how to change shutter in varispeed

[chapcha]

we tried to shot on 100 fps (2k 16:9) on 1/50 sec shutter.
we couldnt do it the shutter won't go less than 1/100 of a sec.
Any suggestions?
Ari

 

[Martin Weiss]

Well, you can't open the shutter more than 360 degrees.

In other words, the max. Exposure time is defined by your fps.
Max exp time = 1/fps

 

[chapcha]

yes but I should be able to work in shutter 180 and 100 fps - as we work in film cameras.

 

[Martin Weiss]

That would give you 1/200th second exposure times.

 

[Stuart English]

Shutter Speed / Degrees

Shutter Speed / Degrees

if you would prefer the shutter to report in degrees, then go to SYSTEM / SETUP / PREFERENCES / SHUTTER and set that parameter to degrees.

The shutter speed is still input in 1 / xx seconds format, but it will be reported in degrees.

See Pages 26 and 53 of the Operations Guide available at www.red.com/suppport

 

[Michael Dorn]

I think the question was different. If you want to set the shutter manually while in varispeed you have to change the mode in the shutter menu. If I remember correctly to RELATIVE (please correct me if I'm wrong since I don't have a camera or manual handy) then you can change the shutter speed by turning the joystick wheel. Also the shutter indicator in the LCD will turn from red to yellow.

Cheers

EDIT: Page 25 of the Operations Guide explains the modes NORMAL, SYNCRO and RELATIVE

 

[Martin Weiss]

So are you suggesting it is possible to shoot 100 fps at 1/50 exposure time?

Is my math totally wrong, or wouldn't this require a 720 degree shutter angle?

(Which would turn the Red into a truly double-revolutionary product...)

 

[Cail Young]

No, you're right Martin.

 

[chapcha]

Thanks to Cail, Martin and Michael on their answers.
May be my question was not very well articulated...
The problem I encountered was that I couldn't handle the shutter manualy and independantly of the frame rate.
e.g every time i changed the fps the shutter changed automatically. Well, that's not normal. What if I want to shoot at 100 fps and on shutter angle of 180 or 90 but I WANT TO CHOOSE?
Strange enough I did gain succes at the procedure when I changed the settings at prefernces to display the shutter at degrees and not in 1/sec.
That was indeed strange but that way I could decide on the shutter angle and the frame rate seperatly.
Thing is: and this is somewhat confusing, but the shutter angle is actually irelevant because the shutter speed changes anyway when we change the frame rate. As opposed to film where the angle stays (unless we change it) the same (normally 180 or 172.8) and the shutter speed changes as we change the frame rate...

 

[Cail Young]

Thing is: and this is somewhat confusing, but the shutter angle is actually irelevant because the shutter speed changes anyway when we change the frame rate. As opposed to film where the angle stays (unless we change it) the same (normally 180 or 172.8) and the shutter speed changes as we change the frame rate...

Let's be clear here. The RED shutter is digital, and scans vertically. It is not a rotating mechanical shutter with a angle to be set. It is set in fractions of a second. Let's talk in 25fps shooting terms, as the numbers are easy.

The RED shutter operates in the following three modes:
NORMAL, where you set a shutter speed (1/50s is pretty standard) and it stays at that speed until the framerate no longer supports it (i.e. if you're shooting over 50fps). The shutter display will be white, or red if you overcrank too high.

RELATIVE, where the shutter auto-compensates for shooting framerate; if you set 1/50s for 25fps shooting it will automatically adjust to 1/200s for 100fps shooting. The shutter display is yellow.

SYNCRO, which allows for fine-tuning of the shutter timing to record CRT displays and the like. I'm fairly sure the display is white or red like NORMAL.

If you go into the SYSTEM menu, you can switch the shutter to be displayed in an angular measure - this does not make the shutter behave like a film shutter when you overcrank, it merely displays in degrees rather than fractions of a second.

Ideally switching to degrees display would automatically change the shutter to RELATIVE mode (yellow display), as this is the only way the display makes sense, but I can understand you might want the choice.

So, in short, if you want to choose the shutter rate when you're overcranking, set it to NORMAL in the SENSOR->SHUTTER->MODE.

However, you were asking to have 1/50s when shooting 100fps - this is physically impossible without frame accumulation which the RED does not currently support.

 

[Dominic Jones]

Ideally switching to degrees display would automatically change the shutter to RELATIVE mode (yellow display), as this is the only way the display makes sense, but I can understand you might want the choice.

Yes, I remember there being some discussion on this before - I can't remember if someone put up a really good reason for this not being the case, so apologies if we're retreading old ground (and also with an acknowledgment that the Red team are obviously frying bigger fish at the moment), but:

Ideally in some future build the camera should really have two modes for shutter - essentially "video" and "film". In video mode, shutter speeds are absolute, and are entered in and displayed in 1/xx format. In film mode, shutter speeds are relative and are entered and displayed in degrees. Simple.

Our kit just went out on a drama shoot with a great DP named Simon Dennis (who is no fool, I might add) who shoots a lot of 35mm. I had to talk him through the shutter system several times as it is so counter-intuitive to have a shutter angle readout that does not change the exposure time vs framerate - it just makes no sense at all!

It's great to have the option of absolute vs relative shutter times, but it just needs tidying up a little to be simple and intuitive - obviously when those code boys get a spare minute or two (sometime in 2010, I imagine!).

 

[chapcha]

I guess you're right...
thanks.
ARI

 

[Cail Young]

Our kit just went out on a drama shoot with a great DP named Simon Dennis (who is no fool, I might add) who shoots a lot of 35mm. I had to talk him through the shutter system several times as it is so counter-intuitive to have a shutter angle readout that does not change the exposure time vs framerate - it just makes no sense at all!

My default setup for our REDs is to set it to degrees and RELATIVE; I never change it from that without briefing the DP at length on the options. Starting with 180° and relative shutter makes it behave the way pretty much everyone expects.