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Showing results for tags 'fs-128'.
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Takahashi FS-128 with 0.75X reducer/flattener on Vixen AXD2 mount 45 X 120s with Nikon D750 (90 mins) Processing in PixInsight and Photoshop I think the funny red ring artifact / glare / processing error actually enhances this nebula. Barry
This is a cheeky single 2 minute exposure of M42 taken from the Ballycroy international dark sky site in Co. Mayo in Ireland. I had intended to take a lot more data but that part of the sky was quite cloudy so I moved on. By the time it cleared I felt that M42 was a bit low. Also, M42 is done to death. :-) The corner issue is just due to badly calibrated flats. Can we turn off the city lights now please? Barry
Date taken: 17th March 2018 from Ballycroy International dark sky site Mayo, Ireland Telescope: Takahashi FS-128 Mount: Vixen AXD2 Camera: Nikon D750 45 x 120s subs (90 mins) Reprocessing this image with new flats has greatly improved it compared to my initial results with underexposed flats taken that night - see the post about the Iris nebula. Thanks for looking, Barry
So after Carole helped me to realise that I was taking my flats wrong, I've reprocessed this image and finally the funny rings have vanished. Original thread TL;DR - I was underexposing my flats, which resulted in failure of calibration to remove vignetting, as well as it introducing weird red concentric oval rings. Last night was supposed to be clear, so I set up in the garden. Cue the Irish weather. I only managed to get PA and focus (you know, the most fun bits) and then the clouds rolled in. Anyway, so instead of imaging, I took a bunch of calibration frames. The setup was slightly different to the lights - 1) temp 4 C instead of -1.5 C (no big deal) 2) camera at different angle to telescope (can't correct dust motes) 3) new camera angle adjuster in path (different vignetting and internal reflections) so I didn't hold out much hope that it would correct the problem. But it did! I used the new bias and darks to correct the new flats, and then the old bias and old darks and new flats to correct the lights. I'm so pleased I've finally figured out what was going on as it's ruined many images for me over the past year+. Thanks again Carole, Barry
Hi guys, this is my effort on the Iris Nebula with a Tak FS-128 from a dark sky site in Ireland. I was being greedy, doing multiple targets on the same night (March 17th) so I only captured 2 hours on this one. Takahashi FS-128 with 0.75X reducer/flattener on Vixen AXD2 mount 60 X 120s with Nikon D750 Processing in PixInsight and Photoshop There's something funny going on with the rings in the background, which I have not been able to get rid of. This was from a truly dark site (Bortle 2) and the subs don't show any sign of these rigns, just the usual vignetting. I think the calibration is actually introducing the effect. I took flats and all that jazz, and did all the calibration in PI so I don't know what I'm doing wrong. Has anyone seen this kind of thing before? Comments and suggestions welcome! Barry
Date: 17th March 2018 Location: Ballycroy international dark sky site in Co. Mayo, Ireland Telescope: Takahashi FS-128 with 0.75 reducer flattener Camera: Nikon D750 Mount: Vixen AXD2 Just 20 x 120s subs for 40 mins integration (far too little!). Same circumstances as the previous images I've posted lately - severely underexposed flats ruined images. Helped by this forum to realise problem. New flats with slightly different setup miraculously fixed problem. Comments and criticisms welcome, and thanks for looking. Barry Okay, I promise I'll stop spamming images now!