Jump to content
Sign in to follow this  
BAB414

Red Helium Fan

Recommended Posts

A quick anecdote:

 

I recently did a reshoot for a film using two Red Heliums (they said the 8K was mandatory). The fans, even at their lowest settings, made everything on the booms unusable. Once that was clear to everyone and they decided to max out the fans anyway, the cameras were still overheating and would cut after about 8 minutes, not long enough for the takes we were doing. They had to bring the cameras outside the stage to cool down.

 

Anyone ever hear of anything like this with the Helium? Camera department tried everything to no avail.

Share this post


Link to post
Share on other sites

Here's from a colleague. No mention of long takes, but you get the idea of what's required. It's more about target temperatures. If you want long takes in a warm environment, you need to have a black shade map with a higher target temperature set. Or just don't do long takes. Treat it like film. Roll and slate and call action quickly, and cut quickly at the end. Collaboration required with ADs and everyone else!

 

"We have an extremely helpful DP and camera team. At Prep stage i contacted the DIT and DP regarding fan speeds. The DIT asked if he could leave the cameras on 'Adaptive' and i told him that would not be possible due to my past experiences and noise testing on various films and at <rental house> in their sound testing booth with <tech> from RED. He was open to changing that idea, and with the DP copied into all emails we formulated a plan. I told him that other colleagues had used a system whereby the 'Black Shading' was mapped for various different target temperatures, thus having the ability to set the target temperature to something achievable based on each location/situation, and change it instantly along with the custom black shading map if the cameras wanted to heat up/cool down to a level unanticipated. I then contacted ex 1st AC, and now <RED technician>, to chime in and he said this was perfectly feasible and acceptable and offered to come out to one of our camera test days. <The RED tech> and his assistant arrived and helped set up the black shading maps. We then tried the 'Adaptive Preview, Quiet Record' setting which i found a little unpredictable and variable in its noise levels. We agreed that on wide exteriors where the cameras (3 of them....) would be nowhere near the dialogue we would leave the cameras in 'Adaptive'. We also agreed that whenever i needed to on exteriors and all interiors we would run the cameras fans on Manual 30% Record speed with the Preview (i.e. idle) speed at whatever the DIT needed to keep the cameras cool without fluctuating the temperatures too greatly (which is undesirable in the same way as overheating the camera or setting an unachievable target temperature). He constantly monitors the core temperature versus the target temperature and adjusts the preview fan speed to create the best workable balance. Having <RED technician> visit us and let us know what is achievable really gave everyone confidence in our workflow and i am incredibly grateful to him for that.

We also agreed that if i could hear the cameras i could ask for the fan speeds to be dropped to 25% (their lowest setting), which has happened twice in small rooms so far (day 4 of shoot). I am confident that at 25% the RED HELIUM is no louder than an Alexa on 'record low'. At 30% it is slightly louder but within acceptable levels for most situations (apart from two cameras in very small rooms, and/or quiet close ups with actors at minimum focus, close to the lens).

We have all been collaborating professionally and after knowing a couple of times i would not hear the cameras due to them being on long lens and asking for the fans to be turned up to 40% i have the trust of the camera dept and DIT who know i'm compromising whenever i can. We are now at a wonderful stage unprecedented in my experience with Reds - i can set the fan speed to whatever we need it to be, by asking the DIT who can manipulate the cameras instantly using an APP on his phone. I would say that the Helium is the best RED so far in terms of fan noise and if set up correctly with black shading maps for different temperatures and a camera department who are happy to collaborate the cameras will not impact the dialogue acquisition.

 

Generally our starting point interior setting is Manual, 30% Record and 75% Preview.

 

(BTW, 75% on a Helium is nowhere near as loud as 75% was on a Red Weapon, which sounded like a hairdryer).

Share this post


Link to post
Share on other sites

Ouch, you figured out a workaround with a helpful and cooperative camera department but it still feels like as much fun as a hole in the head. 

Share this post


Link to post
Share on other sites

Strange reading as this is all a mix up between DSMC1 and DSMC2 bodies.

 

Epic is where you can choose the fan speed % but Weapon (wich can also be Helium as Helium is a sensor name) you choose the target temp of your sensor in C but not the fan speed in %.

 

In DSMC2 bodies like Weapon, Epic-W, Raven, Scarlet-W (W for Weapon) you set the target temperature from the sensor wich is maxed out at 48C. I usually use Adaptive mode set to 46C. Weapon has a heater on the sensor to get at temp rapidly even in cold environment. When you foresee a shooting in low temp (-10C) you could a) lower your sensor heat and black shade callibration to 30C or B) keep the heat of the body by obstructing slighlty the heat intake. If the camera gets overheated it will get laud fastly and you will hear it so, I think, there is no risk to block the vent.

 

For older bodys called DSMC1 like Epic-M, Epic-X, Scalet, you still have the opportunity to work with the FanPlate wich is the best tool out there to control your camera temp and internal fan speed. The older versions of the lower fan did much less noise.

 

Nowadays the DSMC2 bodies from RED make much less noise than the previous DSMC1 bodies. The important factor is to get a as high as possible sensor temp callibration and with the help of the camera crew ask for that. The more heat the sensor has, the best picture noise response it has, this could also be an argument to increase the sensor temp.

 

See you

 

Pat

 

PS: Monstro, Gemini, Helium, Dragon, are all sensors wich don't tell in wich camera they are in.

Share this post


Link to post
Share on other sites
On 5/11/2018 at 10:39 AM, Patrick Tresch said:

PS: Monstro, Gemini, Helium, Dragon, are all sensors wich don't tell in wich camera they are in.

 

Although all of those (except Dragon) are quite new sensors so can only be in the latest body type, and not in the older bodies. 

Share this post


Link to post
Share on other sites
On 5/11/2018 at 12:39 AM, Patrick Tresch said:

The more heat the sensor has, the best picture noise response it has, 

 

this is against common knowledge (and also against basic physics).

it's the opposite: lower sensor temp reduces sensor noise and you'll have a hard time convincing any experienced camera crew to calibrate their cameras to higher temps (unless they are really sound friendly)

chris

 

Share this post


Link to post
Share on other sites
On 5/20/2018 at 11:56 AM, chrismedr said:

 

this is against common knowledge (and also against basic physics).

it's the opposite: lower sensor temp reduces sensor noise and you'll have a hard time convincing any experienced camera crew to calibrate their cameras to higher temps (unless they are really sound friendly)

chris

 

 

Could you explain your "common knowledge"?

My findings are it's best to reach blackshade target temp or have it a bit hotter than to have a cold sensor.

 

Pat

Share this post


Link to post
Share on other sites

well, not sure what there is to explain - it's simply that camera sensors and electronics in general perform better at lower temperatures.

that's why all manufacturers use camera cooling, and why nearly all cameras for astro imaging use a peltier element to keep sensor temps as low as possible (as does Arri).

 

I'd expect your test results come from the fact that your camera has been optimised for a certain operation temperature and not to room temperature.  It might even be that in some camera designs there isn't much difference at all because the main source of noise comes from somewhere else, my main point is you'll have a hard time convincing any AC to run the camera at higher temperature to keep it quieter (not only because of sensor noise but also because of stability).

 

anyway, for the technical nitty gritty, do a web search - here's a research paper I've found with a few minutes of looking around:

IVCNZ.2009.5378403.pdf;jsessionid=06E04F

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×