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Everything posted by beka

  1. Use your 4mm eyepiece on a brightish star, center it in the field of view and focus in or out slightly. The star will de-focus into a doughnut shape with a few bright rings which should be perfectly concentric when collimated. If the rings are asymmetric then you have to use the knobs at the back of the scope to align the mirror. You have to re-center the star after adjusting and checking again. There should be instructions on how to use the knobs in the scopes manual. There are screws that lock the mirror in position which should be loosened first. You then use the adjustment knobs and re-tighten the lock screws when you are done. It is not difficult after a little practice. You can also try in the daytime with a high contrast point like object in the distance. Cheers!
  2. Hi All, I have used the NexStar 114 which is also a Bird-Jones 1000mm FL 114mm diameter scope and it seems the collimation is critical for getting a good image. Though the primary is spherical it has a short focal length and my guess is that there is a lot of off axis aberration - so the mirror has to be aligned to the lens in the draw tube. Best
  3. Hi PATRIOT SKYNET, Your scope is not the most ideal for planets. You will have to use your highest power eyepieces to get good views of the planets and you should be able to see some detail on Mars, Jupiter and Saturn when the conditions are favorable. Uranus and Neptune will be tiny disks with no detail and you would be lucky to see Pluto at all. However you will have to learn how to collimate the scope to get the best views as this instrument is quite sensitive to misalignment. It is an excellent scope for wide field low power views of star clusters and the Milky Way so I would suggest you try this aspect of as astronomy which you may find to be very interesting. The kit eyepieces (assuming they are from the Celestron kit) are not really too bad. I used them for a long time before purchasing better quality eyepieces. The 6mm and 8mm may be difficult to use because of there low exit pupil so I suggest you use the longer focal length ones with the barlow. You can buy better eyepieces later if you decide you want to get more serious with the hobby. Best!
  4. Hi Silent Running, no I didn't get the field derotator. So far I have just taken short up to 30 second exposures and stacked them with the software doing the derotation. I would like to hear from someone who as experience with the device to know how practical and easy it will be to use. Best
  5. Hi Silent Running, no I didn't get the field derotator. So far I have just taken short up to 30 second exposures and stacked them with the software doing the derotation. I would like to hear from someone who as experience with the device to know how practical and easy it will be to use. Best Meant to quote Silent Running's post...
  6. Well now I can see that while the colors on my laptop are faded as compared to my Samsung phone, they actually do appear pink here as well. I adjusted the color curves with Gimp and I think they are improved.
  7. O Yes same on my phone, but it did not seem so on my laptop. I will try to improve them.
  8. I played with the curves for Saturn a little in Gimp to bring out the cloud bands. I think the Encke gap is not a processing artifact - I believe that I had seen it visually at 400X some time back. Best!
  9. Hi All, I took the following images of Jupiter and Saturn with my CPC 1100 scope and my NexImage planetary imager (old no. 93712 640 x 480 model). Seeing was generally bad with the planet dancing all over the place but there were brief sharp moments. I took about 10000 frames at 15 fps. using oacapture. When I first tried to stack using AS!3 (AutoStakkert 3) using Wine on Linux, I found that it would not open compressed AVI files so after some Google searches and reading through forums, I found that I could use ffmpeg to convert the AVI file to a series of jpg images. Unfortunately AS!3 crashed when I tried opening maybe 100 or so images, but I later found I could convert the compressed AVI to uncompressed AVI which it opened and stacked (with basically just the default settings and about 25% of the frames) without problems, I deconvoluted with rawtherapee ,and finally used the unsharp mask of Gimp a little. While I am not unhappy with the results I think I could have done better had I used my Bahtinov mask for focusing and initially captured to an uncompressed AVI. Thanks for looking!
  10. Deciding to take another crack at planetary imaging since my last and only attempt about 7 years ago, I started setting up my CPC 1100 on the 5th floor deck of a childhood friends hospital building. He helped me carry it up a couple of flights of stairs and to place the OTA assembly on the tripod. While he curiously looked at his reflection through the corrector plate, worrying me with the prospect of a nose print, I collected the accessories I needed to start the imaging session. My friend who was in the meantime fumbling around with something on the deck, found a signboard thing which he happily declared would be his next canvas (he paints on all kinds of things) and went downstairs leaving me alone with the scope. I soon found that the power extension cord was too short and would not allow me to connect the power adapter - so I did a very foolish thing. I tried to lift the scope tripod on all supported by my body and decided it was doable. I slowly moved along the deck to place the scope nearer the power outlet... and then disaster! The azimuth clutch being loose, the OTA swung around and hit me on my left brow. I staggered thinking that was the end of my telescope but I somehow managed to maintain my balance and placed the scope down safely. I put my hand to the place where I had been struck by the OTA and it came away bloody. Looking in a mirror I was alarmed to see the left side of my face covered in blood. I washed my face and saw that luckily I just had a tiny superficial cut just below my left brow. I pressed some tissue to it and it stopped bleeding in a few minutes, and I continued setting up and imaging for a couple of hours. Recently someone asked on this forum about how manageable a CPC 1100 was to handle and I posted that I managed to set it up alone which was the case most of the time, but I have to admit it is was not the best advice. In the end I was not unhappy with the results which I will post in the imaging section. Thanks for reading!
  11. Hi NovaeSci, I am enrolled currently in the UCLAN BSc course. I would agree that it is excellent and challenging (the latter maybe because I am a MD). I can't say how well it will prepare you for the MSc and PhD levels. Regarding math you will need something a bit more than IGCSE level - some basic calculus is required even for the level one courses. If you wish to get the degree in a reasonable time you will need to do two or three courses a year. Part time I have found two courses a year my limit. Best
  12. Hi George Jones, I am of similar height and weight to yourself and 52 years old. I just about manage to assemble the CPC 1100 on my own. I keep it on the tripod in the house, to use it I take the OTA assembly off the tripod and place it on a waist high table. Then take the tripod out, then come back in for the OTA assembly. It is fiddly placing the OTA back on the tripod outside but manageable. Best
  13. Hi Tharsus55, You need an Celestron SCT T-Adapter and a Canon T-Ring or equivalents. You will not need spacers or extentions. If you don't already have it a Focal Reducer/Field Flattener would be useful. Best
  14. Congrats on your decision. I am at about 2300m altitude and judging from the discussions on this forum the seeing at my location seems to be better than most folks in UK have, so I am in favor of larger apertures and pushing my equipment to get the best resolution and to pull in the faintest objects. While by no means scientific I tried to look at images I had done with a Canon D700 (30sec subs) on Celestron 102SLT and C11 scopes to compare to faintest stars captured and it was 15.95 and 17.95 mags respectively - which also appears to align roughly with theory. On the exoplant observing, this reference A Practical Guide to Exoplanet Observing basically says that size matters - fainter and therefore more stars will be observable. All the Best!
  15. If it maybe interests you now or in the future you can also do serious science with the 16" like exoplanet transits...
  16. Hi All, My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you. Best.
  17. Very interesting shots, what was your camera? Best
  18. beka

