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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Benefits of shooting 8K / Epic-W

Gene, I think a large part of the noise improvement is the smaller noise structure. I'd guess that 4k helium vs 4k dragon would be more similar than 5k dragon vs 8k helium. I don't think people will rate helium at 2000 iso at a 4k resolution crop, I think they'll rate it at 800 or 1000. iMHO. My unscientific tests have me rating helium 8k at 1600, but shooting 8k at 2500&3200 with minimal noise increase perception. The key word here is "perception". Which is why I think you're right to realize a large component of the improvement is grain size.
 
Björn Benckert said:
Both cameras max out at 300Mb/s so when shooting in the dark or such then lowest compression on both gives the same data rates. In other words helium can not produce more data then weapon can.
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True, but the lower noise floor of Helium means that it may preserve more detail since its not spending fewer on noise. At least in theory.
 
Gene Sung said:
Is the better low light a result of the Helium sensor engineered to be more sensitive or is it because an 8K image downscaled to 2K hides / makes the grain smaller?
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The former, Helium has less noise, which is impressive since the pixels are smaller. The Dragon 8K VV will benefit from the latter.
 
Stacey Spears said:
You are absolutely right, I was just thinking that the big change was the lower noise floor. [/COLOR]
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Both helium and dragon have the same signal-to-noise ratio listed of 80db. Is there a different "noise floor" spec you are referring to? If not, what reason do you have for thinking the increased resolution is not the main noise improvement?
 
Jack Allred said:
what reason do you have for thinking the increased resolution is not the main noise improvement?
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Who needs reason when you have eyeballs? :)

You can download plenty of Helium R3Ds exposed in a variety of lighting conditions. Simply export an 8K image from Redcine, Resolve (or whatever you use to debater) then crop the centre 6K, then re-export. Then look at the noise. Increase ASA and repeat. Decrease ASA and repeat. You're going to see a quieter noise floor than what you've seen on Dragon. 6K compared to 6K.

The 8K-to-6K factor is just an added bonus. As Graeme said years ago, resolution is like whiskey. The more you distill, the purer the end product. :)
 
Alex Boothby said:
Who needs reason when you have eyeballs? :)

You can download plenty of Helium R3Ds exposed in a variety of lighting conditions. Simply export an 8K image from Redcine, Resolve (or whatever you use to debater) then crop the centre 6K, then re-export. Then look at the noise. Increase ASA and repeat. Decrease ASA and repeat. You're going to see a quieter noise floor than what you've seen on Dragon. 6K compared to 6K.

The 8K-to-6K factor is just an added bonus. As Graeme said years ago, resolution is like whiskey. The more you distill, the purer the end product. :)
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I don't need to download helium r3ds because I have my own epic-w and Scarlet-w. I've done my own side by sides, which is why I'm asking Stacey what his reasoning is, or if there's a noise floor spec I'm not aware of. I assume you've done tests... How different is the noose floor at same resolution that you've found?
 
Jack Allred said:
If not, what reason do you have for thinking the increased resolution is not the main noise improvement?
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Visually see the difference in noise when going 1:1 on a Xyla chart of Dragon and Helium. To the point about resolution, you can either set Helium to 6K and compare to Dragon at 6K scaled down to 2K or you can compare against the Dragon 8K VV, which is much more difficult at the moment due to scarcity. Mark and Phil are the only ones we know that are in a position to do that.

We don't know if the published 80 dB is actual measured S/N ratio or theoretical S/N ratio based bit-depth. 80 to 82 dB is pretty common S/N ratio for a 16-bit A/D in a pipeline of some sort vs. the A/D by itself.

Is there a known method to measure S/N ratio of a camera? Years ago I used a Tektronix VM700 to measure the S/N ratio of the analog video (component) outputs of a DVD player. There are various techniques to measure number of stops. And then the amount of acceptable noise near black is subjective as everyone seems to have a different amount of tolerance.
 
Jack Allred said:
I don't need to download helium r3ds because I have my own epic-w and Scarlet-w. I've done my own side by sides, which is why I'm asking Stacey what his reasoning is, or if there's a noise floor spec I'm not aware of. I assume you've done tests... How different is the noose floor at same resolution that you've found?
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Hey congrats. I don't have access to a Helium yet, but it sounds like you are in a better position than most to compare Helium to Dragon. I admit that the specs are confusing, especially the 80 db spec. As a compositor and colourist I really only care how the noise floor looks and behaves when you beat on it.
 
Thx Alex and Stacey, I might shoot a 4k vs 4k test this week for comparisons. If I do, I'll send you guys r3d links.
 
As the 180 degree that we are following for FPS.

in the still world, photographers stays minimum speed on the similar number of the focal length to not to blur image

ex) 50mm = shutter speed 1/50, 500mm = shutter speed of 1/500.

so if this is the case, I would change the shutter speed a bit faster than it should be in order to take 30 Fps on your epic-w.
 
Minu Park said:
As the 180 degree that we are following for FPS.

in the still world, photographers stays minimum speed on the similar number of the focal length to not to blur image

ex) 50mm = shutter speed 1/50, 500mm = shutter speed of 1/500.

so if this is the case, I would change the shutter speed a bit faster than it should be in order to take 30 Fps on your epic-w.
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Of course the 1/focal-length equation for still photography addresses only camera shake, not subject motion. There are all kinds of reasons why one might need a much higher shutter speed to stop a fast-moving subject, or a longer shutter speed to properly blur it. Moreover, the 1/focal-length equation really only covers that short period of time when one really is trying to not shake the camera. For any shot of any length of time, there will be camera movement, and how much camera movement there is much more determines the proper shutter speed.

I would recommend ignoring how the stills world handles shutter speed and consider only the formulae from the motion world (about camera shake, pan speed, relative subject speed, desired look, etc.).
 
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