FX1 exposure Settings

[Randy Sanchez]

Im just looking at a friends FX1 because im thinking of buying one second hand.. Given my circumstances i cant afford anything more than a second hand FX1 at the moment so if you reply please work with me on that rather than suggest i buy something else.. I may buy something else down the line but right now i can get a good deal on an FX1 so its my best option.

So I wanted to know, if you are filming in a theatre where a stage has lots of bright lights flashing around, how can you get solid control of exposure so that the performers faces wont be over exposed ?

It seems like whenever i adjust iris or shutter or gain, they all appear to have a similar result they just darken the overall image.. Shutter speed obviously creates a strobe effect if you go too far but there doesnt seem to be any control over just the high levels.. I use Vegas to edit and i know i can tweak with the levels plugin after i have filmed so im guessing you run conservative settings that maybe too dark live and then brighten in post ? Is that the only way ?

Id really appreciate to hear from anyone who has experience with this and can offer me some tips..

Out of the three options.. Gain, Shutter and Iris.. Which would you say is the order of prirority for adjusting first.. Would you adjust gain lower first then iris and shutter last ? Thats what im guessing, is that accurate ?

Thanks in advance.

[Adam Gold]

Instead of the FX1, you should really consider... just kidding. I shot theatre stuff for years with FX1s and they do a great job. Not as sharp or brilliant in low-light as the newer cams like the FX1000/Z5, but still, lovely images.

Here's the secret the "pros" don't want you to know: The FX1 does better in Auto mode than you can possibly do on your own. The secret is to kick it into SPOTLIGHT mode, lock it into INDOOR WB, and leave everything else on AUTO. Flawless all the time.

The FX1 has a dedicated SPOT LIGHT button. When activated, the faces are perfectly exposed and the blacks stay black. If the faces are still too hot, you could set AE SHIFT to -3 or -4 and see if you like how that looks.

Also, set up a Picture Profile where you specify the AGC LIMIT at 12dB, and the AT IRIS LIMIT at 6.8.

Originally Posted by Randy Sanchez

Would you adjust gain lower first then iris and shutter last ?

This is exactly what the cam does by itself in AUTO mode.

[Vito DeFilippo]

That's interesting Adam. I've never used the spotlight function, because I couldn't figure out what was supposed to be the point. I thought it just stopped the iris down a bit further then the usual auto iris, because auto would open up too far for the average amount of light in the frame, thus overexposing a spotlit face.

Are you saying there's more to it?

Thanks.

[Adam Gold]

I'm not sure there really is any more to it than that, although there was some discussion a while ago (on another forum) that maybe this function also tweaked the gamma curves a bit. Not really sure, but all I know is it works pretty well on all my Sonys. I think what I like about it is it's shifting the exposure intelligently and faster and more accurately than I can in response to shifting lighting conditions.

If it didn't do more than just stop down a bit, I'd think you could do the same thing with AE SHIFT alone. So maybe there is more to it.

[Vito DeFilippo]

Thanks. Sony's manuals are so obscure on these points that it's hard to figure out what's going on sometimes.

[Adam Gold]

Yeah, no kidding. It's often been said that they are obviously translated by someone who knows neither Japanese nor English... Howlingly funny until you desperately need to figure something out.

[Randy Sanchez]

Originally Posted by Adam Gold

Instead of the FX1, you should really consider... just kidding. I shot theatre stuff for years with FX1s and they do a great job. Not as sharp or brilliant in low-light as the newer cams like the FX1000/Z5, but still, lovely images.

Here's the secret the "pros" don't want you to know: The FX1 does better in Auto mode than you can possibly do on your own. The secret is to kick it into SPOTLIGHT mode, lock it into INDOOR WB, and leave everything else on AUTO. Flawless all the time.

The FX1 has a dedicated SPOT LIGHT button. When activated, the faces are perfectly exposed and the blacks stay black. If the faces are still too hot, you could set AE SHIFT to -3 or -4 and see if you like how that looks.

Also, set up a Picture Profile where you specify the AGC LIMIT at 12dB, and the AT IRIS LIMIT at 6.8.

