The Definitive Guide to WBPP: Post Calibration Tasks

[@GlennMartinPhotography]

The splitting of osc channel data in post processing for possibly better registration is great to know. Be interesting if split osc data could be easily integrated into narrowband data - or is that taking the concept a bridge too far..?

[@AdamBlock]

Not at all- Splitting the RGB for narrowband imagery when using OSC is really somewhat required. For example, when capturing H-alpha light only the red pixels of the CFA really record this signal. So splitting the channels and having the Ha "monochrome" data might indeed be useful.

[@ExoPhotography1]

Would you say that the new PSF Signal wweight in WBPP making sub frame selector absolete?

[@AdamBlock]

I guess not...there are some other parameters in SFS - but I am quite biased about all of this. I am the type that favors SNR over other metrics... so all of the handwringing about eccentricity and FWHM is not my thing.

[@AdamBlock]

but... for an automatic SFS... PSF Signal Weight is really very good.

[@Hidden.Light.Photography]

I have a major issue with registration none stop no matter what. I have manually looked through my images and got rid of ones that were not good. I start WBPP and everything is good until I get to registration and they immediately start failing due to no putative star matches. My last run with M101 I had to change a bunch of settings in registration and finally got all but 10 to go through. I cannot figure out what’s going on.

[@AdamBlock]

Usually this issue is due to either hot pixels or very poor star quality (sometimes out of focus). Of course, this is a strictly data driven issue. Without seeing images it is almost impossible to say. My above guesses could be totally wrong..but those are the common reasons. Because you likely do not have very many stars in your frame, and also because you probably used short exposures (less than 300 sec)... all of these kinds of problems become important (where on starry fields they would not be). You can use StarAlignment to output the stars it thinks it sees in a frame and this can help sometimes figure things out.

[@Hidden.Light.Photography]

Thank you for the reply! Would I be able to send you the subs? I know focus wasn’t an issue as my stars were sharp and I deleted the frames that had streaking due to wind. My star field wasn’t that big as I was using an ASI585MC on a Celestron OMNI XLT 150 OTA.

[@Hidden.Light.Photography]

Is there a way to register with minimal stars in frame?

[@AdamBlock]

@@Hidden.Light.Photography It is very rare not to be able to do it. Are you a member of my site?

[@AdamBlock]

It does not appear if you are. I hope you understand I get so many requests for help...I need to prioritize helping my members (it is something of a benefit). I hope you understand. Pls correct me if I am wrong.

[@paulsubject9003]

Similar to the question of whether SFS is obsolete, is it still worth blinking lights to take out really cloudy ones or ones that are streaky due to e.g. winds, or does the WBPP deal with those issues adequately?

[@AdamBlock]

Human Eye/Brain is currently *always* better. So blinking images if you have time cannot hurt anything right? Whether the math will give proper weights to poor images is something you simply have to test. There is no all-encompassing answer to "will WBPP (or any algorithm) deal with the issues ADEQUATELY." That is a "weasel" word. :) But once you know the range of quality your images have - you CAN use WBPP to do this without blinking. You just need to know your data.

[@paulsubject9003]

​@@AdamBlock I guess I should have just asked whether you blink your data? Just curious...

[@AdamBlock]

@@paulsubject9003 Sometimes... see..that is the thing. If I know the data was taken under good conditions... I don't worry about it too much. If data was taken across many nights of varying conditions... yeah.. I will take a look and see if I need to intervene.

[@paulsubject9003]

@@AdamBlock Thanks. Seems like I need to pick out a bunch of varying quality images and run some tests to see the impact of CC, local normalization etc. on the final images.