alacant

OK, so what is this photo? Your description was (I think!) that you needed a little extra movement toward the telescope. Do you need to move away or toward the tube to reach focus? If the former, you need the m54 extension fitted. BUT that is supplied only to get an eyepiece to focus. Anyway, for reference, here is a gso f5 at focus with a dslr and the gpu cc They are all within a mm or so of each other, depending upon how far you have the primary mirror adjustment screws tightened. The m54 extension is not needed with any of the gpu, Baader or sw 0.9 ccs. You would however need the m54 extension if you were using the gso cc. Cheers

Hi AAMOI, which feature of PHD2 do you need which is not available with EKOS' -excellent- internal guider? I can't think of any! Cheers

The M42 adapter and ring which causes tilt and vignetting. Remove it. Doesn't make sense. That's the same as if you push in the cc fully and wind the focuser outward to achieve the same camera position. The dslr focus position with the standard secondary is with the focuser wound outward about 10mm with the cc tight up against the neck of the focuser clamp. Are you sure you are collimated? Cheers.

The bodge of the Baader cc is still connected. Firstly, if you haven't already, tighten one of the primary mirror springs -almost- fully and recollimate using only the other two. Now remove BOTH Baader rings from the coma corrector. Here the the link in full in case anyone missed it last time: https://linuxcostablanca.blogspot.com/2021/04/baader-coma-corrector-spacing.html

The coma corrector is not at fault. Please see this article for details of how to connect. The TS photon Newtonian reflectors (aka gso) come with a m54 extension ring on the focuser. Remove this and you'll be able to achieve focus easily. Please post a shot of your focuser so we can see its components and we'll be able to guide you. Slightly different models have been used over the years. Cheers

Regrettably, how not to do it! Real data from actual cameras and telescopes rarely take any notice of what theory predicts, so it's a big +1 from us for looking elsewhere. We neither recommend following the method given in this thread. It is misleading at best. Try instead some the myriad of first rate modern software dedicated specifically to astro-image processing. They all have free trials. If you wish to pursue the methods here correctly, there are many up to date demonstrations, those of special note being Doug German's excellent hands on guides. Cheers

Hi Neither do we. Nice image. You maybe able to get more out of it by adding dark and flat frames to the mix. This is a few minutes in StarTools. You may like it. Anyway, HTH and keep up the good wortk:)

Again?! And still your stars are all white. Let's agree to disagree. You tell me that the stars are all white. I say they're not:) Cheers edit: Just to finish, Here is my version. With my data. Complete with coloured stars!

Sorry: @jager945 This is almost certainly why your colour calibration does not work. Yes. Process it. You'll see the difference;) Cheers and thanks for your time.

As Ivo explains, colour calibration must be performed upon linear data. Your workflow alters the data before you calibrate it. Here is a successful photometric calibration, including the resultant .tif HTH NGC4565- 28 x 5 min,101g-fotometrica.TIF.tif

Easiest is to screw a 2" filter into your coma corrector or nosepiece. if you have only 1.25" filters, I think it's gonna vignette but you could try one of these. HTH

Is your method distinct to that which the photometric colour calibration in e.g. Siril (example in this thread) does?

Which software?

Hi Thank you for postingyour version. It seems however that your method colours only the galaxy, leaving the stars white:( Cheers

@vlaiv please could you use the OP's image? I'm sure that would be far more useful. Siril has a good photometric star colour calibration if you need a reference. It only takes a minute or so. Cheers

The OP said there was no colour in his image. There is. Whether it's the correct colour, I don't know. Please show us the image correctly processed:) Cheers

¡Bienvenido a bordo!

Hi Had a quick coffee-break go. I'm not sure it's much different, but do bear in mind my total colour deafness! Oh, don't forget to dither between frames and stack using a clipping algorithm... satellites;) I like StarTools. What's wrong with its colour? Cheers

StarTools? I didn't use StarTools. Sorry if it's not perfectly balanced. I raise my hand. I'm hopeless at that! Cheers

Hi Nice shot. To my eyes at least, the colour looks ok. But I'm the last person to ask about colour;) Maybe you could try adding flat frames to the mix and/or try cleaning the imaging train? Cheers

Hi Love it. I'd recommend anyone to have a go with a st80 before spending €silly on other oft recommended telescopes. Any slight aberration can easily be corrected in modern software.

Hi No need. One of these will allow you to control everything you need for astrophotography via your 'phone, cheap tablet or your fast laptop anywhere there is an Internet or newtork connection. Indoors for example. Your local astro club will make one for you at a fraction of the cost of the commercial product;) Cheers and HTH

Preparation of data for StarTools is covered here. HTH

Yeah, absolutely. Do it. There are good shots to be had when using altaz mounts. Just keep it simple.

Hi For dither -and the subsequent clipping algorithm- to be used to advantage, the field of view should only be changed between frames. Not constantly during them.