Gain (Exposure Lock with Photo Button Trick)

[mute]

Yes, theres a bunch of threads, but i just want to make sure i understand it clearly.

To avoid gain you use Tv mode, set you shutter, aim your camera at a bright light so it fills the lens, lock the exposure, With the exposure being locked at 0 and now looking at your subject everything that was dark before is now a very dark and crisp black. Right now at 0 there is no gain, and everytime you up the exposure +1 it adds 1.5dB of gain.

[PadawanGeek]

Yes, something like that.

But if you have a mini SD card, press the photo button halfway down and it will show your your aperture so you can calculate your gain

[Lunchbox]

I did it a little bit differently. Zoom out all the way. Then point to a light source. Half press photo button to check the aperture value. Slowly move the camera away from the light source and keep checking the aperture value. Lock exposure immediately when the value drops to F1.8.

[Max Goldberg]

I did it a little bit differently. Zoom out all the way. Then point to a light source. Half press photo button to check the aperture value. Slowly move the camera away from the light source and keep checking the aperture value. Lock exposure immediately when the value drops to F1.8.

This is exactly what I do because it allows you to use cinemode. If you are moving the exposure slider and shutter speed and f-stop are staying the same, it is adding gain. I keep sliding it down until I get to f1.8 and 1/48 shutter speed. (In low light. In good light, the f-stop should be higher.)

[d1g1t]

Or just turn on Spotlight mode. Turns gain off, but also turns off manual white balance for some reason.

Always locking exposure makes for more film-like footage IMO, so in the end I prefer the Tv method so I can also adjust white balance manually.

-- Kevin

[Ian-T]

I did it a little bit differently.

That's basically what I do...but if there is not a sufficient light source for you to use you can use the cam's own led light and shine it on something (I use my hand or a nearby wall sometimes). Works like a charm.

[DFv2]

Here's what I do when using cine mode to guarantee 1/48 shutter and NO gain at the same time. Your mileage may vary:

I use the half-press photo button here... so you need the miniSD.

1) Zoom all the way out.
2) Aim at any light source you like, check and recheck apature/shutter.
3) Try as hard as possible to aim at something that will produce a 2.8 - 1/48 setting.
4) LOCK IN the 2.8 - 1/48
5) Adjust exposure at will, the upper limit will be +6 (1.8 w/no gain) and the lower limit will be the bottom of the barrel -11.

Here, you have a wide range of availible exposures (-11 to +6), ALL with a 1/48 shutter and ALL with no gain. Just my .02.

[Lunchbox]

That's basically what I do...but if there is not a sufficient light source for you to use you can use the cam's own led light and shine it on something (I use my hand or a nearby wall sometimes). Works like a charm.

hehe.. I always carry a small LED light in keychain. Let me PM you I can send you one.

[mute]

Here's what I do when using cine mode to guarantee 1/48 shutter and NO gain at the same time. Your mileage may vary:

I use the half-press photo button here... so you need the miniSD.

1) Zoom all the way out.
2) Aim at any light source you like, check and recheck apature/shutter.
3) Try as hard as possible to aim at something that will produce a 2.8 - 1/48 setting.
4) LOCK IN the 2.8 - 1/48
5) Adjust exposure at will, the upper limit will be +6 (1.8 w/no gain) and the lower limit will be the bottom of the barrel -11.

Here, you have a wide range of availible exposures (-11 to +6), ALL with a 1/48 shutter and ALL with no gain. Just my .02.

What if you need the shutter to be at say 1/100 for the subject youre capturing. Then what would you want the ap. at and what would the values be for no gain?

[Rumpelgeist]

To avoid gain you use Tv mode, set you shutter, aim your camera at a bright light so it fills

the lens, lock the exposure, With the exposure being locked at 0 and now looking at your subject everything that

was dark before is now a very dark and crisp black. Right now at 0 there is no gain, and everytime you up the

exposure +1 it adds 1.5dB of gain.

No. "0" does not mean no gain. This may help: http://www.elurauser.com/articles/manual_mode.jsp

Here are possible apertures and gain values:



One step is either 1/4 of an f-stop or 1.5 dB of gain which is the same (one f-stop equals to 6 dB of gain).

