teoria_del_big_bang
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Posts posted by teoria_del_big_bang
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2 minutes ago, scotty38 said:
Yes I went with the heater too. It is expensive yes but at least I can add flats and FlatDarks to the sequences now for any rotations I've done.
I'm also keen on being able to close the flap after imaging but that's a nice to have and wouldn't have prevented me going out last night to see why my plate solving was playing up up only to find there'd been a rain shower. All seems to have dried out ok though....
Always one of my worries when I leave it out all night.
I really would love to build an obsy with automatic roll on off roof, but as a short term think I might try to integrate a weather station, or at least a rain monitor so I can close the flap if this happens.Steve
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19 hours ago, scotty38 said:
Just ordered one 🙂
It seems a bit expense but well worth it.
Did you bother with the heater or not ?
Steve
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When I first looked at my stretched flats I thought they were horrendous, several big donuts, some visible on all filters, some specific to each filter, and offset vignetting, just like yours.
But after the initial surprise when I started to look at them in Pixinsight I could see that the actual difference in ADU between the almost black after stretching in the corners of the frame and the light area in the middle was actually very small, and the difference between the donuts and the lighter areas even less. It is just the fact that flat frames when auto-stretched are actually stretched so much to differentiate between these areas.As states in above replies the real test is whether the flats improve the final stacked image and removes the donuts and most of the vignetting. If it does then no t to worry, if it doesn't then more than more than likely either something has moved in the image train between the lights and flats, or the calibration of the lights or flats has not worked correctly.
Steve
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2 minutes ago, TakMan said:
The choice to only dither in RA is to help those folks with mounts that perhaps don’t play nicely when the guide star in Dec is thrown - perhaps taking an age to recover. Especially those that have the PHD quite setting changed from ‘auto’ to North or South only guide commands. Helps if you end up in constant backlash and then the mount is jumping from one side to the other…,
So not really applicable if dithering but not guiding I presume ?
Steve
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4 minutes ago, StuartT said:
Thank you!
Is there a reason to have dither in RA only set to ON? I would assume that this might 'create' walking noise. Wouldn't it be better in both RA and Dec to mix things around more?
Pass on that one.
I actually use PHD2 and when that is selected the dither in RA only is off, I just switched over to direct guider to see if the option of changing the amount of pixels in dither was still there (which it is), but when I selected direct guider it seems to default to be on, no idea why - unless I accidently clicked on it when using the snipping tool to get the screen shot ?????When I had PHD2 selected:
When I selected Direct Guider:
If I select it to off then next time it remains off, so no idea why it defaulted to on the fist time, unless like I said I accidently clicked it.
But I would agree with you that it should normally be selected off.Steve
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Deep Sky is not your strong point - You could have fooled me 🙂 , thats a great image.
Steve
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11 minutes ago, StuartT said:
Ok. Many thanks both. I must admit, I didn't think about having to increase dither amount because of binning, but it makes sense. Only thing is I don't know if there is a setting for that in NINA. (or at least, I haven't found it)
Steve
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I have been wanting to fit a rotator for sometime now to be able to frame images better and easier.
My setup at the time is an Esprit 100ED, QHY268M and QHYCFW3 FW.
So with this I have 55.7 mm BF to fit all these into. The camera, FW and 5mm bolt-on to 48 mm spacer that comes with the camera (or FW can't remember which) uses 35 mm leaving 20.7 mm.I found buying one a bit of a nightmare with not that much advice out there how to adapt rotators with differing threads and bore diameters to your specific set up. Then to add to the issues if using mono with FW there is very little room within the BF to fit a rotator let alone then having to add any adapters due to differing threads.
First I bought a Pegasus Falcon
My first attempt was to use the Pegasus Falcon rotator, with a width of only 18 mm it looked like it would fit, however, the 54mm threads meant I needed to use the adapters to 48mm available. I bought one from RVO together with a 54mm to 48mm male to male and male to female adapters. According to the specification the male to female should take no spacing up and the male to male should add 1mm so this should only take up 19mm of the 20.7 mm available and with some thin spacers around the female to female adapter to allow some gap between FW and rotator should work just fine.
pegasus-falcon-rotator
BUT, on receiving the rotator it actually measured 18.5 mm without adapter and with adapter measured 22.1 mm, an incredible 3.1 mm more then the published dimensions. This was a blow because the rotator seemed really well made, I like the Pegasus kit, but I knew I could get it to fit but would need me to get some sort of bespoke adapter made, or the very least to machine the current 5 mm spacer that came with camera down to 3.4 mm.
