bomberbaz

Do you have the walkthrough on this method, the one I read seemed at odds with what your saying.

I was thinkiing for use with stacking comet pics and the auto detect function in DSS. It isn't picking the comet up so wants me to align (manually) 80 frames, thought if I gave it a tweak it might be able to pick it up.

I have three images below, all from same data with one slight difference, dither during background extraction. I followed the advice below and got a much tidier image after background extraction. However as you can see below, the first image is a horrible looking thing and the second one much tidier. Difference being I used the dither during background extraction which evened things out nicely. Both top two have had siril auto-histogram stretch Things are still very noisy though, walking noise still there in them but less prominent and gradiant removal has been far more successful than previous tries. I tried saving without using the siril auto-histogram and then tinkering in gimp and that gives the bottom image. I think I can get better but I am very satisfied in getting to this stage and shall continue to work at it. Very tired now though so will try again some more anotheer day.

Where do you keep the scope when not in use?

Thank you for that, some very useful information there. I am either not, over or under doing certain parts within the underlined statement by the sounds of it. I shall try again and see if I can further improve results.

That is precisely what is occuring. I am ending up using so much process to remove walking noise and severe gradiant that the end results are losing the natural look. Very frustrating but I am stuck with my garden as I cannot go elsewhere that is darker to gather data for other reasons.

I am using the zwo 183mc pro camera and yes, I have a a library of D, F and DF's. They are recent too. I restacked some data that had shown bad walking noise using DSS but this time I activated darks optimisation which made a noticeable difference. The noise was still there but definately improved upon the previous version. I now have some additional data which has been dithered but not had chance to add to the original data. I also noticed after posting this there is also a dither tickbox in Siril - background extraction. Not sure how or if it works but it's something else to try and improve things.

I know the best cure for walking noise is not getting it in the first place. Dithering and good PA being the two methods as far as I am aware. I also read that taking your subs over several nights would, when stacked even out the walking noise. However, I took my subs over three nights of M108/97 and the walking noise was awful, however I did not dither. Currently taking some more subs with dithering to add to the others to quieten it down although I doubt it will cure it altogether. Gmic had a useful tool to dampen it down (denoise smooth) and other tinkering in Gimp. Wondered if anyone else has other ideas for removing noise.

Three, please do explain?

Ok so not added a load of data to the first M42 from the other day which can be seen first with the second one below. I have tripled the data from 7 minutes to 21 minutes but as with adding more data you add more noise. This comes from an already immensely light polluted back garden. All I have done is stretch and gradient removal, no star reduction carried out. The biggest issue is gradient, it really is quite horrendous and this can be seen in the third image to show what I am dealing with. I have a hotel car part 50 yards to the right side of my house with a squillion watts of lighting illuminating it. I remove part of the gradient in Siril and the rest in Gimp, however I lose image quality in doing so but I am improving, slowly. 7 minutes 21 minutes Gradient

Put up some kind of screen to keep it out of your garden, only answer really.

Hello. I have some Fits and I was looking to sharpen them up pre stacking. They are comet fits so was just looking to brighten it a bit to help with DSS picking up the comet. Am I taking a sensible approach or am I entirely looking in the wrong direction. Does anyone have an alternative (not Siril) option if PIPP isn't a good idea? cheers steve

I would go without glasses. Once you get used to the feel of not wearing them whilst viewing (it can seem strange at first), you should be fine imho.

I have shockingly bad astigmatism, an astronomers worst nightmare in optical terms as well as needing varifocals and here are my solutions. Exit pupil of greater than 3.5mm, I use a either a televue dioptrix or wear my glasses or use astigmatism correcting contact lens. I prefer contact lens but the other two options are acceptable depending upon what I am viewing. An exit pupil of <3.5mm I put up with the astigmatism. I find it is generally not too severe in the smaller exit pupils and barely noticeable once I get down below 2mm. When using my large binoculars nearly always use contact lens. I can use glasses too but CL are preferred. Hope this helps. Steve

Does anyone have a link to the Siril comet stacking workflow, can't seem to find it. I found the one for DSS but with 300 frames to stack, a manual job does seem long winded.

Only 7 minutes of data using optimised 15 second subs, no filter, Evoguide and FF and ZWO 183MC pro. Very pleased what I have managed but this was really only a test of settings, very encouraging.

Deep Sky Stacker, I find it the easiest and most straight forward (and it is free)

Lee, it is a very fast moving comet, 36 minutes is going to have movement no matter what you do. Try reducing the number of frames and go for say 10 of the best consecutive minutes with just darks, you may not need dark flats and flats. If there is still walking try 8. It is so bright you won't need much.

A year ago I started out like you, no idea what I was doing. Some might say that's still the case 😉 Anyway, I now use ZWO ASIAIR software for capture of data. If I didn't use that, I would use sharpcap instead. For processing at first I played around with Gimp, That is until I was introduced to Siril, so now I use Siril. (Siril is very easy) With Siril you can 90% process your data to give you a decent looking image, the process for this is largely automated. After just tidy up a little in Gimp, both Siril and Gimp programmes are free.

According to @Don Pensack review on here Vixen 30mm NLVW... - Eyepieces - Cloudy Nights the design is probably same/similar to an erfle, more suited to a longer focal length ota. I am beginning to wonder if I should cancel mine now, twas an impulse buy and reading this review (and a few others which are readily available), other than looking nice and being vixen, it isn't all that spectacular.

telescope house also same price but I think they are one and the same

Should work nicely in my 102ed and my existing eyepiece at that size isn't the best. Order placed, thanks for the heads up

Send it back and get your money back. Then come back on here and ask for advice before purchasing again. In fairness to yourself you won't have realised this but it is not the best scope anyway. It is a bird jones design, more info here. What is a "Bird- Jones" optical configuration? - Reflectors - Cloudy Nights

Don't think you could do that mate, the lens arrangement in the scope will be set to focus at F10. It won't be a case of chopping it in half and making it F5. You could install a 0.5 reducer and that would make it F5 but it would have to come to focus of course and a reducer tends to bring the focus point closer in sometimes preventing this.

Good report Lee and you hit some reasonable targets too. With a faster ST80 you will yield a brighter, more detailed result on DSO galaxies & nebula.