F5.6 corresponds to 12 EV steps where built-in ND filters kick in. If your aperture is F2 or narrower, then there is no gain. Therefore, aiming for F2 is much simpler than for fully open iris, you don't need to count EV stops.

What if you need the shutter to be at say 1/100 for the subject youre capturing. Then what

would you want the ap. at and what would the values be for no gain?

If you want shutter at 1/100 then set it to 1/100. Adjust aperture with Exposure slider and verify actual value it with the Photo button.

[DFv2]

What if you need the shutter to be at say 1/100 for the subject youre capturing. Then what would you want the ap. at and what would the values be for no gain?

That is the beauty of cine mode, it WANTS to maintain a 1/48 as long as your aperture is within range.

You would have to use TV mode and set the shutter, then check and recheck aperture with the photo button. Again, as long as you are zoomed out you wont be getting gain with exposure locked showing aperture >1.8

After that, you will see that it stays 1.8 but the screen gets brighter with every + of the exposure... That's gain.

[lukeness]

Spooky Aramis... that was your 666 post.

Mute, Aramis is right. Just because the exposure is at "0" doesn't mean it's zero gain. This is how I do it. I do everything the same as most everyone... zoom out, go to TV mode etc...., then when I point to a bright light, I lock exposure and immediately put the exposure down to -11 or however far it'll go. Then I check the settings with the photo button half way down. I proceed to click up on the exposure while checking the photo button every time I move it up one. When the setting repeats itself (for example: f1.8, 1/30repeats), then you know it added 1.5db of gain. I click back down one exposure setting so that it's at the first f1.8, 1/30 setting, then I lock. That would be zero gain.

No. "0" does not mean no gain. This may help: http://www.elurauser.com/articles/manual_mode.jsp

Here are possible apertures and gain values:



One step is either 1/4 of an f-stop or 1.5 dB of gain which is the same (one f-stop equals to 6 dB of gain).

F5.6 corresponds to 12 EV steps where built-in ND filters kick in. If your aperture is F2 or narrower, then there is no gain. Therefore, aiming for F2 is much simpler than for fully open iris, you don't need to count EV stops.


If you want shutter at 1/100 then set it to 1/100. Adjust aperture with Exposure slider and verify actual value it with the Photo button.

[zephyrnoid]

It's been a year that the HV20 has been on the market. Thousands of words have been written about how to over ride the camera's Auto exposure modes and do this without adding gain. So many well meaning people have put so much effort into research, testing, text and video tutorials and yet, one year later....
1) There is no single best method that anyone can simply pick up and use.
2) Not a single truly comprehensible tutorial- sorry if that hurts anybody's feelings.
Part of my job is to write clear and concise instructions for failproof results.
If anyone feels they are an expert in this process of controlling the exposure and they wish to author a marketable tutorial, I'd be delighted to assist.

[BobbyMurcerFan]

Or just turn on Spotlight mode. Turns gain off, but also turns off manual white balance for some reason.

Always locking exposure makes for more film-like footage IMO, so in the end I prefer the Tv method so I can also adjust white balance manually.

-- Kevin

Do you know if white balance is reset when switching to Spotlight Mode?

In other words, if I set the white balance to something other than auto in Tv Mode and then switch to Spotlight Mode, does the white balance setting from Tv Mode persist?

THANKS MUCH!

Well I did some testing by taking stills while in Tape Mode. And the answer seems to be that Spotlight Mode always resets to Auto White Balance.

[Hannibalekta]

Does anyone have an idea what to do, when using a 35mm adapter? Its not possible to use the cell phone trick cause if you are zoomed out, its dark from the adapter. Mh...

[DFv2]

It's been a year that the HV20 has been on the market. Thousands of words have been written about how to over ride the camera's Auto exposure modes and do this without adding gain. So many well meaning people have put so much effort into research, testing, text and video tutorials and yet, one year later....
1) There is no single best method that anyone can simply pick up and use.
2) Not a single truly comprehensible tutorial- sorry if that hurts anybody's feelings.
Part of my job is to write clear and concise instructions for failproof results.
If anyone feels they are an expert in this process of controlling the exposure and they wish to author a marketable tutorial, I'd be delighted to assist.

