StuartT

Thanks. I find PHD2 to be somewhat impenetrable to be honest. I've tried reading the documentation but it makes very little sense to me. I didn't even realise you could change the calibration process! I'll give this a try

I am finding that when I calibrate (first pointing to the equator) I get an error saying 'not enough calibration steps - results may be inaccurate'. This is the log viewer diagram. Surely if there aren't enough steps PHD2 could just do more? What's stopping it?

Thank you! Yes they do. Yes, I am using an OAG. Hence I used the FL of the scope (and reducer - which is spelled incorrectly in the profile 🤣)

Apologies. I shouldn't have included the text. I was meaning the diagram. Thanks for explaining. Does it matter that the red and blue lines are not aligned with N and W? does that rotation just indicate that my guide cam is rotated relative to the meridian and equator?

Can anyone explain what this is telling me? I can't seem to find any documentation on this (Andy Galasso's Analysing PHD2 guiding results doesn't include calibration) Thanks

as usual a well-informed and helpful answer. Thank you! So in order to get the best raw data for analysis in PECPrep should I just run the guiding asst for a while? Presumably that will just be the mount behaviour without guide pulses?

Thanks for this. Can I ask what you think of the alternative approach - using the 'predictive PEC' algorithm in PHD2? I hear it's very effective

Hi @vlaiv sorry to be late to the party here, but I am just getting to grips with PEC. I am curious as to why you say guide commands have to be switched off? I have just analysed a PHD2 log file and analysed in PECPrep with only the 'auto filter' added. Here is what I got. The PEC curve is created is not a pure sine wave, but has a higher frequency oscillation (period 11, mag 33.4) added to the main worm gear period (period 198.7 mag 100). Is it ok to load a curve like this into EQMOD? Thanks! (or is it just easier to let PHD2 do everything by selecting the 'predictive PEC' algorithm as Cuiv recommends?)

Thanks. for explaining. Makes sense now.

not sure what you mean here. The dB scale is logarithmic. A Bel is a power of ten. So a decibel is a tenth of that. Hence, 40 dB is 10^4 (or 10,000)

Err..

Thank you both. Yes, I am very happy with this one. I am pleased to have so much detail visible. I shall be adding some more data from my new Askar D2 filter for some Sii signal (if the Rosette has any)

Yes, I agree. I think the tool must be flawed. I even made the measurement on a preview containing only nebulosity (because stars would have a much higher SNR). 1:10 000 sounds wildly improbable

8h 40m, Esprit 150, ASI2600MC, L Extreme

3h 50m, Esprit 150, ASI2600MC, L Extreme

I guess no one knows... 🤷‍♂️

I've just discovered the SNR script in PI and so naturally I was curious about my images. A recent colour sub measured at 28-30 dB (depending on channel). An integrated result measured 38-40 dB What should I be considering a good SNR? (40 dB is 1:10 000 which sounds like it's quite good for SNR?) Thanks

I found I needed double the exposure time for the D2 as Oiii and Sii are fainter than Ha. So I used 300s for the L Extreme and 600s for the D2

Here is what I did. Initially from the frequency response curve for my OSC I estimated the proportions of RGB that make up the three emission lines. Hα = 80%R + 15%G + 5%B Oiii = 95%G + 45%B Sii = 75%R + 15%G + 5%B Method 1 integrate data from each filter separately 2 SPCC each image 3 Register the two images 4 For L Extreme filter split RGB create Ha = 0.8*R + 0.15*G + 0.05*B create Oiii_LExt = 0.95*G + 0.45*B 5 For Askar Oiii / Sii filter Split RGB create Oiii_A = 0.95*G + 0.45*B create Sii = 0.75*R + 0.15*G + 0.05*B 6 Add the two Oiii images with simple addition Oiii = Oiii_LExt+Oiii_A 7stretch the three images (Ha, Oiii, Sii) 8 Use LRGB combination L blank R Sii G Ha B Oiii 9 Postprocess - as usual

I agree. In fact, I just posted a slightly more stretched version to Astrobin. (Original now replaced). Thanks

I created the Ha, Oiii and Sii channels from the RGB of each filter (using the response curves of my camera), then merged the two Oiii channels (as both filters pass that). Then did an LRGB comb (black L and SHO for RGB).

This image is a combination of 3.5h with an L Extreme filter (Ha and Oiii) and 3.5h with an Askar Sii / Oiii 6nm filter to produce an SHO result.

Overjoyed to report that my 'first light' with the new mini PC went like a dream! Everything connected up perfectly (and stayed connected up), sky was crystal clear and my guiding was the best I have ever had at 0.38" (about one third of my imaging scale!). I was in astro heaven basically. 😍 So I got over three hours on the Soul with the L Extreme and here it is (ready to add the Sii data to it with my new Askar filter)

Yes, it turns out I had to explicitly turn on sharing and give permission to "Everyone" - even though that wasn't necessary when connecting drives in the opposite direction.

Ah. Yes. That fixed it. Thanks. For some reason I didn't have to do that the other way around. I guess RDP did it for me.