Forum

Pages: [1]   Go Down
  Print  
Author Topic: Red Dragon Results  (Read 649 times)
dosdan
Jr. Member
**
Offline Offline

Posts: 50



« on: March 04, 2014, 12:06:49 AM »

This a comment for this page on the website
As I understanding it, multi-sampling is the similar to in-camera image stacking. So if 2 exposures were combined, the effective ISO is 1/2 of that used in individual exposures and the combined sensel has an apparent FWC 2x bigger.

Some questions:

1. Your noise correlation detection method picks up spatial NR. Can you introduce a method that will detect temporal NR?

2. The ISO 104 figure you measured. Isn't this equivalent to the same rendering brightness level of a single ISO 104 shot. So a 2x multi-sampled image that measured ISO 104 would actually be combining individuals exposures, each using approx. ISO 208?  Isn't the measured ISO of 104 on a 19MP APS-H sized sensor indicative that the achieved FWC is not abnormally large, multi-sampling or not?

3. How is motion-blur prevented between individual exposures in the multi-sample? Would this mean that fast pans or high-speed action would unpleasant if recorded at 24fps?

Dan.
Logged
noirist
Newbie
*
Offline Offline

Posts: 8


« Reply #1 on: March 04, 2014, 12:45:44 AM »

The Red cameras have an HDR mode that takes two exposures per frame in the camera and then combines two exposures into a single frame in post. That mode has the motion blur issue you mention in your post. But DxO did not measure the performance of the Dragon sensor in that mode. The DxO analysis is for the normal single-exposure mode.
Logged
dosdan
Jr. Member
**
Offline Offline

Posts: 50



« Reply #2 on: March 04, 2014, 06:27:47 AM »

That mode has the motion blur issue you mention in your post. But DxO did not measure the performance of the Dragon sensor in that mode.

As, I understand it, in the standard mode of operation, multiple exposures are also performed to make 1 video frame. This is not for HDR reasons per se (HDR mode, as I understand it, would involve combining shots taken at different exposure settings and then tone mapping the result into a more usable DR), but rather for temporal NR. This temporal NR produces the extremely high measured DR, unexpected in a APS-H 19MP camera.

If I'm correct in this understanding, then motion blur could still be an issue.

Dan.
« Last Edit: March 04, 2014, 09:04:17 PM by dosdan » Logged
noirist
Newbie
*
Offline Offline

Posts: 8


« Reply #3 on: March 05, 2014, 07:27:27 PM »

That mode has the motion blur issue you mention in your post. But DxO did not measure the performance of the Dragon sensor in that mode.

As, I understand it, in the standard mode of operation, multiple exposures are also performed to make 1 video frame. This is not for HDR reasons per se (HDR mode, as I understand it, would involve combining shots taken at different exposure settings and then tone mapping the result into a more usable DR), but rather for temporal NR. This temporal NR produces the extremely high measured DR, unexpected in a APS-H 19MP camera.

If I'm correct in this understanding, then motion blur could still be an issue.

Dan.

You're not correct in your understanding.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to: