"the camera shoots 1/400 sec fully stopped down (to f9.6)!

Obviously, this aperture with a 1/3" chip gives a lot of lens diffraction,"

I am no expert on this and my calculator sometimes makes mistakes :), but I arrived at a diffraction limiting f value of 6.9 for a 1/3 inch HD sensor, base on f 8.6 limit that someone has estimated for my D7000 camera. f9.6 is only one stop past this limit so I would only expect a slight degradation, not "a lot". Have you actually experienced severe diffraction limited degradation? (Bear in mind that lens and sensor imperfections will mask diffraction to some extent.)

"It just seems kind of bizarre to me that a modern video camera can't expose using a standard shutter speed (ie, 1/48 or 1/60) in bright light without adding ND filters in front of the lens."

Whatever in the world makes you think that?
The photodetectors in both CCD and CMOS imagers have a noise floor and a saturation limit. Combine that with the limitation of diffraction from the iris and wierd look of using a too fast or too show shutter speed and you should be able to understand why professional video cameras incorporate a number of neutral density filters. Those that do not will certainly perform better if you put them, as needed, in front of the lens.
To the best of my knowledge there hasn't been any significant development is the design of the actual photodectors used in video cameras, all the progress has been in how we deal with the charge that the photons have created.

Bob.

Musicvid, the NX70U is a video camera. These shutter speeds correspond to North American framerates of 24p and 60p, which is why I'm calling them 'standard'.

Yeah, I have tested the camera and things break down fairly visibly at f9.6 compared to f4.0.

Bob, Maybe I didn't phase my question right. I'm aware that ND filters are used extensively with film cameras, but it seems odd to me that a documentary-style run-and-gun video cam can't shoot in bright light at a standard shutter speed without a 6-stop or more accessory ND filter.

In comparison, the Canon XF100 has an internal ND filter (switchable), plus you can dial negative gain, so there's no need to add external filters.

I am curious which of these two cams is more the norm within its class: add-on filters needed, or capable of handling daylight on its own...

Andy,
If you'll follow along, you will see that my analogy is correct.

The only relationship between frame rate and shutter speed is that it limits the slowest theoretical shutter speed available, but not the exposure value in a given reasonable lighting / subject scenario. They are mutually independent. So there is no basis for designating the baseline as "standard."

Actual shutter speed lies on an axis with ISO and aperture, in conventional terms. Once the proper EV is determined, still and video photographers often give weight to either the shutter speed or the aperture to achieve a certain result. When the aperture is at or near its minimum for a given shutter speed, or we want to reduce DOF, we start thinking about adding ND.

It sounds like you are wanting more internal compensation (+ND or -ISO) in full light, and not a smaller aperture or faster shutter speed for your purposes. All very reasonable.

So based on your own numbers (1/400th @ f9.6) I did some quick backfiguring for you. Your camera has a native ISO somewhere around 150, which is not unreasonably high. In auto mode your effective ISO is about 36, or the equivalent of 2 ND. Again, wanting more internal compensation is not wrong in itself, but let's see what we would have to do to achieve that.

In order to shoot at 1/50-1/60 in full daylight at ISO 150, you would need the equivalent aperture of f27, which isn't an option. At f8 (more reasonable?) and the same shutter speed and ISO, you would need the total equivalent of 3.5 ND, not 6 as you suggested. That would give you the equivalent of ISO 13-14.

Switching to auto mode, you would need an additional 1.5 ND to achieve the same EV. None of these numbers sound terribly unreasonable, but if we narrow down your wants to another 2-4 stops of internal compensation, that is not terribly unreasonable either.

That all being said, 1/60th would only be used with a rock-steady tripod, not handheld or run-'n-gun, unless some deliberate blurring of camera and subject movement and / or low available light is part of your plan. Usually we think of 1/125th using a normal lens focal length as the minimum shutter speed for "reasonably" sharp handheld results in daylight, either in still or video photography.

Hope this makes my comments easier to incorporate in the context of your original post. Also hope my quick calculations are correct.

;?)

Well,

I guess that opens up a whole new door of questions. I was assuming that filmmakers are always trying to shoot around 1/48 (for 24p) even when it's handheld documentary footage, unless they're going for a specific effect, ie extra or less motion blur.

If that's not the case, and higher shutter speeds are used for 'normal look' shots, I was completely unaware of it...

I looked at the specs for this camcorder, and it seems the shutter speed will go all the way to 1/25th, so such slow speeds are possible, of course limited by the actual frame / field rate. So slap on some ND, set the aperture to f8, and experiment!

Some blurring (deliberate or not) in combination with slow motion as a documentary technique can be effective. I'm thinking perhaps of monochrome footage of the Vietnam-era demonstrations, or maybe even Fellini.

