Bizarre behavior on one stack.

Shooting in macro mode, techniques, tips & tricks
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GracieAllen
Posts: 27
Joined: 08.04.2015 00:19

Bizarre behavior on one stack.

Post by GracieAllen »

Windows 10 Pro, 32GB memory, 5700XT gpu, SSDs everywhere, HF 7.6.6
I've been running image stacks for ages. And I've been running stacks of these things today with no trouble.
I have a small set of 9 images - this isn't a macro - I'm shooting down the side of a radiator. The first 7 are lit by blue light, and the last two have a red light added. I didn't plan it, I THOUGHT the stack was done, and moved the light into position.

This stack won't process correctly. Everything looks fine, but the output is really odd. Here are a couple images:
210227_2931.jpg
210227_2931.jpg (106.75 KiB) Viewed 638 times
210227_2938.jpg
210227_2938.jpg (110 KiB) Viewed 638 times
Capture.JPG
(398.3 KiB) Not downloaded yet
The first image is the 1st image in the stack. The first 7 are lit the same. The second image is the 8th image in the stack. It's red.
The last image is a screen snip of Helicon Focus after the processing was done. I put image 1 in the left frame. You can see it's at about a 45 degree angle. It APPEARS to do that with all 7 of those. Images 8 and 9 are oriented normally. In the right frame is the output from Helicon Focus...

If I ONLY process the first 7 images, they're fine...

It's not a big problem since I didn't intend to have some blue and some red images, but why is this causing the rendering to create such an odd output?
GracieAllen
Posts: 27
Joined: 08.04.2015 00:19

Re: Bizarre behavior on one stack.

Post by GracieAllen »

Hm... I thought this was odd enough to pique someone's interest... Nothing?
BobStone
Posts: 56
Joined: 03.06.2017 10:13

Re: Bizarre behavior on one stack.

Post by BobStone »

Are you shooting raw files? If so, try reversing the order of the stack.
GracieAllen
Posts: 27
Joined: 08.04.2015 00:19

Re: Bizarre behavior on one stack.

Post by GracieAllen »

I am shooting RAW, though I also tried rendering the first 7 images - the blue ones, saving as a tif, and then rendering that output with 1 of the other images as a .tif. So, 2 tifs. didn't matter. I presume it has to be the color change, but I don't know why that would confuse helicon focus...

How do I reverse the stack? HF SEEMS to do some kind of algorithm where it orders the images. I've watch it reverse the images and run them.

Rename all the images?
BobStone
Posts: 56
Joined: 03.06.2017 10:13

Re: Bizarre behavior on one stack.

Post by BobStone »

At the bottom of the file list, click the gear icon. Change the sort order.
GracieAllen
Posts: 27
Joined: 08.04.2015 00:19

Re: Bizarre behavior on one stack.

Post by GracieAllen »

Cool. I didn't realize I could change the sort order - or know why I would.

In any case, nope. Put the red one's first and it looks like it did previously. The FIRST red image is straight up and down. The second is turned at an angle, as did everything after that. I REMOVED the first red image from the render, and it STILL did the same thing. Remove the 2nd red one and it's fine.

Kind of interesting - fortunately I don't NEED this one to work, so it's not a big deal. I WOULD like to know WHY it's doing this so I can be sure NOT to do it in the future.
BobStone
Posts: 56
Joined: 03.06.2017 10:13

Re: Bizarre behavior on one stack.

Post by BobStone »

From what I have been able to discern about how HF deals with creation of the DNG output, HF uses EXIF data from the last image in the stack. Not sure if it uses the last in numerical order or stack order. The EXIF data does have info about color corrections made in, for example, Camera Raw. However it does not appear that you had made any adjustments before the stack was processed.

If you later figure this out, be sure to post your findings!
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Catherine
Posts: 596
Joined: 29.04.2019 22:38

Re: Bizarre behavior on one stack.

Post by Catherine »

Based on the resulting image, the problem is unexpected image alignment. It's very unconventional to have such a color shift in the stack, I wouldn't consider it a proper, valid focus stack. But at the same time I don't think that's why you're getting this unexpected rendering result. Rather, I suspect you have audtoadjustment settings that are too broad. Go to the Helicon Focus preferences - Autoadjustments, press the "Reset" button at the bottom to load the defaults, press "OK" and try your stack again.

If that doesn't change the outcome, click through every one of your source images to make sure they are properly oriented and that the contents of the image is what it should be (don't just trust the thumbnails in the sources list).
GracieAllen
Posts: 27
Joined: 08.04.2015 00:19

Re: Bizarre behavior on one stack.

Post by GracieAllen »

Thanks Catherine...

I don't consider it a valid stack either. I thought the the camera was done shooting the stack when I slid the other light into place. I just processed it to see if Helicon would do anything interesting and abstract, which it did, but not what I was expecting.

I DO have broader than normal settings in the auto adjustments. And they've worked pretty well in the past. I've had some pretty big movements and rotations that Helicon Focus has handled really well - as in even a reasonably close examination didn't show how badly aligned things started out.

In this case, I've looked at all the images in the develop module of Lightroom and they're all correct. I processed them in a variety of ways: all 9 - 7 blue ones, two red ones, the 7 blue ones and 1 of the red ones, the 7 blue ones, the 2 red ones, then the two outputs. They all result in effectively the same output. With my settings, HF seriously does NOT like that blue-red shift. If I set the autocorrection at the defaults it mostly just complains about the large brightness variance.

I just figured it was odd and interesting, so I put it in here to see what folks thought.
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