Topics

filming (multiple) CRT on Alexa LF

bart van otterdijk
 

Hey all,

For an upcoming project set in the early nineties we’ll be filming multiple CRT screens/televisions with 2 alexa LF’s and a Mini..

How would we best go about this??
I thought genlocking all the CRTs, having them on the same electric circuit and ‘phasing’ the individual camera’s but it would be even better locking the camera’s too to the video source, no?

Could we do this via the EXT port on Alexa or the RET port maybe?? The TC port?

Years ago we had the sync box from Cinematography electronics on the old film cameras but now I’m a bit in the dark..

any thoughts??


Bart Van Otterdijk
DOP/Operator/1st AC
Belgium

Graham Futerfas
 

Typically you’d contact a vendor that manages this, including the TV’s and the playback.

I believe the old CRT’s were converted to 24fps for playback on set, and could be colored to tungsten white balance if necessary. The companies that I know that do this have a warehouse collection of converted TV’s. Remember, standard CRT’s are 29.97, not 24fps.

Also, that was meant for film at 24fps, not 23.976.

That said, not sure how the vintage converted TV collection is holding up these days. I’ve had them on set a while back and seen them not work so well, but these TV’s are really old! One company I know who does this, 24 Frame, might have some answers, and can be more camera-specific. www.24Frame.com I’m sure there are other companies out there, as well.

Best,
-Graham



---
Graham Futerfas
Director of Photography
Los Angeles, CA
www.GFuterfas.com
---

bart van otterdijk
 

It will be for a European TV-series so we’ll be shooting 25 fps.
Not sure if it will be CRT computer screens or TV-sets, probably a bit of both.

I know there’s one scene in a bar where there’s about 3 TVs. Don’t know if there’s gonna be the same images on all 3 sets or different ‘channels’ in the scene.
In the first case a synchronised (genlocked?) playback on the 3 sets.

Maybe if we’d have playback with a TimeCode out we could feed that into the 3 camera’s? This would probably mean hard-wiring all camera’s TC ports to the playback source using EXT TC..


best,
B!

Bart Van Otterdijk
Belgium



On 17 Aug 2018, at 04:33, Graham Futerfas <gfuterfas.cml@...> wrote:

Typically you’d contact a vendor that manages this, including the TV’s and the playback.

I believe the old CRT’s were converted to 24fps for playback on set, and could be colored to tungsten white balance if necessary. The companies that I know that do this have a warehouse collection of converted TV’s. Remember, standard CRT’s are 29.97, not 24fps.

Also, that was meant for film at 24fps, not 23.976.

That said, not sure how the vintage converted TV collection is holding up these days. I’ve had them on set a while back and seen them not work so well, but these TV’s are really old! One company I know who does this, 24 Frame, might have some answers, and can be more camera-specific. www.24Frame.com I’m sure there are other companies out there, as well.

Best,
-Graham



---
Graham Futerfas
Director of Photography
Los Angeles, CA
www.GFuterfas.com
---

Marty Brenneis
 

This kind of falls under the heading of: If you have to ask then you should hire a professional. (I'm one of those but I'm in the states.)

You have a few things going for you. You are in 25FPS country. That means you can run all the devices at 25FPS.

You will need a playback operator no matter what to manage the playback sources. In that case you might find one who is old and gray who remembers things like Genlock and PAL and composite video.
If you can find some time base correctors or scan converters that have composite outputs or S video outputs that can feed the TV sets you will have better luck.

The other thing you have that we didn't have back in the film days is a monitor from the camera that is really your final image. With film we had to use skill, experience, and faith to get the right thing on the image.
You can set up a test and point the camera at it and see what you are getting.
There are wireless genlock systems out there that can all jam together and then feed sync to the cameras without wires. Jam them when you start filming for the day and then again after lunch.
With all the sources genlocked to a master sync source and the cameras following a local jammed sync source you should be in good shape.
The other thing going for you is the possibility to go to a shutter angle of nearly 360. That can help make the screens look better than it would at 180, but you might not like the action.

You may also need an old gray TV repair person to keep the TVs working.

The other option is to find some TV chassis and have a good prop person mount some 4:3 LCD panels in place of the CRT. That all depends on the look that is needed and how prominent the TVs are in the scene.

Any decent video engineer should be able to handle the syncing of monitors and cameras. Feel free to email me to chat offline. I do have a friend in Prague who is a top notch video engineer and not bothered by weird setups.