As a geezer who shot a lot of movie film, I would mention that my Arri S 16mm had no variable shutter. Later camera designs like the Eclair added variable shutters. Generally exterior shots with Ektachrome Commercial (ISO 16) were around f8-f9. The Arri had a 180 degree shutter and a 24 fps exposure of 1/48 sec.

I see a lot of video shot with higher shutter speeds and generally it bothers me. Camera movement, particularly strobing pans are a bit like fingerrnails on a blackboard. ND filters are the answer most of the time.

Ralph

"That all being said, 1/60th would only be used with a rock-steady tripod, not handheld or run-'n-gun"

That is completely wrong.
Cameras that shoot moving images traditionally specify shutter as angle not speed and the standard shutter opening angle is 180deg. As you change the frame rate the angle remains the same. So at 24fps the shutter angle being locked to 180 deg gives a shutter speed of 1/48 sec.
Pretty well everything you see on the silver screen is shot at that shutter speed, on tripods, dollies, cranes or handheld.

The blurring of motion from the 180deg shutter is a vital part of achieving acceptable motion rendition. Faster shutter speeds at anything below around 60fps can cause motion to look jerky, most modern movie cameras do have the ability to change shutter ange, a smaller shutter angle can be used, primarily to deliberately introduce a jerky / strobed feel to motion. Shutter speed is generally not used to control exposure. All of this applies as much to video cameras as it applies to film cameras, the physics of moving images remains the same regardless of the recording medium being film or digital.

It is not uncommon for movies to be shot entirely at a given stop. Exposure is then controlled with ND filters in front of the lens or by lighting to a stop.

There's also implications for encoders shooting motion with small shutter angles.

To answer Andy_L's question it is normal for video cameras to include mechanically switchable ND filters in the optical path, just before the sensor or the beam splitter. You get either 3 or 4 choices for the amount of attenuation. 3 is very common but Sony's Z5 has 4 to give better exposure control. The absense of ND filters is one of the differences between the consummer cameras and the prosummer cameras, ND filters are relatively expensive.

If you are buying ND filters to use if front of the lens do not buy cheap ones, especially high attenuatation ones. The cheap one may not block IR light leading to IR pollution of the image as video cameras are quite sensitive to IR light.

Bob.

Also, in video, "shutter speed" only relates to how long the photons on the detector image sites are counted (charge accumulation). It has nothing to do with how long the photons are exposed to the image detector surface (unlike film cameras) which is always 100% of the time. If there is too much light on the sensor you will saturate the detectors sites at any "shutter" speed. Thus you will likely need ND filters in direct sunlight.

Bob, I'm sure you are correct from the "angle" perspective, but that does not make my statement "completely wrong," not by any means. I can promise that your 1/48th number is relative to angle and frame rate in the context of cinematic film shutters, but is not a relevant conventional shutter speed equivalent as mine (and Sony's) are. For your number to be true, the camera in question would need an effective aperture of f/27 or an effective ISO of 13.5 to expose properly in full daylight, and every frame with movement would be blurred, none of which is so. Prosumer video equipment doesn't operate at a single fixed shutter speed, and you know that.

This is from the official specs listed in Sony's product literature for the NX70U. It is given in conventional shutter speeds, and this is how they are accessed within the camera, by the OP's own report:

Shutter Speed 1/6 - 1/10000 (Manual Shutter Speed Control)

So you can see that even Sony doesn't publish its specs in relative terms, but in conventional time units.
I'll stand firmly by my advice to not hand-hold at less than 1/125th actual shutter speed, based on regrets suffered over the past 50+ years almost every time I've done so.
I think we've beat this horse until it is sufficiently dead.
;?)

"Bob, I'm sure you are correct from the "angle" perspective, but that does not make my statement "completely wrong," not by any means"

Agreed and in hindsight I should have said something like "looking at it the wrong way".

"I can promise that your 1/48th number is relative to angle and frame rate in the context of cinematic film shutters, but is not a conventional shutter speed equivalent as mine (and Sony's) are."

That is correct, the 1/48th second shutter speed is only applicable at 24fps, change a film cameras frame rate and the shutter speed changes accordingly as the two are mechanically linked.

"For your number to be true, the camera in question would need an effective aperture of f/27 or an effective ISO of 13.5 to expose properly in full daylight, and every frame with movement would be blurred"

In full daylight one would normally add ND filters either as provided by the camera or externally. All the prosummer cameras will start frantically blinking an ND warning if the F Stop reaches silly numbers.

