Posts: 25
Threads: 10
Joined: Sep 2014
Posts: 25
Threads: 10
Joined: Sep 2014
Apologies if this has already been discussed.
I've been doing long exposure, night time lapses for several months now, and keep running into a problem with flicker. A problem that no amount of deflickering can solve.
This is because I keep seeing frames that are exposed identically next to each other in a sequence with varying brightness in the center of the image versus the perimeter.
Because of these frames, I would often run into great difficulties in the deflickering process. Two frames can have the same Visual Luminance value, even though the edge and center luminance values vary. Shifting the reference area does not help, as the deflickering process tries to correct for a level of brightness in one part of the frame, it makes other areas of the frame flicker instead.
I do not use the Dehaze slider, as it's an adaptive process that can apply different effects to different areas of a picture, relative to the next picture in a sequence that may be panned a fraction of a degree.
This got me thinking that I must be running into this problem with one or more of the sliders.
Turns out, after much experimentation, both the Contrast and Clarity sliders work the same way. A frame is analyzed and adjusted based on that frame only. These sliders can have drastically different results on two different pictures in a sequence that appear to be identical in every way. They may create a vignette or hotspot on one, and not alter the next photo at all!
As much as I love using these sliders for stills, I will now only do so with great hesitation, and will have to check for any flickering problems they may cause in future night timelapses.
Thought this might be of interest to others.
Frame 1 of 2 with Contrast and Clarity Sliders Utilized
Frame 2 of 2 with Contrast and Clarity Sliders Utilized (Hotspot in middle of frame)
Frame 1 of 2 without Contrast and Clarity Sliders
Frame 2 of 2 without Contrast and Clarity Sliders (No varying level of brightness in different areas of frame)
...now to the next issue, how to get rid of all the damn purple from the A7S
I've been doing long exposure, night time lapses for several months now, and keep running into a problem with flicker. A problem that no amount of deflickering can solve.
This is because I keep seeing frames that are exposed identically next to each other in a sequence with varying brightness in the center of the image versus the perimeter.
Because of these frames, I would often run into great difficulties in the deflickering process. Two frames can have the same Visual Luminance value, even though the edge and center luminance values vary. Shifting the reference area does not help, as the deflickering process tries to correct for a level of brightness in one part of the frame, it makes other areas of the frame flicker instead.
I do not use the Dehaze slider, as it's an adaptive process that can apply different effects to different areas of a picture, relative to the next picture in a sequence that may be panned a fraction of a degree.
This got me thinking that I must be running into this problem with one or more of the sliders.
Turns out, after much experimentation, both the Contrast and Clarity sliders work the same way. A frame is analyzed and adjusted based on that frame only. These sliders can have drastically different results on two different pictures in a sequence that appear to be identical in every way. They may create a vignette or hotspot on one, and not alter the next photo at all!
As much as I love using these sliders for stills, I will now only do so with great hesitation, and will have to check for any flickering problems they may cause in future night timelapses.
Thought this might be of interest to others.
Frame 1 of 2 with Contrast and Clarity Sliders Utilized
Frame 2 of 2 with Contrast and Clarity Sliders Utilized (Hotspot in middle of frame)
Frame 1 of 2 without Contrast and Clarity Sliders
Frame 2 of 2 without Contrast and Clarity Sliders (No varying level of brightness in different areas of frame)
...now to the next issue, how to get rid of all the damn purple from the A7S