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Posts posted by teoria_del_big_bang
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15 minutes ago, Spongey said:
The FWHM is quite consistent over the frame, deteriorating by 0.5-1px in the corners, but this looks concentric around the optical axis so doesn't imply tilt to me.
Eccentricity, however, drops significantly as you get out towards the corners though, and by looking at the offending stars it seems like a little more space is needed.
Interesting that you're beyond the recommended distance already, what corrector is this? Also I assume you've accounted for filter thickness in your backfocus calculations?
I will go with that my eyes are not to 1 px anymore.
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1 hour ago, tooth_dr said:
Trying to work out the spacing - does it need some more or less spacing?
I too would say it needs more spacing but not much. Probably messing with less than 1mm spacers.
Is it me or are the stars a little worse on the bottom corners, which maybe tilt ?Steve
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8 hours ago, dannybgoode said:
Platesolving is magic. You have a camera and I assume some form of imaging control software so you just need an EQDir cable to attach your computer to your mount.
And clear skies ha ha
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22 minutes ago, dannybgoode said:
Next question then. Are you looking to use goto for imaging or visual work. If imaging then forget about the handset and star alignment etc. Just get an EQDir cable and platesolve. It'll always be many times more accurate and much quicker.
+1
You still need good PA but plate solving for imaging is really a game changer, bang on target every time and you can even get your camera bang on same framing as a previous night by using an image from the previous night in the plate solving.Steve
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Forgive me if this is me being naive but if you polar align accurately, as you think you are doing , then goto a well known bright star about mid point up from the horizon (one on Orion's belt for instance pretty visible most of night at present) can you get an idea how far you are out and whether it is a long way out in both Ra or Dec or just Ra?
If Dec is somewhere close but out in Ra then time being wrong is the most likely, dec then sounds like location (I think anyway).
One reason for asking is I had exactly the same recently, because I am imaging and I plate solve was not really an issue but I was just curious to why it was so far out and when I did this DEC looked pretty close (just looking along the axis of the scope as I do not have a finder) but Ra was out and roughly about an hour in time. Now I am not sure why but in my I-Optron I had to use the handset and enable daylight saving time, which makes sense but I would have thought as we are currently on GMT it would not make a difference until BST and clocks go forward, but it did make a difference and after this the image was in view and needed very little adjustment when plate solving.
Sorry if this is total nonsense but seemed to get me on target.
Steve
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Just looked back over my early data to make sure my memory wasn't playing tricks on me regarding the exposure length.
Before guiding it looks like 3 minutes was pretty normal for me without significant star trails on images like Orion, Andromeda, Bodes rosette. The stars are not perfectly round as you would expect when properly guiding but you have to zoom in pretty close to see they are a bit oval.
Below is an unstretched single 3 min unguided image I took and a significant zoom on the two ringed stars and you can see they are oval but still make a reasonable image at normal frame size.
I think I did do some 5 minutes but cannot find the actual images at moment so maybe there was beginning to show significant star trails and so I limited myself to 3 mins until I were guiding.So maybe my thoughts about 5 minutes unguided were a bit ambitious but still I really think with your scope and mount 1 to 2 mins unguided should be achievable, there maybe signs of mis-shaped stars very slightly when zoomed in but to look at normal frame size should be pretty good, hopefully somebody will either back that up or correct me if I am wrong.
I think a posted single frame will really help somebody see what your issues may be.
Steve
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Hi, Yes sounds like you have everything right but with an ED80 you should get much longer than 10 secs with just mount tracking and unguided.
I stress I am still pretty new to all this so not like some of the experts on this site but I initially really struggled guiding even though I had the camera and guidescope (in the end was just me), I cant even remember what the issues were now but couldn't get PHD2 to work in the first few sessions and trying to guide was taking me all night so just decided to get some images rather than messing about with guiding and I got up to 3 mins, with a very similar scope, and no huge star trails (stars not perfect but looked reasonable at normal viewing).
So with that scope I think you should do similar (walk before run and all that so say aim for 1 min).Now if the other stuff is right is it just your wobbly patio ????
Do you have a sub longer than 10 seconds you can upload maybe that will give a clue (to someone on SGL at least if not myself).
Above all do not despair, if I can do it then it is not too hard believe me.Steve
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They are both actually great images and although no expert the background looks very black, most images are not usually so black, which I guess will be due to the clipped blackpoint as Peter has pointed out so the data is there but you will loose some of the feint stuff by doing this and so could be even better 🙂
Steve
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Great image 🙂
Steve
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1 hour ago, Quetzalcoatl72 said:
I'm not sure exactly what the mount is supposed to sound like, wish i could compare with someone on a night out but that's impossible at this current climate. When I try to fix things I always seem to make them worse so I'll leave the gears till guiding is sorted.
Some good advice above but if you are worried about the noise your mount is making then you may have an issue there.
Can you make a video (with sound) on your mobile without any background noise?
I should think a NEQ6 should sound similar to a HEQ5 which I have used in the past and when slewing at high speed do make a fairly loud whirling noise, but it should be like a pretty constant noise not really a worrying gears clashing noise (difficult to explain) but when tracking is should be almost silent, if you get close you hear a high pitched ticking noise, around every second or so, but really you have to get close it is quiet.
Are you sure your scope is balanced well in both Ra and Dec ?
Balancing a telescopeAnd I totally agree with investing in some guiding, but first get the basics right.
You cannot expect guiding to put everything right.
You need all the basics right before you apply guiding. Guiding is just the last step to achieving long exposures and just applies a small adjustment to mount tracking to overcome small issues such as periodic issues of the mount, or issues due to not 100% perfect PA etc.What scope are you using ?
Without guiding you should get more than 10 seconds without seeing any real visible star trails when tracking.
This I think does depend to some extent on the focal length of the scope but with a good NEQ6 I should think 30 seconds should easily be possible and even 1 minute if a relatively short focal length (only a guess but I think I managed 3 to 5 mins with 430mm focal length scope on a HEQ5 without guiding) .
I suggest you look into why longer exposures are not possible.Your mount needs to be stable and a NEQ6 should be stable if all is correct.
So a summary of things to get right before guiding:
- Scope needs to be well balanced in Ra and Dec.
- Do not walk around the mount when exposure is in progress if you think the base is dodgy. But a good solid base is ideal (even a flattish lawn or grassed area is better than wobbly pavers or patio)
- Polar Alignment needs to be good, I am not saying perfect but you need a polar scope and check you are setting it correctly (Polaris is close to earth axis of rotation but not exact so needs an offset that is time and date dependent) check you are polar aligning correctly with polar scope or use PHD2'2 Drift Alignment or other methods of polar alignment.
- Is mount 2nd hand - could it be faulty ? If 2nd hand and is making weird noises whilst tracking then this needs correcting. Make a video and post with good sound and no background noises (could do inside during day - just slew using handset at max speed and also put into tracking mode).
If all the above are good then you should be able to get reasonable unguided exposures (I would think anyway) and certainly 30 seconds. Then when unguided exposures are good look into guiding and then 5 mins or more may be the normal but do not expect guiding to take you from 10 seconds to 10 minutes that just does not happen.
I am not expert on Astro-photography by any means and only took it up 3 years or so ago but the above is based on my short experience so far, I think it is correct and hope it helps.
Steve
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If you can't get one anywhere I could 3D print something that should do in plastic. I am not after any profit so basically just postage and around a quid for the plastic, PM me if you want to go that route.
Difficulty is getting the inside diameter just a good fit for the dew hood.Steve
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Sounds like a real good evening, you can tell from the post it was enjoyable. 🙂
Steve
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4 hours ago, Jamgood said:
From Gmail groups.
This is a known bug (#485), sorry you ran into it. Luckily, there is an easy workaround -- you can just remove the file phd2.1 in your Home folder, then start phd2.
Hope that helps.
Thanks, if it happens again I will try that 🙂
Steve
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4 hours ago, symmetal said:
Have you tried the 'killall phd2' command as described as an option here which should kill all instances of phd2 it thinks are running.
Alan
Hi, thanks, yes I tried that and I think it said no instances of PHD2 running (I think can't quite remember) but even so after running that command it just came up again when I started PHD2.
Only way (at the time) I found was to totally remove PHD2 and then re-install it, then it worked.Steve
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1 hour ago, Jonny_H said:
Thanks Steve.
In my situation then I guess I will be roughly the same minus the primeluce clamps and filter wheel + filters so I should be just shy of the max payload.
Oooo I don't know what to do! I think I need to stop over thinking it! 😆
Its a great scope, and in years to come if looked after will command a good resale price.
And, I think without those bits you mention it will be well in.I guess it's a matter of whether you think you will never upgrade your HEQ5. If you think you might (and also these are easily re-sellable bits of kit) then you can't go wrong.
It he HEQ5 is your forever mount (and for many it is as it is a great mount for AP) then still no reason not to but yo will have to just watch the other added bits but that's not difficult and perhaps not a bad thing.Also when I buy expensive bits of kit I think how sought after are they, if it is a bit of kit that many people would happily have then I always think that what I am actually spending is about 1/3 of the actual cost as it should hold around 2/3's their value (as things currently stand - of course could change) so instead of thinking I am spending £1,800 I would think of it as spending £600 and putting the rest to one side for now.
