Adjusting the ISO?
- Thread starter cap10kirk
- Start date
Barry_Green
Moderator
That is how it is done.
traviswears
Well-known member
Wish there was a way to tweak the ISO on the fly w/out having to go back into the menu. 3 options are nice but not enough for run & gun field work.
Barry_Green
Moderator
That's been discussed much, and lots of us agree that more control is better than less, and I've asked them to add that to future designs.
I don't understand why not? It's been enough for every video camera since the dawn of time... in fact, after doing tons of field work in video cameras, I can say that ONE ISO is usually enough. Adjust exposure using the ND filters and the iris... man, back when I was shooting events we *never* touched the gain. Ever.
I'm not saying it wouldn't be desirable to have more options, of course it would -- but when you say it "isn't enough" I don't understand that. I mean, it may involve working in a way that's different to how you're used to working, maybe, but adjusting exposure by the ISO is not a typical video workflow; neither is adjusting by shutter speed. We always glued the shutter speed at 1/60th, set the gain on low, and adjusted exposure by using the iris or the ND filters (or both, of course).
Barry that works in ENG for typical pro video cameras, but this is not a typical video camera. The dreadful 14-140 is as close to an ENG lens as there is for this thing, and f4-5.5 through a zoom when you're running through different rooms is a killer, and has me fumbling through the menus trying to find gain between whatever was set in high, which is now too high, and mid, which is now too low. The next best suggestion is too just not use the camera at all in ENG. If I had a Sony 900 out in the truck Id go grab it, but when the client asks me to take the AF off the sticks and follow someone around for B-Roll, this camera demands flexibility the lens does not give.
Barry_Green
Moderator
Right, it's less convenient, but ... I don't know, to say it isn't "enough"? Like you couldn't actually do the job?
(and yes, I agree that using the AF100 for ENG-style work is far from ideal anyway). If I had to do it, I'd probably use the 14-140 at ISO 800 or 1600, and just use the iris wheel. Of course, the bigger problem there is that the iris wheel response is so slow on the Lumix lenses...
(and yes, I agree that using the AF100 for ENG-style work is far from ideal anyway). If I had to do it, I'd probably use the 14-140 at ISO 800 or 1600, and just use the iris wheel. Of course, the bigger problem there is that the iris wheel response is so slow on the Lumix lenses...
traviswears
Well-known member
well, as of now, my primary lens is Nikon 17-35 2.8 w/manual aperture ring. It has stops 2.8, 4, 5.6, 8, 11, 16, 22. The perfect exposure outdoors between 2.8 - 4 or 4 - 5.6 sometimes can't be found easily with just a simple ND flip.
granted, the NDs are a lifesaver and I'm glad for them but I found yesterday that a little ISO tweaking was needed to get the right exposure. I wasn't able to control iris as well as I could've with a good ENG lens. Going from bright sun, to shade to indoors wasn't impossible but it was just a little more difficult than it could've been had the unusable iris wheel been able to double as ISO control.
granted, the NDs are a lifesaver and I'm glad for them but I found yesterday that a little ISO tweaking was needed to get the right exposure. I wasn't able to control iris as well as I could've with a good ENG lens. Going from bright sun, to shade to indoors wasn't impossible but it was just a little more difficult than it could've been had the unusable iris wheel been able to double as ISO control.
In my view, the archaic concept of a fixed, pre-set ISO should've been tossed out a decade ago, along with the film cartridges (and DV tape for that matter). Aside from challenging lighting conditions where it's necessary to set a fully manual exposure, I don't want to have to touch the video gain control either. What I want is to set the aperture and shutter speed using my own judgment, and train the light meter on the area I want the camera to expose. It should then select the hottest exposure that won't blow out the highlights, and hold those initial settings for the duration of the video take. The entire concept of a fixed ISO set in coarse 1/3 stops is an obsolete concept from the film era that obstructs my workflow rather than simplifying it.
Barry_Green
Moderator
I agree that fixed ISOs in 1/3-stop increments is indeed obsolete, we should have a totally variable gain knob just like with volume. Hopefully, going forward, such concepts will make it into production models. Just like having two fixed white balance presets has finally yielded to allowing us to variably choose our white balance.
That said, I still don't think that having three positions on a switch "isn't enough". More control and more options would be better, yes, but I still think you can get the job done. I used to do that job on a DVX100 with the gain set at zero and the only way to adjust was the iris, and it was all I needed (and, all that any video shooter has ever had, I should add!) It's enough. May not be ideal, you may think of ways you could do it better, but it's still enough.
That said, I still don't think that having three positions on a switch "isn't enough". More control and more options would be better, yes, but I still think you can get the job done. I used to do that job on a DVX100 with the gain set at zero and the only way to adjust was the iris, and it was all I needed (and, all that any video shooter has ever had, I should add!) It's enough. May not be ideal, you may think of ways you could do it better, but it's still enough.
