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Big Ian 65

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Everything posted by Big Ian 65

  1. Hi Guys, All my astronomy gear is disassembled and packed away ready for our move back up North… so it looks like there will be a break in my astronomy endeavours for a while, until we get settled and see how the skies are in North Lancashire! I hope to get setup in a reasonable time frame a post some new pics then! Thanks for all your support and advice over the last year or so! Cheers, Ian
  2. You're too picky - I love this image - I assume this is your 72ED - I have a CPC925 and I can only dream of that field of view!
  3. Hi all, had a try at another EAA session on the evening of 16/06/23 into the morning of 17/06/23. The results are a bit disappointing, I think the fact that we didn't have complete darkness, local light pollution and poor seeing didn't help! Anyway, here are the results - in the spirit of showing the poor sessions as well as the good!
  4. Here are a few more images I managed to grab between clouds while out looking for the Supernova.
  5. This evening I managed to capture an image of the recently discovered Supernova in M101 - It is designated SN 2023ixf. You can see it, as a bright spot, in the upper spiral arm in the attached image, just below and to the left of NGC 5461. The image is a stack of 97 frames totalling 873 secs of exposure. Taken with a SV705C camera through my CPC925 and 0.63x reducer. No processing, just stretched in Sharpcap. It is awe inspiring to see the power of such an event!
  6. Hi Everyone, please see attached some more EAA images from the evening of 18/05/2023 taken with my CPC925 and SV705C OSC camera. I am uploading the Astrometry.net annotated image as well as each plain image to allow viewers to locate the targets. (I hope this works OK it will save me tagging each image) Please let me have any feedback you may have?
  7. Hi Everyone, please see attached some more EAA images from this morning of 19/05/2023 taken with my CPC925 and SV705C OSC camera. I am uploading the Astrometry.net annotated image as well as each plain image to allow viewers to locate the targets. (I hope this works OK it will save me tagging each image) Please let me have any feedback you may have?
  8. Thanks Peter, that explains a lot… I sometimes fall into the trap of thinking that because the software can do something, then I MUST use it… I am coming to the conclusion that for EAA it is best to keep it simple and be more productive at actually observing amazing things… which after all is why we are doing it! The flip side is the unknown and that eureka moment when you enable a setting and all of a sudden your average view becomes a great view! I guess as Pete (Xio1996) told me - sometimes you have to stop faffing and get on with the observing (my words - not his, he is far more eloquent 😉 )
  9. Thanks again Pete, the recommended settings I was referring to are the ones in the smart histogram ‘brain’ dialogue box, once you have run the sensor calibration, it uses the results and the limiting parameters you dial in to recommend gain, exposure and recommended number of subs…it does a scan of the current live target image to decide. So far for me it has worked quite well… when I put in limiting parameters of say max 10 sec exposure and total exposure limit of half an hour it tends to recommend a gain close to the gain crossover point… for my camera it is around 295 and then around 200 subs of 3-5 sec (at least in that order of magnitude) I seem to have got reasonable results after less than half of the recommended total exposure time - it seems that after a certain no of stacked images the gain in clarity is not worth the extra wait… at least for my eyes and equipment! After all that, it sounds like the other Peters empirically derived method shows that using a fixed preset exposure has reasonable results and allows easier production and use of calibration frames… I guess the big question is does this approach with good cal frames give better results than trying to optimise the gain/exposure ratio to minimise noise and maximise light capture… Hopefully we will get some clear skies again soon so I can try some different options… I guess this is all part of the fun! As I have said before, I am still constantly amazed at what the EAA method allows me to see from my back garden in light polluted Margate - it is more than I ever hoped for from home astronomy, and as you said - those eyepiece things now seem assigned to the bottom drawer! With your help I now have the outside scope setup nicely and other than a couple of trips outside to check the power lead is not fouling I can sit inside and align, focus and capture remotely in the warm!
  10. I like this approach Peter - will definitely give it a try!
  11. Hi guys, I have a few more questions, which also seem to have a bearing on whether flats and darks work in Sharpcap. What colour space do you guys use is RAW 8 bit reasonable or is RAW 16 preferable? And when do you need to change colour space? Do you guys use region of interest and routinely change the capture area? If so when and why - or is it just a simple matter of framing? To Bin or not to Bin… thoughts and benefits/downsides? I found out the hard way that flats and darks (obviously) have to match capture area and Colour space - I felt such a plonker when I tried to apply different size and different colour space D&F’s… Der! and final question for today… how do you ‘nudge’ the black and intermediate level bars in the histogram… I really struggle with the resolution of dragging with the mouse?
