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Need advice picking a technology for this problem

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Jim Leonard
Need advice picking a technology for this problem
on Jan 7, 2014 at 12:10:56 am

I will be consulting for a group that has a requirement to shoot moving images of various non-broadcast-standard computer monitors. By "non-broadcast-standard", I mean that the video output of these devices are not 59.94 -- some are arcade games that have a vertical refresh rate of 54.8Hz, some are handheld devices using a gas plasma display, some are VGA monitors running in 320x200 mode which has a 72Hz refresh rate, etc.

The best way to solve this is to vary the shutter to match the refresh rate when shooting; however, I've been out of touch for a few years with the most recent advances in cinematography tech and was hoping someone could recommend the best device. My questions:

1. What offers more fine control over shutter speed: Video cameras, or DSLRs? (Most DSLRs I have access to have only fixed shutter speeds: 1/40, 1/60, 1/100, etc.)

2. The subjects will be displaying horizontal motion. If DSLRs offer better control, is there any way to deal with the rolling shutter problem in-camera? (the organization does not have resources to post-process the video)

3. Finally, does anyone have any real-world stories of what devices and methods they used to address this during a shoot?

Thanks in advance. It's very hard to find advice for this via google because all searches for "variable shutter speed" or "custom shutter" or similar always seem to result in links to tutorials about exposure.


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Rick Amundson
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 12:24:37 am

Jim, I believe a video camera will be your best option as most "professional" models will allow a finer shutter adjustment to deal with monitor refresh rates. The rolling shutter wouldn't be a s big of a problem in what you are doing unless the motion on the screen had a lot of vertical lines moving very quickly across the screen.

I don't have any specific stories, especially of late, as most screens I shoot are LCD, phones, tablets or replaced in post but back in the day, the variable shutter for CRT's were invaluable.

Best of luck!

Rick Amundson
Producer/Director/DP
Screenscape Studios
Bravo Romeo Entertainment
http://www.screenscapestudios.com
http://www.bravoromeo.com
http://www.indeliblemovie.com


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Jim Leonard
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 12:46:50 am

"The rolling shutter wouldn't be a s big of a problem in what you are doing unless the motion on the screen had a lot of vertical lines moving very quickly across the screen." Unfortunately, there will be a lot of exactly that.

Thanks for the vote for a professional cam.


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Rick Wise
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 12:30:37 am

Will you be shooting more than one device in the frame during each shot? Even if you have two of the same type, their refresh rates will not be in sync unless they are gen-locked. If the answer is yes, more than one at a time, the only solution is to put green screens on each and treat in post, for which there is no budget.

As to which cameras offer fine control over shutter speed and shutter angle, both of which can effect the roll-bar problems, you may get some answers from others here. You can also look up the specs of any cameras you are considering. The higher end the camera, the more you are likely to be able to fine-tune. Another budget issue....

Rick Wise
Cinematographer
San Francisco Bay Area
http://www.RickWiseDP.com


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Jim Leonard
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 12:53:00 am

[Rick Wise] "Will you be shooting more than one device in the frame during each shot?"

Thankfully, no. Only one device will be present in each shot.

"You can also look up the specs of any cameras you are considering."

Hopefully, but they have specs such as (quoting from the Sony NEXFS700UK page) "Manual:60i/30p/60p: 1/3 - 1/10000". This isn't specific enough; I can't tell if this is a range of included shutter speeds, or if they are implying that ANY shutter speed in that range can be selected.


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Todd Terry
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 3:54:20 pm

Definitely go for a "legit" video camera, not a DSLR.

Today almost any mid-to-higher-end video camera will have a "clearscan" mode for the shutter, where you can dial in the very exact shutter speed you need (expressed in Hz rather than in fractions of a second or degree angle). For the most part, DSLRs won't do that.

Rick is right about only being able to shoot one source at a time, if the refresh rates are different. It's good that you don't have to do that.

Last week we shot some night footage in a park here of skaters at an outdoor ice rink. All of the trees surrounding the rink were loaded with Christmas lights. All very pretty, but they were LED lights so we had to clearscan shoot with our C300 so they wouldn't flicker. But we learned they were either of different types or on different circuits or something because we could never find a setting that would take care of all the flicker... fix some, and others start flickering. Fix those, and the originals were flickering again. Good that you won't have to deal with that.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Jim Leonard
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 3:57:34 pm

Thanks again, "clearscan" is likely the term I'd been missing. Very much appreciated!


