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Dellis

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Posts posted by Dellis

  1. I agree, Nexstar shows what's visible as default but you can change the setting to show all. Not sure why you'd want to to but it's there. I've just re-read it in the instructions and I quote;

    " If you want to explore the entire object database, set the maximum altitude limit to 90⁰ and the minimum limit to -90⁰. This will display every object in the database lists regardless of whether it is visible in the sky from your location."

    Hope that helps.

    Dave

  2. Yes it's all my fault that the clouds have rolled in, my new scope arrived yesterday one of the bargains from FLO a C925/CG5 GT. Great service as expected from FLO, a few emails exchanged over the weekend order placed on sunday boxes arrived on Tuesday. I spent last night setting up the basics, trying out the Nexstar, adding my 2" diagonal, removing the standard finder and fitting the Telrad. I fitted the polar scope but didn't have time to calibrate or align it.

    Looking at the forecast today I was hoping for a clear evening and left work in beautiful sunshine, looking good so far, I arrived home and setup the mounted with a very rough polar align (polar finder still not calibrated or aligned), mounted the scope and went in for a bite to eat while the scope cooled. I'd ordered an Astrozap dew shield with the scope but they're out of stock so the next little job was to knock up one from an old camping mat. I don't need too much time for the scope to cool as it's stored at pretty much ambient temperature.

    After dinner I went out and started the alignment routine which was slightly interesting as I hadn't aligned the Telrad but I did a two star align using the first two recommended stars Capella and Rigel, I didn't add any calibration stars or complete a handset polar fine tune but slewed to Jupiter with a 16mm ep fitted and there was Jupiter just off centre at 146x mag. I was really pleased with the accuracy considering the fairly sloppy set up routine. The view of Jupiter was spot on a really nice first target and one close to me heart as it was the first ever object I observed with a telescope. I aligned the Telrad and was keen to check collimation slewing off to a bright star and if was spot on! This is the third new Celestron SCT I've owned and all three have arrived in perfect collimation which never ceases to amaze me bearing in mind the journey they have all made half way around the world. I popped a 26mm in and slewed to M42 which was again very close to the centre of the fov. This time the murk had set in so I can't really pass comment apart from the clarity of the stars. By now the high clouds were starting to form and I called it a day after a very pleasing first hour with my new scope.

    I'd was a bit concerned about the mount and it's ability to carry the C925 but I needn't have worried, there's a bit of wobble while focusing but it damps almost immediately and wasn't an issue. As has been reported widely the motor are a bit noisy when slewing but not as bad as I'd expected. All in all I'd say the mount is close to it's limit for visual but perfectly acceptable however it wouldn't cope with this weight of scope for photography which isn't an issue for me as I'm purely visual.

    Dave

  3. Morning

    I normally use the 2 star set up option from the menu due to the fact that I can never achieve a successful 3 Star.

    However

    Due to the brilliant clear sky last night I finally did it. (and my silky skills of course) Cough splutter choke :)

    As a result every single object I selected was bang in the centre of the lens, even when changing between magnifications. How impressive is that ?

    I managed to see loads and loads and lots and a bit more on top of the loads and lots :D It has more than made up for the lack of viewing lately.

    What a rewarding hobby this is.

    It views OK on mine can someone quote it for me :rolleyes:

    Sent from my GT-P7510

    There you go.....

    • Like 1
  4. Hi Dave, thanks for the PM,

    Ive had a look at the website and notice the ones you use have a threaded bolt attached. Do you use this bolt to attach the magnet to the tube... with the weights then sticking by magnetism to it, or do you use the bolt to fix the magnet to the weight and then use magnetism to attach to the tube .

    By the way how heavy are the magnets themselves ?

    Cheers,

    Astronymonkey

    The magnets weigh approximately 200 - 300 g each. I thread the weights onto the magnets and use the magnets to attach to the scope, I have four weights 3 x 1 kg and 1 x 0.5 kg and attach 2 x 1kg to the front and use the 1 kg and 0.5 kg to adjust the balance (these are the weights pictured on the thread I pointed to above), I need a fair bit of weight as I have a Telrad plus a 10 x 50 finder before I even think about a nice heavy ep :) Don't forget you need around 3 x the weight of additional accessories in balance weights.

