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  2. Today
  3. Had two decent imaging sessions tonight and last night. Taking my darks now, so will be done soon.
  4. Solid cloud now so packed up. Roof closed and rig set up for darks. Now taking a set of darks to match the Heart and Soul SII lights. Off to bed now. Goodnight and good luck to anyone still up.
  5. 2 hours of SII Heart and Soul and still going...
  6. Started off well around 9pm, clear out, observing from home. It seems like lots of LP here but my observing spot is shaded from direct local LP which helps immensely. The 300p flextube is a doddle to take outside and set up. Set it up in under 4 minutes without rushing. Properly dialled in the ES HR coma corrector for my 21E for the first time on the 300p closely following the ES instructions, and then temporarily mounted my Telrad. Finally got to observe sitting down, my cheapo observing chair does the trick. 21E through the ES coma corrector gave outstanding views, tested it on the Pleiades, just sharp right to the edge and the view seemed to wrap around my head. Then over to IC405 Flaming Star Nebula with the OIII filter which was quite nice, a fair bit of nebulosity visible. And I was sitting down for a change, so nice to relax and enjoy the views. Winning! I swapped to 17.5 Morpheus and Hb filter just to test, and was quite surprised, almost shocked when I was able to just make out the Flame Nebula next to Alnitak, could even see the dark lane running through the middle. I moved down to B33, ever the optimist. I won't say 100% I got the horsey from home, but I definitely caught a bit of IC434 and a very fleeting dark patch with averted vision. I've had better seeing conditions than tonight here, so there's a chance I'll bag it with confidence from home some excellent night, which I never thought would happen with a 12" dob under some LP - need to measure this with an SQM-L soon. I'm guessing 20.8. I then went over to Ursa Major to chase some galaxies, but conditions went downhill very rapidly and the air turned to soup, the humidity crept in and lost a lot of stars overhead, so packed it in about 30 minutes ago. Still a good night, the forecast earlier was for 100% clouds
  7. Oh .... well.... maybe... but there is lot of low level faint material there. If you raise the ambient darkness it will start to look like a snow-storm....
  8. 1.25 and 31mm may be practically the same on a tape measure but the Astrodon 1.25 mounted filters have significantly smaller area than the 31mm unmounted versions due to the overly large metal frames on the 1.25. In imaging terms I guess the steeper the light curve the more this impacts on the image. Dave
  9. It seems to me that you got guiding under control. Nice round and tight stars.
  10. I must be older. To me, these are the only true floppy disks https://www.renderhub.com/firdz3d/floppy-disk-5-25 They also came as 8 inch disks. I've also stored computer programs on audio tepes. Anyway, back from memory lane, I keep the original raw files and discard all calibrated/registered files. I don't store intermediate images. PI will store a complete history in a project file.
  11. Now have just over an hour of SII Heart and Soul and still going, With the possibility of rain in a few hours I plan to stay up and watch the images coming in as long as I can or until cloud covers the view.
  12. What happened next ? I'm a big believer in sharing knowledge and experience - it has been the big enabling win delivered by the internet. I always try to keep my account in balance; taking information and giving back (after applying the received information). Consequently, the next day (and feeling rejuvinated), with this in mind, I reflected upon what had been achieved. Rolling any steel sheet without tooling, is a major challenge ... 304, over a length of half a metre, could (understandably) be considered madness. Yet, I'd got pretty close, and I had the video footage (including the cutting to size). The mental break had been made, vis a vis using the tube for the scope ... but I hadn't tested the concept of 'shot peening' to fix the radius ... nor had I attempted 'annealing'. It was a new day, and the 60mm jubilee clips had been delivered - 2 off. Hmmm! Why hadn't I order 8 off? ... er ... cost, obviously (and I didn't know that I would need 8 off) Time to try the bizarre 'garden weed burner' that I had picked up at Lidl for around a fiver ... I knew that I would need it one day One is supposed to heat the entire piece to cherry red, and quench ... but in fact, 304 can simply be heated to cherry red. Quenched is apparently better, but it is not an absolute requirement. Using a butane torch, means that a small portion can be heated to cherry red, but this cools as the flame moves on. ... and it becomes very difficult to know, where exactly 'cherry red' has been achieved. As it turns out ... it is not too critical. From the photo below, you can see that I did not achieve an even 'heat' ... yet thankfully, it annealed. A plasterers tub contained the water, so it was quenched. ... and then assembled onto the rolling pin form, again using a ratchet strap in the middle, and a jubilee clip towards each end. The assembly was then shot peened - obviously avoiding the straps. The result was encouraging ... particularly where the jubilee clips had been used. ... and the shot peening HAD fixed the curve (to a significant degree). We now had a half-pipe. The lower half was correctly curved, but above the centre-line there was a band of steel that had not rolled ... except for where the jubilee clips had been attached. Proof of Concept Time to reflect upon what had been learned Clearly, a lot of jubilee clips would help matters ... but having a sheet width that was larger than the circumference, would provide an overlap, that would clamp & roll the edges. As such, it could be rolled with one overlap, then re-rolled to overlap the opposite edge. OR A length of sheet could be placed over both edges, to force both edges into a radius (aha...) This morning, I was mulling these details, when my eyes alighted upon the scrap strip of 304 that I had recently parted. Wow! Maybe it would be wide enough to cover both edges (yes) ... and what about photographing it, to show everybody how a 0.4mm sheet of 304 grinds and forms a 