PhotoGav

Ah ok, as I was typing I did wonder if the day number was literally the day of the year. I reckon it's always better to ask a silly question to get an easy answer though! Thank you for your help. All I need now is a run of sunny days and plenty of surface activity at varying latitudes to follow!

I knew there would be more questions...

What do you use to work out which 'day' from the Stonyhurst discs to use?

Nicolàs, you total superstar, thank you for your detailed explanation of the techniques required. That is just so perfect... I love this forum!!!

Your help will enable the next generation of astronomers to be inspired.

Many thanks,

Gav.

1 hour ago, inFINNity Deck said:

I have my camera aligned with RA/DEC. The rotational axis of the Sun can then be found using a Stonyhurst disc, see for an animated one:

http://www.oasi.org.uk/Misc/Stonyhurst/Stonyhurst.php

Nicolàs

 

Thank you very much Nicolàs, that is great. Everyday I discover a little more how little I know about astronomy!!! I now need to ask a multiple questions regarding how to do all of that...!

Am I right in saying that aligning the camera with RA and Dec is as simple as rotating the camera until movements in RA cause the image to move in a level line across the middle of the sensor from side to side and in DEC until level up and down across the middle?

With regards to the Stonyhurst disc - are you able to elaborate a little more on how to actually use that with images on the computer, please?

I would like to gather a set of solar images to allow my GCSE pupils to calculate the differing rotation speeds of the sun’s surface. The problem is establishing which way is up! Is there an easy way to work out where north is on the Sun and place that at the top of the camera chip? I look forward to hearing what you all recommend. My current method is to compare my live view with the most recent image on GONG and rotate the camera to get as close as possible to that orientation. I sometimes tweak rotation in post processing too.

That’s fabulous! How many frames in total are in the time lapse?

I'm really starting to like this double stack on the Lunt LS50THa! Here are a few shots of today's Sun, including a rather lovely filaprom:

1 minute ago, JeremyS said:

I have a related q. 
I have a Lunt 50 and it’s wonderful. I’m using it visual only.

Would the next step up in image quality be:

1. adding a Lunt 50 double stack filter to the existing Lunt

or

2. Going for a Lunt 60 single stack scope

?

I’m sure @Nigella Bryantwouks say Lunt 60 plus double stack 🤣

Good question (and yes, Lunt 60 with DS would be ideal! Hey, why not the 80?!!?). I will be interested to hear what people say.

I think that there is a significant increase in contrast with the DS on the 50, though I have only used it with the camera so far, not with an eyepiece.

Certainly the cheapest next step would be a DS for the 50 (though not exactly cheap!).

4 minutes ago, JeremyS said:

Looks very good to me @PhotoGav 👍🏻

Thanks Jeremy. 

Here's a close up that I took as well (with a 2.5x PowerMate):

So, I took the plunge and acquired a Double Stack for the Lunt 50. I gave it a test drive today. Here are the results...

Single Stack:

Double Stack:

Conditions were reasonable, but not perfect - it was quite hazy by the time I was up and running.

I think the DS definitely has great potential, but I'm not convinced that I have found the best tune for it yet. The bright area of the image is quite narrow and I found it difficult to get it in the correct place. I felt as though it either showed one side or the other in best contrast, but never the two together. Any advice on tuning and that sort of thing would be most welcome, please!

2 hours ago, Highburymark said:

Looks like you’re picking up some nice detail in single stack Gavin. And as the Sun is pretty blank at the moment, you wouldn’t really appreciate the full benefits of a second filter right now.
But when activity increases, double stacking transforms views of surface features like filaments. Instead of just being perceptible, they become dark and detailed, in sharp contrast to the brightness of the background chromosphere. This provides a real sense of 3D, particularly if they also arch over the solar limb, into a so-called ‘filaprom’. The mottling across the rest of the disc becomes more defined, and you get a clearer appreciation of the swirling detail around active regions and sunspots. As John says, views are slightly dimmer, but certainly not enough to diminish views in any way. 

Thank you, that’s good to hear. It certainly sounds like it would be a worthwhile addition. I have an opportunity to pick up a second hand DS ‘in perfect condition’ at a sensible price. I think it is rapidly becoming too good an opportunity to turn away. At least I would then be ready for the increase in activity due as we move back towards maximum, eventually!

3 minutes ago, laudropb said:

Nice image. I don’t image myself but visually the double stack brings out surface details which I just do t see with the single stack.

Thank you. It is good to hear that the DS does add a significant enhancement.

1 minute ago, laudropb said:

Hi Gav. I was in much the same position as you last year. I am purely visual and wondered if the outlay for a double stack for  the LS 50 could be justified. I read in some reports that it dimmed the image too much and rendered the views of proms less detailed, while others said it was a great improvement. I finally bit the bullet and ordered a DS unit from FLO. It has turned out to be one of the best decisions I have made. The difference in the surface detail is night and day. Yes it did s the image but not to any great detriment. As for the proms, it certainly does not make them any worse and on certain occasions I think it improves them. I also find that it enlarges the sweet spot and greatly improves low mag, whole disk views. Definitely one of my best decisions.

Ah ha, thank you, that is a very interesting and helpful reply. It looks like you may have pushed me over the edge!!

As an example, here is my image of the Sun in Ha yesterday (2021-04-05). What would a Double Stack do to improve this image, if anything?! Or do I need a completely different set up to make a difference?!

