Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.


  • Content Count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About winfij

  • Rank
    Star Forming

Contact Methods

  • Website URL

Profile Information

  • Location
    San Jose, CA
  1. Thanks all. This was captured with my Atik 11000 camera on a Pentax SDHF-75 OTA. I took sequence of 80 exposures of 20 seconds each, then cropped, aligned and stiched into an avi in MaximDL. John
  2. Hi all, Not been on here for a long while, but dug the scope out tonight for pretty much the first time this year to grab some images of the NEO flyby as it was clear here. Here's a link to the resulting animation sequence on youtube: 2005_YU55 Flyby.avi - YouTube I've also attached a single frame from the sequence. Did anyone else manage to capture the event? Cheers, John
  3. Very nice result there Rob. Out of interest, what scope/ccd combo did you use for this? Also - which method did you use to combine the Ha with the LRGB? John
  4. Just thought I'd add my voice to the cheering throngs - a great image and fine processing there Rob, John
  5. That's a great reprocess Eddie - the touch is much gentler, avoiding the crispness of the original yet still managing to bring out even more of the fainter background nebulosity. Bravo. John
  6. Thanks for all the nice comments all. Ron - I'd absolutely love to get some color data for this, but the clouds are back and it's been raining all afternoon. Maybe it'll clear up a bit next week, but it looks settled in for now. Mike - this was a stack of 115 x 10min subs, all unguided with my Art11002 through a Pentax SDHF-75 I'll update this thread if the clouds part and allow me to get some RGB before the target moves out of the prime imaging altitude. Cheers, John
  7. Hi all, I've not been around much since the xmas break - work's been busy, but I managed to get the scope out for 4 nights over the last week. I wanted to have a go at imaging Sh 2-240, which is a really faint target. There are a few images on the web, some very good, but not too many in total. From the outset, I knew it would require a lot of long exposures, but with my main scope out of action I had to use my 75mm aperture scope, imaging unguided. The small aperture meant even more exposures were needed, but with an automated setup it was mainly a case of waiting for good weather. I was using my 7nm Ha filter, which does a reasonable job of cutting out the moonlight - this was imaged starting just after the full moon, not ideal, but that's when the good weather started. Even after stacking over 19 hours of subs with the 7nm filter, the nebula was only 15 ADU brighter than the background, so processing was tricky and good calibration essential. I used 100 sky flat field images to give a good correction to allow me to push the processing as much as possible. Click the image below to see the imaging details and full size image. If you're using IE7 and can't view the link above, try this Hope you like it - constructive criticism welcomed Cheers, John
  8. I think from the first release of the new algorithms, they went straight from nearest-neighbor to VNG - quite a change! Doug told me he thought they were using bilinear and was a bit surprised when I showed him it was still nearest-neighbor John
  9. Hi all, Just found this thread. I'd agree wholeheartedly with Mark - the key to analysing the performance of debayering algorithms isn't to look at the widescale color balance - that's easily (and arbitarily) changed, but rather to zoom right in and look at how they handle the nuances of changes from one color area to another - the edge of stars being especially tough due to the relatively sharp transition to black. My plugins do indeed generally perform no automatic post-conversion conversion processing, so should give a direct representation of the color captured by the camera, which is almost never with a black sky (unless you live in the outback). I did add options to perform an automatic background adjust and balance adjust for convenience, since the Maxim process offered them, but those are no different than the seperate tools already available in Maxim. I was under the impression that the "high quality" conversion in Maxim now did VNG, from conversations I had with Doug George. John
  10. Hi all, Although I captured the data for this shot back on October the 25th, I only finished off the processing to get it ready for my web site tonight. Equipment details : ART11002 through Pentax SDHF-75, unguided Exposure details : Ha = 14 x 300s (70 mins) binned 2x2 Notes: This is a somewhat uncommonly imaged nebular pairing - the two just fitting into the field of view of my widefield scope nicely. Sh 2-171 is the bright nebula at the bottom of the frame, with the dimmer NGC 7822 arching above it. On the right hand edge of NGC 7822 the open cluster NGC 7762 can be seen with a size of 14 arcmins. Click the smal image below to go to the web page with full details and a link to the full size image. If you're using IE7 and the page fails to load correctly, click here to see the full size image. Hope you enjoy it. Cheers, John
  11. Looking good Ant - it's a tough target with Alnitak washing everything out. I had a go at tweaking the levels to try and compensate a little - attached. John
  12. LOL, well, it's all unimportant if you're guiding, since that will keep the target centered and the amount of image rotation you'll get by being aligned to the true pole rather than the refracted pole is probably the least of your worries
  13. A quick look on the web shows that T-Point is correcting to the true pole, not the refracted pole. If you were to use ProTrack, that includes refraction correction. The ME doesn't include King rate tracking, but they do have instructions on the web site for making the offset adjustment to the refracted pole, which is the next best thing, although ProTrack is even better than King rate, since it compensates for a lot of other factors as well. John
  14. The King tracking rate uses an algorithm which dynamically adjusts the mount tracking rate to compensate for the effects of atmospheric refraction. Otherwise, even perfect mechanical tracking will show some image drift over time, as the atmosphere refracts the light, changing the apparent position of the target. It's really only a problem with lower elevations though. John
  15. Does the mount use King tracking? Otherwise, were you aligned on the real pole or the refracted pole? John
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.