Every piece of footage I and many other shoot is shot with a fixed shutter angle of 180 deg, all the Sony "CineAlta" cameras provide the facility to specify shutter opening as an angle. Every frame of movement is blurred, that is a vital part of motion rendition, check just about anything on my YouTube channel, almost all shot with 1/50th second shutter, I have the shutter switched Off. The only exception is footage shot with our HC5 which doesn't have that level of manual control.

"I'll stand firmly by my advice to not hand-hold at less than 1/125th actual shutter speed, based on regrets suffered over the past 50+ years almost every time I've done so. "

If you're shooting 60i that's not too far off nominal shutter speed, the nominal shutter speed for 60i is 1/60th. At shutter speeds much faster than 1/125th you will start to get unpleasnt outcomes, ones that you'll see a lot of in sporting events where fast shutter speeds are used to facilitate slomo extraction from the same camera. Personally I find it very annoying, not that I watch much sports anyway :)
On the other hand sticking to the normal 1/60th for 60i or 30p shouldn't create any unnatural amount of motion blur. In fact I've oftenly shot 50i with a 1/25th shutter speed, just to get more light on dark stages. With dancers the "look" is quite acceptable adding a certain etheral feel.

In summary, if we're only talking about the difference between 1/60th and 1/125th the difference is not that great at all and not really worth much discussion. On the other hand shooting at 1/500th especially 24/25/30p is not going to yield very pleasing results. Sony do sell screw on ND filters for the consummer camera largely for that reason.

More on topic Vegas provides both motion blur and supersampling for those doing motion graphics for exactly the same reason, to get proper motion rendition.

Bob.

I guess if one references their viewing experience to 20th century cinema, frame blur and slow frame rates are OK, at least "safe."

But even that conventional thinking is changing, with major films being shot at 48p and 60p, and the growing realization that especially at higher frame rates, higher shutter speeds can give outstanding clarity and still be aesthetically pleasing and effective, without venturing into the stroboscopic range.

big kids shooting 4k "film" are pushing for higher rates especially if there's a lot of cad to be integrate. motion is corrected/smoothed in post editing,etc,..... but expensive to do..... a lot of motion/camera tracking.......

But the advice on ND filters is priceless....... cheap ones can have many problems besides ir leakage... internal NDs are priceless for the run&shoot crowd is my understanding..... :-)

"But even that conventional thinking is changing, with major films being shot at 48p and 60p, and the growing realization that especially at higher frame rates, higher shutter speeds can give outstanding clarity and still be aesthetically pleasing and effective, without venturing into the stroboscopic range."

YES, YEAH, welcome to the club :)

That's why I said "Faster shutter speeds at anything below around 60fps can cause motion to look jerky,"

Long ago in a heated debate elsewhere I pointed out that the younger generation gets their entertainment at quite high frame rates and the movie business needs to take that on board if it doesn't want to lose its audience. That's one of the very few times in my 10 years in this game I've not felt an idiot for speaking up in an august crowd.

Bob.

If the OP is still around, I think I can summarize the last half of this discussion.
Apparently the geezer still photogs and geezer cinematographers have agreed to disagree on what constitutes good shutter speeds for guerrilla ENG and documentary work in the 21st century. It's worthy of note that both camps started out with film and mechanical shutters, and tend to think in those half-century-ago terms.

The cinematographers say keep it smooth and safe. Of course they usually work on tripods and may not fully appreciate how hard it is to hold any camera steady enough to get sharp frames on the go. Add some focal length and it becomes impossible.

The one surviving still photog (me) sides with the younger crowd, saying sharper is better (up to a point), and if you can't do it with a tripod, do it with shutter speed. As such I tend to think image stabilization may work better at higher shutter speeds and frame rates, and it's super easy to add the blur in post if wanted. With a longer lens, getting sharp frames becomes mission-critical because any camera blur becomes greatly exaggerated.

But as Bob pointed out, we aren't that far apart. I'll agree right now that 1/500th at 24fps borders on the ridiculous, and if you're already stopped down, that would be the time to add some ND. There, I hope I've been somewhat fair to both camps.

In my experience, professional video cameras provide onboard ND and a little bit of DB rolloff, all of which can be set manually. Some professional cameras also provide a degree of shutter control, which can be set manually.

Prosumer and consumer cameras may or may not have built-in ND or attenuation. Cheaper cameras will compensate for bright situations by increasing their shutter speeds. Unfortunately, this changes the look of movement, usually giving it a kind of strobing or staccato jerkiness.

The problem with cameras doing this automatically is that two shots could have very different looks to their motion. If you're working professionally you'd want to be able to lock the shutter speed down so that this doesn't happen. The idea here is that you should manually set the shutter angle/speed to meet your own artistic or technical needs. You should control the shot rather than the camera controlling it.

