Re: Live Stacking Beginner help
Posted: Fri Sep 21, 2018 8:33 pm
Don
Thanks. I was were you are now about 18 months ago and asking the same questions, then a few things started to fall into place. Its all about the histogram at the end of the day.
https://docs.sharpcap.co.uk/2.9/#Using% ... 20Stacking
BTW, I use a Bahtinov Mask for focusing - best £20 I ever spent.
I will not edit the document yet, wait to see if there is any other feedback - I did write it fairly quickly (< 3 hours, untested and not proof read, which is pretty shoddy by my standards). If the document turns out useful to others, it might end up being put in the Tutorials forum (Robin might have a view on that?).
Dave
Thanks. I was were you are now about 18 months ago and asking the same questions, then a few things started to fall into place. Its all about the histogram at the end of the day.
https://docs.sharpcap.co.uk/2.9/#Using% ... 20Stacking
My usual route is curves/levels repeatedly to extract the image, then satuaration, brightness/contrast, black level/exposure. Here there already was an object, so nothing really to dig out plus when I went into curves the histogram had vertical lines (gaps). I take that as the image being stretched to breaking point and will only deteriorate after that. This was from the book Photoshop Astronomy by Stephen Ireland (not cheap but very informative).was only using the brightness/contrast tool and curves
None of the examples are really targeted at Astro images, what I did was to find out how to do something in Photoshop and translate it to GIMPish. With a better understanding of processing, I can manage within GIMP entirely. I am at the point of stopping my Photoshop subscription.resigned myself to studying the GIMP user manual
Oops! I must have caught something switching between Gimp, Word and the Snipping Tool. I have rerun my notes and 0 is ok. keep is simple.you also changed the output level to 60
The same thing. Size is a personal thing, which really comes about by experimentation. With 700x500 there has to be compromises and trade-offs. I always go for 'looks better'."scaling" and "re-sizing" an image
I used to have a Nexstar 6SE so I understand where you are coming from. I used to carry out the initial alignment using finderscope + eyepiece. As confidence (ability) grew I started using finder scope + camera. I turn on the reticule in SharpCap that way I am not guessing where centre is in the FOV. I also noticed that changing optics from eyepiece to camera resulted in centre being shifted. I now align using the optics that I will be imaging with i.e. camera + focal reducer (for example). When I am aligned, I stay aligned. Best to practice this on partially cloudy nights.At least if I can properly center the image
I didn't know I had a beautiful one, must have been lucky that night. Where is it?beautiful image of M27
My view is that with the single PNG, if something goes wrong, then there is nothing. My personal preference is save the RAW frames and save the stack. That gives instant gratification and some data to practise with for stacking and processing. I am very much of the mindset 'capture data and take it away to process'. For me Sharpcap is for capture and Nebulosity etc are for processing. I mainly use Siril now for calibration & stacking with GIMP to process.Would you recommend saving the SharpCap live capture as a RAW FITS file and use other software for further processing (e.g., Deep Sky Stacker, Nebulosity), or using the tools in SharpCap and saving the as viewed png file as I did
To be honest I never really bother about orientation, just grateful to get something on the sensor. You can upload your image to astronometry.net to have a look. For me correct orienation will be part of my evolution.picture appears rotated
BTW, I use a Bahtinov Mask for focusing - best £20 I ever spent.
I will not edit the document yet, wait to see if there is any other feedback - I did write it fairly quickly (< 3 hours, untested and not proof read, which is pretty shoddy by my standards). If the document turns out useful to others, it might end up being put in the Tutorials forum (Robin might have a view on that?).
Dave