  12. Thanks for the advice Pete, I appreciate your thoughts… Do you think it’s better to try and use recommended gain and exposure settings for each target then? That of course is a ball ache for matching the darks, I made a flats ‘filter’ out of two layers of T-shirt material and an embroidery hoop which works ok on those days when the sky gives a reasonable illumination - will probably try the light panel off Amazon too…
  13. Thanks for the advice Peter - I will try your technique regarding darks - will let you know how I get on! TBH I have been using the smart histogram for each target and using its recommendations for exposure and gain - it does seem to give reasonable results - down side is that the gain changes for each target! Do you think it is feasible to run the dark tool prior to each target?
  14. Hi Jonathan, the next image after the Iris nebula is C7, then two images of C12, and two of C21… I assume that you cannot see the file names of the images - does anyone know how to show the image file names in a post?
  15. Thanks Steve, yeah it was busy but fun… I would really like to get the noise down a bit more if possible!
  16. Thanks for the response Jonathan, have you tried calling your local authority about the street lights - I had real problems with a badly sited lamp, and I phoned KCC and spoke to a tech guy in their street lighting team, he was really helpful, he dropped the brightness at 22:00, and again to a lower value at midnight. It really helped - these new LED streetlights are remotely programmable apparently, all I had to do was give him the serial number painted on the Lamp post and the post code! I am also keen to hear what everyone thinks about the benefits (or not) of using Darks and flats with a modern CMOS camera for EAA with sharpcap ( I also have an IMX 585 based camera) with supposed low amp glow!
  17. Hi All, I managed to get my back focus distance set closer to where it should be, and had first light with my focus motor fitted! Seeing was not the best, and there was a lot of Dew forming! These images were taken on the evening of 2023-04-29, through into the morning of 2023-04-30. This time my calculated Focal ratio is 0.55x after uploading some of the images to astrometry.net which showed my pixel scale to be 0.462 arcsec/pixel. I firstly had a look at some old favourites, then commenced my foray into the Caldwell Catalogue, which has some stunning objects. The Sharpcap FWHM focus tool worked well after I dialled the settings in to suit my setup. My next learning exercise is getting my head around producing some Master calibration images to hopefully improve the results of the live stacking in Sharpcap - any advice from you seasoned pros out there would be appreciated - It is clear that the images need calibration frames adding, but having no experience producing the Darks and Flats correctly, I guess I just need to get stuck in and do it - I have tried the Dark, and Flats tool in Sharpcap with limited success it seemed to fail because the light frame colour depth was different, I also think I may have light leaking in which spoils the Darks too! Anyone have a cheat sheet to simplify the exposure settings etc for taking calibration frames? Celestron CPC925, 0.63x reducer, SV605C camera, Starsense and Celestron Focus motor - Mele Quieter PC mounted on OTA running CPWI, Sharpcap and ASCOM Server - RDPing in from Home PC running Stellarium. (Oh and I love Skysafari Pro on my Ipad)
  18. Thanks Peter and Jonathan, sorry I didn't post the individual image exposures, however they were all taken around the Sharpcap recommendations for optimum exposure (smart histogram) of around 295 gain, between 5 - 8 second exposure time and between 5 and 80 stacked images. I have already (mechanically with spacers) set up the back focus to approx 105mm - however it looks like a few days before the weather is likely to co-operate! I will post an update once I have made some progress!
  19. More EAA Sharpcap live stack Images From the evening 03/04/2023 - CPC925 2350mm FL - SV705C camera.
  20. Some EAA Images form The morning of 03/04/2023 - Native Focal Length CPC925 (2350mm) SV705C Camera
  21. Hi All, My EAA adventure continues... I had a short window last night so got my scope out and did a bit of live stacking using my 0.63x focal reducer for the first time. The reducer was attached directly to the scope back, my 2" mirror diagonal screwed directly to the reducer, and my camera fitted directly to the diagonal (ie. minimum light path) Immediately it was obvious that the reduction was way more than 0.63x, which was subsequently confirmed by checking some of the stacked images on astrometry.net. The actual reduction turns out to be 0.415x. My preference was to use the diagonal to ensure there is no risk of the camera impinging on the mount at high elevations, however it is clear this is not an option... I brought the scope in, removed the diagonal, and fitted some m42 spacers to try and get closer to the 105mm back focus specified by Celestron, but by then the clouds had arrived... so I have been unable to try again to take some frames and calculate the corrected focal length, and by trial and error get close to the specified 0.63x reduction. I assume that this back focus error created the much larger field of view and distorted star shapes (look like hearts - at least to my eyes). I am looking forward to the next clear night and next trial! I attach a few of the nights images for info.
  22. Hi Pete, I hope you are well, just thought I’d drop you a quick message to let you know that I had a good session last night with my setup, configured as you kindly advised.