And...If I had hired someone to shoot video for me and they provided something shot at a high shutter speed without my specifying it, I'd be p*ssed. I wouldn't hire the person a second time.

Rob Mack

"The idea here is that you should manually set the shutter angle/speed to meet your own artistic or technical needs."

Exactly.
Unlike the world of the stills photog in the world of film and televison where motion is the thing, shutter speed is not used as a mechanism to control exposure. Obviously it will control exposure but in our world its primary impact is on how motion looks.
For that reason prosummer and pro cameras have built in ND filters. A lot of the very high end cameras don't but it is expected that the DP / cameraman will fit a matte box to the camera and carry a kit of ND filters.


Now if I'm shooting stills handheld the slowest shutter speed I'd use is 1/125 but I really am hopeless at holding a camera still so I'm much more comfortable using the fastest shutter speed I can, if I could afford gyro stabilized lenses I'd be buying them.


Here is a good example of what happens, you only need to watch the first 30 seconds or so full screen to see the difference between the HC5's fast shutter speed and the EX1's locked down shutter.



I really should have had a matte box with another ND filter in it. I also should have had earplugs and a ND3.0 filter over my head. I don't like to make excuses for my bad work but that shoot was a nightmare, my wife and I were on the brink of sun stroke.

Bob.

We are moving the discussion into another related area i.e. whether the camera is an observer of the story you are telling/recording, or whether it is a participant. If 'shakeycam shooting, and stroby pans call attention to the camera's presence it will affect the audience's interpretation of the story. Much of the reason for image stabilization lenses and programs is to reduce drawing the audience attention to the camera.

Because 35mm cameras were generally not suitable for hand holding, shooting from sticks as the standard. With the Eyemo and 16mm cameras, hand holding became possible. Underwater filming evolved the other way, from a fluid moving neutrally balanced camera, to one on a tripod with a longer lens filming a cleaner shrimp.

Does it help your story to call attention to the camera? It is up to you.

Ralph

"It just seems kind of bizarre to me that a modern video camera can't expose using a standard shutter speed (ie, 1/48 or 1/60) in bright light without adding ND filters in front of the lens"

Well most of the prosummer cameras include ND filters in the camera.
Take a look at the HXRNX5U, it has 3 of them plus clear. The HXR-NX70U has none. One is roughly double the price of the other.
If you want to wrangle the problem in the NX70U you could buy a cheap screw on matte box and a set of good 4x4 ND filters. I hope 4x4s will cover the FOV without problems. Thing is by the time you pay for that the NX5 is not looking so expensive.

"Is this common in professional cams?"

No, they either have built in ND filters, been that way for the decade I've been in this game, from the PD150 to the PMW-350, all have built in ND filters.

The RED and Alexa don't, you generally use them with a matte box and carry around $2K worth of ND filters with you.

The NX70 is not a professional camera, not in the sense most people working in the industry would use the term. Even the EX1/3 I don't consider professional although I'll probably annoy a few people saying that.

"In full auto mode, some kind of ND filter or gain attenuation kicks in, allowing you to expose in sunlight at f4 and 1/288 of a second. A little better, I guess"

According to the specs that camera will go down to -6dB gain. Using negative gain can be problematic, you can lose latitiude depending on how the camera is setup. It might be just fine in this camera.

Bottom line is you just need to pony up for some external ND filters. You need a matte box, the screw on ones can be a problem if you don't have some form of lens hood or some way to control incident light from hitting them. Another advantage to a matte box is it can make a little camera look like a big camera, cheap way to impress clients :)

Bob.

Thanks for all the well-considered input! I've picked up a Heliopan ND .9 filter, which looks like it might still be a little hot for a target 1/60 f4.0 in daylight, but it's getting me a lot closer than 1/1000 without...

Maybe at some point Sony will update the camera's firmware to allow manual shooters to dial negative gain or the internal ND filter (whichever it is that's reducing exposure in the full auto mode).

I am kind of intrigued by the idea of shooting faster shutter speeds and then adding motion blur in post, though that sounds way too good a deal to be true. I'll have to do some experimenting with pans and shutter speeds and Vegas' motion blur and see what the result looks like.

Thanks again!

MV was giving a few good technical reasons to use higher shutter speeds. For example, if you know you'll use a stabilizer plugin in post, or if you know for a fact you'll do some other process that would benefit from crisp frames that lack motion blur. Slow motion in post seems like a good candidate too. So it's al about making informed decisions rather than blundering through a shoot and fixing things in post.

Rob

"With the Eyemo and 16mm cameras, hand holding became possible."

You're the expert on this, but wasn't it also around this time that Arri began playing with variable shutters?