2026-10-09 APP 2.0.0-beta48 has been released !
This is mainly a bug fix release for the reported bugs in beta47. In addition it has a significant User Interface performance improvement noticable when you need to process 1000s of images in APP.
2026-10-03 APP 2.0.0-beta47 has been released !
This is a very big release... many code optimizations/rewrites, many parts of APP are much faster and more precise, especially star analysis and registration are much faster ! Big mosaics will go much faster 🙂
And we introduce a new preview filter, which includes the new Adaptive Deep Sky Stretch and a General Levels Stretch, this has been long over due. The old preview filter (the panel on the right side to stretch and preview your data) has not been updated for a couple of years and it is a critical part of any APP session.
Adaptive Deep Sky Stretch or ADSS is a much more intuitive stretch algorithm. It is also color preserving (which is a great new addition in itself ! ) which means that the highlights are no longer bleached, color is maintained from the linear data while stretching. You can simply stretch your data using the sky background level and signal width sliders which work much easier and more intuitive. You no longer need to fiddle with the old complicated sliders with zoom buttons. All the zoom buttons for the sliders are made redundant. And you can enter slider values in the slider value fields yourself. I will make a youtube video in the coming days to explain and fully introduce ADSS. Once the video is ready, it will be highlighted on the forum.
RGB Combine upgrade !. The RGB Combine Tool has been rewritten mostly. The tool is faster and easier to use and most importantly, the Luminance slider to inject a luminance channel or channels into the RGB composite is now working correctly. It no longer bleaches the RGB colors. Combined with the new ADSS preview, you will get much better and easier great composites with great color! I will also explain this in a new youtube video.
I am new to using flats etc so probably something I've done wrong, but my light frames look they are being massively over-corrected for vignetting by my flats when I calibrate them (see pic attached of a calibrated light frame!). I've put an example of a light, flat and dark frame in this folder if anyone can help have a look and tell me if I've done something wrong? https://drive.google.com/drive/folders/1GffIM_bEM6-_ybE1NugnPy95oM_Wx_mC?usp=sharing
I used an iPad with white light to do the flat frames by placing it directly over the lens - they looked good to me, if a bit underexposed. I created DNG files with the exposure brought up slightly to see if that made a difference but it didn't. The original raw file, and one DNG of the flat are in the folder above.
I'm using a Nikon D750 astro-modified and these were with sigma 28mm @ f/1.8 with ISO 1600 and 60 secs exposure.
Any advice much appreciated!!
You say you put the iPad directly over the lens... but do you then add a hood or dew shield for imaging? You must have the image train exactly as you image. I've found that dew shields and extension tubes can add stray light to the image if they are not flocked well enough. This can cause vignetting. The flat will unfortunately also contain this stray light but it must to properly calibrate the lights.
@astrogee didn’t use a lens hood or anything when taking lights, and then balanced the lens and camera on the iPad to take the flats - to me at least, the flat also looks about right for the vignetting in the light frame - but then it massively brightens the edges and darkens the middle for some reason?
Hi Callum, @cwhite939
You indicate : I've put an example of a light, flat and dark frame in this folder
In this case, the overcorrection is not unexpected, you also need to add either bias or darkflats to have a correct calibration workflow. Did you use bias or darkflats as well?
Mabula