I am not saying that is right but helps me feel a bit easier about the big spends.Also most of all think can you afford it, really?
If it is beyond what you can afford really then maybe wait till you can but for sure do not buy something and then wish you had waited and saved or just spent that extra bit of cash. I have in the past and I always ended up buying what I really wanted eventually and then ended up loosing on the one I bought to begin with.Hope it all works out 🙂
Steve
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20 minutes ago, carastro said:
I have an HEQ5 and an Esprit 100. It's fine on it's own with a finderguider Atik CCD camera and EFW.
But if I try to mount anything else on top, it's overweight. i.e. I tried adding my Samyang lens and CCD and EFW on top and that was too much.
Carole
I can confirm that the 100ED with usual astro gear is right on the limit. but useable.
When I bought mine and replaced my WO73 I could not balance with the CW right at end of the CW post and bought an extension which is not ideal.
I did not like the extension so ended up removing a few bits of extras that took it over the weight at which I could balance (mainy the adjustable SW Guidescope mount which is a great piece of kit but pretty weighty and not really needed for AP).
When I was getting the weight down I actually weighed everything myself so if of any use:What is on top of mount:-
New Geoptic saddle and puck (replaces old saddle & puck so not too much difference) ------------ 1.02 Kg
Losmandy Dovetail -------------------------------------------------------------------------------------- 0.67 Kg
Primaluce clamp used on Losmandy at top for safety to stop rig sliding down when fitting to mount 0.29 Kg
Supplied Scope Clamps (420g each x2) ---------------------------------------------------------------- 0.84 Kg
Esprit 100ED + Flattener + 20 mm spacer -------------------------------------------------------------- 6.30 Kg
SX Filter wheel + filters ---------------------------------------------------------------------------------- 0.78 Kg
ASI 1600 MM Camera ----------------------------------------------------------------------------------- 0.43 Kg
Vixen Dovetail on top of Main Scope rings to mount guidescope to --------------------------------- 0.47 Kg
Guidescope, guidescope mount & Altair Guidescope ------------------------------------------------- 0.85 Kg
TOTAL ---------------------------------------------------------------------------------------------------- 11.65 Kg
I didn't weight the dew bands and controller for these but they are not much.
This was after removing the adjustable SW guidescope mount.
Steve
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Yes everything is bolted together apart from the last spacer that screws to the flattener.
I can;t really feel any slop in the focusser that is causing tilt and not sure I personally can see evidence of any n the few images I have take,, but not too experienced with tilt and how to cure i.Steve
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Does anyone know how to centralise this ?
Or is it really not a big issue ?I assume there is something to adjust on the focusser but what ?
I would be grateful if somebody has ad the same issue and managed to centralise this on a Esprit.
Steve
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Having just fitted a new FW and camera (QHY268M & QHY FW3) to my Esprit 100ED my first attempts at flats look a bit odd.
An unstretched flat looks reasonable.But when auto-stretched left is new setup and right is with my old setup (ASI1600 & SX FW but same 36mm filters) stretched to same degree
The original setup looks much more centralised to me whist the new setUp the centre of the image looks to be towards the bottom of the image.
Using CCD Inspector, again new setup on left.
So do I have a problem and how do i overcome it ?
Steve
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After 3 nights running EKOS / KStars without any serious issues tonight cannot get PHD2 running at all.
Everytime I start it I get the following errorI have shut everything down and rebooted, I have shut down any instance of PHD2 using terminal and still get this issue .
Steve
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I have only taken Ha so far and for 25K tool 30S, which is a bit long perhaps but that was with full brightness of my panel.
But also my Ha is 3.5 Nm so will take longer than your 6 nM. Difficult to compare as it depends on filters and light intensity.Steve
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With my QHY268M I am still experimenting with flats.
I did use 25,000 but so far best final images I have obtained are not using any flats so far. In fact a straight stack of uncalibrated lights has really given as good an image as any calibrations so far.
Now some of this might be my ding so cannot put too much on that yet as I need to do a few more tests yet.Steve
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5 minutes ago, sulaco said:
If I flash the camera with the arm7 driver I’m assuming it might not work on windows anymore?
The drivers are on your laptop / computer / or RPi running the acquisition software (Stellarmate) so the software can communicate with the camera, the camera needs flashing with firmware.
Steve
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OBSERVATORY ROOF TURNED UPSIDE DOWN IN HIGH WINDS - OUCH! 😱
in The Astro Lounge
Posted
It did get a bit breezy up here recently.
I am glad nobody got hurt and hope all your gear was undamaged.
Unfortunately these things are sent to try us, as if we didn't have enough to contend with.
Hope its all back in action soon, although probably a week or two anyway before the skies clear.
Steve