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thomasv

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About thomasv

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    Cambridge, UK
  1. thomasv

    Astrophotography in Hawaii

    Hi Chris, Lucky you, Hawaii is on my wish list. I guess a lot of it is down to personal preference, but where wide-band can work well is at dark sky locations. I like keeping things simple when I travel, so normally stick to a DSLR and often don't even take a laptop, just an intervalometer. I found that my StarAdventurer couldn't cope well with 200mm+ focal lengths unguided, but I guess you must have tested your setup. Re imaging at high altitudes, after trying it, I decided to stick to 'base camp', however my attempt was in the 'winter': Enjoy!
  2. thomasv

    Tripod for SW-SA

    I'm very happy with this one, really solid, fluid head can be removed: https://www.amazon.co.uk/Velbon-DV-7000N-Video-Tripod-PH-368/dp/B00U2IA3PW
  3. Right, getting there, de-installed the 64x version and freshly installed 4.1.1 32x version. Selected a few frames for a quick test and it seems to have worked. Just another one of those windows mysteries I guess. Now just need to do it for real.
  4. Thanks, still no luck though, reduced the number of stars to about 1800 by moving the star detection treshold slider and selected a frame as reference frame, but wouldn't stack on the comet. I think I need a fresh start by re-installing DSS, try the 32bit version this time. Thanks for the suggestions.
  5. Still fighting DSS to stack my 46P subs, so made a time-lapse instead. 89 x 1min, taken on 27 Dec with Fuji x-T1 and Samyang 135mm. Size of frame is 2.2 x 1.7deg. Have a much better quality avi file, but that's 214MB, so need to figure out how to convert it to MP4 in better quality (for this one I used youtube ) DSCF4370avicropbright2mb.mp4
  6. Between around 20000-23000.
  7. The green circles are stars marked after registration, don't know if it's normal. I should have said I'm using DSS 4.1.1 64bit version.
  8. Trying to stack some 46P captures in DSS, but it doesn't come out correct. I first register all light frames (I have no calibration frames), then going through each sub and manually marking the comet nucleus with the comet tool, then do a Kappa-Sigma stack. The comet still appears stretched in the stacked image while the stars are aligned. I've attached a crop of the first and last sub, the resulting stacked image, and a screengrab of dss. Any suggestions appreciated, I haven't tried changing the parameters of the stacking, and subs are pretty wide-field, could that be an issue?
  9. We were lucky enough to spend two weeks over Xmas and New Year on La Palma with the family. It was my first visit to the island and loved the place. First week we stayed at the Northwest (Puntagorda), that coincided with full moon, so did not do much imaging wise. However, a very memorable moment was when stepping outside between the main curse and dessert of Xmas eve dinner and within 5 seconds of looking up, I saw a large fireball meteor sweeping accross the sky and breaking up into several pieces. Second week we stayed about 10mins drive from Santa Cruz, so was worried about light pollution from the capital, but the first night it become obvious that the sky was still one of the best I've ever seen. The small light pollution is in the form of sodium lights, so can be dealt with by filters (apart from some flashing LED xmas lights around). The equipment I took was a Fuji X-T1, modded Canon 6D, Samyang 135mm and 35mm lenses, and Fornax lightrack II. Unfortunately, at the end I couldn't use the Canon as I found out there that its remote release connector is different, I use a Canon compatible intervallometer for the Fuji, and just assumed it was the same for the 6D. At home I've been using the 6D with the laptop, which I did not take with me to minimise the amount of kit. Learnt the hard way that everything needs to be tested before the trip and assume nothing. Anyway, I was enjoying using the X-T1 / 135mm combo on the Fornax, it was very quick to set up and worked very well. Fast lens meant that max exposure I needed was 2mins, which the fornax coped with easily. We visited the GTC and was hoping to see one of the other telescopes, but I've messed up the booking and bought tickets for the GTC twice, so that will have to be another time. Also drove up to the observatories in the evening and was hoping to do some imaging, I unpacked the equipment, but was so cold with strong winds (at some point I had 3 jackets on) that I basically bailed and just did some very wide field shots. The fun bit was when we got too cold and was ready to go down, the car wouldn't start. It was around 10pm, nobody around, no moon, so pitch dark. I'm still not sure why the car battery went flat, I run the Fornax off the cigarette lighter socket, but its power consumption could not be the reason. To have voltage in the cigarette lighter, the key had to be turned to ignition on, so I guess in that state something was taking current in the car, we did not have any interior / exterior lights on. We thought we might have to sleep in the car, when after about 20mins I saw a car driving down, jumped in front to ask for help, and the chinese couple inside very kindly helped to push the car to jump start it. This was a major struggle as the parking platform was lower than the road, so the car had to be pushed up the ramp. When the car eventually started I was ready to hug those friendly people but they were in a hurry... The sunset and the views of the milky way were amazing up there, still I've decided after this adventure that I rather put up with the little light pullution I have on the balkony of the nice warm house and my bed nearby. So, overall a few mishaps, but it just means that I definitely have to go back again in the summer, timed so that it coincides with new moon. Anyway below are some of the quickly processed images I took, also have some 46P data but haven't managed to process that to give anything decent yet. All processed in Astroart / Gimp, however my processing skills are not very advanced, still need to learn about layers, masking, etc.
  10. thomasv

    Fornax Lightrack II experiments

    OK, sorry. Can you tick the DEC box near the bottom to display the DEC trace. If both are drifting away in a straight line, I would have thought it's ought to be a polar alignment problem. I thought that guiding assistant gave an estimate of the polar alignment error, but I now can't find it anywhere in the log viewer, so I think it may only display it while it's running live.
  11. thomasv

    Fornax Lightrack II experiments

    I wonder if something has moved at 22:17, the trace is nice and horizontal before, then there is a jump and then iit starts to diverge, indicating probably that polar alignment has shifted? Don't know what it could be, tripod or wedge, would you mind posting a picture of the setup?
  12. thomasv

    Fornax Lightrack II experiments

    You start guiding as normal, which will first calibrate the system. Then tools --> guiding assistant will open a new window, disable 'dec backlash' measurement and start. This will then disable the guiding and uses the guide camera to measure the accuracy of tracking, leave it running for about 20mins. Make sure that the camera type (pixel size) and guide scope focal length are set correctly under PHD general settings, so that the results in arcsec are correct. You will need to download a separate piece of SW called PHD log viewer to then analyze and display the guiding performance. This takes the PHD guide log file as input, which is normally in your Documents folder /PHD.
  13. thomasv

    Fornax Lightrack II experiments

    Sounds promising, great. Would be interested in seeing a graph of the tracking performance with PHD's guiding assistant like I posted above to compare against the performance of my 2nd hand unit.
  14. thomasv

    Fornax Lightrack II experiments

    Hi, I wonder if the colours are assigned in the reverse order to the pin numbers. I'm not actually sure what the picture represent, is it the connector on the cable, or the socket, and looking from which direction. I've checked, I did what you describe: - blue --> purple - yellow --> green - black --> red You can test if the PHD commands get through to the mount by using the manual guide option and listening to the sound of the mount. The high pitched whistle doesn't change, but there is a lower frequency noise (murmur) that changes frequency slightly if you issue left/right commands.
  15. A couple of pictures I've taken with the evoguide mounted on a fuji X-T1, both of course heavily cropped.
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