tomato

With regard to trusting a courier, I presume FLO have one they are happy with for large, expensive scopes. I don’t know if they use a premium service and they no doubt get a discount for the volume of business they put their way (and if they don’t, they should!) I nearly bought a second hand Paramount but went for a new Mesu for the same money. That was a good call.

Yes, that’s the reference I made to the pulsar exhibiting three levels of brightness, the minimum level, the maximum level and the two interpulses of equal brightness, either side of the main peak. With sufficient data and resolution these should be discernible, I need to analyse all of the data to see if they are present.

Not seen this before, thanks very much for sharing.

Yes, the pulsar is indeed the highly energetic remnant from the supernova recorded by the Chinese in 1054.

This is a bit different although the idea and practical experiment are certainly not new. While recovering from Covid, @Tomatobro came across a BAA article which described using a rotating shutter to capture the variation in optical brightness of the Crab Nebula Pulsar. By using a spinning chopper disk such that the light path is interrupted 30 times a second it is possible to capture variations in brightness with extended exposures. The original setup called for a hefty scope (14" SCT) but with more sensitive cameras now available we thought it might be possible to capture something using a 6" refractor. @Tomatobro made a stepper motor driven 8 vane disk mounted in a light proof alloy enclosure which could be mounted between the Esprit 150 and an ASI 178 camera. He also constructed a programmable control module to achieve the required RPM for the disk. The challenge was to make an accurately balanced disk so no unwanted vibrations were transmitted to the imaging train when it was in operation. Last night 3 sessions were completed, each of 100 x 20 sec subs. There was visibly some change in the brightness of the pulsar on individual subs but this has been enhanced by stacking the brightest and dimmest subs to make a crude gif animation. So far I have only analysed the best session, the pulsar actually exhibits 3 discrete brightness levels but I'm not sure this set up is sensitive enough to capture this. Is it a genuine capture? Well, the varying brightness of the nebula is a concern, but it is the pulsar that is varying in brightness while qualitatively at least the other stars have a constant light output. It's not much to look at but when you know that the photons are coming from a star about as big as a city but 1.5x the mass of the sun and spinning at 30 times a second, it's quite something. Rotating disk housing and stepper motor Control Unit

An amazing vista, there is just so much dust and yet in reality it is so tenuous, it only becomes visible on this epic scale. You should both be appointed (along with @gorann) to the Celestron sales team.😊

First class, nice to see those very dark dust channels in the nebula, I thought I had a hair in the gate when I saw them on my effort!

It occurred to me that Autumn 2022 is over and I have yet to image M33, one of my favourite targets, for this this season. So this is 7.43 hrs made up of 116 x 2 mins of Esprit150/QHY268Mono and 107 x 2 mins of Esprit150/QHY268OSC. Calibrated and stacked in APP, processed in PI with the now obligatory BXT,SXT and NXT tools with some SPCC, Histogram and Curves transformation. SXT left (legitimately, I presume) a lot of stars associated with the galaxy as well as the foreground stars, but they seemed to process OK. I also have 210 mins of IMX571OSC data from the year before, so I added this into the mix to produce a 10.93 hr integration for the second image. Thanks for looking. 7.43 hrs 10.93 hrs

Sorry to hear about your troubles with the second hand scope, I guess it is always a bit of a gamble. Several years back now I purchased a second hand Esprit 150 from the classifieds. It looked like it had never been out of the flight case but I drove to the other end of the country to inspect it first hand and get an impression of the owner, reasons for sale etc before committing to the purchase. None of that helps your situation. If ~£225 would get you an optical report and an estimate of the cost of putting it right (if that’s an option) then I think that is still worth doing to help you make an informed decision. If it is not viable to try and fix it, just how bad are the aberrations? This might upset the optical purists but I take a somewhat pragmatic approach to dodgy star shapes. I bought a RASA and soon found out I could spend several nights fixing tilt or spacing issues, or I could image with it, getting wonderfully deep images in a single night then, dare I say it, crop the frame or use StarTools or other software to improve the star shapes. I know that option is not for everyone, but I think it is important to get something positive out of all of this expensive kit on a regular basis, rather than eternally tinkering with it in pursuit of optical perfection. I leave that to the JWST.

Do you get a massive range of quality values when you analyse the subs? I usually discard the worst 5% excluding any obvious outliers and then let APP weight the rest for contribution to the stack. I’m usually satisfied with the result given the improvements that can be made with BlurXterminator etc but maybe I’ve got too much of a relaxed approach to this stuff.