    The dimensions of the weights are 65mm dia x 40mm for the 1 kg and 65mm dia x 20mm for the 0.5 kg, these are within 30 grammes based on a specific gravity of 7.85 g/cm3 for mild steel and allowing for the threaded hole, they can be fine tuned if an exact weight is required by drilling to reduce the mass. The accuracy doesn't matter as they'll be attached to the magnets, but I just wanted to have exact weights so they could be used for other purposes if needs be.

    Hope that's of some help.

    Dave

    • Like 1
  5. Hi Dave,

    Do you have any more details and photos of your counter balance set up ?

    I have a Lightbridge and was thinking of how best to go about this but you seem to have a really neat solution so any further info would be great,

    Thanks,

    Astronymonkey

    Have a look at post number 5, the link on that post takes you to the right page of the e-magnet website and I've used the E622 type.

    Dave

  6. Having got a bit fed up of humping the scope in and out I decided to add some wheelbarrow handles......

    file-133.jpg

    I tried bolts with wing nuts but they were too much of a faff in daylight let alone in the dark with freezing fingers so had a rethink and opted for brackets on the side of the base that the handles could slide under and just lift - easy peasy and works a treat. I extended the handles beyond the wheels so I could store the handle vertically without having to chock them.

    Dave

  7. I've pretty much decided to bite the bullet and buy one and will opt for the V2 as the head is exactly the same as the Pro with the only difference being the more robust tripod and the addition of a Losmandy dovetail clamp. I don't need a Losmandy dovetail clamp and a 2" tripod is around £120 which turns the V2 into the Pro for £920 minus the Losmandy.

    Dave

  8. My first go-to was the Celestron Nexstar which after a sticky first session where I had the latitude and longitude values the wrong way round I found to be easy to set up and accurate. Second was another Nexstar this time with GPS and this was even easier to set up and just as accurate. I always three star aligned and this probably helped with accuracy, both were altazimuth. I currently have an EQ5 with Synscan and again easy to set up and accurate, I use this mount with my 102mm refractor.

    For me go-to helped get me started and allowed me to see objects I did not have the ability to find. I now like the go-to on my small scope but really enjoy the hunt and satisfaction of finding objects myself with my dob. Best of both worlds and why not :)

    Dave

  9. I currently own and use an EQ5 to mount my 102mm F7 refractor and am considering getting myself an iOptron Minitower to replace the EQ5. I've dabbled with astrophotography but it's not for me so I'm thinking I would like the ease of setup and viewing comfort offered by an altazimuth mount and with that in mind I'm interested in users experiences of the Minitower particularly with regard to stability, vibration and reliability. If I go for one it may well be a used V1 although I may go for a V2?

    Dave

  10. The above power set it is ok but please use a fuse just in case ! use a 10 amp fuse for a big set up or 5 amp for small

    I haven't used a fuse for two reasons:

    i) the cigarette lighter plugs that plug into this are fused.

    ii) the connection to the battery is via crocodile clips and these are only attached when in use.

    Dave

  11. Just typed the above and realised that I’m typing on my work laptop which is a Windows machine and I have one of my Macs with me so I’ve cross referenced the machines and found where the problem is.

    Stellarium on the Windows machine agrees with Skychart on the Mac.

    Stellarium on the Windows machine DOES NOT agree with Stellarium on the Mac.

    Before I did this comparison I double checked the setting in all three programs and they are all identical so it looks like the issue is with Stellarium on my Macs and I’ve no idea how I sort that one!

    Any ideas?

    Dave

  12. Sorry but can you clarify that statement, azimuth is the 0-360deg reading around the horizon, altitude the reading from horizon to zenith. So when you say 'azimuth is higher' I take it you mean 'azimuth is greater' and not literally 'higher' in the sky?

    There don't appear to be any current bugs relating to incorrect Alt-Az on the Stellarium bug tracker, so might be worth searching/posting on their support forum, http://sourceforge.n...arch/?q=azimuth , which also has a link to the bug tracker if that doesn't help.

    I'd be very surprised if such a major bug had gone unnoticed, but who knows? I'd be more inclined to assume it is something more subtle about the configuration of one or other of the two applications that is producing different results. As someone who has dealt with a lot of 'bug' reports in software down the years, I can tell you that if you really think it is a bug, the more evidence you can provide that it is not human error or misconfiguration, the better. Things you would be best off proving to your own satisfactionL

    - Have set your altitude properly?

    - Have you made an error in lat/long, e.g. if you needed to convert between decimal degrees and dd mm ss or vice versa that is any easy way to get it wrong, but I'd have thought it unlikely with a 4 degree error.

    - Start by aligning the az circle to Polaris as that should be fairly close to zero (obviously not exactly) rather than aligning to one star you have looked up and then navigating to another. If the error is different (you can mentally account for the current az offset of polaris easily enough), then that might point you in the right direction as to the source/

    - Try using Skychart to calibrate the dob and then look for some other targets with it. At least that 100% proves that Stellarium is giving you duff information rather than operator error.

    - Are you running the two programs on the same computer? If not, check that they have the correct date, time and daylight savings settings.

    1. Yes I mean greater - it was late...

    2. Set at 38 metres which is correct for my location

    3. Checked lat/long

    4. I did set to Polaris initially then susequently set to other objects - should have made that clear

    5. I haven't used Skychert to calibrate the dob but the differences I was seeing between Stellarium and Skychart were in line with those I was seening between the dob and Stellarium - I will try with Skychart but the earliest, cloud permitting, will be the weekend

    6. Stellarium and Skychart are running on the same machine a Macbook Air - all settings are identical; lat/long, time, date, altitude (Ihave a second Macbook which has exactly the same settings as the Air which I looked at later on to compare Stellarium on both machines and they were in sync)

    Thanks for the input and if anyone else can think of anything else to check please let me know.

    Dave

  13. It could be that your home co-ordinates are not spot on in Stellarium to give an accurate AZ position , and the fact that objects track across the AZ grid with time.

    EQ co-ordinates are fixed with ref to the sky whereas AZ are fixed relative to the terrestrial position of the observer.

    HTH.

    Steve.

    Hi Steve,

    The GPS coordinates are spot on and are set exactly the same in both Skychart and Stellarium.

    Dave

  14. I've added a levelling base to my Dob to get better accuracy using the azimuth setting circle, I'd previously had accuracy issues and attributed this to the base not being level hence the modification. Anyway I get out this evening, the first semi clear sky since I finished the base, carefully levelled the base turning the spirit level to ensure everything was done to reduce any chance of errors all good so far. I then fired up Stellarium and looked up the Alt Az for Betelgeuse and adjusted the pointer on my scope base to match the azimuth then spun the scope round to Merak read off the azimuth referred back to Stellarium only to find it was a couple of degrees out. I went back in and double checked the time and location I had set on Stellarium and it was and still is spot on. I repeated this throughout the sky and it was the same story.

    I'm back inside now having spent the evening trying to understand the problem, re levelling the base, re checking Stellarium, re aligning and all to no avail, I've even checked the accuracy of my degree circle which is spot on. I then came to the conclusion Stellarium was wrong opened up Skychart checking location and time against Stellarium and both are identical. I then looked at a few alt az coordinates for various objects and found a discrepancy between the two programs with Skychart showing 4 degrees higher azimuth reading than Stellarium exactly what I'd seen earlier with the scope after aligning to Polaris. Thus Stellarium appears to be showing incorrect alt az coordinates.

    The obvious answer is to use Skychart but I find the program very clunky when compared to Stellarium so would prefer to find out what's going wrong.

    I have another machine running Stellarium and that shows exactly the same alt az as machine number one????

    Any ideas?

    Off to bed now....

    Dave

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