--
Marty Brenneis
droid for hire
24frame.tv
marty@...

Mako Koiwai
 

Our old trick was to shoot at 25 fps and with a 150.15 degree shutter … I assume this is for the US?

At that magically combination there is NO LINE on a CRT.

I’ve never had to do this with a digital camera … so I don’t know how close you can get to that shutter. With an Arri film camera we would use the RCU and set it for 150 and 151 degrees and then use the hand wheel to find that extra 0.15 degrees.

You can try being close to that setting. In one direction you will eventually see a Black Line forming … in the other direction a White line forming …


makofoto, s. pasadena, ca

bart van otterdijk
 

Haha, Marty..  ;-)

With the camera tech at the rental we also emailed Arri and their response was to go with TC or for the mini ‘jumper' sdi2 to a genlock in. 
I used the cinematography sync box a few times in the old days with 35BL4 and SR2 & 3 and that always worked out just fine. 
You are right in stating that now we have the benefit of being able to see the results in real time only it’s vague to me on how to get the right signals/genlock into the camera’s and adjusting those.

Yes we’re in 25fps land. I hope the footage they want to screen is also 25fps but there might just be some NTSC too?
My first guess was to have a betacam something player with a TC or genlock feeding all monitors/TV sets. This is hoping that all TVs would display the same image..
Then lock camera’s to that.

Arri closed their mail with: 'stick some greensceen on the monitors and tracking points and do it like everyone else: in the post!' :-)
That was also my first hunch..
Lot less hassle and easy to do in post with the option of (re-)timing the sequences on the TV’s, even changing the whole content if need be..
And saving the cost of hiring a professional, shipping all the gear and dealing with customs and carnets, flights, hotels and so on. 

Still this keeps me puzzled and I want to know the answers. On simple -one camera (or 2)- setups we’ll go with the Phase option in the LF cameras and that’ll work just fine. Kinda like with the SR and BL4 camera’s. No worries there and no real need for green screens although that also offers options. Not up to me as I’m not the DOP on this project.

Yes, we’ll need a playback operator -with all the gear set up just right- should we go with this option.


thx for your input,

b!

On 17 Aug 2018, at 18:20, Marty Brenneis <marty@...> wrote:

This kind of falls under the heading of: If you have to ask then you should hire a professional. (I'm one of those but I'm in the states.)

You have a few things going for you. You are in 25FPS country. That means you can run all the devices at 25FPS.

You will need a playback operator no matter what to manage the playback sources. In that case you might find one who is old and gray who remembers things like Genlock and PAL and composite video.
If you can find some time base correctors or scan converters that have composite outputs or S video outputs that can feed the TV sets you will have better luck.

The other thing you have that we didn't have back in the film days is a monitor from the camera that is really your final image. With film we had to use skill, experience, and faith to get the right thing on the image.
You can set up a test and point the camera at it and see what you are getting.
There are wireless genlock systems out there that can all jam together and then feed sync to the cameras without wires. Jam them when you start filming for the day and then again after lunch.
With all the sources genlocked to a master sync source and the cameras following a local jammed sync source you should be in good shape.
The other thing going for you is the possibility to go to a shutter angle of nearly 360. That can help make the screens look better than it would at 180, but you might not like the action.

You may also need an old gray TV repair person to keep the TVs working.

The other option is to find some TV chassis and have a good prop person mount some 4:3 LCD panels in place of the CRT. That all depends on the look that is needed and how prominent the TVs are in the scene.

Any decent video engineer should be able to handle the syncing of monitors and cameras. Feel free to email me to chat offline. I do have a friend in Prague who is a top notch video engineer and not bothered by weird setups.

--
Marty Brenneis
droid for hire
24frame.tv
marty@...

peter white
 

I remember button on button off button on till the line disappears!


On 18 Aug 2018, at 3:04 am, bart van otterdijk via Cml.News <bartvanotterdijk=me.com@...> wrote:

Haha, Marty..  ;-)

With the camera tech at the rental we also emailed Arri and their response was to go with TC or for the mini ‘jumper' sdi2 to a genlock in. 
I used the cinematography sync box a few times in the old days with 35BL4 and SR2 & 3 and that always worked out just fine. 
You are right in stating that now we have the benefit of being able to see the results in real time only it’s vague to me on how to get the right signals/genlock into the camera’s and adjusting those.

