DPReview TV - What is 'open gate' video recording and why should you care?

good info here! learned something 'new' i didn't know so far, thanks! :-)

it's then pretty much similar to how the term Dynamic Range in digital photography and video was borrowed from the audio industry, while the imaging industry of the film era (as well as today) already did (and still does) have terminology like Exposure Latitude, Reciprocity Law Failure and things like that ... (well, after all, younger generations in any industry often get away with older generations 'terms and conditions' for some reasons, don't they?) ;-)

Karl, the video made some good points and depending on your background worth watching. I just found it an odd use of a terminology that, apparently, neither Chris or Jordan were aware of.

One further point with regard to the term as applied to current digital projection technology in use in theaters. Open gate, when used with regards to a digital projector will refer to the projector's maximum light output at whatever the intrinsic white point is of the projection system before any setup is performed to achieve a particular colorimetry, including color space, white point, contrast ratio, etc. Once a projector is setup to a reference standard, light output will often be substantially reduced...the amount depending on the standard chosen.

Hirozontal was one of the best Japanese filmakers of our time 🙏

Ah yes the much acclaimed Hirozontal-san.

Sorry, typo: Hirozontaru

Own it Own it,

If you're renaming shutter angle, you should probably consider that most digital video solutions don't have a physical shutter involved in the process in the first place. "Exposure ratio" perhaps.

It's another case where the terminology is opaque and archaic, but you could argue (unlike sensor size) that few are actually going to be misled by it. Another term that's more obvious and easier to learn would be better, but barring widespread adoption people will still need to learn the old term during a transition period. I don't care enough on that one to mind, but it's going to take something like agreement between manufacturers to get the change imposed widely enough to have effect, and I still doubt you'll get pro video to move.

Camera manufacturers can't even agree terminology on IS/VR/OIS/VC/OS...

"shutter ratio" certainly makes more sense than "shutter angle"

it needs to have the word "shutter" in the name because that's the primary function that has to be addressed when the frame rate is changed.

several people out here have claimed that electronic shutter isn't a shutter at all, but that's simply not valid.

the z9 that people keep posting as an example, lists shutter speeds despite not having a mechanical shutter, because it uses an electronic shutter.

That actually, at least for me, was a better explanation than the whole video (sorry Chris and Jordan).

But isn't that trowing the composition in filmmaking out of the window?

Happy to dive in and nerd out with you! Plus, bonus, since I work with Chris and Jordan, I now get to rib them about the new feather in my cap :)

For the composition, well, it all really depends on if you're properly planning for your shoot (story boards, shot lists, blocking, lighting, etc) or if you're taking a 'fix it in post' attitude and just hitting record with no thought given to composition or any of the other stuff that, well, making photo and video actually fun to make.

Many filmmakers in the past have shot on a 4:3 ratio, but knew all along that they intended to crop to a certain ratio for the finished product. Some filmmakers even went as far as putting tape on the monitor to makes sure that while they were exposing a 4:3 frame, they were composing for 1.85:1 with tape markers to give them a frame.

So why did these filmmakers shoot in 4:3 film? (1/2)

35mm film and Academy ratio. When super wide aspect ratios became a thing, the film itself didn't change, just the framing and composition filmmakers were using in that frame.

For filmmakers that didn't frame to the final aspect ratio, some opted to compose for the middle sections of the frame, in order to give them options in the edit that let them pan across a frame or reframe a scene without having to blow up the negative and risk grain.

With TV in the 60s and VHS by the 70s, some filmmakers were even shooting the entire frame with plans to create a version for theaters and a second version for TV that avoided hacking off the sides haphazardly.

By the DVD era, you may have seen this without realizing it when the full 4:3 was sold as "full screen" or when distributors used 'pan and scan' to move around a wider aspect ratio to create a 4:3.

It's funny, 16:9 wasn't even a popular format until TV's changed their screen sizes and consumer cameras made 16:9 capture the default. (2/2)

You could explain the “open matte” is a related / connected concept.

But that's how most language works. Once a term is established and works, there's little reason to change it, if the alternative method basically does the same. Even if it works differently now in practise the artistic effects of changing "shutter angle" are still the same.

