**OLD** Part 5: WBPP 2.0 (PixInsight): CMOS / OSC Flat Dark Example

[@MrBebopbob]

Boy do I wish I had started with this series of videos! Thank you for the deep dive into image calibration. I have a question regarding multi-year image capture. I have collected (OSC) data for several galaxies over a couple of months. Each night I take Flats and Flat-Darks (thank you for clarifying that these should be considered Darks). Being a scientist (with very little experience), I have experimented with different offsets, exposure times and a couple of filters (LPro2 and LEnh). 1) Can I reasonably use WBPP with these data. 2) will WBPP take into account different flats for different nights? Thanks.

[@AdamBlock]

Yes. You can use keywords to make certain you are matching the correct calibration data with the matching light frames. However, your experimentation may make things complex in that there is no outward facing indication that these sensor parameters are different (it should be in the FITs header). If you are really clever, as a safety check, you can use one of FITs keywords (like gain or offset) to make absolutely certain you are matching correctly- otherwise, you need to rely on your memory or attention to detail.

[@MrBebopbob]

@@AdamBlock Thanks Adam. I have taken thorough notes (because I am an OCD retired engineer). I have been going through my files to determine which ones are worth keeping. I upgraded my mount, which has improved my data significantly. Thank you very much for your videos. They are just what I was looking for as a step up from the Light Vortex tutorials (which are excellent for a first step but are a little light on the why).

[@claude77573]

At 10:10, you mentioned that we should refer to the "previous section" for your description of how to create a Cosmetic Correction. Where is that? The previous Part, Part 4, dealt with Flat Darks.

[@AdamBlock]

I may have changed the order of the videos long ago... I am certain to do it in other examples... see Part 6 where it do it early on. You just create a CC instance on the desktop that is setup (with Auto in this case).

[@claude77573]

@@AdamBlock Got it. Thank you.

[@gator-freighterlpd-1334]

I noticed if you label them Dark_Flats, it'll put them into the proper list using +Directory in V2.3.2.

[@richtemen]

Hi Adam. Great tutorials! I keep my Pixinsight always updated. Currently, I have WBPP v2.2.0. It is not quite the same as your tutorial, and I am having a couple issues where things are different from your tutorial. Do you have an updated version?

[@AdamBlock]

Well..that is the tough part. These things are ever evolving. You will find there is an update in this series... explaining 2.1. Version 2.2 has some new features- but everything you need to know in terms of utility you will get if you watch all of my videos through the 2.1 update. Indeed, these updates take into account some of the suggestions I made to the developer as improvements! :)

[@normanhey8016]

Great series--thanks, Adam. Two questions: How does one know if one has a "well behaved" CMOS sensor? Is there a down side to just using (raw light-raw darkmaster)/(flat-flatdarkmaster) for any CMOS?

[@AdamBlock]

There is no downside to using a matching dark for your flats. Please see the Calibration sections. The only "downside" is..if you have a well-behaved sensor, you would be unnecessarily taking dark frames for many flats (if you have multiple ones). Otherwise my recommendation is to match darks to light data which has to work! Usually CMOS cameras with any kind of amp glow were a big red flag for making certain to use matching dark frames. Other less obvious CMOS misbehavior would be discovered by poor calibration results likely.

[@normanhey8016]

@@AdamBlock Thanks! My camera (QHY168c) doesn't seem to have an amp glow problem. So should I use a master bias to calibrate my flats or flatdarks? I have a flatdark library already and a masterbias-will they do the same thing. If I understand it correctly, they do.

[@AdamBlock]

@@normanhey8016 Yes...you might indeed have a nice well-behaved camera. You can do a quick test! Calibrate some images with your exactly matching flat dark..and just do the same thing with your bias. Register and combine the images. See if the combined images look different...if they do not...you are golden! It is somewhat important to combine a handful of images. It will make certain you can see the difference if there is one.

[@esbenhoffmann5421]

Hi Adam. Thanks for your videos. They have made me use PI and WBPP now. and not DeepSkyStacker I'm experiencing a bug I can't understand. Right now I find that if I add too many dark, then PI can not stack my lights. If I'm under 15 dark no problem. but if I get to 20 dark, or more, PI can not stack my images. And the only thing I change is the number of dark. When I see my pictures I thought they look good, but I have a little doubt if they are 100% in focus, as the temperature changed that night. Is there an easy explanation for my problem. my camera is a ZWO294 mc, then an OSC. Greetings Esben from Denmark

[@AdamBlock]

Sorry "Can't stack" is a general statement. In order to figure out what is going on- you need to say the specific error that WBPP says. The logfile will also show you what the problem is. There is no limit on the number of darks... BUT- you can experience a problem like this if you run out of memory on your computer. If this is the case... it isn't a PI problem... it is a hardware issue.

[@MrBebopbob]

Make that multi-day (love spell checker).