Whilst not too difficult I decided to return the rotator and and order the Deep Sky Dad rotator which already had 48 mm female threads and a slightly thinner thickness of 17.5 mm and so should fit easily.Deep Sky Dad Rotator (FR1)
This did indeed fit without issues.
The optional 48mm female to male adapters available from DSD add nothing to the BF.
I also ordered the optional hand set to be able to rotate when stood at the mount.
With some thin additional spacers I was able to get the exact BF required.
It works effortlessly with both EKOS and NINA (I am sure other software too but these are the ones I have used).Although I have not done any scientific tests, other than check my images before fitting and after, and giving it a bit of a shake by hand to see if I can feel anything, I can see no evidence of added tilt due to the bearing in the rotator, the video below shows some fairly extreme tests done by DSD to prove this.
Software wise it just seems to work a treat, in both NINA and EKOS when plate solving to an existing image it rotates the camera to get the framing pretty much bang on (I guess as close as I set the tolerance).
I really cannot seem to see any shake (for want of a better word) either up-down, left to right, or even in an angular direction.
Although at first in the angular direction there was a bit of movement, which did not seem to affect images unless I moved it by hand, but then I found there is an adjusting screw that moves a jockey pulley to tension the timing belt, and with a small adjustment any backlash in a rotational direction was eliminated.The only minor issue I had to begin with was actually getting the plate solving to work properly in EKOS. It appeared to work and as well as moving the mount to achieve the correct framing it also moved the rotator but it was not exact framing, in fact it was pretty random what angle it ended up at. EKOS seemed to try but gave up after one rotation and the angle sometimes was near on some targets but tens of degrees out on others. All I had to do was check the box for reverse direction and it worked a treat.
Now I have changed to using NINA I have not had a proper session to test everything out with the plate solving but I assume I will have to do the same in NINA.So all in all I am absolutely over the moon with this purchase and love it. Makes framing so simple and "bob-on" every single time.
At the time of writing (Feb 2022) the price was 430 Euros, 20 Euros for the optional hand set and 15 euros for the M48 female to male adapter and 24 Euros DHL delivery.
But that is without VAT so there is about 23% to add to this for VAT and other costs when it is imported to UK.Some images of it on my set-up
Steve
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I don't know if there is.
I recently added an automatic rotator and makes life so much easier as the plate solving now also rotates the camera and new images are absolutely spot on to the master image I provide to the plate solver.But, prior to that what you suggest is basically what I was doing (but tbh I never asked the question if there was an easier method 🙂 ).
All in all it did not take too much messing, I basically took a picture then looked at the two side by side, comparing it to the previous frames or stacked frames, and roughly worked out an angle difference and direction and then manually rotated the camera and took another frame. Maybe, needed to do that 2 or 3 times and it would be close enough that a small crop would take any mis match away.I know that doesn't help you at all but certainly how I was doing it.
Steve
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8 hours ago, Stuart1971 said:
Strange one…I too had a couple of odd errors tonight in NINA with my QHY268c, to do with the cooling graph, the temp was coming down on the camera, but the graph showed that cooler was not on, and the cooler power line was flat at the bottom of the chart…this changed after about a minute or so….🤔🤔
Very odd about the voltage monitor, I hope just a one off blip.
The cooling issue I have had the very same in EKOS where the cooling seems to get confused and have read one or two other threads on other forums with the same issue, always easily resolved by rebooting the camera and only seems to happen in the initial cooling not when cooled and running.
I do not know it these issues are all down to the driver but many threads are out there talking about QHY's flakey drivers.Steve
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No chance of any imaging up here tonight, thick with cloud and very wet
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1 hour ago, PESKYWAABBIT said:
Light, flat, dark and bias frames for each of the above filters?
For the ASI1600 camera I would forget the Bias frames, I was always told the camera was unstable at very short exposures and after asking about this several times the consensus seemed to be not to use them.
But lights, of course, Flats yes, and darks at same exposure, gain. offset and temperature as the lights to calibrate the lights and also darks to calibrate the flats.I always used Gain 139, offset 30 and -20 C for this camera, but this may not necessarily be the only (or even best) option but what I used after advice from this forum.
1 hour ago, PESKYWAABBIT said:What combination of filters should I be using? Should it just be L, R, G and B together in one stacked image. Or L, SII, Ha, and OIII in a stacked image? What are the rules?
In theory there are no hard and fast rules but generally depends very much on the target.
Some are best to use LRGB, but these can be greatly affected by light pollution and often get tricky with near full moon especially if target is close to the moon.
Most galaxies are best with LRGB or some people also add Ha as well.
