People ragging on the 7D/any CMOS cam seem to be FULL OF IT

Barry_Green said:
Film is shot at a wide variety of shutter speeds. There's nothing magical or sacred about 1/48. I've owned film cameras that had default shutter speeds of 1/40, 1/43, 1/50, 1/60, 1/80, and even 1/120 (Beaulieu 6008Pro, its default shutter angle was 90 degrees!)

Film is COMMONLY shot at 1/48, but there's no rule that says you have to, and various film cameras have various exposure times.

It's all about the shutter angle; the film cameras I've had have shutter angles of 90, 144, 156, 172, 180, 220, and 240 degrees (IIRC).
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Yes, I knew that. I was wondering, however, if the 1/48th speed specifically avoided the scrolling/flicker problem.
 
1/48 specifically *causes* it with CMOS cameras.

With film cameras it's totally irrelevant, because film cameras get the flicker based on the frame rate, not the shutter speed.
 
Couldnt test 7D stutter in 25p ,have only footage from camcorder.
Anyway i dont know if theres any sense to compare because it wont change anything, it is like it is,when i would get the chance then ill try to post 7d test.
 
Barry_Green said:
1/48 specifically *causes* it with CMOS cameras.

With film cameras it's totally irrelevant, because film cameras get the flicker based on the frame rate, not the shutter speed.
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Bit simplistic to say just frame rate. A combination of frame rate, shutter angle and of course the base power frequency / Light sources being used.

I think some are also confusing strobiness on camera movement, specifically pans and panning speeds with the extra issues that CMOS shutter artefacts bring to those circumstances. And then there's flickering or strobing light sources which are a different set of issues again.

that's 3 different issues.

EDIT. Also barry you made reference to what I believe to be a bit of an urban myth....that is that the BBC don't consider super 16 to be good enough for HD.

This is not official BBC policy as far as I know, but a preference for some of their HIGHLY COMPRESSED DTV / HD channels. Basically they compress them so much that they can't handle Super 16. More so than many in the US get (including the BBC us channels).

I've yet to see anything on the BBC online deliverables documentation that specifically mentions not using Super 16. Let me know if you find an official link.

They have recently shot Life On Mars, Spooks and I believe Merlin on Super 16. Not really evidence of a no super 16 policy.

Anyone seen "the wrestler" ? It looks great in a cinema and on Blu Ray. Again, how can it be that super 16 is not good enough. Take a look at this interesting and comprehensive article from the guys at Arri.

http://www.arri.de/fileadmin/media/arri.com/downloads/Camera/Tutorials/SystemsTechnologyBrochure.pdf


jb
 
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John Brawley said:
Bit simplistic to say just frame rate. A combination of frame rate, shutter angle and of course the base power frequency / Light sources being used.
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Well, no, the shutter angle is pretty much irrelevant, which is really the whole point of "HMI Safe". Line frequency is one of those obvious ones that, while perhaps I should have mentioned, is just common sense. Of course if someone's looking at an HMI-safe-speed chart, they're going to choose the one appropriate for their power cycle.

If someone's gonna shoot with a 10-degree shutter angle, maybe they'll get some flicker even at HMI-safe shutter speeds, but as a general statement I stand by what I said.

EDIT. Also barry you made reference to what I believe to be a bit of an urban myth....that is that the BBC don't consider super 16 to be good enough for HD.
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http://www.bbc.co.uk/commissioning/production/docs/hd_guide.pdf
Look at page 17, where it says Super16 is "not considered to be HD."

Or, look at the slide presentation they made at the 2007 HD Masters conference. Page 8, where the title of the slide is "what is considered to NOT be HD":
http://hdmasters2007.com/pdf/Presentations/HDM2007_Quested-BBC.pdf
 
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Barry_Green said:
Look at page 17, where it says Super16 is "not considered to be HD."

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The link you provided has a heading that says general information about more common formats.....They don't consider Super 16 to be HD even if you supply it to them on a HD tape.

