bomberbaz

It's fine really olly, the data wasn't the best and losing it doesn't bother me. I am spinning enough plates as it is. However thinking about it, nothing wrong with having a reserve project to learn more about. I shall recover the data to my back up drive and have a go. My processing skills need improving, so maybe use this an an opportunity to learn something new!

I have got to the bottom of this in another thread. It was a comedy of errors on my behalf but thankfully with the help of other peoples input and hindsight of the mistakes it has now been sorted out. The main error above is a variable level output from a tablet being used as a whitescreen, that is what has led to the uneven image results. A sheet of white paper and a slow rotation of the tablet device evened out the flats and the latest results were significantly improved.

Thanks Guys, especially @ollypenrice but all who chipped in. I have had to bin the M81 data, various changes to the camera chain means I am going to struggle with it and simply cannot be bothered with it now. However the M3 effort below is a little over 30 minutes worth, which has only had a simple stretch is how I know it should look from my garden. Gradient right to left from the hotel car park lights across the road. I re-did darks, dark flats and flats. Flats done as per advice from Olly and Jacko, results speak for themself. cheers steve

I think there is a very good chance the problem lies there and also I shall follow olly's advice re rotating the screen for a more even light grab

Thanks Olly, that all makes good sense. Just a quick question of you, would a massivly out of focus affect the image being received, as it was a very long way out of focus for the 2nd flat and I only realised this last night. Schoolboy error.

I am having a lot of problems with the ASI Air and I am wondering if there is a link between that and this issue. I will post up links to light plus calibration that relate to the above shortly though to see if there is anything that can be gained from this.

Thanks for the reply, these were taken Monday, the scope was dry when I brought it in, no evidence of dew. I am completely baffled but one thing 9is the scope, an ED72 is new so maybe a visual session is needed to rule that out as a problem. That said, the problem seems to me at least to revolve around the calibration frames.

I ordered a ZWO single filter drawer from FLO and a spare filter holder. For those that do not know there is a V1 and V2 drawer, but they are not compatible with each other. (I did not know any of this either) So the upshot is my V1 spare holder wouldn't fit into my V2 drawer, so I pinged an email over to FLO and asked if I had made an error. I knew I had but didn't know "how" I had! Next thing is an email from FLO apologising saying their site should be clearer about the V1 / V2 thing, also that a V2 replacement was posted out free postage, finally a return label was emailed to me to send the other V1 version back to them. Absolutely first class service guys, above and beyond expectations there. 👍👏

Ok so yesterday I put up the top image showing the wavey gradient and so now I have also attached the accompanying master flat. This FLAT is 0.16 seconds, just the tablet screen dimmed and laid over the top of the scope. As you can see quite uneven and suggested to be the reason for the poor image which seems feasible. The tablet screen not giving an even glow being my thought. Next the new image and flat (also below) showing the central region blown. The accompanying flat though seems decent. New flat 0.9 second, two pieces white paper and a brighter screen on top. Histogram at 50% The base light data is the same for both and yes the flats are in the right order. Stacked in ASTAP. What is going on here, I am mystified! This is the second batch using the new flats.

Just looked at the L2 filter, there is a smudge print on it, might be the problem or it could be the lights although they are new ones. Think I shall start again, clean my filters with some isoprol, blow out the focal train for dust and do a new fresh batch. EDIT> The flat fit below explains it, very bad indeed. Flat_160.0ms_Bin1_183MC_gain115_20230425-174344_0011.fit

Hello all. Just a very brief overview of a comparison I did for no other reason than I had a few minutes to kill. There is only a small amount of data (about 30 mins) on M81 at the heart with M82 and NGC 3077 off to upper sides. The images are messy but these are purely stacks including usual calibration files, I have done nothing else to them so I just thought I would stick them both up. DSS is well known and simple to use, ASTAP is a little more involved but none the less not too difficult once you learn how it thinks! Top one, DSS, bottom ASTAP. I would welcome opinions and will post again when I have added further data to see if there is anything else.

reading a what? 😉

Hello Han. I have been trying to figure out how to do this procedure but for the life of me cannot get my head around it. I have read the guide ASTAP, Astrometric Stacking Program (hnsky.org) but there is no mention or walkthrough to guide you through the process. Do you have anything that shows it step by step? cheers steve

I am not aware there is more than one bin option in ASI AIr, I shall have a look later

What I did vlaiv was 2x bin in ASI Air whilst taking the subs, this is why I cannot understand as they should be B&W given that 2x bin can only be given you only have the one red, one blue and two green, or am I missing something very simple.

Thanks for that, I had already played around in that area but even trying playing around with the above, I cannot figure a way to create a B&W fits, still getting colour. Probably doing something very basic wrong!

Hmm this is what I did, 2x bin but still have a colour image. I have confirmed the binning in ASTAP but have a colour image. Seems something is not quite right.

Never actually looked at that interface and was looking at the file checking/stacking part of the interface, doh!

Simple question really. I was under the impression that binning OSC camera's gave you results in mono, is this not the case 🤔

Just had a look through the documentation page and cannot find an algorithm for removing the RGB bayer pattern from OSC camera FITS. I thought it could bin the pixels and remove them. I don't suppose anyone else can help me here? @ONIKKINEN @happy-kat @Paul M ?

Thanks for the reply, yes free is always a great price. I have to be honest the main thing that interests me is the bayer algorithm for OSC cameras. I recently rekindled my interest in spectroscopy and only having a OSC is detrimental to results. Having a free programme to equalise the pixels into a mono, binned super pixel is cheaper and as effective as mono. Well at least this is what I am hoping for.

Has anyone got any experience with using the ASTAP programme, I would like to know more about it The home page for it is here ASTAP, Astrometric Stacking Program (hnsky.org) but having had a quick whizz through it, it appears to be something of a one page bible! Anyway, before I dive in head first I feel some background info and user experience would be a good idea if there is anyone who can help with this! cheers steve

I am using a 183mc for obtaining spectra for spectroscopy purposes. It really helps your results if you can use black and white. My camera isn't B&W so I can bin, however the FITS will still retain most of the bayer pattern in them. Is there a way of removing bayer pattern from the raw FITS images to smooth out my results.

tell me what's on your list? the real one that is hidden away from prying eyes 🫢😆

A timely thread this as my table is currently full of gear (mainly eyepiece) I am considering selling. I shall spend a little more time sitting and thinking about this before I list any of the items. That said, I have been mulling this over for about 4 months as it is!