Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-18-2019, 07:13 AM   #1
Site Supporter
Site Supporter
Karen the Star's Avatar

Join Date: Jun 2019
Location: Sapporo, Hokkaido
Posts: 134
About stack on Photoshop

I often use Photoshop's stack function to combine many photos to one for getting a photo that describe light trail in the night (time lapse photography) somehow, when I use stack, I found that if I set stack mode to average, light trail is not conspicuous, however if I set mode to maximum, IQ will be blurry and no longer sharp as before obviously. Could somebody tell me the reason for this?

Thanks a lot

10-18-2019, 07:50 AM - 1 Like   #2
Site Supporter
Site Supporter
MossyRocks's Avatar

Join Date: Nov 2017
Location: Minnesota
Photos: Gallery | Albums
Posts: 966
When averaging shots the trails will get dimmer as there are more shots where the star is not covering that pixel than when it its. To avoid this you want to use the maximum/brightest method for stack as that will give nice bright images of the trail but will amplify the noise elsewhere in the image. I've never had problems using brightest/maximum when stacking images where it ends up blurry in the foreground unless you have movement although I don't know what you are shooting at so it may just be some bad noise that is eating the foreground detail.

My suggestion is to do 2 stacks, one using maximum for the star trails and then another one where you align the frames for the foreground and do an averaging stack. Then combine the 2 separate stacks to get the best of both worlds with the bright trails in the sky (maybe go and do some aggressive noise reduction to the sky stack first) and low noise possibly sharpened foreground.
10-18-2019, 08:01 AM   #3
Site Supporter
Site Supporter
Karen the Star's Avatar

Join Date: Jun 2019
Location: Sapporo, Hokkaido
Posts: 134
Original Poster
QuoteOriginally posted by MossyRocks Quote
When averaging shots the trails will get dimmer as there are more shots where the star is not covering that pixel than when it its. To avoid this you want to use the maximum/brightest method for stack as that will give nice bright images of the trail but will amplify the noise elsewhere in the image. I've never had problems using brightest/maximum when stacking images where it ends up blurry in the foreground unless you have movement although I don't know what you are shooting at so it may just be some bad noise that is eating the foreground detail.

My suggestion is to do 2 stacks, one using maximum for the star trails and then another one where you align the frames for the foreground and do an averaging stack. Then combine the 2 separate stacks to get the best of both worlds with the bright trails in the sky (maybe go and do some aggressive noise reduction to the sky stack first) and low noise possibly sharpened foreground.
It's really a very clever way for solving problem, i will try, thank you very much
usually my stack will be 50 pieces, maybe too many?...
10-18-2019, 08:22 AM   #4
Site Supporter
Site Supporter
MossyRocks's Avatar

Join Date: Nov 2017
Location: Minnesota
Photos: Gallery | Albums
Posts: 966
QuoteOriginally posted by Karen the Star Quote
usually my stack will be 50 pieces, maybe too many?
Probably not. It is only too many if photoshop is choking on it and running out of memory in which case you can always stack in batches, so have a bunch of smaller stacks and then stack the results. It may have problems aligning things with 50 images though for doing the foreground stack so you may want to do that in 5 batches of 10 and then combine the 5 results. Using 50 images would result in very dim trails as the trail would be about 1/50th the brightness of the star on a single image.

Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, light, mode, photography, photoshop, stack, technique, trail
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Still Life Short Stack Roadboat24 Photo Critique 8 10-28-2019 03:10 PM
Landscape Pond Cloud Stack aitrus3 Post Your Photos! 5 10-02-2019 06:52 PM
Night Andromeda with the K-1 - 18 Image Stack Colorado CJ Post Your Photos! 11 10-28-2018 05:38 AM
Lightroom 2 - auto stack RAW with JPEG? Propagate changes through stacK? Eruditass Digital Processing, Software, and Printing 13 09-24-2009 07:35 AM



All times are GMT -7. The time now is 05:31 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top