles/manual_mode.jsp

The article is largely about Elura 100, not HV20. But the principles are the same for all Canon consumer camcorders.

[altero]

Can anybody with a better English or ear than mine, tell me please what is Patrick saying at 02:28? It's the most important thing: what to do with the camera for having access to the manual control of the gain.
I guess one have to cover the objective, so no light goes inside, but I just can not understand what he is saying.

[Anx]

I didn't notice this mentioned on here, but I use a slightly different approach that was outlined off of the Brevis35 owners group. They reference this thread and video at the start, and at least with the 35mm adapter I like the results:

1. All the basic steps are the same, with the exception that you turn on 70% zebra in the settings section
2. Set to TV mode, 48fps, fully zoomed out
3. Frame something that is basically 50% zebra'd, 50% normal
4. Lock exposure - if you do this you'll end up with the full range of -11 to +11, at 1.8F
5. Change the exposure to +9.

At least with what I've been playing around with (which is well lit), this looks to me better then Cine-mode. I can't take any credit for these settings, they're all from Dennis at Cinevate (Brevis), and he fiddled around to find his favorite, and for my money I like them as well. It's also worth pointing out that for the 35mm adapter I have to zoom in a bit, which changes the stop to something like 2.6 (which is fine, since most of my lenses are 2.8's).

Anyway, not sure if anyone else will find this approach useful, but I figured it was worth pointing out at least.

[Rumpelgeist]

From the video:

You have to be fully zoomed out to set aperture.

This is not true. You can set aperture at any zoom. The problem is that the largest possible aperture is known for sure only for full wide and for full telephoto. These are the numbers in the manual and on the lens. But you can find out maximum aperture for any given zoom position simply by experimenting. Obviously, if the aperture is smaller than f/3.0 then there is no gain, does not matter what zoom is.



If it is larger than f/3.0 but smaller than f/1.8 then you have to do a "press photo button halfway" validation. Lock exposure, check current aperture, add "+1" exposure and check aperture again. If it got wider then there is no gain. If it did not change, then gain kicked in. Simple.

4. Lock exposure - if you do this you'll end up with the full range of -11 to +11, at 1.8F
5. Change the exposure to +9.

Did you mean to say "Change the exposure to -9"? Because otherwise what you are doing is meaningless. You already at the verge of gain to kick in at f/1.8, increasing exposure will increase gain. I assume that you want quite opposite, you want to make sure there is no gain.

[zephyrnoid]

I hate to do this.
Our generous tutorial poster is thanked for his effort. Unfortunately, it's hard to follow the movie and harder yet to refer to it in the field.
If someone is willing to help me, I'll put together a fast "Cheat Sheet" that anyone can follow quickly without the need for a video payback.
I can do the layout and screen shot illustrations if someone else can break the process down precisely in an ordered list.
Thanks!

[Ian-T]

If it is larger than f/3.0 but smaller than f/1.8 then you have to do a "press photo button halfway" validation. Lock exposure, check current aperture, add "+1" exposure and check aperture again. If it got wider then there is no gain. If it did not change, then gain kicked in. Simple.

Thanks for the chart. Your explanation and this chart kind of makes things more clear for me now (I'm a more visual type of person). Before I did not know at what point, when in telephoto, gain kicked in.

[lukaswit]

Could you tell me where I can enable a option showing an aperture and shutter on LCD like in this tutorial movie, because I can't find this option for few days.

[drmadison]

Could you tell me where I can enable a option showing an aperture and shutter on LCD like in this tutorial movie, because I can't find this option for few days.

There's no option for that...
If you half-press the photo button (on the top of the camcorder) WITH a minisd card in the slot, it will show the aperture. I have until now had no minisd card in there so I just get the red "you have no card to take a photo on you idiot" icon flashing at me.

[freeflight]

I read both Barry Green's article
http://www.dvxuser.com/V6/showthread.php?t=96502
and elurauser's article
http://www.elurauser.com/articles/manual_mode.jsp
To sum them up, both indicate that in TV mode of fixed shutter speed, HV20 will try to max out aperture first, then it will increase gain if max aperture still can't bring enough light. With this said, what's is the point of pointing to a bright light source, lock exposure, etc?

Given a scene, the amount of light is fixed. Once you choose your desired exposure or effect (dark or normal or bright), there is really only one correct/good exposure (EV value). You have three parameters to change, shutter speed, aperture, and gain (ISO) that you can't change directly. For example, in TV mode you choose shutter speed say 1/48s for film like look, you get a aperture of F2.8 at wide angle end (max aperture F1.8), then your are sure you won't have gain.

All you need to do if to verify you aren't shoot wide open (at max aperture), then you avoid gain. If you find you shot wide open for a dark scene, then it is time to add more light or use slower shutter speed so you can reduced aperture that HV20 won't add gain.

If you change exposure instead of adding light or use slower shutter speed, you deviates from you desired exposure/effect. For example, you shot at 1/48s and F1.8, and the scene is dark so gain probably kicks in. You can reduce exposure so you shot at a lower aperture. You do avoid gain this way, but your picture is much darker due to negative exposure compensation. You can possibly fix (increase) exposure in postprocessing, but it ususally add noise. My experience from still image processing confirms this.

