Mar 28 2026 APP 2.0.0-beta40 will be released in 7 days.
It did take a long time to have the work finished on this and it will have a major performance boost of 30-50% over 2.0.0-beta39 from calibration to integration. We extensively optimized many critical parts of APP. All has been tested to guarantee correct optimizations. Drizzle and image resampling is much faster for instance, those modules have been completely rewritten. Much less memory usage. LNC 2.0 will be released which works much better and faster than LNC in it's current state. And more, all will be added to the release notes in the coming weeks...
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.
Hello!
I got a question regarding the drizzle.
I wanted to use it for images I took with my 300mm refractor, which leads to quite some undersampling.
However, I am not entirely sure how to understand the settings.
The example given is that droplet size of 0.5 and scale of 2 is the same as 2x drizzling.
But what would happen with 0.5 droplet size and scale 1? It will not add more pixels, so nothing should happen, right?
Is it recommended to adapt the scaling based on the droplet size as well? For example, 0.75 droplet + 1.5 scaling, or is the same scaling alright with any droplet size?
What happens with a droplet size > 1? Will that decrease the resolution?
Sorry for the many questions, I am a bit confused on how I should adapt the settings properly.
Thank you!
CS Tobi
Hi Tobi @tobigh3,
Thank you very much for your question.
The example given is that droplet size of 0.5 and scale of 2 is the same as 2x drizzling.
Indeed, that is what commonly is called 2x drizzling.
3x drizzle would be scale 3.0 and droplets even smaller like 0,33
But I think you better look at it differently and realize that there are 3 factors to adjust to perform drizzle and get different results. Beside scale and droplet, the drizzle kernel will also affect results.
The first and most essential thing about drizzle is that it is a noise injector and this is directly controlled with the droplet size for a given scale and kernel. Lower droplets give more nosie and possible more sharpness and vice versa. So the best droplet setting is dependent on how much sharpness you want to achieve and how much noise you can live with 🙂
I would recommend that you simply use scale = 2.0x and vary the droplet size between 1.0 and 0.5, experiment a bit to see what the differences are.
For Bayer/X-trans Drizzle, simply use 2x the droplet size as compared to drizzle on monochrome data. So with OSC/color data and Bayer/X-trans drizzle, droplets of 2.0 equal droplets of 1.0 (we need to fill the CFA holes).
Also, if you keep scale 1.0 but use droplets lower than 1.0, you might not fully see the sharpness increase because there are not more pixels to show it, and the smaller droplets do inject more noise. So better the other way round. Increase scale to 2.0x and then lower the droplets step by step until you get a good balance of sharpness and noise.
Use the Crop composition mode in 6) Integrate to only integrate a small part of your field of view for testing and getting the correct values for drizzle. When you get good parameters change the compostion mode to full again and make your integration 🙂
Oh once you have found nice parameters, do test what happens with a different drizzle kernel, you will probably see different results on you star borders...
Please let me know if this explains it a bit more.
Mabula
Hi Mabula,
That clears up a lot, thank you for the detailled explanation! 🙂
Which one is the recommended kernel for drizzling? I didn't change anything there as I thought the default one will be the best.
Also, from what I understand, bayer drizzle is generally better than regular drizzle, is that correct? Or are there situations where regular drizzle has an advantage?
Thank you!
Best regards
Tobi
Which one is the recommended kernel for drizzling? I didn't change anything there as I thought the default one will be the best.
In my experience with using APP the default settings seem to be the "best" settings in most situations. But it depends on your data.
Also, from what I understand, bayer drizzle is generally better than regular drizzle, is that correct? Or are there situations where regular drizzle has an advantage?
drizzle => monochrome data
bayer drizzle => osc/color data
Alright, thank you!
One more question just came up:
If I want to combine for example RGB + Ha + Oiii, should all of those be integrated on the same drizzle settings? For example, since Oiii is usually noisier, I could decide to not drizzle there, but drizzle my Ha. Will this become a problem when combining them in Photoshop for example?
Alright, thank you!
One more question just came up:
If I want to combine for example RGB + Ha + Oiii, should all of those be integrated on the same drizzle settings? For example, since Oiii is usually noisier, I could decide to not drizzle there, but drizzle my Ha. Will this become a problem when combining them in Photoshop for example?
This should not be a problem. But if you drizzle with too low droplet size, the stars could have clear drizzle artefacts, then it can become a problem which you can solve by using higher droplet sizes 😉
Mabula