Some have strong Ha, or OII and SII emissions, and so the NB filters come into their own.
Often there are strong Ha but very little OIII or SII and so you might do RGB and Ha and use the Ha in the Luminance or even part as Luminance and part added to the red channel.It's a bit of a "horses for courses" thing and not always easy to get your head around (I am still trying). I find to begin with a good way is to search for images of the intended target and look at what others are doing, you are lucky in that you have a very popular camera and many of the images you find will be taken with the same camera.
I would pick a relatively easy target, like Orion, Horsehead, they seem to be very popular targets at moment but read up as much as you can, no point taking lots of images with wrong filters and getting very little data so always do some test shots and stretch them to see what is there before taking several hours of data.
And I have just started to use NINA and if you have a windows Laptop, or computer of some description, then you cannot do much better than to use NINA,
I am still very much learning so this is just what I have learned, many with more knowledge may give better advice 🙂
Steve
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Here are my results, top two are mode 1 and lower 2 Mode 0.
In each case top of the two are my results and lower are @Stuart1971Certainly in mode 0 both pretty much the same, in mode 1 mine is slightly worse for fullwell anyway.
What I am not sure of is whether my test was totally valid, I am using my flat panel as a light scource and it suggests using a natural light source, also I did not go and cap my scope for the darks but just turned off the plat panel light and selected the SII filter (I would have to remove the flat panel to fit the scope cap) so although in a darkish garage I suspect some ligt will leak through for the darks.Steve
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Looks like they did some selection of the chip they tested then eh
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Sorry, just read your post again, when I first read it I thought you said the results you got made it look more appealing, now I see you said that QHY made it look more appealing.
I need to go to spec savers.
Yes I agree somewhere I have the results from when I ran the sensor analysis and I think they were also a little worse than published, sort of in the same ball park but I think less, I will have another look see if same as yours.Steve
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And regarding getting the right BF then I fine THESE are essential.
I would think getting it to the nearest 0.5 mm is going to be good enough.
Steve
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27 minutes ago, powerlord said:
No just a random number example. It says with efw, and my 1600 for altair o. 8 it's 30.33, but i put 25 for who knows why. Zwo says 29.5 + 20mm efw.
So dunno why they are saying 0.83 more. But I was way off last time.. It comes from trying to get the right things out in the dark at midnight. Duh
Ah I see 🙂
What is a little odd though is that if you select the ZWO filter wheel but no filter the figure is 28.50
But then add the LRGB it then is 30.33, so +1.83 mm for the filter, which from what I have been told means the ZWO filters are 5.5 mm thick, seems a lot.
And if they were ZWO NB filters its different again at 29.5, so if you have NB and LRGB you cannot get the correct BF for both ?????
The 29.5 could be right as it is adding 1mm and I guess the filters are 3 mm thick so that's the 1/3 width of filter I have been told to add by others on SGL.
But just looking on FLO now at ZWO filters it says they are all 2 mm thick.
I must admit this calculator seems right until you add the filters, unless this adding 1/3 thickness of them has been wrong advice but when I look at my images it seems to work for me.TBH I am not convinced this calculator is right, but I don't profess to be any kind of expert .
Steve
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What results look like the published values (within reason) ?
I am still looking at your results and taking it in but certainly the fulwell looks very similar to the published chart, but figures a bit lower if anything than the published data.
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Read Noise looks almost same as published.
Am I missing something (normally do 🙂 )
Steve
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36 minutes ago, powerlord said:
No bother. What I find a pain is mostly trying to work how how I can get Bf of X with the multitude of 42mm adapters I have. You know.. Its say 36..i have a 10, and a 20, but no 6. I have a 15 but no 1..i have a 21 and a 15..ah there we go. Etc.
Is this with the ASI1600 and filter wheel ?
36 mm seems a lot of spacers if it is, the camera will have 6.5 mm between the front of the camera and image plane that means the filter wheel is only 55 - 6.5 - 36 = 12.5 mm wide - is that right ?
Steve
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1 minute ago, AstroNebulee said:
I like the look of this indeed, shame though it doesn't have my ovl field flattener on it as with my sw 72ed with rotator, 2 inch zwo ir uv filter and my 294MC pro shoukd be 55mm but I think it's more like 56mm with the star pattern I'm getting.
If you have a filter after the flattener then it will be more than 55 as you need to add 1/3 thickness of the filters.
Normally filters are between 2 and 3 mm so usually BF is around 55.7 to 56 mm, so you are probably right about it being 56 mm.If its a LP filter screwed into the flatttener and before the flattener then you don't add this 1/3.