Shooter
Veteran
Basically you want an automatic ISO yet you still want to set the stop and the shutter speed.
How would you set these if you did not know what the ISO (asa) was?
What happens when the light and shade changes within the scene. eg .in a pan or when the subject moves in front of the window or from a lit area to a shadowy area?
Ideally, I'd set shutter speed to control motion blur and aperture to control depth of field. What would make an automatic ISO usable in practice would be a good histogram display or waveform monitor. With the light meter trained on my subject, a half-press on the shutter would set ISO and the histogram would show me the exposure profile. If it was too hot, I'd lower it with an ND filter. If it was underexposed, I'd readjust aperture and/or shutter speed to get a better exposure. I'd also want to be able to set a gain limit in advance, to keep worst-case ISO noise under control.
Personally, I wouldn't want the camera to make any further exposure adjustments after I hit the shutter button, for the duration of each take.
Shooter
Veteran
You would have to be very confident that varying the ISO gives you consistent / constant scene to scene results. (gamma, noise, knee etc)
Currently it is recommended (in the manual) that you black balance whenever you change sensitivity.
Also ...what you suggest is a very global way of exposing all the tones / levels across the frame. I guess thats just a consequence of any "automatic" exposure control.
Currently it is recommended (in the manual) that you black balance whenever you change sensitivity.
Also ...what you suggest is a very global way of exposing all the tones / levels across the frame. I guess thats just a consequence of any "automatic" exposure control.
Well, it's not really about convenience, it's about speed. And I would encourage those who downplay the need for this design feature, also to include with their opinion whether they've actually used this camera for a client in a paid situation that becomes an ENG situation. If you don't ever really do it with the AF100, then you're speaking hypothetically. I can speak from experience, that if this camera had been tested with its likely and unfortunate 14-140 lens combo in ENG, the need for an ISO adjustment on that fine function wheel wold have become quickly apparent, Yes, Panasonic never claimed this to be an ENG camera (good thing), but with a remote focus/iris control, I've found it's pretty darn good, at a pretty decent price - as long as your light doesn't change a whole lot. Walk into a room with different lighting, and that slow 14-140 is going to make your fingers do the walking into the menu, because 3 positions end up not making up for the limits of exposure with that lens. Same holds true for putting different lenses on the front. Apparently ARRI got it figured out for the Alexa. A new breed of camera in a multitasking era demands an unconventional approach, alongside the old familiar ones.
Shooter
Veteran
Why would anyone design a function into a camera designed for a different purpose?
By your own admission the "unfortunate 14-140 lens combo in ENG".
If one does a certain type of work ( esp.paid for) and it works for you in that role ...why not use a lens more suitable to the task?
Just asking.
BTW - I would vote for the ISO adj. on the Iris Wheel..and Not the shutter/ frame rate wheel ..were it ever to happen. The iris wheel will always be redundant to me otherwise.
By your own admission the "unfortunate 14-140 lens combo in ENG".
If one does a certain type of work ( esp.paid for) and it works for you in that role ...why not use a lens more suitable to the task?
Just asking.
BTW - I would vote for the ISO adj. on the Iris Wheel..and Not the shutter/ frame rate wheel ..were it ever to happen. The iris wheel will always be redundant to me otherwise.
Yes, when you factor white balance and individual RGB gamma curves into the mix, exposure becomes a non-linear function and ISO may no longer be simply scalable. But in practice, I almost always attempt to make best use of the camera's limited dynamic range by setting exposure levels just short of blowing out the highlights. With well-engineered firmware, I have no doubt the camera could do this more reliably than I can. I use color correction in post to handle scene-to-scene exposure variations in my own work, and I expect that correctly exposed auto-ISO footage would be no different.
Because it simply makes it a better camera, period. There's no sticker on the top of the AF100 which says, "Do Not Use For ENG". It is still a video camera, and the image it produces is superior all around to my HVX, and is on par with many 2/3" camera costing far more. If I'm using it to shoot pretty interviews because the client loves the look, as well as I, he is going to eventually ask me to follow Jerry, Mr. Type A CEO around the building as he shakes hands and does his thing. I'm prepared for that with my gear - but I don't have 20 seconds to go strolling about the menu while my subject strides off.
As I've said, it can do ENG pretty well with remote Focus/Iris. If there were a better, faster ENG lens for this camera, the iso flexibility would be less needed. There's nothing else that covers the ENG focal lengths of the 14-140 in one lens and also has the quiet servo capability via remote rig mounted remote.
I am the sort of person who believes in improving something even if it's already good. It can be better, and would not be a risky function, as is the VFR.