If you don't change exposure, you shot with gain and picture is grainy/noisy. But you can also do a noise reduction in post.

To me, if a vide isn't exposured properly (too dark or too bright), it isn't viewable. I'd rather view or work with a correctly exposed video that is slightly noisy.

My 2 cents.

[zephyrnoid]

hate to do this.
Our generous tutorial poster is thanked for his effort. Unfortunately, it's hard to follow the movie and harder yet to refer to it in the field.
If someone is willing to help me, I'll put together a fast "Cheat Sheet" that anyone can follow quickly without the need for a video payback.
I can do the layout and screen shot illustrations if someone else can break the process down precisely in an ordered list.
Thanks!

[Rumpelgeist]

I read both Barry Green's article
http://www.dvxuser.com/V6/showthread.php?t=96502
and elurauser's article
http://www.elurauser.com/articles/manual_mode.jsp
To sum them up, both indicate that in TV mode of fixed shutter speed, HV20 will try to max out aperture first, then it will increase gain if max aperture still can't bring enough light. With this said, what's is the point of pointing to a bright light source, lock exposure, etc?

I have to confess: I am the author of the article on elurauser website. I found out this "press photo button halfway to read aperture" trick myself by playing with my Elura 100 camcorder, then I found Barry's article about the HV20.

I find Barry's article unnesessary complex and convoluted. I believe that there is no reason of pointing to light source. What for? Need to read current aperture? Press the photo button. Need to set aperture? Select Tv mode, choose shutter speed, then lock exposure and adjust to your liking, checking current aperture with photo button. Not enough EV range? Well, in this case you can point to a dark area or, conversely, to a bright light source just to set a different baseline for built-in light meter, then lock exposure. Then you can adjust exposure and the range will be different, but what is the point of shifting the range, say, to smaller apertures if you shoot in low light? You won't see anything.

In regards to locking exposure. The point of the exercise was to use the HV20 in manual mode and to control shutter speed, aperture and gain at the same time. Merely using Tv mode locks the shutter speed, but aperture varies automatically, and sometimes you do not want that.

But you don't have to lock exposure if you don't want to. You can force the camcorder to do it for you. Say if automatic aperture is f/7.3, you may want to bring it two stops down to f/3.7 for more shallow DOF effect. You cannot simply increase exposure because you will blow up your video, so you need to screw on an ND2 filter. Photo button trick shows where you are at.

Given a scene, the amount of light is fixed.

The exposure lock allows to lock the exposure (duh!) so when lightning conditions change slightly, like when you pan or when a person's black contour appears in a brightly lighted doorway the camera would not change exposure automatically. Also, if you shoot the same scene on different days, you likely want to stay at the same aperture to make video from different days look identical. Here exposure lock helps. You lock exposure on the first day and write down what settings you are using. On another day you set the camera into the same mode and add/remove lights if needed. Even if you shoot indoors, the lightning on sunny or cloudly day will be different.

Once you choose your desired exposure or effect (dark or normal or bright), there is really only one correct/good exposure (EV value).

Sometimes the camera may overexpose or underexpose in automatic mode, so you may want to lock exposure and take it one-two notches down or up. Also, you may want to go for an under/overexpose effect for artistic purposes. Granted, you can do the latter in post.

[toxotis70]

If i have to do a shoot to a location with various lighting conditions, how do i lock the exposure ?

[Noel]

This is great stuff. Anybody know if you can also do this for Sony's and Panasonics. Such as the panasonic sd1 or sony cx7. I found th Cine/24P/f1.8 + 1/40 no gain is very nice. Dark black noiseless background. Also anybody trie this with the Canon CL3 lighting?

[scroll1]

thanks for the video tut.
Just a simple question though:
When you lock exposure on a light source, do you wait for the camera to adjust itself automatically to that light or do you point and lock before it gets a chance to auto-adjust? Is there a difference in the end result?
thanks

[Nacho]

I found a GREAT tool to read the shutter speed, exposure, AND gain from the hv20:

http://translate.google.com/translat...&hl=en&ie=UTF8

It ROCKS!!!
Thanks to elCutty for that!

[deerel]

Great guide. Love it!

[seider]

so what i was wondering now was: if you do lock the exposure and appature after pointing it to a light, (and the apature is f.18) you cant see anything, and if you want to see something you have to increase exposure which increases gain. whould this happen in a better lit situation?

[Ian-T]

Just increase the light and not the exposure.

[seider]

Just increase the light and not the exposure.

by light you mean lighting of room. what if its outdoors? or would it already be bright enough if it was sunny outsize?

i wish i could test this my self, but i just got a new hv20, and i dont have the charger!!!

[Jessica]

Thanks Patrick! veeeery nice trick!

[funkg]

OMG i think canon just disabled the half press button trick on the newer batches! It's not working for me in film mode, even with a midi sd card inside arg! am i doing something wrong? The half button display does work when the camcorder is in camera mode, but not in video mode, which is completely useless to me!

[tcindie]

it doesn't work while recording.. but it should work. I seriously doubt Canon has changed anything.

[funkg]

man it's not working when stopped or paused. when I press the button half way I get this flashing red "off" symbol on the bottom left of the screen, what's going on here?

[Worley]

Have you formatted the SD card?