Steve
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35 minutes ago, StuartT said:
I have been using NINA for a while now and I really love it. But I was watching a video the other day which explained the "noSync" function, but I didn't understand it.
Normally, when I do a plate solve in NINA it computes from the image how far away it actually is from where it thinks it is and adjusts the telescope position to match. I thought that was 'syncing' I assume this then also means that if you slew to another target, the scope is more likely to be in the right place because of this syncing because the mount now has a more accurate knowledge of its position following the plate solve (i.e. the mount has updated its model of the sky).
Having seen the video I think all you say is correct for most amateur imagers with affordable gear.
Some permanently mounted advanced telescopes must build their own map of the sky and so that map does not want disturbing by small adjustments the plate solving does to get the exact framing.
It also mentions that sometimes syncing near the Meridian can confuse the telescope, but not sure what issues that can cause. Even if it did screw things up a bit surely when you slew to another target it would just plate solve again and put things right, maybe needing a couple of extra images and syncs to achieve it ?
As it is a pretty recent addition I guess most of us can just leave this off without any issues.Steve
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15 minutes ago, StuartT said:
Am I correct so far?
That certainly is my understanding (although as I have learnt what I think is correct is not always so 🙂 )
Steve
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1 hour ago, powerlord said:
Trailing all this in and out at night is becoming tedious..
Observatory build in progress...
I find getting it all back in when the clouds come the worst, taking out can be done in daylight and I am eager to get going but at some hour past midnight when everything covered in frost, and I am tired is really a pain.
And, I have been saying for the past couple of years "I must build an Obsy this year", because of this and the fact that often you just have to take what chances you get in UK due to weather. Often every weather app says clouds and early on looks bad so I don't take the gear out, but then taking dog out before bed the sky is pretty clear but then can't be bothered to set up or there is only an hour or two clear enough to be of use.
So with an Obsy that is easily possible just to do an hour here and there if that's all the weather allows.
Only think that has stopped me is that 3 years ago we decided we were going to downsize and move house so put this off. But, with Covid and daughter getting ready to flee the nest (son already gone) we have not moved yet.
Whether we get on with it this year or not I am not sure but thinking maybe just build one, maybe with a pier or just use my tripod for now then when we move take it with me build a permanent pier and re-erect.Steve
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All my short questions about astrophotogrpahy and just in general.
in Getting Started General Help and Advice
Posted · Edited by teoria_del_big_bang
Wow a lot of questions there, and I certainly am not experienced enough to answer them all.
Due to my limited knowledge in some of the questions posed I have not answered some of them and even the ones I have the answers are to the best of my limited knowledge.
But one reply I am sure of is that pretty much all of these questions (and probably all the ones that you will have soon) will be answere in a very easy to understand format if you obtain a copy of "Making every photon count" by Steve Richards".
This was my first purchase before I bought any equipment and really is a must for anyone starting out with AP 🙂
Short answer is yes, but together with your light pollution you have to pick your targets, some of the dimmer targets will be difficult id not impossible.
You can improve things by using some form of dual narrow band filter even with DSLT (I should think so anyway).
Has your EQ5 mount a goto capability ?
If so and you can connect to it with ASCOM or INDI then you could platesolve and sync the mount to automatically find your target.
If not then not sure, but probably take some exposures, long enough for the stars to be seen and then star hop.
I would think you need to connect the DSLR to a laptop, or computer, via usb.
Most DSO's cannot be seen in live view of camera so have to take shortish exposures, but long enough for something to show up when the image is stretched on your laptop, normally not more than 10S is enough for most DSO's to show something recognisable.
I have not even tried planets yet.
Planets and DSO's require totally different approaches, and really different equipment.
With the equipment you have you may find planets very small and adding barlows I do not think will yield very good results (but as I say I have no planetary experience so only my thoughts).
Without guiding you will not get very long exposures without good PA.
There are several bits of software you can use to check and adjust your PA if you have your DSLR connected to a laptop.
I have never tried with a DSLR but assume no different to using a dedicated camera.
You cannot use your main camera and scope for guiding you would need a guide scope and seprate guide camera.
If in a light polluted area then you will benefit from some sort of LP filter or a dual narrow band filter.
Yes. Depending on the distortion at the outer edges depends on the amount of crop you will need for a decent image.
No, the quoted payload would not include the counter weights, but keep in mind that for AP it is not advisable to go any where near the maximum payload for any mount.
Steve
EDIT: Just noticed that @vlaiv has replued whilst I was typing, if his advice differs from mine then I would rely on his advice before mine 🙂