LRTimelapse Forum

Hi Gunther,

maybe you can help me with this. In the scene below I used the Holy Grail method during this sunset. I used LRTimelapse in the post processing including Visual deflicker. But the holy grail steps are still visible around the sun while it is setting. It is fairly obvious that I used 5 different combinations in this shot, the last one around second 6.

What could I do to make this smoother? Or is that not possible? 

I can provide more details if needed. 

thanks

Simon Plat




 

This is not flicker, the area around the sun is just blown out. And this area is bigger before the adjustment and smaller after the HG-Adjustment.
In such cases, where the sun ist visible so brightly, you have to underexpose a lot and use very small steps (1/3 stops) in order to not see this kind of "pumping".
You can try pulling down the "highlights" in Lightroom on the keyframes in order to ease this a bit for this sequence, but if the highlights are really blown out, I'm afraid it will be hard to fix it, because the image information is just not there.

Hi Gunther,

thanks for your quick reply.

In the case of this sequence there is no over exposure in the processed photos. There is some in the original RAW files while the sun is visible. After sunset (the end of the scene) nothing is overexposed (by far), not in the RAW, not in the processed files, and still I see the HG steps. I used ND filter (ND8). I have this often, also with other sequences. Apparently it happens both with adjusting aperture (vignetting?) and shutter speed.

I would love to hear your thoughts on this

regards

Simon Plat

I can only judge, what I'm seeing in the sequence that you linked to above, and there I see the typical pumping of blown highlights with a sunset.

If in another sequence, after the holy grail processing you still see minor "steps" just use the visual deflicker with an appropriate reference are and probably one or more "refine" steps, to get rid of them.

Gunther,

what do you mean by 'pumping of blown highlights' if it is not over exposure? I'm afraid I don't understand that part. 

The preview window in LRTimelapse shows that there is not much room to underexpose much more than I did. 
(not sure if it is possible to post photos in this forum to show it)

Still searching for that thing to change in order to prevent this, thans for your patience!

Simon

What I see in your demo sequence is a blow part around the sun. Watch only the sun and you see that pumping.
Even if you think you have a right exposure, that part os overexposed. The sun in fact is always overexposed, since it's too bright. You can only make the area around the sun that blows smaller or bigger by defining the exposure on the camera.

If you allow me to, I can send you the histogram of the RAW file or the RAW files involved: there is not a single pixel overexposed in the ones where the sun set under the horizon. On the contrary I made it all fairly dark to prevent from blowing out. 

I had this effect before in a very dark sequence. In that case I changed the aperture to the widest possible on the lens (not a very good lens). That also introduces vignetting so I tried to explain the effect by this: vignetting made the corners darker so LRTimelapse consequently could make the lighter parts lighter.

The fact that I involve you is that this now also happend after changing the shutter speed. So now I have no explanation any more. Maybe LRTimelapse can only work with limited changes in exposure? Maybe even there is a problem whit the number of pixels in the photo that are totally dark (that is the case in some of the transitions in the demo). Maybe it is related to the limited quality of the lens used?

You advised small steps earlier. What would be about the largest steps allowed to make smooth transitions? 

I am in the proces of experimenting with deflickering a crop. I let you know when that worked out well.

Can you send me that raw sequence you compiled above via wetransfer (support(at)lrtimelapse(dot)com, then I will check, otherwise I guess we will not make progress on this.
I always shoot and process Holy Grail sequences without having those problems, but like I said - it's a combination of shooting technique and processing.
I'd do 1/3 stop steps only.

Thanks Gunther, I just send the last part of the sequence including some of the HG steps. In this part the sun is away and nothing is over exposed.

The worst effect was actually at the end but I threw it away so I don't have it anymore.

Simon Plat

Okay, it's exactly as I expected. The adjustments are to big and therefore the images after each adjustment have blown highlights.
You can clearly see it when you crop into on of those and then check the histogram in Lightroom:


I only pulled down the exposure, and if the Histogram on the right side looks like this then it's a clear indicator for blown highlights.

This is just a sequences that has not been exposed properly, LRTimelapse cannot do anything to fix this.

So again my recommendation: expose so that the sun doesn't blow, make only 1/3 stop adjustments - if possible avoid adjustments at all, while the sun is still visible.