UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Before I release it, I will make sure that everything is working properly and then I will release it.
Can someone explain why some of my drizzled images, when following the recommendations in the app to use Bayer xtrans drizzle result in a distinctive crosshatch pattern when zoomed in at 100% it's prevalent in colour but more so in monochrome images. Using the non recommended rizzle process does not achieve the same result.
Can someone post an updated video showing how to use the drizzle process properly?
Here are a couple of videos that may help you.
The first one is in German but you can put the subtitles in the language of your preference and it does a good job. Also the images are pretty self-explanatory.
In the second video (in English), it also does an introduction of how to use the RC tool to find out the scale and drop size values depending on the characteristics of your camera and your telescope.
Overall:
Kernel: topHatKernel or SquareKernel.
Droplet size: between 0.7 and 0.9 (in normal conditions)
mode: drizzle if you have a mono camera and Bayer/X-Trans if your camera is OSC.
Scale: around 2.
RC´s webtool:
https://www.rc-astro.com/mtf-analyzer/
First video:
Second video:
Regards...
Thank you but what causes the crosshatch pattern and why does it insist you use bayerxtrans when extracting the Ha or O3 should this not be clearer in the little instructions that pop up?
Still no answer to this question
Bayer X-Trans is only for camerasensors with a bayermatrix, OSC cameras.
Patterns can show up if you have a small number of images to drizzle. The more images the better.
And your images have to be dithered well and often.
@nicholas64 you want to extract and in the intergration drizzle at the same time? I did that but i get squares. The reason i think because its a color camera and not mono, APP is extracting HA and show it up in mono image, while you use bayern in drizzle. That is for color. So i am testing if i need to stack first in color with drizzle and after that load the intergrated file only and do extraction
I’m also experiencing a similar problem with APP in my drizzled image. My setup:
- ASI2600MC (OSC)
- SIGMA 135mm @ f/5.0 (so, well under-sampled)
- Antlia 5nm ALP-T Dualband Ha/OIII
- Zwo AM5
- ASIAIR Plus
I captured a set of 60 subs dithered on DEC and ALT for each frame (10 pixels).
I processed them in APP with the usual master calibration frames (FLAT, DARKFLAT, BIAS).
Kernel: topHatKernel
Droplet size: 0.8 (but tried 0.9 and 1.0 as well)
Mode: Bayer/X-Trans
Scale: 2.0
After following the drizzle tutorial mentioned above and by Sascha from View Into Space, I ended up with a nice image, but there’s a subtle, yet visible horizontal fabric pattern in the background of my stacked image when zoomed in at 100%.
The stars are obviously less pixelated though.
I thought the issue might be due to insufficient data or not aggressive enough dithering, so I shot another set of 70 subs with a 30-pixel dithering distance… same result. I then shot 53 more subs the next night and added them all together (183 subs in total), but I still can’t get rid of that subtle fabric pattern.
Click, it's more obvious in full view:
droplet size <1 is way to small for bayer drizzle. I bdrizzle about 1.5-2.0, you do need much well dithered data too. Best is to test different d-sizes on a cropped integration
@xyfus Thank you for your reply. I’ll increase the droplet size to 2.0 and see what it does.
Not a direct answer to your question, but my recipe in drizzling is Droplet size 0.75 and Scale 1.5. I've sometimes (very seldom) used Droplet size 0.5 and Scale 2.
Been sucessful with lots of setups, including ASI2600MC.
/Stefan