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Mark Suszko
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 7:37:53 pm

Just one follow-up: You don't say if you are shooting these screens in a way that also shows off their outer cases, or if you are only interested in the content of their screens. So I thought I'd mention that besides shooting off the screen with a clearscan-equipped camera, there may also be an alternative or supplemental way to go, using a deck and a scan converter connected to the VGA connector on the devices that have one. If you use a really high-end scan converter, you can replicate most of the moves you'd get using a camera lens, but without any intermediate transcoding, and without any lighting issues.

When I did projects like yours, I often ended up using a mix of lens-shot footage and scan-converter footage. if you live in or near a large city, good scan converters are rentable for reasonable rates. My personal rule of thumb is really good ones start at a thousand bucks to buy, though you can get something as cheap as 99 bucks, if you don't ask too much from it.

BTW, clearscan is the Sony brand name for the feature you seek, but other brands offer the same thing by a different company name.


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Jim Leonard
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 7:47:29 pm

Thankfully the organization is already using scan converters and capture devices for screens that have either near-broadcast rates or native video generation. My question was to help address the devices that have no "video out", such as handheld gaming devices. (I know that some handheld devices have video out and/or development kits with that capability, but the items in question do not.)

Good point about the different terms for this feature; I found the following:

  • Clear Scan (Sony)
  • Synchro Scan (Panasonic)
  • Variable Scan (JVC)

However, the tech specs of most of these state that the feature starts at 60Hz and goes upward, which won't help me with anything lower, but this can probably be addressed by using an even multiple of the native rate and playing with ISO settings (ie. if native rate is 55Hz then try shooting clearscan at 110Hz, etc.)


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Todd Terry
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 9:20:22 pm

[Mark Suszko] "BTW, clearscan is the Sony brand name for the feature you seek"

Wow, I never knew that, Mark... I always thought "clearscan" was a generic term. Education is never a waste.

I just opened the menu of my C300 to see what it was really called there, on my Canon menu it is listed as "Clear Scan"... two words, capital "C" captial "S."

And now I'm going to go grab a Kleenex on my way to the Xerox machine.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Mark Suszko
Re: Need advice picking a technology for this problem
on Jan 7, 2014 at 10:25:15 pm

Did you know that the "HL" in Ikegami camera model numbers stands for "Handy-Looky"? No lie: the manufacturer's sticker on one of our HL-79-E had it all written out.


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Jason Jenkins
Re: Need advice picking a technology for this problem
on Jan 8, 2014 at 5:55:04 pm

Just the other day, I learned that the "B" and "H" in B&H Photo Video stands for Beards and Hats. If you go to BeardsandHats.com it forwards you to B&H Photo Video.

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


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Todd Terry
Re: Need advice picking a technology for this problem
on Jan 8, 2014 at 6:03:41 pm

[Jason Jenkins] " "B" and "H" in B&H Photo Video stands for Beards and Hats. "

Oh. My. God... haha.

I know quite a few people who've always called B&H "beards and hats" for years, but I've never called them that (certainly not in a forum) thinking that might be construed as anti-Semitic (the "B" and "H" are actually the initials of the couple who founded the place).

With the forwarding link though, it's good to know that apparently they have a sense of humor about it!

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Jason Jenkins
Re: Need advice picking a technology for this problem
on Jan 8, 2014 at 6:16:47 pm
Last Edited By Jason Jenkins on Jan 8, 2014 at 6:17:38 pm

[Todd Terry] "I know quite a few people who've always called B&H "beards and hats" for years, but I've never called them that (certainly not in a forum) thinking that might be construed as anti-Semitic (the "B" and "H" are actually the initials of the couple who founded the place)."

Honestly, it never even crossed my mind that "Beard and Hats" might be considered anti-Semitic. I certainly don't feel that way.

I always assumed that B&H were the initials of the founders, but now I'd like to think they just had a sense of humor from the start!

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


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