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7170

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About 7170

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    Nebula

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    Surbiton, London
  1. Very impressive Lars! You say 30 hours of integration time, how many frames in total and what exposure time plus ISO for each one, that would be interesting to know. When I see images like this I think back to the time when you had to use film, with manual guiding. Just imagine if someone had told us back then amateurs would be taking pictures like this in the not so distant future, i'm not sure we would have believed it!
  2. It hasn’t been great here for a while, I’m assuming it’s because someone close by has recently bought some nice new equipment! With the evenings getting lighter the season is nearing and end for me as I have to work during the week so can’t stay up late.
  3. If I had to buy a modern version of the radios you have quoted for RA, I would save up and go for an IC-R8600 (with latest ICOM firmware update) running in IQ-OUT mode connected to a PC running HDSDR. 5.12MHz bandwidth at 16 bits and 24 bits for all smaller bandwidths. Around £2,500 new so a very serious investment. I would give the ones you have quoted a miss for RA unless I knew they were all in spec, even then a 9000 could cost £1500+ for a great condition one. I would expect to have to change the capacitors in many of those radios if they have been used a lot too. Also not having full computer control would frustrate me. SDR is the way to go these days for me at least.
  4. I have a a copy of CS4 which I still use and haven’t felt the need to upgrade. But I would strongly advise anyone to check out the very latest version of GIMP, it really is very good. Especially when you consider it is free!
  5. Well, last night there was a break in the clouds and I managed to get some more images of Cassiopeia. The table below is using the same settings as before but this time with a stack of 10 for lights, darks and bias. With the exception of a few the magnitude variance is smaller. All of the ones with a large variance are in general not at the center of the FOV, are close to/at saturation or are not close together. The wide FOV means flats are probably required and this could account for some of the outliers. @Captain Magenta, no I have made no adjustments for the position in the sky as Cassiopeia was directly above and all the star comparisons are using the one stacked frame. Another possible source of error could be a result of the colour of the star and the sensitivity of the CMOS to each colour. All I've done is take an average of the three colours and done comparisons on that, and a star with an uneven colour distribution could therefore be out.
  6. I've been trying to do some photometry with my DSLR with a view to using it on variable stars as a quick "grab and go" solution when there is a gap in clouds etc. Rather than looking at variables I decided to start off with comparing some fixed stars to identify how well I can estimate magnitudes with my DSLR, and the table above shows the results. Using only two stacked frames (5s, ISO 800, F3.5 on my 5DMk2) with no darks, light polluted london sky, and just one comparison star I seem to be able to get to around 1% variance for the majority of the readings, with the worse being 2.54% out. Trying Chi Cas, against Upsilon1, Upsilon2 and omegaAnd comes up with M4.67 which is mag0.03 different (0.55%). I'll be honest I am surprised at the results as it is not all that far off the 0.01-0.02 mag range often quoted for looking at exoplanet transits for example. Has anyone else tried this exercise as i'm interested to know how these results stack up - good or bad. The only thing I know for sure is I couldn't get it that close visually using my eyes!
  7. I’ve almost made the switch for image capture. Previously I was using APT/PHD2/CDC/eqmod etc on my regular Windows 10 laptop that would be outside with me without issue but I really wanted a remote option so I could sit inside in the warm and automate a session plan. I started looking at Indi/Kstars/Ekos again with a view of putting it on a Pi3 if it worked for me. I put the latest build of Ubuntu onto an old netbook which was gathering dust and installed the latest version of Indi and Kstars and teamviewer. It all works ok except for two points, firstly it is slow and secondly after about half an hour tracking in PHD2 and using Ekos’s internal guider, guiding begins to play up. Never had this issue with Windows. I had an older version of Ubuntu on the netbook many years ago and it ran quickly so clearly the newer version needs better hardware or a lighter weight desktop. So much so it is faster to just run APT/PHD2/CDC/eqmod on Windows 7 on the netbook and access with teamviewer remotely. I really like the session automation in Ekos but it’s no good if I can’t get it working with reasonable performance on that netbook. Seems like many of the Linux distributions out of the box have put on weight in recent years! Something people used to laugh at Windows for doing at every release.
  8. As a follow up i've been doing some Photometry recently and ran the image of M27 though it and it picked up the following number of stars above magnitude 11 to put things in perspective in a suburban environment (based on the TYCHO-2 catalog). magnitude 11: 13 magnitude 12: 129 magnitude 13: 93 magnitude 14: 40 magnitude 15: 20 magnitude 16: 5 The dimmest star being magnitude 16.683.
  9. 7170

