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  1. Past hour
  2. The wife would definitely agree with me being a Nebula, she is always complaining about the gaseous clouds I leave behind.
  3. Today
  4. Gabby76


    Hello and welcome to the forums
  5. Is the Universe rotating? Since we cannot see it's center or objects beyond it how can we say it is not itself rotating as most everything in it that we know of is? So really four questions, is it? and how we might know? And what other means are there to make measure it is not or is if indeed we can determin it is not or is and how those conclusions might be made? I know this question has been asked before so in this post I ask more than just the basic question...
  6. Hello and welcome :)
  7. Wow, what a chunk of silicon dioxide have YOU! Congrats. You know, you could get a Pentax body to shoot the pictures onto... (I have two. Love 'em. Not as well supported with software as Canon or Nikon, but well enough.) Now you qualify for posting in the Pentax Forums Astrophotography group, too. Really great group of people, can't say enough good things about 'em. Come to the Pentax Dark Side. We have cookies. (I couldn't decide between that and "Now strike down your Canon body and take your place at our side".)
  8. I'm getting around 0.8" on a good night, 1.2" on an OK night. I'm using a Stellarvue SV70t-IS, effective focal length of 336mm. That's with an Orion 50mm guidescope on a finder shoe, which is hardly ideal. As for what you can shoot with a CEM25P -- oooh, an excuse to post my Horsehead again?
  9. Some more positives. I used to use mine with an Altair 110mm Frac without any major vibration issues and everything settled almost immediately ! ...... every mount I have had has some form of vibration at very high power, so far this mount has bettered my previous mounts in every way. The only scope where I had some vibrations issues with was an 8” SCT which has a focal length of around 2000mm !!! Balancing and levelling precisely takes about 30 seconds ! and is a must for any mount if accuracy of the goto system is required. In addition the mount is very light and portable, has no wires to get tangled up, is almost silent in operation, tracks targets like an apache brave and the battery lasts for about 8 hours .....The mount contributes greatly to making my observing sessions hassle free and extremely enjoyable
  10. For many years, 35mm film was the most popular format and so this formed folks' standards of lens "length". So a 500mm was a fairly extreme telephoto, a 24mm was a very wide but not crazy-wide lens, and 50mm approximated naked-eye perspectives. "Crop factor" is just a way to relate the piece of the image circle that a smaller sensor lops out to the 35mm mental standard; a 35mm lens on an APS-C sensor looks about the same as a 50 on 35mm. But focal length is focal length, so if you put a 35mm sensor behind, say, a 500mm F-L telescope, you will get a picture identical to a 500mm telephoto on a 35mm film camera. The image circle at the focal plane of a 500mm telescope is exactly the same, no matter what sensor you put there to capture the light. Bigger sensor? More of the image circle. Smaller? Less. Since sensors can have wildly different pixel densities, the same number of pixels might represent all of the image circle for one sensor, or a tiny piece of it for another. For example, my Pentax DSLR has pixels about 4.8 microns across. My ASI183 has much smaller pixels (2.4𝛍), so a given object would cover twice as many of them in each direction, and appear bigger if those pixels were shown on a computer screen at the same scaling. However the Pentax sensor is physically bigger, so it can use a bigger percentage of the image circle and so capture a bigger object. You would think that a vast number of tiny pixels would always be the best, and yet it turns out to be not quite the case. The smaller the pixel, the more susceptible it is to noise, generally speaking, which is why cell phones perform so much more poorly in low light than DSLRs. So it's a classic engineering tradeoff. Another factor is the limiting resolution of the optics, but even more so the wavering induced by motion in the atmosphere ("seeing"); a really super-high-resolution sensor merely devotes lots of pixels to lovingly depicting the blur as a star or feature jumps around during the exposure. For most folks, the sweet spot is between 1 and 2 arcseconds per pixel. Astronomy.tools has some neat calculators for playing around with this stuff, e.g. CCD suitability.
  11. Hello, the mount will have 2 separate knobs/ bolts that it uses for clutches on this mount. When they are tightened (not overly tight) you can use the slo motion controls. They are not slip clutches though, if you tighten them and then force the mount by hand you will scratch the holding surface. Get the telescope pointed towards Polaris and you should be able to track fairly well, it just takes some practice If you have not done so, read the Astro- baby guide to collimation a very good write up. Remember to remove the corrector lens from the focuser before collimating this telescope, replace it when done. (pay attention to which direction it goes in!) The Meade 15mm is a good choice with this telescope as the included eyepieces and barlow are quite poor quality. I would actually suggest replacing them with a 9 or 10mm and 25mm GSO or Revelation Plossl, good quality for the price. The 3x barlow is more power than the telescope is capable of so set it aside.
  12. Nice set indeed, cool to see them side by side like this.
  13. SIDO

