Share:

We have updated the forum software 🙂 ! We are now working on upgrading the whole site and the Forum to a dark theme...  so please refresh your internet browser twice to properly update the forum appearance AND functionality... Check your internet browser for the refresh function, on windows, this usually is the F5 button, but it depends on your internet browser.

[Sticky] MBB (Multi Band Blending) - What does it and when do you change the settings for it?  

  RSS

(@foschmitz)
Red Giant Customer
Joined: 2 years ago
Posts: 63
August 2, 2017 07:30  

Sorry for another question:

In the workflow tutorial you suggest to enable MBB and a setting of 5%. In one of Sara's videos she uses 9%. Can you explain to me the difference and when to best use which setting? 

Thanks a lot and sorry for the many questions 🙂

Best Frank


ReplyQuote
(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 2056
August 3, 2017 10:33  

Hi Frank,

No problem at all 😉

MBB or Multi-Band Blending is a tool to blend images into each other. It will reduce stack artefacts at the borders of regular integrations and will remove seams in mosaics.

In most cases a value of 5-15% is okay. For regular integrations, usually 5% is nice. For mosaics it really depends on the amount of overlap between the mosaic panels. If the amount of overlap is about 10%, setting MBB at 10% will work very nicely.

So the MBB % is relative to the image dimension of each frame independently in the stack. Setting at at 10%, will mean that the outside 10% of each image will be blended.

If you experiment with the %, you should get a good feeling on how it will work on your data.

High percentages like 25%, are only needed if you have images that overlap for say 25%.

Low percentages like 1-2%, will still blend, but will be too little in most cases.

An example, 10 images of 5 photographers of the Rosette Nebula:

St avg 6600.0s NR x 1.0 LZ3 NS full eq add sc BWMV nor AA RL noMBB St
St avg 6600.0s NR x 1.0 LZ3 NS full eq add sc BWMV nor AA RL MBB5 St
St avg 6600.0s NR x 1.0 LZ3 NS full eq add sc BWMV nor AA RL MBB15 St

  • First image is without MBB,
  • second with MBB 5%,
  • third MBB 15%.

In this case possibly the MBB % is best around 20-25%. You can clearly see that 15% is better than 5%, but that there is still room for improvement possibly.

Kind regards,

Mabula

p.s. made a sticky of this as well..

Main developer of Astro Pixel Processor and owner of Aries Productions


ReplyQuote
(@foschmitz)
Red Giant Customer
Joined: 2 years ago
Posts: 63
August 3, 2017 14:31  

Awesome thanks for your answers! 


ReplyQuote
(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 2056
August 4, 2017 18:17  

You're most welcome Frank 😉

Main developer of Astro Pixel Processor and owner of Aries Productions


ReplyQuote
(@toddy)
Molecular Cloud Customer
Joined: 12 months ago
Posts: 4
March 22, 2018 16:11  

If your source images don't overlap much (ie:  scope tracking the target well), is MBB useful?

How much extra processing time does it take?


ReplyQuote
(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 2056
March 24, 2018 15:09  

Hi Toddy @toddy,

Thank you for your questions and welcome to the APP forum 😉

If your source images don't overlap much (ie:  scope tracking the target well), is MBB useful?

ie:  scope tracking the target well, so that would mean, the images overlap for almost 100% right? They nearly have the same field of view. Then yes MBB will still help by reducing stack artefacts at the borders of the integration. If the images have very little overlap onthe other hand, MBB becomes very important.

How much extra processing time does it take?

Yes, processing time is inpacted by using MBB, because a weight map needs to be created of the image and that needs to be used in integration for integration weights. The actual impact really depends on a lot of factors, but a fair estimate would be that MBB enabled increases integration time by 15% perhaps. It depends on the amount of images, the amount of CPU cores, the type of diskdrive used etc..

So it won't impact integration time by doubling it, but it will increase the integration time by

0.1-0.2 x integration time

without MBB roughly. It's simple to test off course, integrate 10 frames with and 10 frames without MBB. The actual MBB % shouldn't have impact on the processing time.

Kind regards,

Mabula

Main developer of Astro Pixel Processor and owner of Aries Productions


ReplyQuote
Share: