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About Delboy_Hog

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  1. Looking for the older, white version of the ASI-air. If anyone is thinking of moving onto another system, or upgrading to the newer, red ASIair, I'd love to hear from you regarding your old one! Many thanks, Derek
  2. Yes, unmodified camera, and yes, with the field flattener / focal reducer that's specifically recommended for the Skywatcher ED80... I think the approach you suggest is right - taking different exposure lengths to cater for the bright star and the faint nebulosity, and combine them in processing? I guess though that the reflection would still be there in the longer subs, so perhaps Pete's suggested approach of attacking it in photoshop might be the way forwards? I've also wondered whether having Alnitak absolutely central in the subs would help prevent light bouncing around at strange angles...some testing required, I guess!
  3. Following this one with interest - I've encountered a similar thing in my last attempt at the Alnitak area, though my blueish blob appeared in a slightly different place. 5 min subs, ED80 and Canon 1100d. I'd assumed it was a reflection, but wasn't sure what to do about it. Is your image above cropped at all? If not, both our bluish blobs appear to be roughly equally distant from the centre (or edges) of the frame from Alnitak, so I'm guessing that's the culprit, but which piece of glass is doing the bouncing was beyond me. Given its location I'd struggle to process it out convincingly... Like you MylesGibson, I was pushing the exposure length to give me a sporting chance of catching the nebulae...and similarly , ran short on total number of subs, and had no calibration files. I guess a greater number of shorter exposures might help, and I gather that you can use star masks and the suchlike to 'contain' Alnitak, though those are processing skills well above my current skill level! How long an exposure is too long, for a bright star like Alnitak?
  4. Picture above wasn't hugely clear, so here's another - If there are any DSS experts out there, I'd be extremely grateful for any advice on what I might have done wrong here. Stacking FIT files - you can see the DSS output below (I've tinkered with the histogram so you can see the image properly - although I'm not sure what the X-shaped histogram is about??) - I've never seen this before. It's always placed the data across the full screen, rather than cramming it all into just one quarter of it? Any thoughts?
  5. Hi all, Attempting to stack and process a bunch of files in DSS, but the file that's churned out only seems to have data in the top left quarter...... Taken with a modified canon 600d with an Ha filter, but captured by an ASI-air as FIT files, rather than the usual RAW files I'm used to using straight from the DSLR (I haven't yet figured out how to save the images as RAW files to the DSLR at the same time as the ASI-air saves the files as FIT on its micro-SD card). The tiny JPG file that the ASI-air produces of each photo suggests there's data registering across the sensor, so I'm hopeful I've just missed a step in the stacking process..............? It's M33 in Ha, and on a slightly hazy night, so whatever's there is pretty faint! Anyone seen this before, or know of a potential fix? I'd be very grateful for any advice! I didn't know if DSS had issues stacking FIT files so I even attempted to convert them to TIFF files first...still no luck...although I might have done it wrong! Image below straight out of DSS....
  6. Thanks everyone - I'll have a tinker with some alternative stacking softwares to see what I can do, and be sure to get my dither on (along with some proper calibration frames!) next time out! Hopefully I'll be on here with a beautifully low-noise image in the not too-distant future..... (goes to check weather forecast)…. Thanks again
  7. Thanks Olly, I'll take a peek at AstroArt over the weekend and see what I can do! Thanks again! Derek
  8. Hi Olly, hope you're well? It was a little warmer, I believe (I was trying to see if there was any data recorded on the individual files that would tell me the sensor temperature at the time it was taken - sure I've seen that before but can't find it now). Maybe I need to do some testing to see how the 600d reacts to different temperatures when it comes to noise. We've probably not got many warm nights left here this year now, but if it's going to get this ugly I might have to hibernate this camera next summer! You can see a sample frame below, which is fairly representative of the others - looking at it now in more detail, it's not pretty!! But I'm not sure I see the angled lines here? For comparison, a sample frame of the Heart and Soul taken with an 85mm camera lens. It's quite a striking difference in smoothness. Taken with the same camera settings (5 mins, iso 1600), but as you say Olly, different nights, so potentially different conditions. I'm wondering if there was some high level cloud that crept over while I was sneaking a hot chocolate inside?
  9. Thanks for this Johneta, yes dithering sounds like the best way forwards on this one to clean up future images significantly! I've seen a bit of debate on the dithering vs darks topic on here - you've found that you don't need darks if you've dithered?
  10. Hmmm, yes I did wonder, as you say, especially with a long (and last night was cold too!) session. It's clear-ish here tonight so I'll have another tinker with the kit and see if I can resolve this! The desire to have a nice, portable, plug-and-play setup for taking to dark sky sites was one of the big motivations for me trying to get the SA up and running effectively, and going down the ASI-air / 120mm mini-guider route. I have an old Celestron 7ah power tank which has served me very well over the years, and if I can figure out the right adaptor / regulator, may yet be the solution here! Thanks again for your input on this.
  11. Some other possibilities I've been pondering... Mechanical: I've seen a couple of cases of this error message being (potentially) linked to 'backlash'. I don't really understand this too well, though there are some references to some SAs being too "tight" and apparently there's a screw (or something) that can be loosened off to reduce this. Does anyone know if the issue I described sounds like something that could be caused by strong backlash? The distance the mount travels each step of calibration is small, and does seem to go back on itself occasionally, rather than smoothly and continuously moving away from the guide star.... Power to the mount: I'm currently using the 4 AA batteries rather than the DC 5v / USB approach. The AAs are all a quarter to a half 'full' - I wonder if it's safe to assume that if the batteries can drive the mount when pushing the slew buttons, they have enough power to drive the mount via the guiding? O should I be trying again with batteries at 100%....but then I would think that standard batteries maintain their function reasonable well through the second half of their lives? Power to the ASI-air: I'm using a 5v 3.4a USB power bank - that should be more than enough to power the ASI-air (to avoid confusion, this is the old version, I gather the 'pro' has different power requirements) to do it's thing and to send pulses to the mount......right?! I do have a 4a+ power bank somewhere that I could try, I guess, but can't imagine the Air pulling that much, especially as the power requirement to move the mount comes from the mount batteries, not the Air, on this version. Settings: I appear to be doing things differently from the various youtube tutorials I've found, in that I don't have the ASI-air connected to the DSLR, and just have the main camera set as 'none' and the telescope set as 'on-camera ST4'. I can't imagine that not connecting to a main camera would impact on the guide camera's ability to calibrate though? Unless as Gilesco mentioned, the settings might have to be a certain way... Any and all thoughts / suggestions would be much appreciated!
  12. Ah okay, that makes sense, and thank you for describing - yes I think the ST4 cable is the only option with the SA. Hmmm, your point on the need to have multiple options set a particular way could well be the issue, and the ASI-air interface is (I'm told) very similar to PHD. I'll have another scroll through the menus and see what I can find. Thanks again!
  13. Hi Gilesco, Could I check what you mean when you say 'directly to the mount'? I've been relying on the ST4 cable from ASI-air to the mount (and did check it was plugged in!), but haven't clocked a setting I could change to suggest a different way - have I made a ridiculously rookie error and there's something else I should be doing?! Thanks for your thoughts!
  14. Thanks MarkAR, definitely checked that one - picking stars manually that blur etc with guide-cam focus change and that blur and move when I nudge the mount!
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