June 24 2026 APP 2.0.0-beta46 has been released !
Improved internal memory configuration (lower ! memory usage), fixed beta45 startup issue, fixed Set Save Directory & 2-panel mosaics.
May 27 2026 APP 2.0.0-beta45 has been released !
Fully Multi-Threaded LNC, many improvements for the registration engine, platform upgrade, and further tuning of internal memory consumption and memory release back to OS.
Apr 14 2026: Google Pay, Apple Pay & WeChat Pay added as payment options
Update on the 2.0.0 release & the full manual
We are getting close to the 2.0.0 stable release and the full manual. The manual will soon become available on the website and also in PDF format. Both versions will be identical and once released, will start to follow the APP release cycle and thus will stay up-to-date to the latest APP version.
Once 2.0.0 is released, the price for APP will increase. Owner's license holders will not need to pay an upgrade fee to use 2.0.0, neither do Renter's license holders.
I shoot with a long focal length scope so I shoot a lot of 2x1 and 2x2 mosaics.  I generally have a lot of overlap as I shoot Alt/Az so I rely on Multiband Blending (MBB) to hide the seams.  In general, the higher I set MBB the better, but that makes me wonder: What is the downside of moving the slider all the way to 50% when I have a lot of overlap versus playing around with 15%, 25%, 35% and seeing where it finally doesn't further improve the seams. What is the tradeoff of pushing it higher than necessary. Â
1) Is it just a performance tradeoff? (I can certainly live with that)
2) Of does Multiband blending cause each light to contribute less near the border so the SNR suffers the higher you push it? (For me, this would be a big reason to not set it too high.
Great feature BTW and I really look forward to the new rewritten Mosaic features!
- Steven
Hi Steven @readyjetty,
Very good question 🙂
1) no there is no performance tradeoff, a higher MBB % is exactly as fast as a lower %. If you have a lot of overlap, by all means simply use 50%, I do myself because it gives the best result. Any gradients after MBB are also easier to remove with the Remove Light Pollution Tool.
2) No, no clear downside as well on SNR I think. Do test it 😉 make an integration with MBB 25% and one with 50% and check the SNR in the integration header. Did you try that?
2.0.0-beta39 will come soon !
Mabula
Just as I posted the question I realized, "gee I should test it for SNR", so I did. I did a large mosaic stack of M31 with many panels with 0%, 10%, 20%, and 50% MBB. Here is the noise metric on the green channel after normalization measured with both APP and PixInsight.
What it says is that it does increase noise generally (there is one exception), but by a modest amount. PI reports more of a difference than APP, but they are fairly modest in both cases, but it does appear that the advice would be to keep to the amount that you need and don't arbitrarily push it higher. At the worst, you increase noise by 2-8% and lose about 4-16% of your equivalent imaging time jumping all the way from 0% to 50% MBB depending on which SNR measure you rely on, but jumping from 20% to 50% is only about a 2-5% loss in productivity (which I calculated as the square of the SNR ratios).Â
If I had to venture a guess as the the reason, if the weighting of the pixels of a light are decreased simply because they are near an edge (perhaps you use a linear gradient from 0 to 100% over the width of the MBB setting), then one could expect this is equivalent to a bit less data.
This is only one test, clearly different tests will vary, so as I have the opportunity to test more, I'll report additional results.
Hi Steven, thanks for testing it so thoroughly !
Indeed, this is more or less what I would expect.
The SNR reduction comes indeed from the weighting for the pixels to remove those seams/artefacts with MBB. The higher the MBB, the lower the weights and thus it is like adding a little bit less data, but for a good reason, it helps to have the data be smoother.
So from a purely noise perspective, MBB has the effect that noise is less reduced while stacking. From a stacking artefacts perspective, MBB has the effect that the result looks much better of course.
The SNR loss of only 1-5%, for me, is totally acceptable with a smoother integrated result due to the blending. If you have a stack of roughly 100 images, it is very hard to visually see the quality difference between stacking 95 or maybe 105, right? While turning on MBB, if usefull on the data because of clear seams without MBB, greatly improves things.
I guess it depends what is more important to the user and I suspect most will find that the MBB effect clearly outweighs an SNR loss of a couple of %.
I fully agree with your conclusion, if you do not need MBB 50% and already have the seams nicely removed with MBB 10%, then go with the 10% because the SNR will be better overal 😉
Mabula