This is exactly what the cam does by itself in AUTO mode.

Thanks for the help... That first line had me going for a sec :)

Ive got a a friends camera at the moment and he doesnt use it other than auto mode so im left to figure it out myself... I have been playing round with it since i first posted and discovered the picture profile.. I wasnt aware of the extra settings in there.. The AE shift you mentioned, i tweaked that in picture profile and i have been pointing the FX1 at my lights here at home and turned zebra on.. That combined with spot light has lowered the look of the exposure a fair bit and the zebra lines are significantly less.. So im hopeful that will solve it when i film this friday..

In the past my friend who owns the camera has filmed in all auto mode and some times the exposure has still been too much, i think he even did have spotlight on also.. But the AE Shift looks like it will compensate even more.. What i liked about that was when i moved the camera to another darker area of the room it adjusted itself to be brighter again, but then lowered when i returned to pointing at the light, so if the shots on stage are changing from bright to dark it should follow it quite well...

One question though, i have AE Response under menu set to fast.. Is that the only way to tweak the speed at which it changes ? It seems pretty good but if there was a way to make it a bit quicker that might be good.. If not should be ok..

Also with the gain and iris settings in picture profile.. What would setting them at 12db and IRIS LIMIT OF 6.8 actually do ? Is that going to add further reduction to exposure ? When i change from 12db to off for gain it seems to look the same here, would that change under different conditions ?

I have learnt a lot in these past few hours though just by playing round and also from the help you have offered.. cheers.

[Adam Gold]

Yeah, I forgot to mention... believe it or not, you actually want AE RESPONSE set to SLOW. Yes, if you swing to a darker area (or the lights go down) you'll have a dark picture for a while, but you want that, as that's what the Lighting Designer intended. Then your cam will slowly adjust so it isn't sudden and jarring. Here's one case where SLOW is definitely better. I have all my cams set that way.

The AGC limit is so your cam will not introduce too much grain and noise while it desperately pushes the gain to 18dB. I'd rather have the picture be a little dark than too grainy. The Iris limit doesn't really come into play in dark environments like the theatre, but the sweet spot for this lens is around f4 or 5.6. Stopping down further (again, extremely unlikely in a dark theatre, but possible) would take the lens into an area where you might get Chromatic Aberration (purple fringing) as well as making your DoF too deep. I'm not obsessed with shallow DoF like some, but the Auto Focus works so well that it's nice if you can throw the BG out of focus a little when on a performer's close-up.

Also, remember the GAIN switch on the side of the cam isn't for turning the Gain on or off; it's for switching from AUTO to MANUAL and the only way gain would be off is if you have it set to zero on one of those hard switch positions, and have the switch in the right place. I always have the L set to Zero and made sure the switch is on L at all times, so if I did kick from Auto Gain to Manual, the level would indeed be zero. But this trips up a lot of folks.

Oh, one more thing: Your auto focus will go crazy when the lights go out between scenes. Either shift to manual focus just before this happens, or leave the cam on Manual at all times and ride the PUSH AUTO button like crazy. Huge potential for disaster with the latter but great if you stay on top of it. Nothing worse than getting the show into your PC and finding out an entire act is out of focus. And no, your LCD is not a reliable indicator of this.

[Tom Hardwick]

Adam's nailed it - spotlight mode! The spotlight mode is an intelligent mode (unlike the backlight mode). It has a good 5 stop range, quite incredible, and like him I've used mine for stage productions and marvelled at what it has brought home.

I'm not with Adam on the CA though. That's not aperture dependent, whereas diffraction most certainly is. So take his advice, beware of shooting at apertures smaller than f/5.6.

tom.

[Adam Gold]

Yeah, I think diffraction is what I meant. The danger of knowing just enough to get myself into trouble.

[Randy Sanchez]

Awesome info i do appreciate it.. I have learnt a lot just in the past 24 hours and feel we should get a much better production this friday than previously.. I will let you know how it goes..

[Matthew Harris]

do you use your "auto" settings all the time or just in the above mentioned theatre setting?

[Marcus Martell]

So how was the shot?