'U' channel. After cleaning off the flash, the scrap strip of sheet was inserted over the tube edges... (just fitted ... phew!) ... and pushed down the length. Applying the lessons learned... Ratchet straps worked Jubilee clips worked better Shot peening worked Okay ... time for detailed work. I decided to fully commit to the task. It was now or never, to prove that 304 could be rolled into a tube from flat sheet, without a rolling machine. The principal strategy was to strap the tube to the form, using ratchet straps and jubilee clips ... with the jubilee clips centralish, spaced at around 80mm apart. This 80mm section of tubing would be micro-peened. The assembly would be then blown off, and the jubilee clips repositioned, with one clip just on the peened surface ... the other around 80mm distant etc. Hammer Peening How could I forget? Don't forget! Hammer peening provides two major benefits: Breaks the grab friction of the strap, and the tube (on the form) ... enabling two more tightening turns on the jubilee clip Enables the edges to be peened through the scrap strip (inaccessible to the peening machine) ... locking in the curve that has been formed (could this be it?) Note: I also used a high tech peening machine. You are most likely at best, to have a sand blaster. If so ... shot blast media can be purchased, and this will do the job. Otherwise, you can use a common or garden 'peening hammer', to lock in the curve. The thinking coalesced How many times have you been doing something, when your thinking coalesced? It's normal. That's why the last part of the wall (that you built) is better than the first part. Otherwise known as 'getting the hang of it'. Which I did. ... with the edges getting an ever increasing beating (to the levels of 'If' ) Here is the final config, as it came out of the Peenmatic 620S... Looking good. ... but would it be round? ... would the edges have rolled? Results Hmmm! Not perfect. However; not too bad for a first attempt at hand rolling steel (never mind 304 inox). It measures 63mm diameter at one end (the last end worked on), and 65mm diameter at the end that I started with. Clearly, the edges have not fully rolled ... but they have been rolled Transport for the baffles? At median 32mm radius it grips like something that grips a lot. However, the baffles will be bonded within the transport tube. This presents the opportunity to form the radius to 30mm. (say, clamping the tube to the baffle, with a jubilee clip, during epoxy curing.) One thing is certain ... I will have more than sufficient baffle material. Therefore, this transport tube can be built up with baffles ... allowing a 'free attempt' to be made. What a great back-story for the scope, if this tube can be used Final Thoughts If I can make it happen, I guess it will be the only scope in existence with a hand rolled baffle transport mechanism. The sensible option would be to have a sheet metal worker roll one with rollers. Or even easier ... simply buy a 60mm diameter tube in aluminium and slot it with snips, or a jig saw ... perfect in 20 minutes! But ... setting off on a voyage into the unknown (and sticking with it), can also be fun and enlightening. The hardest times are remembered the fondest
  13. The pictures show the mount with a Vixen type saddle attached. There is a saddle already built in to the mount. Has a standard counterweight bar. If the attached saddle is removed, the counterweight bar can be attached to that side of the mount. This would allow the built in saddle to be used. All in very good condition. Asking £135 plus postage. £125 if Vixen saddle is not required. Plus postage.
  14. Centripetal forces are not high enough to flatten the Earth due to the planet's density and the resulting gravitational forces which resist the flattening effect - best you get is the oblate spheroid. It's all about balancing of forces. Spin the Earth faster and the centripetal forces will flatten the Earth , trouble is it will also fly apart - see what happens when you spin the pizza too fast! It's the same process that flattens out the solar system . Now who want's to start a discussion re centripetal v centrifugal Jim
  15. Yesterday
  16. Both cameras use the same sensor, as far as I know, sensitivity should be the same. But a usb 3 camera should be faster in sending images, hence a higher frame rate. You should also check which software supports either camera.
  17. 3/8" Photo Adapter for HEQ5 / AZ5 tripod. The gap for the EQ5 tripod head location peg has been widened to accomodate the peg. This has been done by others. The adapter has a 3/8th inch threaded stud at the top and a 10 mm threaded hole. This allows adapter to be attached to an EQ5 tripod and then attach smaller mounts with 3/8th inch thread such as a Berlebach Castor mount. Asking £28 including UK postage.
  18. With a dslr: Bias frames with the lens covered (a plastic lens cap is not enough), same iso as lights. Shortest exposure time possible. The more the merrier, but at least 50. Darks with the lens covered (a plastic lens cap is not enough), same iso and exposure time as lights, and as close to the same temperature as possible. As many as possible, at least 20. Flats, at the same aperture as the lights, if you use a lens. Preferably also the same iso, but not necessarily. Note the iso and exposure time. Flat darks, at the same settings as flat frames (iso, time) with the optics covered. Bias and dark frames correct electronics in the camera, so they need the same electronics settings: exposure time, iso and temperature, as the light frames. Flats correct optical issues (shadows from edges and dust), so they need to be taken at the same optical settings as the light frames, same aperture, camera orientation, etc. Flat darks correct the electronical issues of flat frames, so need the same camera settings as flats, iso, temperature, exposure time. If you use darks and flat darks at the very same settings as lights and flats, you don't need bias frames. Otoh, darks don't always work with non-cooled dslrs, and you replace them with bias frames. You can also replace flat darks with bias frames.
  19. This might be worth a read and following up on the ideas? https://physics.stackexchange.com/questions/25950/why-are-some-galaxies-flat James
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