Yes we’re in 25fps land. I hope the footage they want to screen is also 25fps but there might just be some NTSC too?
My first guess was to have a betacam something player with a TC or genlock feeding all monitors/TV sets. This is hoping that all TVs would display the same image..
Then lock camera’s to that.

Arri closed their mail with: 'stick some greensceen on the monitors and tracking points and do it like everyone else: in the post!' :-)
That was also my first hunch..
Lot less hassle and easy to do in post with the option of (re-)timing the sequences on the TV’s, even changing the whole content if need be..
And saving the cost of hiring a professional, shipping all the gear and dealing with customs and carnets, flights, hotels and so on. 

Still this keeps me puzzled and I want to know the answers. On simple -one camera (or 2)- setups we’ll go with the Phase option in the LF cameras and that’ll work just fine. Kinda like with the SR and BL4 camera’s. No worries there and no real need for green screens although that also offers options. Not up to me as I’m not the DOP on this project.

Yes, we’ll need a playback operator -with all the gear set up just right- should we go with this option.


thx for your input,

b!

On 17 Aug 2018, at 18:20, Marty Brenneis <marty@...> wrote:

This kind of falls under the heading of: If you have to ask then you should hire a professional. (I'm one of those but I'm in the states.)

You have a few things going for you. You are in 25FPS country. That means you can run all the devices at 25FPS.

You will need a playback operator no matter what to manage the playback sources. In that case you might find one who is old and gray who remembers things like Genlock and PAL and composite video.
If you can find some time base correctors or scan converters that have composite outputs or S video outputs that can feed the TV sets you will have better luck.

The other thing you have that we didn't have back in the film days is a monitor from the camera that is really your final image. With film we had to use skill, experience, and faith to get the right thing on the image.
You can set up a test and point the camera at it and see what you are getting.
There are wireless genlock systems out there that can all jam together and then feed sync to the cameras without wires. Jam them when you start filming for the day and then again after lunch.
With all the sources genlocked to a master sync source and the cameras following a local jammed sync source you should be in good shape.
The other thing going for you is the possibility to go to a shutter angle of nearly 360. That can help make the screens look better than it would at 180, but you might not like the action.

You may also need an old gray TV repair person to keep the TVs working.

The other option is to find some TV chassis and have a good prop person mount some 4:3 LCD panels in place of the CRT. That all depends on the look that is needed and how prominent the TVs are in the scene.

Any decent video engineer should be able to handle the syncing of monitors and cameras. Feel free to email me to chat offline. I do have a friend in Prague who is a top notch video engineer and not bothered by weird setups.

--
Marty Brenneis
droid for hire
24frame.tv
marty@...

bart van otterdijk
 

On the LF it’s not a problem since there’s a phase function. Set TC to rec run, assign a user button to ‘phase sensor’, Run the camera and push the button until the black line disappears.
Haven’t found this function on the Mini though… Anyone??

Guess if all monitors in my example are genlocked this could work. Bit of a Hassle since it needs to be done again on every take on all camera’s. How to do it on the mini?
Better even would be if all camera’s would be locked to this signal too so this phasing is not necessary.

b!


Bart Van Otterdijk
DOP/Operator/1stAC
Belgium

On 18 Aug 2018, at 09:17, peter white via Cml.News <Whiteyprods=icloud.com@...> wrote:

I remember button on button off button on till the line disappears!


On 18 Aug 2018, at 3:04 am, bart van otterdijk via Cml.News <bartvanotterdijk=me.com@...> wrote:

Haha, Marty..  ;-)

With the camera tech at the rental we also emailed Arri and their response was to go with TC or for the mini ‘jumper' sdi2 to a genlock in. 
I used the cinematography sync box a few times in the old days with 35BL4 and SR2 & 3 and that always worked out just fine. 
You are right in stating that now we have the benefit of being able to see the results in real time only it’s vague to me on how to get the right signals/genlock into the camera’s and adjusting those.

Yes we’re in 25fps land. I hope the footage they want to screen is also 25fps but there might just be some NTSC too?
My first guess was to have a betacam something player with a TC or genlock feeding all monitors/TV sets. This is hoping that all TVs would display the same image..
Then lock camera’s to that.