That's not the same as not accepting super 16 material.

Your comment referred to the BBC not considering it as being worthy of broadcasting.

Clearly this isn't true, as evidenced by the continued broadcasting of drama that have in fact been shot using super 16.

jb
 
BBC does not consider Super16 to be HD, but apparently ABC does. John Inwood: "footage from the Super16 camera was not only sufficient to air in HD format, it looked terrific". Per BBC 720p is not HD. HPX300 does not produce HD, because it has only 1/3-inch sensor. BBC is full of it, yet AFAIK it breaks its own rules now and then.
 
Barry_Green said:
I said the BBC doesn't consider Super16 to be "HD". And supplied two different documents that support that assertion.
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Indeed you did. But the context was a general discussion about formats and infers a conclusion can be drawn (and many have) about fidelity and suitability for broadcast and only reinforces the popularly held myth that the BBC had somehow decreed that they had stopped accepting super 16 originated material.

So Im seeking to clarify what many hold to be a judgement on the suitability of super 16 originated material.

The BBC engineers consider Super 16 to be the equivalent to SD because of the severe limitations they have self-imposed with their highly compressed HD transmission pathways. Something that is NOT the case in most of the rest of the world.

The BBC have different people that commission content and seem to happily ignore this view.

The BBC are still commissioning content that is originated using Super 16.

Perpetuating the myth that Super 16 is somehow not worthy of consideration amongst today's drama and content creators is at best misleading. There are other issues that would rule out super 16, but image quality at origination would be way down the list.

jb
 
If you want to make a case for Super16's overall quality, that's one thing, but how do you take two statements from the BBC, the presentation at the hd conference and then also their hd guidebook, as anything other than saying that the BBC doesn't consider Super16 as "HD"?

Whether they violate that rule or not is their own business, just like how Discovery doesn't consider Super16 or HDV or HVX to be "HD". They have the ability to make exceptions to their rules if they want, that's their business. And they frequently do, as HDV shooters are always so quick to point out.

However, if we were to advise someone "go ahead and ignore their stated guidelines, they'll accept S16 or HDV anyway, trust us" then we would be doing the producer a disservice.

The BBC said in their HD guide something to the effect of "S16 is not considered HD, you'd better check with your coproducers before you decide to use it." If the co-producers accept it, and the BBC approves it, fine... but that would be an exception to the stated policy, and someone planning to produce content for the BBC had better have that clearly established before they embark on a production using those formats.
 
I've always heard this about the BBC also. But I don't think anyone here was agreeing or implying that "16mm is not worthy of consideration amongst today's drama and content creators",.... and I don't think anyone here is crazy enough to believe that. Most programming probably don't come close to meeting this silly standard which is probably why they allow a lot of it to sneak through. Their highly compressed HD transmission scheme is their own issue and not the rest of the capable HD world.
 
Yeah, I remembered that “Scrubs” was shot on 16mm. I see where it says a lot of folks thought it would not hold up but they were proven wrong. I think most of the time these same folks who make such a claim has never really tested the waters and speak out the side of their necks. I don’t watch too much network television myself but I have seen a few episodes of “Scrubs.” It looks just as good as or better than a lot of HD shot content on TV.
 
Yes, Scrubs is shot on super 16mm but is mastered onto digibeta I believe. For HD transmission, they must do a up-conversion. Nevertheless, it looks great. I see the grain a lot of times, but that often adds to the sharpness. I prefer the look of it to a lot of similar shows shot with the Sony F950 (which is HD).

Ian-T said:
Yeah, I remembered that “Scrubs” was shot on 16mm. I see where it says a lot of folks thought it would not hold up but they were proven wrong. I think most of the time these same folks who make such a claim has never really tested the waters and speak out the side of their necks. I don’t watch too much network television myself but I have seen a few episodes of “Scrubs.” It looks just as good as or better than a lot of HD shot content on TV.
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