    Hello form Florida

    Welcome to SGL MrPizza (nice handle buy the way) We have some great imagers Florida and other locations as well so you are in for more than you bargined for Best of Luck and Clear Skies of course... Freddie.
  14. Thank you for the delightful views!
  15. Hello Chaza, do your binoculars have threads for filters? A O-III, H beta and UHC would be good for nebula viewing. The Baader Neodymium is a bit of a “jack of all trades” filter when starting out.
  16. Anything further on this curious event?
  17. Hello Kronos, this is a bit late as a reply for your trip. Use a rocket bulb blower to get the dust off of the mirror, the only time you definitely need to look at cleaning is if something organic like tree sap, bugs and such are on it. The old adage for cleaning mirrors is if you are unsure if it needs cleaning is to wait a year, then decide A very soft camel hair brush (woman’s makeup brush) can also be used to get rid of some dust on the mirror or along the edge of eyepiece lenses. (Gently of course) When not in use keep caps in place, shower caps work well on newts to keep dust and insects out of the tube.
  18. From my limited experience with EQ mounts (I stick with alt-az mounts), what you were doing sounds about right. There are slip clutches on each axis allowing you to freely move the scope about the sky. Tension is generally adjustable on them to some degree if you need to fine tune the resistance. Once you stop pushing the scope, it should stay put if everything is balanced properly without any need to "lock it" in place. If you have the polar axis generally pointed at the north star Polaris using the latitude adjuster set at 45 degrees and swiveling the base (something you need do only once per session), you should be able to track an object using just one slow motion control. This is the one advantage undriven EQ mounts have over alt-az mounts. Alt-az mounts require nudging in two axes, which becomes natural pretty quickly. I don't think single axis tracking is enough of an advantage to overcome all the EQ disadvantages, though. You can always turn it into an alt-az mount by tipping the latitude adjuster to either 0 or 90 degrees, depending on which way works better for you, and assuming it tips that far and that the counterweight shaft is removable for one of those two modes.
  19. Hi all, A bit of a moan here, but also something other amateurs like myself "may" need to be aware of. I could be wrong with my "assumption", so feel free to correct me. I was collimating my Dob with the standard peep sight to put the secondary mirror in the centre of the sight tube. I even took a photo and measured the distances to get it close I then aligned the primary mirror reflection so it was centred in the mirror as per the standard procedures. Everything was lined up nicely and the primary centre spot was (no pun intended) spot on. I read an article on configuring your secondary mirror more precisely as I was not sure of my abilities to do so using the peep hole. The directions said to first put the cross hairs on the sight tube over the centre mark on the primary mirror regardless of where everything else was. So, I put the crosshairs on the primary and adjusted the secondary collimation screws until the primary centre spot was under the cross hairs. BUT, no matter what I did, it put the secondary mirror way off the perfect centre and nothing I did (following the rest of the logical instructions) would get the cross hair over the centre mark while the secondary mirror properly reflected the primarys centred reflection. In the end I went back to just lining everything up with the peep hole, but wondered why it wouldn't work... My assumption... I took the photo down the tube and overlayed it with a symmetrical cross hair lined up with the vertical wire on the tube. This is what I got. I do not know if this is enough of an error to stuff everything up, so could the more learned Users comment please. Thanks George
  20. Rodd

    M82 HaLRGB

    Thanks Dave--its early here-about 9:30 but cloudy as usual. The last month has been the worst its ever veen I think Rodd
  21. That's a nice colourful M82 Rodd, just had a rare couple of hours decent skies here, don't know what time it is over there but it's 02.30 here and I'm off to bed. Dave
  22. TOA 130 with ASI 1600. It has taken a long time to collect this data due to the weather. I was finally able to add 26 5min lum subs. I wanted more but I'll take what I can get. debating wheter more lum would be beneficial. I would like to clean it up a bit. I used a super luminance composed of the Lum subs and the RGB subs. Red: 46 5min Green: 53 5min Blue: 51 5 min Lum: 26 5 min Ha: 99 5 min
  23. 240 seconds = 360 teeth on the worm gear
  24. I use the aluminium/ pluck foam for most accessories and eyepieces as well as a few HPRC cases for more expensive eyepieces. This is my HPRC2700 travel case, it holds the SV80mm refractor, BV/ OCAs, various eyepieces and filters as well as my Herschel wedge, Zeiss/ Baader prism and mirror diagonal. Under the blue foam section are 3-2" eyepieces.
  25. Similar vintage and capacity would be the eq8 and i have seen used ones less than that CGE pro.
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