My rig is set up for a refocus if the FWHM numbers change by more than 10%, and this usually happens 15-20 subs in and thereafter for the entire session. The scopes are permanently set up in the dome so I don’t think it is temperature change, I put it down to focus sag as the scope changes orientation and/or change in atmospheric conditions as the altitude changes. It’s a real deterioration as the numbers are always much better after the refocus.

The Lazy Geek video is a bit of an eye opener, thanks for sharing. I think it is not great when a YouTuber can invest in a spectrometer to check the performance of his filters while some manufacturers do not appear to be applying the same standard to their quality checks. I'm not so keen on his suggestion that they (or dealers) start asking a premium for the 'superior' filters, I think they should first ensure all filters meet or exceed spec if they are being offered for sale, before embarking on a tiered pricing system.

This is 13.5 hrs of data made up of 212 x 2 mins with the Esprit150/QHY268mono and 193 x 2 mins with the Esprit150/QHY268OSC. The moon was absent over the 3 nights, but Orion moves across the sky just above my neighbour's house at the bottom of the garden, and they have invested in a wood burning fire that was going full chat every night so the FWHM figures were nothing to write home about. I tried channel extraction on the OSC stack and then using LRGB combination in PI but I had to push the processing hard to get any colour. I then saved the Lum file as RGB and stacked this with the OSC file and got much better colour. I'm not sure if this is a bona fide processing method but it seemed to work for me. Calibrated and stacked in APP, processed in PI (thank goodness for BXT, SXT and NXT) and finished off in AP. Thanks for looking.

This is M78, captured over three nights in January under reasonable conditions (no moon) but still ditched about 5% of the subs due to high cloud. 13.5 hrs made up of 212 x 2 mins with the Esprit 150/QHY268mono and 193 x 2 mins with the Esprit 150/QHY268OSC. I saved the Lum stack as an RGB file and stacked this with the OSC file, it seemed to give a better result than combining them as LRGB. Calibrated and stacked in APP, processed in PI with SPCC, BXT, SXT, Histogram and Curves Transformation, PixelMath to recombine, then NXT applied. Finished off in AP.

That’s a really fine Spaghetti Nebula. Once you have the fundamentals in place, I think it’s good to have a go at some of the more challenging targets, at the end of the day most of them just need more integration than the brighter ones. Wierdly, I find they can sometimes be more straightforward to process since they often don’t have the big dynamic range issues that M31 and M42 have, for example.

I have a Mk 1 Mesu and the drive motors are solidly mounted, no play in them whatsoever. However, this may not be helpful as I know you can disengage the drives on the Mk 2. It does sound mechanical to me and would endorse @Jonk’s suggestion to send a video clip of the mount to Lucas.

Very impressive result, all those hours have really paid off.👍

Hi Olly, just press the Select AI button and the options appear. Wow, I've just passed a processing tip onto Olly, albeit a straighforward instuction, talk about Stranger Things...😉

We use tools to capture data and process it, some tools just make it easier. I used to manually focus with a Bhatinov mask but now let the auto focuser, camera and software do this for me and this is the point, achieve an accurate and reliable result (nearly!) every time. If and when processing tools can do this on my raw data, I’ll follow the same path. Can software do this on arguably a less quantitative aspect of AP? Time will tell. Sorry Martin, now way off topic.

I’m not knocking drama, but I get quite enough of that from my family without bringing it into my hobby.☺️

Even with the help provided by the Xterminator suite of processing tools, I don’t think I’ll ever fully warm to this aspect of AP, although I find it much more painless since they came on the scene. I’ll definitely get the 30 day free trial of “EffortXterminator” if/when it is released and if it can produce results better than I can with my data then I will make a purchase and then happily concentrate more on the data capture side of this hobby.

It is a bit off topic but I think I get at least the concept of the ‘just right’ Astro image. For example, some amateur APODs are breathtakingly good, but I’m less enthusiastic about others with (IMHO) garish colours and over done detail. It is indeed incredibly hard to get it just right, to date in 8 years of trying I think I may have got somewhere close to the sweet spot a couple of times but that’s all. If we could process the detail and colour in images scientifically ‘by numbers’ I would probably embrace it but despite some recent advances I don’t think auto processing is here yet.

Yes, taking cameras off and putting them on a F7 refractor is a lot less fraught, I do it a lot!

Last night I started an imaging session under what were quite cold but promising sky conditions. Three subs in high cloud came over forcing me to quit the session. However, I had put my 1KW heater on in the warm room, and yes, you guessed it, in my frustration at the conditions I forgot to switch it off.😱 The socket is behind where I sit so this is going on the door: Mind you, the warm room was lovely and toasty this morning...

Congratulations to the winners, I had a go but none of my efforts were worthy of an entry. Imaging just stars is hard.