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Pietrach

Image stack for long exposure - problem

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Hi 

i have a series of nearly 40 images taken from a tripod each at 1/15sec. I wanted to stack them, align, and use Median stack to mimic a long exposure. This works flawlessly in photoshop, but I get all sorts of problems in AP. I do file, stack, select auto align, and on you go. The effect, with Median selected is very poor. Not only there is no or very little movement (long exposure) visible in the clouds, but also the images are more miss-aligned than they were comparing to manual stacking in layers.

This is the resulting image from auto stack in AP (APauto-fail.jpg). 

APauto-fail.jpg

This is an image where I manually blended all 39 images placed on individual layers, without any alignment for images - as AP does not allow to auto align layers without using a stack as far as I know.

APmanual-ok.jpg

Am I doing something wrong? All images are exactly the same size.

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My guess is that there are too many soft edges (clouds, waves) and not enough hard edges (rocks, mountains) for the auto alignment to work properly. (Or at least in Affinity Photo.) There seems to be a related problem in auto aligning astronomical images.

John


Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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2 hours ago, John Rostron said:

My guess is that there are too many soft edges (clouds, waves) and not enough hard edges (rocks, mountains) for the auto alignment to work properly. (Or at least in Affinity Photo.) There seems to be a related problem in auto aligning astronomical images.

John

If this is the case, then it is extremely disapointing, as this image is not, by any stretch of imagination, lacking features which the software could use for alignment. Especially that the individual images were pretty much aligned any way.

Auto Alignment is a must for me. Enough to be a deal-breaker.

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Why did you go for a stack? I wonder if you wouldn't have gotten a more evocative powerful image with an actual long exposure.


iMac 27" Late 2015 Fully Loaded, iMac 27" Mid 2011 both running High Sierra 10.13.6 - Affinity Designer/Photo, Publisher Beta 1.7.0.140, Illustrator CC, Inkscape, Blender, Sketchup, Pepakura Designer, MTC, Pixelmator & Pixelmator Pro + more... XP-Pen Artist-22E, - iPad Pro 12.9 B|  

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29 minutes ago, firstdefence said:

Why did you go for a stack? I wonder if you wouldn't have gotten a more evocative powerful image with an actual long exposure.

I would I agree, but at that time I did not have an ND filter with me. Sometimes I also use this technique if it is very windy and risk of camera movement to high, despite the tripod.

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On 9/11/2019 at 2:04 PM, MEB said:

H Pietrach,
Yes, I've started checking this yesterday but I'm still working on it/would like to take a deeper look at this. 
I will get back to you soon. 

@MEB can I please ask for some feedback on this issue?

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Hi Pietrach,
I'm sorry for the delay getting back to you. You haven't did anything wrong. Affinity's auto-alignment options unfortunately don't get a better result with this set of images. I've logged this and passed the files to the dev team for inspection/feedback.
I will update this thread as soon as I have more info.

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