ngc1535

I appreciate you guys mentioning my method for star de-emphasis. Yes, I came up with it back in 2018... well before BXT. In my most recent video (NGC 1491, Fundamentals) I leverage BXT to do this job. If you understand my original methodology... you can probably figure out what I did. However, being a member of my site will save you from guessing. -adam

Regarding the information to work on (Tomato)- this is a BXT specific or special requirement.. .it has always been true for any deconvolution.

Correct. You do not have the S/N (in most areas) necessary to enjoy the benefits of deconvolution (of any type). -adam

Just to clarification... the latest image I published on AstroBin (linked to above) is from my own effort. It is not the same at the M51 data in the video (which is from a friend and I used his data as an example in my tutorials- it was taken with a 16-inch telescope. My latest version is with a telescope twice the size). I do think my latest version is pretty good since it leverages many tools and techniques of today. The original image I produced from this data is from 2011. -adam

Goran, For clarification to clear any doubt- in the video I operate on linear images that were created after RGB combination (having been DBE'ed and SPCC corrected). Concerning the artifacts- all deconvolution algorithms produce them. The extra work you suggest you should have been doing all along if you deconvolution of any sort. This suggests nothing new and is not more frustrating than before. There is a good argument it is less frustrating. all you need to do and compare traditional decon to BXT. BXT with modest settings minimizes a number of artifacts that traditional decon produces. -adam

It might be because with WBPP it is now using Average Sigma Clip for a frame number of 10... did you set the sigma thresholds for this? The defaults will not reject much if anything... which is why your things are likely showing up. If you want to experiment, lower the Sigma Low to 3 (or maybe even 2.5) from a default of 4 and see what happens. (most people do not use Average Sigma Clipping... ) I will send a note to Roberto... perhaps should have used regular Sigma Clipping in my opinion. -adam

Not only am I releasing videos on WBPP... but I am making them public. https://www.youtube.com/playlist?list=PLAzMa9eIVQkDnrwzRCDLYB3JGoJz7tlxF There are still a few more sections to go... and the section I hope to release tomorrow is the most important one I think. -Adam Block

I agree. I use Cosmetic Correction (auto) as an incremental step. Anything that it does not take care of- is likely to be handled during rejection in ImageIntegration. -adam

It is true that after you have calibrated data in hand, you can apply Cosmetic Correction. There are THREE different methods of using Cosmetic Correction. I use the Sigma method (which is relatively automatic and quite robust. You can be particular about it and determine hot pixels somewhat empirically by measuring one of the dark frames. (All of this is explained in my lessons. ) I don't like "1)" above as much because it doesn't work in every case. Thanks! -adam

Yes! This is something of pitfall of "automation" through scripts- it isn't always obvious what the order of operations is. Great job on working through the videos and I am very glad they are helpful! Sincerely, Adam Block

HI all, There may be some confusion here. Cosmetic Correction is a kernel filter that is run on data after they are calibrated with biases, darks, and flats. Cosmetic Correction (basically a hot pixel filter as well can have potential uses for column defects) is not connected to darks in the sense of calibration, scaling, etc. I do demonstrate it is possible to scale darks- which has some benefits regarding maintaining a dark library for a cooled CCD camera- but it comes with some pitfalls that deal with hotpixels and occasional scaling errors through dark frame optimization. It is almost always better to subtract a dark of the same duration if you have a high quality master in hand. This is a subtle connect between dark frames and Cosmetic Correction in that one of the methods of using Cosmetic Correction is to use a dark frame to generate a hotpixel map. But again, this isn't related to the calibration process. Feel free to connect with me through my website at AdamBlockStudios.com if this particular issue is confusing. Thanks, Adam

Alan, Great job on the use of the technique. I appreciate you taking it to heart. As I mentioned in my tutorials on this- even if you do not like outcomes of combinatorial means of processing an image (I used this "trick" as part of a larger thing to de-emphasize stars)- sometimes the individual small methods are useful in and of themselves. -Adam

I would not assume that since an image is published as a NASA APOD that the colors are "accurate." The astronomers (Nemiroff and Bonnell) do not check for this, but are as knowledgeable as anyone in our active community that would spot the weird stuff. I do not believe this image was published as an APOD...but I could be wrong. A *better* assumption is that I took great care in the fidelity of the details and color for images I publish. 😁 Indeed, small green blobs that look like HII regions are, though uncommon, not really rare. It is all too easy to "remove green" blindly (or nowadays SCNR it out) and miss out on some interesting astrophysical things! This is where examining the data closely and letting it be is a good skill (one you have shown with your image!). Another good example of these green blob things is this image: http://www.caelumobservatory.com/gallery/n6240.shtml It happens to be in this galaxy that I discovered my own Supernova..but it was not related to these blobs! -Adam Block