If you keep the term - no need to re-write any of the industry standard literature, and no confusion on set.

it's confusing because for the most part there is no such thing as "shutter angle" and "open gate" these days.

see this definition of a film gate: https://www.studiobinder.com/blog/film-gate-definition/

language evolves; in the 20th century for example over 90,000 words were added to dictionaries... should we stop doing that, and just rely on old words?

if you've ever taken classes in old english literature you'll know why language needs to evolve to be relevant and understood.

I agree that language that causes a lot of confusion or misunderstanding is generally best avoided, but I don't think that a widely used technical term necessarily loses its relevance, just because it refers to obsolete technology. Consider, for example, "blueprint" or "horsepower".

Yes, but why not Verbiest-, Jedlik, Otto-, or Fordpower instead? There never was a car that had a horse in it after all, just as modern video cameras don't have rotary shutters and thus no "shutter angle".

Hybrid cameras yes, pure film cameras no. The one is for photography, the other for film. Note how the Z9 doesn't have a shutter, but still a shutter speed setting?

In filming shutter angle makes sense. Just as T and F spot are different things, but similar. Edit: Hybrid cameras and dedicated video cameras are seldom mixed in hollywood style productions, but definitely can and will in documentaries. It's way confusing and a chance to make mistakes if you have to jump back and forth between shutter angle and shutter speed on the one and the other.

We don't lose anything having settings for both. You can ignore the one that bothers you, even.

Shutter angle is NOT exactly the same as shutter speed. While both do control the exposure time of the image, shutter angle’s shutter speed is relative to the frame rate. So a 180 degree shutter angle will result in different exposure time per frame depending on the frame rate being recorded (1/2 x frame rate). Shutter speed, doesn’t lock relative to your frame rate so isn’t an interchangeable term.

Which is important when you record slow motion or time lapse, where you want to keep the shutter angle constant to retain a unified look (as opposed to the shutter speed)

"all cars have horsepower ratings, including electric cars, it's not an obsolete term."

Yes, which is exactly my point. It's widely used, although there's no longer any need for knowing how an engine compares to draft horses. Same with blueprints, which haven't been blue for decades. Lots of words have lost the connection to their original, literal meaning, but are still not considered obsolete.

@MrWalrusGumboot - "Shutter angle is NOT exactly the same as shutter speed"

if you had read this thread before posting you'd have seen that i addressed that already: "...there are more accurate terms for portraying the relationship between shutter speed and framerate than "shutter angle", which means nothing."

chris was ranting about the phrase "open gate" for the same reason; the terminology is wrong and it doesn't make sense.

@MILC man; "video cameras do not have rotary shutters, "

The Arri D-20/D-21 would like a word ;)

"the camera manufacturers promote nonsense like "shutter angle" because they apparently feel that it's a good excuse for raising the prices of the gear."

You are just talking so much nonsense.

@MILC man
Please enlighten me with other common industry terms that describe the relationship between shutter speed and frame rate better than shutter angle does.

@MrWalrusGumboot - "common industry terms" is not relevant here, because that is the problem not the solution, you've missed the entire point of the discussion.

we've already covered better options in the comments.

@Mnemon - "You are just talking so much nonsense"

grow up.

@matted - "The Arri D-20/D-21"

well, if you don't mind using gear from 2005, o.k. :D

@AdamT
Noct is the new measuring system the US have chosen to replace the Imperial system.

The difference is Chris is using the "Noct" as a tongue-in-cheek reference to the ridiculously weighty Nikkor lens. It's an inside joke for viewers of DPReview TV not a serious reference to a standard.

@I have a dream - that’s far too simple! No, you need to use a Noct only for measuring lenses, but cameras must be weighed in Hassys, and camera bags in Loewe Commercials, or something like that.

Did you ever encounter the joys of a short ton and a long ton? Not to mention bushels and pecks and gills (oh, I mentioned them…). And rods, poles, perches, chains and links, and furlongs for distance - the imperial weights and measures were hideous. Good thing no one uses them any more :-)