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About Peje

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    Proto Star

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    Lisburn, UK.

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  1. Peje

    Greetings from sunny Northern Ireland!

    Welcome to the forum, no better place for you to ask questions and get advice from people who are interesting in helping you. It's where I learnt almost everything I know!!
  2. Peje

    Pier Shed - Sealed or Ventilated?

    Thanks. Insulating the walls should be easy enough, polystyrene sheets inside the cavity. The same for the roof, I'm going to do a felt style roof. I'll have a think about how to ventilate, the shed won't be fully sealed as it will have double doors but I accept your point about damp. My main shed doesn't get damp because it has about 500w of electronics running 24-7 so this generates some nice warm dry air
  3. Peje

    Pier Shed - Sealed or Ventilated?

    Thanks Ray. Can you elaborate on vented but insulated? Vents from inside to outside, double skinned wall, vents just into wall cavity, etc.
  4. As title, I'm currently building a removable shed around my pier. The plan is this will hold all of my gear, with the OTA & imaging train permanently mounted. The PC and other electrical kit will be inside a wooden unit I created with a lid to keep it warm in winter / cold in summer (closed for the former, open for the latter). I've been trying to figure out what I should do regarding ventilation. Option 1: Seal it up I can make everything fairly well sealed using brush strips and p-seal. Pro: The shed should stay very dry, protecting my electronics. Con: The shed will heat up during the day, especially in spring/summer. I can mitigate this somewhat by adding an internal skin to form a cavity for insulation. Option 2: Ventilate I can add 100x100mm insect meshed vents, probably around the top of the sides. Pro: The internal temperature in the shed should be very similar to outside, this will reduce cool down time required. Con: The humidity inside the shed will match outside conditions, I'm concerned if this will affect my CCD / USB Filter Wheel. I'm leaning towards option 1 as it is probably safest for my CCD. I'd really appreciate some other opinions. Pete.
  5. I have fiddled nd fiddled but I cannot make it do what you did... could you give me a step by step? EDIT: Not sure this is exactly what I'm trying to do. What I want is to copy a star (Dwarf Planet Ceres) from a sub, into a stacked image in exactly the same place as it was in the original sub. All images are aligned so perhaps I need to do something with Pixelmath and coordinates... another thing I don't know how to do!
  6. I generally don't have much trouble with star masks, I was mutlitasking earlier so wasn't focusing properly. I should have just used binarise and then used convolution to soften the edges
  7. I had a little fiddle on my lunch break today and while I was failing miserable at getting a mask to cover just the larger stars (probably due to doing two things at once), I was able to just use one of my 'normal' starmasks to just give the image a slight stretch (some small / middle stars coming up), then remove that mask and stretch as normal. Screen shot attached. Whilst this isn't life changing, it is an improvement. I am using my worst data on purpose as it should exagerate any changes I make.
  8. Thanks William, it's well out of warranty. I also think I recall seeing it wasn't adjustable. I guess I will just have to save some pennies and orser the one SW designed to match the Quattro. Do you think this is also causing my soft focus or would that be a separate issue? Or potentially you can't tell as the images dont have enough stars. Thanks for your help. Pete
  9. @Oddsocks I've added a few more subs to that folder. I took three without the CC and am taking another 3 with the CC refitted. I don't notice a huge difference (other than the lack of coma) on regular stars and only a slight drop off of the diff spikes with the CC fitted. Does your eye see anything of interest? Probably worth noting some haze blew in while I was refitting the CC. I typically focus using a bahtinov mask first then let SG Pro run it's auto-focus routine while I watch, it used HFR instead of FWHM. There is the option to use FWHM but the user manual says HFR is generally the most accurate. I would be open to switching to FWHM but to be honest I think there's little to be gained. Assuming my issue isn't the CC, I almost always collimate before starting a target so I would expect that to be good. In terms of collimation, I centered the secondary under the focuser at the start of the season and I use a hotech laser collimator to get the primary and secondary well lined up. I find that my Quattro holds collimation very well across temperature and general pointing position. One thing my system does suffer from is a bit of tilt in the imaging train, I'm hoping to cure that this summer with some tactically placed black tape to tighten up the fit of my 2" adaptor in the focuser tube. On the masking, it all sounds reasonable. I spent quite a lot of time last year learning how to tune starmasks, mainly using the mask controls at the bottom, so making nice tight masks is fine. Going to give your method a whirl someday next week on my lunch.
  10. Thanks William, I have removed the CC so hopefully will get some testing done tonight. The rest of the info sounds great, I look forward to trying it
  11. The link below is to subs from two nights, their equivalent calibrated images & the final stack of 237 subs. https://1drv.ms/f/s!AlH5EVOP6MAJsyJ2t0ujPj2yDiwM I've attached a screenshot of the integration settings I used for these, it is linear fit for sets with more than 25 subs. I got this from the 'Inside Pixinsight' book. I use batch preprocessing for the calibration and regristration then run ImageIntegration and finally DrizzleIntegration to give me the final stack. I have noticed that my images never seem brilliantly sharp and diffraction spikes aren't overly dramatic, up til now I had assumed that this is down to me having pretty poor seeing most of the time over here in N.Ireland. If I'm doing something wrong then that would be great news. A question about your stretching, are you saying you just appy a good starmask before you stretch the image? Is it an iterative process with different masks or just using one mask? I don't mind a long process to get good results so I'm open to anything.
  12. I've been using pixinsight for a few years as my image processing software and I have always struggled with keeping star sizes small. I've tried numerous star reduction methods but I've never been happy with the dimmed fuzzy stars they give me. Some methods I can think of: Stretching MaskedStretch - Copying stars into HistogramTransformation strecthed image (Following Harry's tutorial) HistogramTransformation - Using Lightness Mask Post-Sretch Reduction MorphologicalTransformation - Morphological Selection using starmask MorphologicalTransformation - Erosion using starmask Typically I have found that blending the MaskStretch stars in 50-50 with the HistTrans image gives me the best results, but I'm still not happy with the attached. I have wondered if my equipment is the source of my problems, I have a 200mm f/4 Newtonian & an Atik 428 Mono CCD. This gives me a fast scope with a small field of view, pixel scale is 1.17 arcsecs. I have attached two images; one is of my auto-STF of my Lum stack, the other is the blended stretch I mentioned earlier. My question would be, can anyone suggest other methods to try to allow me to produce nice tight stars without fuzzy halos? Thanks in advance, Pete
  13. This is great info, coincidentally Catalina was the comet I failed at a few years ago! I think this thread has given me all the information I need to have a crack at comets this summer.... big thanks to everyone.
  14. Thanks for that great info, it's very useful. Moving back to the DSLR will be advantageous as it gives me a nice large FoV so I'll have plenty of scope to crop away rough edges. I think the plan will be to go for 1min subs, possibly guided, and aim for a couple of hours of data. That should offer me enough detail in the comet while also giving me a good starfield. From there I think the PI comet script should get me close to where I want to be. A good thing about this method is I can practice it with the comet being dim, that should give me a feel for how well it's going to work.
  15. Looking at the comet alignment workflow it seems i just need to shot exposures where neither the stars or comet are non-round. I had completely forgotten about the fact I use a mono camera, will have to break out my nikon for the comet images.

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