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Adreneline

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About Adreneline

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  1. Hi Billy. In answer to your first question I've attached the image with and without the flat - both processed in PI using exactly the same workflow. I've had numerous further attempts at producing flats and they always come out the same. The feedback I had from a CN forum was "if that the way they are then that's they way they need to be to correct errors in the optics"; it's all a function of sensor size and optics train. The differences are pretty subtle I feel.
  2. Thank you for all the advice and the time taken to provide me with some potential ways forward. At the end of the day if I am going to use flats in the calibration process I may as well do my utmost to get them right! The R/F has a 2" matt black adapter nose-piece courtesy of FLO which holds the 2" IR/UV IDAS filter in the drawtube. Downstream of the R/F is a Baader Varilock which has a matt black internal surface but whether it is matt black enough remains to be seen. The VariLock attaches directly to the 414ex camera body; the 414ex nose has been removed. I have to say it's not obvious where the problem may be as I know the inside of the drawtube is matt black. I will give the sky flats a go as well and see how I get on. Many thanks again for all the helpful comments. Adrian
  3. Hi Billy. Attached is the configuration I use for flats - iPad running a 'light-pad' app sitting on the end of the OTA. I adjust the exposure in SGP to get a mean of around 30000. I tape some thick black plastic rubble sack around the drawtube (but not the focusser) and fire off 50 flats at a temp of -10deg - typical exposure time per flat is around 0.18 s. I assumed taking them in the daylight was acceptable as there is plenty of advice saying to use the dawn sky, etc. for illumination through a white cloth. I've just repeated the process and obtained the attached flat - with contour from PI. Any advice would be most welcome. I think I might be heading off to B&Q! AP is a tricky old business!
  4. Thank you for the help and advice. I am using an IR/UV filter to try to address the focussing issue. I have used a BM, the SGP focussing routines and the FWHM tool in Artemis to try to ensure I get the lowest possible HFR/FWHM readings on a given night. I am assuming it is 'seeing' that is limiting images of late; I can't remember the last time we had a really clear night I have also analysed the images in PI and CCD Inspector (trial about to expire!) and noticed a general lack of consistency when comparing results; absolute values cannot be realistically compared although there appears to be some merit in comparing trends in the image analysis data. I will look at taking a series of flats again noting the advice and comments given. I have had problems with light ingress via the drawtube/focusser in the past but perhaps my assumption that with exposure times of the order of 0.05s there would be no significant effect on the flat was wrong. I have noticed there is a lot of variation in the surface finish of the various links in the optics train between the IR/UV filter and the camera sensor so I will look into trying to eliminate any unwanted reflections along the light path as recommended. Thanks again for all the advice.
  5. Thank you for the comments. Regarding the use of the flat(s) I must confess to being lazy! I use the BatchPreProcessing script in PixInsight. I just load up the flats/darks/bias and lights and basically let it get on with it - a cop-out I know but it seems to work for me most of the time - I assume the script applies the debayering at the correct time. The script produces the masters of each type. If I stretch the master flat it looks pretty much exactly the same. I've attached the PI FlatContour script output which shows some variation across the image but I am unsure whether this is good or bad or indifferent - and what impact it has on the final image. Thanks again.
  6. I am trying to work my way up the PI learning curve with this latest attempt at M101 - 28x300s subs plus 50 off bias, flat and dark - all at -10deg. Any advice on colour - too red/too blue ; noise - too much/too little ; sharpness etc. would be much appreciated. I've been chasing down focus problems for a while which I hope I've now largely resolved; I think softness in this image is down to seeing on the night - and a moon! I've also attached my Master Flat for comment - it seems too good to be true! Does a flat like this actually achieve anything? I work very hard at keeping my optics spotless. The 50 flats were taken with the scope pointing directly at a daylight illuminated white ceiling through two layers of white tee-shirt - ~30,000 ADU. Any advice would be much appreciated. Thank you in advance. Adrian SW ED80DS Pro + NEQ6 Pro + 0.85x R/F + UV/IR filter + Atik 414ex osc (fitted with HitecAstro focusing unit and SW motor focus control). SW 50mm finder/guide scope + IMX224 Sequence Generator Pro + PHD2 + CdC + PI
  7. Hi! Have you looked at one of these: http://www.teleskop-express.de/shop/product_info.php/language/en/info/p5632_TS-Optics-50mm-f-6-6-APO-Doublet-Refractor---Day-Night-Scope-and-Tele-Objective.html I've purchased from Teleskop-Express in the past and delivery is typically five days. I've been considering upgrading my SW finder/guider on my ED80DS Pro ; AA scopes seem to be constantly out of stock/awaiting delivery. All very frustrating!