    DSLR M31

    Hi Science562h, Nice widefield image and thanks for the tips. Feels like a lifetime is required to learn and try the different features and options available in all the software packages! So what exactly does the "Pick all black points for all channels" option do to the image. Maybe one trade off is between an aesthetically pleasing image versus one in which you try not to lose any detail. Best
  19. beka

    DSLR M31

    I had a master flat from some time back and it seemed to work correctly for a picture of the lagoon Lagoon Nebula I had posted then. I used the workflow on Siril so I imagine it applied the master flat to each light before the stacking and derotation. I did not take any bias or dark frames but that should probably be the next step. Another question that came to mind is, do I have to match the ISO setting on the camera for the flats and lights. If this is the case I have to do another set of flats. Thanks for the tips.
  20. Hi baggywrinkle, Nice pictures. The one of Andromeda shows a number of small trails when viewed at full size. Are they all satellite trails - maybe Starlink? Best
  21. beka

    DSLR M31

    I stretched and adjusted curves separately for each channel then my mistake was to just merge down the layers for each color channel in Gimp. Here is a version where I recomposed properly I hope - but it brought our the chromatic aberration in the stars. I am still kind of a novice when it comes to astrophotography and processing. I prefer this version because it has some color and the central bulge looks more natural, as does M32. Cheers.
  22. beka

    DSLR M31

    Maybe the flats didn't work but I am thinking it might be due to the derotation that Siril does resulting in the corners not stacking. You can see some of this in the lower left though I tried to crop it out.
  23. Hi BiggarDigger, You must have a seriously dark sky. What would you estimate you naked eye limiting magnitude to be? Best
  24. Hi All, Was just thinking that it should not be that hard to put a Nasmyth focus on some of the bigger alt-az mounted SCT's. It would have the advantage of have a fixed viewing height and you could say, have one side for visual and the other for astrophotography with a flip mirror. I imagine some would not mind the additional cost - considering that people are buying the Celestron RASA's. Any ideas? Cheers
  25. Hi george7378, While doing lot of subs, hours of processing and expensive gear will of course get you better images, I am also in favor of doing quick imaging like these you have done because you do get to "see" things you wouldn't at the eyepiece and you also have some record of your observing sessions. Best
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