    I managed to get all the component software to work, and even had a go at plate solving. Whilst I had some reasonable success with some smaller DSO objects, I am finding the images a bit noisier than I would like, and I think it’s time to change my setup to include the Antares F6.3 focal reducer - however I am now entering the world of “back focus” I currently have a 2” quartz dielectric diagonal with a direct SCT connection, And will install the reducer directly between the scope back and the diagonal. Could you advise how you went about setting the correct distance between the reducer and the camera sensor? How do you estimate the light path through the diagonal?

    cheers,

    Ian

    1. Xio1996

      Xio1996

      Hi Ian,

      Sorry, for the late reply. I didn't see your message. 

      The excepted distance for the Celestron Focal Reducer to achieve F6.3 is 105mm. I would have thought the Antares would be the same. However, the distance depends on what reduction you are after and what distortions you come across with your setup. As an example a user on Cloudy Nights has a CPC-800 and runs his scope at F7 (less spacing) and know star diagonal. Another user on Cloudy Nights double stacks two F6.3 reducers on 8 inch SCT to achieve around F4 (EQ mount). It is all down to personal choice. I use the Baader T2 star diagonal as that is smaller than a 2-inch prism and hence has a reduced light-path while still maintaining a 37mm clear aperture (more than enough for my Altair Astro 294C). 

      I messed around for ages changing the distance in and out and finally settled for very close to F6.3. Not because it was the optimum position but because I was losing too much observing time 😀 Try with the 2 inch diagonal and try with the spacing closer without a diagonal (F7 is better than F10 😀) My camera's USB port is on the rear of the camera so I have no option but to use a diagonal.

      Have fun

       

      Pete

       

       

       

  23. Thanks for the advice Mike and Pete! There is a lot to learn, but the rewards are just mind blowing… after a few years of visual astronomy, and a bit of afocal photography, EAA has shown me things I only dreamed of seeing!
  24. Hi guys, I am looking for some advice on configuring my electronically assisted astronomy rig to improve system integration and improve its operability. Ultimate goal being to have the outside rig operate fully remotely. Current hardware is CPC925 scope with starsense handset and camera, SVbony SV705C IMX585 camera feeding into Mele quieter3 miniPC. Software on mini PC is sharpcap, Celestron CPWI and ASCOM. I am able to carry out initial auto starsense alignment via CPWI, and also use the live stacking feature in Sharpcap. Focussing is currently manual using a Lord Y mask and is at best clunky! I am currently running the scope at native F10 2350mm focal length, however I do have a 0.63x focal reducer which I believe will help with shorter subs, and increase FOV and in turn help with plate solving ability. I am RDPing in via my home Wi-Fi but I am having to manually operate each software independently. I am currently saving for the celestron focus motor which will simplify connection to the mount and integrate remote focussing and mount control via CPWI. My current knowledge of ASCOM is rudimentary at best, and I would like to achieve the following: 1. Auto focussing via Sharpcap. 2. Plate solving via Sharpcap. 3. I have Stellarium running on the inside PC, and would like to be able to identify targets within Stellarium, and seamlessly get the mount to slew to the target directly without manually inputting it into CPWI. What would be a good resource to help my learn how to integrate my system components? Any advice gratefully recieved!
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