  8. Hi andyO Thank you very much for getting to the bottom of this little issue. Disappointing that SW cannot respond though. At least I can now be sure the spacing is not contributing to my focus issues, which I am hoping I have now solved. If only we could get a glimpse of the stars here in the East Midlands that would be good! Many thanks again for all your help, advice and support. Adrian
  9. Hi andyO, I had posted an image of M81-M82 - what I considered to be my first success with a osc camera - and it was suggested I could "lose the R/F so the image was less cropped" - as it was I could only just fit both targets into one image. The focus on that image was not great (an ongoing issue I am gradually sorting out) and so a few more slightly more out of focus stars would barely have been noticed! I'm still not sure I understand the benefit though regarding cropping. I think I might be inclined to take a few images with and without the R/F and see just how much difference it is making over the image as a whole with my 80ED. When I started I used a Canon 70D and the importance of spacing was way above my head - I just connected it all together as per the included instruction sheet and focused up in BYEoS as best I could. It is only since I started using the 414ex combined with a UV/IR filter (as shown at the top of this thread) that I was made aware of the importance of spacing - hence the purchase of the Baader VariLock and this Thread. Thanks again for all your advice and comments - all food for thought. Adrian
  10. Thank you Michael. I am fairly convinced I have my spacing correct for the Atik 414ex - I was just looking for confirmation re. my original photo at the top of this thread and my working premise that 'B'-'D' was 55mm. Thanks again. Adrian
  11. I am very grateful for all the help / advice received but I still do not really understand why there does not appear to exist definitive information published by SkyWatcher as to where exactly the requirement for 55mm spacing is measured from and to. If you look at other manufacturers reducers many give nice, easy to understand drawings showing exactly what is required. I must be missing something somewhere - I am clearly not typing the right thing into Google! On a separate, unrelated thread, I was advised not to use the R/F at all in the image train; at least then I would not have to worry about whether I was using correctly Thanks again AndyO for your input and advice. Adrian P.S. I've attached a copy of the documentation supplied with the R/F - there is no mention of 55mm or any other dimension! I like the way it says "Now, you're ready to take pictures!". The question is - 'of what?'
  12. Hello Gerry. I tried to process your tif file but it would not open for me in either PS ("did not recognise file type" error) or PI ("bad magic number" error - whatever that is!). Adrian
  13. The tape solution seems to work well - so far! I just applied a length directly on top of the machined flat on the draw tube. The tape is 0.1mm thickness (measured with my trusty vernier) but it dramatically increases the coefficient of friction between the focuser spindle and the draw tube. The FeatherTouch may have to be on my 'if only I could afford it' list - it's a long list! I have to say I had not thought of using a length of elasticated rope to support the camera, however, I do use a bungee cord to help support and contain the wires trailing from the various bits of kit attached to the scope. If the tape fails to deliver a long-term solution I'll consider the rope solution. Thank you again for the helpful suggestions.
  14. Hi Waldemar, Thank you for the advice re. CCD Inspector - I will give that a go. I am just becoming a bit obsessed with driving out focus problems I seem to have been plagued with since starting to use a CCD. When I first started I used a Canon 70D with BackyardEoS and found focusing results were generally good. Since moving to the Atik I feel focus has not been so precise, but maybe it is something else altogether different and I am barking up the wong tree. I did have a major issue with the draw tube slipping on my 80ED but in the end I solved that with a strip of high quality insulating tape - there was clearly a need to change the coefficient of friction rather than apply an ever greater force normal to the focus rod. Again that issue only surfaced when I hung the Atik on the end of the scope; it weighs more than the 70D and with the scope near vertical just pulls the draw tube out of the scope body. I seem to spend more time solving problems than taking images! The joy of AP. Thank you again for your help and advice. Adrian
  15. Thank you for your responses. I will check the F/R I have to see if it separates. I was under the impression it was 'B' but then I seemed to find a number of articles that suggested it was measured with respect to the centre line of the lens - but maybe that was a different model of R/F. I seem to have general image sharpness issues and I am just trying to eliminate possible causes. Thanks again.