Z1/FX1 gain control rant
 

Anyone else annoyed by the way Sony has gone to that 3 switch gain button? They used to have it set up that once you fully opened the iris dial that it would then increase the gain.

The problems are:
* Limited to 3 presets that need to be set in the menu. Indoors I usually need 12db so then you're left with a compromise of
0,6,12 missing important middle ranges of 3 and 6
3,6,12 missing no gain and 9
3,9,12 missing no gain and 6
3,6,9 you get into a low light situation that you need 12 and your screwed

* The switch is hard and when you need to adjust the gain during live shooting, you'll get a visible vibration from the switch and an audible click. Even an off camera mic (3ft away) picks up the sound.

I shoot a lot of dance performances with black backgrounds where you have to shoot using manual exposure and it just annoys me to have to toggle that dam switch through the entire performance.

That is only true for consumer cameras. Most professional cameras have the same switch setup as the FX1. I too have a FX1 and most of the time have it set at 9db for theatre video shooting which means the iris is somewhere around F4 to F5.6 most of the time giving good depth of field for the stage. Meaning I can set the focus and leave it that way as depth of field will cover most of the stage unless I zoom to the max. Increasing gain after the iris is full open will give minimum depth of field and require continuously refocusing.

Ron Evans

I agree Pete - I shoot performances and it is indeed a nuisance not to be able to smoothly add gain. I would prefer some sort of wheel or knob which would add gain in 3dB increments. Recently I've been doing pretty much what Ron suggests though. A 9dB gain boost is still pretty clean. For my most recent shoot I set the switch at 9-12-18. There was one scene of the opera where the only light came from two flashlights - pretty crazy for a production in a 3,000 seat theatre...

You can set up a picture profile with a max auto gain limit, say 12db. Then set the switch at 0, 6, 9 or whatever. When it's too dark for that, hit the auto gain button, and it will go to your 12db limit. This effectively gives you a fourth value.

There is a setting which ramps the gain change when you use the switch. For myself I rather have simple metal Nagra switches which give the assurance of taxtile feedback than plastic pretties which have to be stared at whilst you try to hold your shot nd may break.

thx. good tip, I'll use that next time.

still annoyed that they no longer have gain incorporated with the iris control dial.

like bob hart says you can control the speed at which gain changes take place in the menu

Usually no consideration is given to lighting for the video camera. Which means you have to cover a wide exposure range with dark and high contrast lighting. I wouldn't have a problem with them lighting for the audience, unfortunately they usually complain its too dark after they see the video.

3,6,9db give excellent brightness with low noise. 12db is a necessary evil to keep customers from complaining. 15+db is just awful and i refuse to go there.

What setting is that Bob, I must have missed something? Gain setup only lets you assign a gain level to each switch position. Just looked through my Z1 manual and am not sure which setting you're describing....

In addition to the presets, you can control the speed at which gain changes are made. For example if you had your presets 0,9,18 you'd probably want a slow change so when adjusting the gain while shooting you wouldn't see a sudden jump when you changed the gain.

I understand what you're saying, but HOW do you adjust that parameter? I don't see it in the menus. The only slightly related item might be the AE response time, but I thought that only worked with automatic mode.

Specifically, what menu choices do you need to make for this to happen?

I think thats the setting and yes I assumed the same thing until recently.

From the Z1 manual (page 61)

I just fired up my Z1 and this was set at the default (fast). Flipping the gain switch produces a noticeable immediate jump in image brightness. I then set the AE response to slow and tried flipping the switch again. Absolutely no difference from what I could see.

I think this only affects automatic settings, so it's no help for those of use who prefer to keep everything on manual.

My apologies for misinforming you. I use the auto settings to verify my manual settings but oitherwise shoot manual on mostly fixed settings. I thought I was being a clever fellow by remembering the reference from the manual and having tried it. That one got past me.

I tried it and it works for me in manual. set your pre set to 0, 18 to see the difference. when set to Fast it takes a second, Slow takes 3 seconds. although it seems to only effect increase in grain when i went from 18 down to 0 it took 1 second for either setting.

I can clarify this.
 

Even when shooting in full manual, the Z1 will still compensate ever so slightly for exposure. The effect is minimal and really only noticeable when panning/tilting from extremely bright to extremely dark areas and vice versa...and when the AE Response is set to medium or fast. Under these conditions, the screen will appear to instantly gain up or down just enough to be annoying and destroy your shot.

I recommend for most people that they set the AE Response to "slow" and forget about it.

Now, about gaining up and down smoothly...

Step 1
Open a picture Profile and set the AGC limit to your liking. For stage performances, I prefer 12db. Leave this picture profile on while shooting.

Step 2
Run everything in full manual, except for both the iris and gain.

Step 3
Set one of your assign buttons to Spotlight mode and turn it on.

Step 4
Set another one of your assign buttons to AE Override and turn it on.

The iris dial now acts as a single controller for both the iris and gain and will adjust them both in accord with each other as you ride this dial. Effectively, the dial is now controlling what you might call the "brightness" which equates to a setting between -7 and +7. As you "brighten" up the picture, the transition will be smooth and lag slightly behind the dial (by about two seconds or so) resulting in a higher gain setting without the noticeable "click" that you would get with the switch from L to M to H. (As an exercise, you can display the iris and gain settings on the LCD as you do this to see exactly how the two features work together.)

I greatly prefer this "semi" automatic method to full manual for stage performances with lighting changes drastic enough to require gain changes mid-performance. Although it at first sounds amateurish to rely on such a setting rather than go full manual, the smooth transitions between gain settings and the greater dynamic control afforded me trumps the one ill effect...that the camera will tend to slightly overcompensate for a 100% dark stage, The picture does not go haywire or anything like that during this time, but if the lights do come up suddenly for the next act, the picture will be a little bright initially (for a couple seconds) as it adjusts to the new lighting conditions. This effect can mostly be negated by riding the brightness down when the stage goes dark and then ramping back up as the lights come back up. It's really not that difficult at all. Plus, if you are using a less-than-veteran shooter, there is no better way to simplify the exposure process.

Alec Moreno
http://www.1Day1ShotProductions.com