Interesting, I write engineering scopes of work - I'm VERY familiar with needing to write concise, direct and most importantly IDIOTPROOF documents that are received by a wide audience of "readers".

PM me if you're interested, I'd love to work on something like this.

[bluegrass]

Interesting, I write engineering scopes of work - I'm VERY familiar with needing to write concise, direct and most importantly IDIOTPROOF documents that are received by a wide audience of "readers".

PM me if you're interested, I'd love to work on something like this.

and when you have it completed, let's make sure it gets posted as a sticky here on this forum, because I still don't understand fully how best to control do it.

[Rumpelgeist]

and when you have it completed, let's make sure it gets posted as a sticky here on this forum, because I still don't understand fully how best to control do it.

You don't understand what exactly?

[Paul Tarlevs]

How do you LOCK something? Like when it's 1.8 f and 1/48 shutter i go into exposure and move the dial left and that locks it?

[Lunchbox]

You can read this thread

http://www.hv20.com/showthread.php?t=4195

[Ian-T]

While in Cinemode:

1. Turn your camera on and point the camera at a light source.

In this scenario we will use the camera’s LED light. Turn the LED on and point the camera at a wall (or your hand…whatever you choose).

2. Press the joystick “in” once and navigate to the + and – icons on the screen.

At this point the + and – indicator will be grey…which means it is still unlocked. Keep it displayed on your screen …

3. Lightly press the “photo” button on your HV20 and take note of the f stop and shutter speed.

At this point, depending on what the reading says…..move your camera forward or backward...while clicking the photo button in between movements. Once it reads…..f1.8 1/48…then you are golden.

4. At this point you want to quickly press “in”’ your joystick.

Here is where the + and – will be all white instead of grey…This means you just locked in f 1.8 1/48. You can now turn of the camera’s LED light.

5. You can now press the joystick “in’ one last time to take it off the LCD screen. This is important….so you don't accidentally hit it “down” and mistakenly unlock what you just set. I call this…the “Set it…and Forget it” method. If you need to adjust your f stop from here…all you have to do is press the joystick “in” once…and your “locked” settings will appear onscreen. Just navigate left or right to make your necessary changes. It’s as simple as that.


This is all assuming you have an SD card inserted in your cam.

[Paul Tarlevs]

* quote removed by mod *
Sweet thanks!!! And this will get rid of that stupid gain. Is this the key to a nice crisp image?


Thanks a lot. That one post has explained 3 hours of searching through threads that I spent today

[Ian-T]

f 1.8 is wide open on the HV20. You can stay there or click the joystick "once" to the left to sit at f 2.0 1/48.... It all depends on your lighting situation. But yes...this would prevent gain from kicking in and adding that bothersome grain. But remember...light your scene well.

[mute]

Ian-T, THANK YOU ALOT. Thats the best tutorial ive read that makes total sense of how to accomplish this. I just have one question. You demonstrated with CineMode. What if i want to be on Tv Mode and i want a shutter of 1/100? Would i do the same exact thing but wait until its at f1.8 and 1/100, then lock it at that point?

[Paul Tarlevs]

OK I got it now. But how come when I zoom in, the aperture changes is that right?

Heres how I do it.

I press one on my cellphone on tv mode 1/48 shutter and immdeiatelly lock exposure.

I then change the exposure while checking to see the aperture to f1.8.

When it is set to 1.8 and at 1/48 shutter, it is a darker crisper image.


Is this right?



Also should I lock exposure immediatelly or lock it when I see the change f1.8 and 1/48 shuhtter during the cellphone screen.


OR like in DFv2's post:


1) Zoom all the way out.
2) Aim at any light source you like, check and recheck apature/shutter.
3) Try as hard as possible to aim at something that will produce a 2.8 - 1/48 setting.
4) LOCK IN the 2.8 - 1/48
5) Adjust exposure at will, the upper limit will be +6 (1.8 w/no gain) and the lower limit will be the bottom of the barrel -11.





or does it even matter?