Arri closed their mail with: 'stick some greensceen on the monitors and tracking points and do it like everyone else: in the post!' :-)
That was also my first hunch..
Lot less hassle and easy to do in post with the option of (re-)timing the sequences on the TV’s, even changing the whole content if need be..
And saving the cost of hiring a professional, shipping all the gear and dealing with customs and carnets, flights, hotels and so on. 

Still this keeps me puzzled and I want to know the answers. On simple -one camera (or 2)- setups we’ll go with the Phase option in the LF cameras and that’ll work just fine. Kinda like with the SR and BL4 camera’s. No worries there and no real need for green screens although that also offers options. Not up to me as I’m not the DOP on this project.

Yes, we’ll need a playback operator -with all the gear set up just right- should we go with this option.


thx for your input,

b!

On 17 Aug 2018, at 18:20, Marty Brenneis <marty@...> wrote:

This kind of falls under the heading of: If you have to ask then you should hire a professional. (I'm one of those but I'm in the states.)

You have a few things going for you. You are in 25FPS country. That means you can run all the devices at 25FPS.

You will need a playback operator no matter what to manage the playback sources. In that case you might find one who is old and gray who remembers things like Genlock and PAL and composite video.
If you can find some time base correctors or scan converters that have composite outputs or S video outputs that can feed the TV sets you will have better luck.

The other thing you have that we didn't have back in the film days is a monitor from the camera that is really your final image. With film we had to use skill, experience, and faith to get the right thing on the image.
You can set up a test and point the camera at it and see what you are getting.
There are wireless genlock systems out there that can all jam together and then feed sync to the cameras without wires. Jam them when you start filming for the day and then again after lunch.
With all the sources genlocked to a master sync source and the cameras following a local jammed sync source you should be in good shape.
The other thing going for you is the possibility to go to a shutter angle of nearly 360. That can help make the screens look better than it would at 180, but you might not like the action.

You may also need an old gray TV repair person to keep the TVs working.

The other option is to find some TV chassis and have a good prop person mount some 4:3 LCD panels in place of the CRT. That all depends on the look that is needed and how prominent the TVs are in the scene.

Any decent video engineer should be able to handle the syncing of monitors and cameras. Feel free to email me to chat offline. I do have a friend in Prague who is a top notch video engineer and not bothered by weird setups.

-- 
Marty Brenneis
droid for hire
24frame.tv
marty@...

Marty Brenneis
 

If you setup external sync and use some TC generators that are jammed together then you can just roll any time you like.

Ambient has some great videos on how to set this up: https://www.youtube.com/watch?v=WfGGcwG9NNQ

The Lockit box is the best for this function, but there are others that will work too.
Your playback operator should know about syncing up multiple decks and cameras with either timecode or a sync generator.
If the playback operator does not know what genlock means then you should find a different operator. There are some out there with limited knowledge and anything outside the box will confuse them and cost you time.

I am thinking you don't really need to transport gear into the country. A video rental house should have time base correctors or scan converters that output 25FPS PAL. They are easy to genlock and will keep everything lined up. If you spend a bit on the gear and have it all synced and ready to shoot, you save much time on set when shooting because you don't have to futz around bumping lines out of the frame.

I usually use computers as the playback source now. it makes a lot of things easier. They can feed into the scan converter just as easy as the tape decks.

Finding a local video engineer soon should make your life much easier.

Let us know how it comes out.
--
Marty Brenneis
droid for hire
24frame.tv

Geoff Boyle
 

This is from the edited pages.

 

https://www.cinematography.net/edited-pages/25FPSUS.htm

 

Scroll to the bottom 😊

 

Cheers

 

Geoff Boyle NSC FBKS

Cinematographer

Netherlands

www.gboyle.nl

 

From: cml-ac@... <cml-ac@...> On Behalf Of Mako Koiwai
Sent: 17 August 2018 23:08
To: cml-ac@...
Subject: Re: [cml-ac] filming (multiple) CRT on Alexa LF

 

Our old trick was to shoot at 25 fps and with a 150.15 degree shutter … I assume this is for the US?

At that magically combination there is NO LINE on a CRT.

I’ve never had to do this with a digital camera … so I don’t know how close you can get to that shutter. With an Arri film camera we would use the RCU and set it for 150 and 151 degrees and then use the hand wheel to find that extra 0.15 degrees.

You can try being close to that setting. In one direction you will eventually see a Black Line forming … in the other direction a White line forming …


makofoto, s. pasadena, ca