    Pier Project

    Thanks for sharing, I think this is aesthetically very pleasing. Wouldn't fancy having to move/remove it in the future though!
  10. Many thanks Stu. I tried again yesterday evening, this time with 65x60s exposures, it also served as a nice test of Ekos. The moon was out but seeing was not too bad. This is probably as good as I can get here given the light pollution and equipment, with no filters, without resorting to a disportunatually large number of stacked frames which for me takes the impulsive fun out of it. Gain was only 50% so that could have been increased too. You are absolutely right about not letting LP win. Its surprising what you can see here especially on a day where rain has cleared the atmosphere of muck or after 10pm when LP seems to drop, presumarly in line with people switching things off and going to sleep. I've made a note to get in contact with yourself in the not so distant future with regards to coming along to one of your sessions - baby number 2 is due shortly so I suspect I won't get a pass to go any time soon from the boss alas! @carastro, yes there were luminance subs only.
  11. A good episode. Pete's section was interesting as I have my own meteor camera. You have to invest quite a bit if you want to have the same setup as shown on the program (£70+ for the camera, £50+ for capture dongle, £55 for cctv housing, £125 for UFOCapture software etc, plus electricity, plus better F1.0 lens, plus other bits and bobs). I'll stick with my raspberry pi +pi camera setup I think.
  12. Well the imaging season started for me this week. Although the mount is still very poorly polar aligned and the moon was out I none-the-less I had two enjoyable evenings this week, and as a bonus it wasn't too cold! I was hoping tonight would be good too but there is lots of high altitude cloud so have given it a miss. I'm in south west London (Surbiton) so suffer from light pollution, though we are far enough away from the center to have reasonable viewing (especially after 10pm) and on the odd occasion excellent viewing if rain has cleared the muck out of the atmosphere. I usually focus on double and variable stars so don't get wound up about light pollution. I decided to have a go at M27 and the Crescent Nebula as easy targets as I wanted to check all was well with my new guiding setup. I thought I would share the images, not because they are good but because they give an indicator of what someone living on the outskirts of a major city with modest equipment may expect to achieve given light pollution, so hopefully they maybe of interest to some. Dithering was not activated so there are lots of white specs but I was generally pleased with this shot of M27. Quality would have been improved if I had taken it up to 60 minutes. Gain was modest at 28. I'm quite pleased with this one of the crescent nebula given our location. If you look at it through the eyepiece you see nothing. Only when you start to take long exposures and stack do you start to see the shell come out of the sky glow (though only very slightly here). If you didn't have as much light pollution you would have no issues in taken an image of this. One day I want to try it with a UHC or OIII filter. I also took some photos of V2117 Cyg (HD 193837) with 20 second exposures, and slightly above it there is a magnitude 14.9 star, so that is a good guide on the magnitude a camera lets you get down to here without issue. I use APT, PHD2 and EQMOD.
  13. An image of the Sun today at 2018:04:22 14:46:49 GMT taken with a Canon 5dmk2 though my ED80/HEQ5 using Baader ND film. ISO 100 and 1/2000s shutter speed with no tracking as it was a shot before moving the mount. I felt I had to take advantage of the unusually hot and sunny April weather we have had in the UK over the last week, and what better way than a shot of the sun. One obvious sunspot visible towards the top left of the image, with three possible smaller ones to the left of it (though they could be specs of dust as the sensor needs a clean!). I've not had time to look up any details about it yet though.
  14. This is really interesting and inspiring, please keep posting your exoplanet observations here! Out of interest what is your C11 mounted on - Celestron fork or something different?
  15. Many thanks, I used an unbranded 8-24mm 1.25" zoom (exactly the same as the Sky-Watcher 8-24mm), so nothing special on an ED80. I committed a cardinal sin though - I didn't make a note of the actual focal length used. I suspect it was nearer to 24mm than 8mm as the HEQ5 wasn't tracking at the time and it didn't move out of the center of the FOV that quickly.
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