Controlling Exposure on the Canon HV20

[HalD]

I found this interesting article on the Dvx User forum.

Controlling Exposure on the Canon HV20
by Barry Green
http://www.dvxuser.com/jason/hv20/
Cheers,
Hal

[24Peter]

Thanks Hal! What would we do without you... (Sorry - couldn't resist. Barry's article is very helpful - thanks for reminding us it's out there.)

[HalD]

One of the biggest good things about the web is the information on it. On the other hand you see something and a week later you can't find it in the overload of "good stuff to know". As Mal can attest to, a lot of what is asked on HV20.com was asked and answered back 6 years ago on the EditDV forum.
What would be good would be to have a sticky with just subjects and urls to that subject.
Cheers,
Hal

[duketh]

agreed

[tcindie]

True.. but even then I fear a lot of people probably would still just ask a new question rather than look at information that's already here..

[jakenl]

Reading this information regarding manual control of both Shutter Speed and Aperture, I am getting a bit disappointed. This summer I got my Panasonic GS-250 stolen in SF, but that cam was able to manually lock Shutter Speed, Aperture and Gain. Since I am interested in buying the HV20, this will something to give up unfortunately

Something that crossed my mind after posting yesterday:
With my first camera (JVC 157), I hardly had any control over exposure and when filming inside and panning across a window, the whole image turned black to get a 'proper' picture outside. The same thing happened during a wedding. The gown of the bride changed the exposure completely when she passed (and yes, it was the camera not myself ).

Will the HV20 do the same thing as that old JVC 157?

[jakenl]

Nobody?

[Ian-T]

When you say black are you saying totally black or that the picture just got darker? I've never seen the HV20 get a black screen but when I pan to a brightly lit window the picture just seems to get blown out in that area....and the surrounding area in the picture seems to darken a little. Nothing out of the ordinary.

[CJDaniels]

You can lock shutter speed, aperture and gain on the HV-20 what are you talking about?

[Terfyn]

How do you lock gain?

[mbwkrause]

you can't

[Terfyn]

Didn't think you could. Its a pain!

No pain No gain

[CJDaniels]

http://hv20.info/yopu/hv20aperturecontrol.mov

yes you can, the tutorial looks complicated but when you do it two times it is cake walk.

[mbwkrause]

well, it's a workaround that ASSUMES that the gain is locked. But you can't lock it directly...

[Ian-T]

No...it's definately locked...someone was kind enough to put together a chart showing where the threshold is....go above it...and that's where you start to introduce gain. It works everytime.

[lasssman]

No...it's definately locked...someone was kind enough to put together a chart showing where the threshold is....go above it...and that's where you start to introduce gain. It works everytime.

Is that chart available somewhere? Did I miss it? Or is it the one in Barry Green's article?

[Ian-T]

No...it's actually in this forum...someone....please help.

[CBarce]

Is that chart available somewhere? Did I miss it? Or is it the one in Barry Green's article?

is this what you are looking for ??

http://www.dvxuser.com/jason/hv20/

[sine]

It's an old trick that canon elura users have been using for a while.
Here's a link that has the list of aperture settings available with the shutter speed locked. It also charts when gains starts. It's for the elura but the HV20 is not much different in this aspect.
http://www.elurauser.com/articles/manual_mode.jsp
Everytime I need to lock the EV, I just pull out my handy dandy NOKIA and used a blank text message screen and stick that in front of the HV20.

[lasssman]

Here's a link that has the list of aperture settings available with the shutter speed locked. It also charts when gains starts. It's for the elura but the HV20 is not much different in this aspect.
http://www.elurauser.com/articles/manual_mode.jsp
Everytime I need to lock the EV, I just pull out my handy dandy NOKIA and used a blank text message screen and stick that in front of the HV20.

This must be the one ... I'm still struggling with whether the HV20's built-in ND filters mean I don't need any external ones - or whether I need one or two to create shallow DoF in bright sunlight.

[jmorton]

I've found that if you are in Auto mode your exposure will change if the brightness of your frame changes and you can see it change quite clearly and noticeably in your shot.

