Hi all,

On my astro time lapse outputs from LRT I am getting horrible mosquitoing.  I am using the 4k JPG output option.  I tried the TIFF version but it too ends up with mosquitoing.  Are there any techniques to minimize/prevent this? I am shooting with a Nikon D810 and good glass and RAW.  Also wondering if I have more control of bit rate to yield a higher quality output.  Still trying to get familiar with LRT.  Post work is in Lightroom.

Appreciate any advice.

Joe

What is "mosquitoing"? Could you show an example? Are you possibly talking about "Hot pixels"? Those are on your camera sensor. Check the image in Lightroom in the 1:1 zoom view, you should see them there too. The D810 is known for delivering those effects. But please, show us an example otherwise it's only guessing.

This post was last modified: 2017-04-06, 03:31 by Joe_Belanger. Edit Reason: added notes

Here is a link to the time-lapse. I applied some noise reduction but not too much. Notice the thousands of flickering white, powdery "mosquitos", commonly called mosquitoing, and some refer to it as compression artifacts. My output was 4k @ jpg in LRT. Editing done in LR. I am wondering if I will have this issue every time I shoot a TL at night. I do have other TL at night that does not do this. I am looking to control this in-camera if possible. This was taken using my Ramper Pro, which it messed up my intervals a bit, hence the speed change in the TL. When people are shooting astro tl at 3200 iso, how do they manage the noise in post? There is a ton of noise when I zoom in on the original, but not sure if that should be causing all that flickering particles called mosquitoing. Appreciate any comments and ideas that are solution based.

You will need to download the file to see the full resolution and the mosquitoing.

https://www.dropbox.com/s/ygjomvy5v5uvh4...L.mov?dl=0

Joe

This post was last modified: 2017-04-08, 19:11 by Gunther.

That's Noise combined with compression artifacts. The more noise you have, the more compression artefacts you will get too, since the noise eats up the bandwidth of the encoder.
Additionally the sequence is very fast with lots of changes from one frame to the other due to too short intervals and lots of movement from the volcano.
I'd suggest to apply more noise reduction to the first part where it's noisy (keyframe the noise reduction).
Additionally I'd increase the quality when rendering and experiment with "Motion Blur Plus" - this might smoothen the noise too (but due to the fast nature of the sequence it might add ghosting too, so try with "low", and see if it works.
Next time I'd recommend to go for shorter intervals and longer exposure times, especially for sequences with fast changes like this one.