Also, I believe that if your exposure is 2.0 or higher then there is no gain added. I've tried it using the manual control instructions from this forum and it results in very clear shots whereas if you let the exposure fall to 1.8 gain is usually added and your shot gets quite grainy.

JM

[Abe Ford]

I'm getting ready to video a livemusic performance in a not-so-bright nightclub in Brooklyn using two HV20's and trying to accomplish the "NO GAIN" effect, using the wonderful Barry Green roadmap.

I have pretty much decided to shoot in HDV24 mode, using the Shutter priority setting (Tv) set to 48, rather than Cine.

I've done a test using my iPod as the "cel phone" light source and have been able to consistently achieve an exposure range that ends with only two repeated f-stop/shutter combinations. I figure I'm safely in "No Gain" as long as I don't venture into the repeat. (one click from wide open).

I'm totally worried about me or the second cameraman accidentally pushing the joystick UP and losing those precious settings-- I assume that's part of the HV20 adventure. I wonder if there's a trick to preventing that.

Also, *I think* I can do a tape change without losing the 'cel phone" settings, as long as I don't power down.

I wanted to ask for any suggestions and also some sage advice on which Custom settings to change. I don't know if I should change any of them, but I'm thinking of going +1 on Brightness.

Thanks for any input!

AF

[Ian-T]

is this what you are looking for ??

http://www.dvxuser.com/jason/hv20/

Not this one. The one I was referring to is a color chart. It gave the f-stop at a wde angle as well as telephoto....all while showing you at what point gain is added. It's something you could print out and tape to you HV20 if you wanted to.

[Michael Davis]

I'm totally worried about me or the second cameraman accidentally pushing the joystick UP and losing those precious settings-- I assume that's part of the HV20 adventure. I wonder if there's a trick to preventing that.

Just push the joystick in again to get rid of the exposure changing menu. It'll keep the setting until you either turn the camera off or press the joystick and bring the menu back and turn the EXP lock off.

I wanted to ask for any suggestions and also some sage advice on which Custom settings to change.

Stu recommends choosing CUSTOM for IMAGE EFFECT and Setting everything to zero (the slider all the way to the left).

This is from one of his comments at that link: "In fact, the camera setup steps that I forgot to mention above include creating a CUSTOM setting that has COL. DEPTH, SHARPNESS, CONTRAST and BRIGHTN. all set to their lowest positions."

In case you didn't know (I didn't, until about two days ago) Stu is the guy who invented Magic Bullet, the software package that's used in studios all over the world to give video a more filmic look, so I think his is fairly knowledgable opinion to follow. My understanding is that you're doing the cell phone trick to make sure there's no gain, and that brightness slider is basically a "turn on gain" guarantee. That's the only place brightness can come from at that point, is gain.

[Abe Ford]

Just push the joystick in again to get rid of the exposure changing menu. It'll keep the setting until you either turn the camera off or press the joystick and bring the menu back and turn the EXP lock off.

Yes, this is all correct- I'm pretty sure the light will be constant, unchanging so perhaps I can leave the exposure scale hidden.

Stu recommends choosing CUSTOM for IMAGE EFFECT and Setting everything to zero (the slider all the way to the left).

This is from one of his comments at that link: "In fact, the camera setup steps that I forgot to mention above include creating a CUSTOM setting that has COL. DEPTH, SHARPNESS, CONTRAST and BRIGHTN. all set to their lowest positions."

In case you didn't know (I didn't, until about two days ago) Stu is the guy who invented Magic Bullet, the software package that's used in studios all over the world to give video a more filmic look, so I think his is fairly knowledgable opinion to follow. My understanding is that you're doing the cell phone trick to make sure there's no gain, and that brightness slider is basically a "turn on gain" guarantee. That's the only place brightness can come from at that point, is gain.

That's really interesting, thanks for referencing it, too. I wonder if my intention to shoot in Shutter (Tv) mode vs. Cine would change the thinking on that. I guess I'll dial both cameras down in CUSTOM, either way.

Good stuff!

AF

p.s. To assist focus, I'm turning up the brightness on the LCD viewfinders to about 3/4 so there's an image on screen no matter how dark it may actually be recoreded.