Not sure if this is really in the right section, but I thought the right people would see my question in here...

I have a Lunt LS50THa and am wondering whether the expense of a Double Stack unit is really worth it? I use the scope for both visual (mainly outreach) and for imaging. I am pretty happy with my imaging results, but am always keen for better! I have considered the Quark route as I have an Esprit 100, but have really decided that is not best for me as it would be tricky when the Esprit is set up for DSO duties, as it is now for example. I like the full disk capabilities of the Lunt with my Chameleon 3 and I use a 2.5x Powermate to get in a bit closer.

So, what do you reckon - should I go for the Double Stack unit?

Thanks in advance. 

I like that a great deal! Fascinating and different. Where in Ursa Major is this? It looks like it is crying out for some vast mosaic to show the IFN web in context!

I've been meaning to have a look at the balance on my mount for a while and this thread pushed me to action yesterday. Following a bit of tinkering, I concur with @Zakalwe - the current readout in the SiTech software with my Mk 1 Mesu 200 flits around too much to give a reliably steady reading when moving the mount with the handset. However, I found that the current draw when the mount is stopped but running (i.e. powered on but not tracking) gives an indication of imbalance. If there is a draw when not tracking then it is out of balance. My mount was reading 0.00 for the secondary drive (Dec), but 0.02 or thereabouts for the primary drive (RA). I investigated and found that the counterweight had slipped all the way to the end of the bar, so the mount was totally out of balance. I moved the counterweight until the draw was 0.00 and then turned the mount off and checked the good ol' manual way. Sure enough, perfect balance. I recalibrated PHD2 last night and guiding is much better now!!! Oh, silly me... that's about six months worth of (not many) subs that could have been better!

Here is my entry on the theme of Satellites. It is the radio reflections of the GRAVES transmission frequency (143.050 MHz) between 00:54 and 00:58 on 18-03-21. Guess how many individual reflection trails there are!! I call this a 'Murmuration of Starlinks'. The radio antenna is set up to capture meteor events and you can see that there are a few meteor reflections hiding behind the veil of radio frequency interference from the most recently launched train of satellites. Thankfully they do move into higher orbits and become less obtrusive, but my radio data (not to mention optical data) is constantly being bombed by Mr. Musk's addition to the constellations. 🤨

That's a beauty, Steve. How wonderful to have had sufficient clear and dark skies to actually gather enough data to make an image. It feels like forever since that has been possible. This is a fabulous target, with so much going on in the Bok Globules area and you have done it great justice. I would have liked the image to have been presented 'the other way up', i.e. rotated through 180˚, but that is only so that I could make out more easily The Donkey, The Duck, The Leaping Leopard and The Labrador's Head within the dusty bits!!

@Xiga - that is a fantastic tutorial, some really great techniques in there, thank you for sharing. Great picture too, well worthy of the win! Congratulations!

This data set has been sitting on my hard drive since last summer, waiting for the right moment... well that moment finally arrived. Here is my image of The Iris Nebula (NGC 7023):

While gathering the data I noticed that loads of subs were photo-bombed by space hardware. I thought it would be interesting to do a stack that didn't remove any of the trails and here is the result. Yikes! I haven't counted how many there are, but it seems to be hundreds...

The image comprises 3 hours in each of R, G & B, along with 13 hours of Luminance. A total integration time of 21 hours.

Kit used: Esprit100 and QSI-683-WSG8 with Astrodon 31mm filters, all on a Mesu-200.

Processed in APP and PS.

Thank goodness for the sigma rejection algorithm when stacking!!!

Clear skies all!

37 minutes ago, Rodd said:

The red filter is i, the green filter is v, and the blue filter is b.  Ha is h, but I have found the Ha subs to be unusable--very weak and noisy, full of streaks and lines.  The Ha signal is strangely not that bright.  Maybe these galaxies don't have much Ha.  Its a shame because I love adding Ha to galaxies.  

There is a c filter too--and a couple of others, but I don't know what they are.  I wish they would label the darn things :LRGB Ha, OIII, and SII.  The filter names are not easy to find either--I have not found them.  I took a guess that i was red.  I knew v was verde (green).  b was obvious, as is h. Other than that, I have no clue!

Thanks Rodd, I will brave the system again and see if I can get a bit further. 

With regards to filter naming, I was under the impression that V stood for Visual, i.e. around the Green wavelengths. I like the idea that it stands for Verde though.

Superb images and an interesting project. Do you have further information about which filters were used for the data here? I have briefly looked at the Hubble Archive, but not yet fathomed what to look for to create a colour image. All help gratefully received!

I totally agree with the OP, too much data would be a problem. I currently have six full data sets [Ed. when has a data set ever been agreed to be ‘full’?!!?] sitting on my hard drive waiting to be processed. I just struggle to find the time to sit down for the hours required to do a data set justice. Especially at the moment with so much screen time for everyday life, the last thing I want to do is spend more time at the screen. So, on the one hand, thank goodness it hasn’t been night after night of clear skies in the UK, on the other hand, it is totally depressing that there have been only a handful (at most) of usable imaging nights here since about September / October last year. I open the sitting room curtains each morning, see my observatory and reassure it that it’s time will come soon!

We should all learn from the Sara Parable... it saddens me that such a great astrophotographer no longer feels the desire to open their observatory. Long live cloudy nights and single scope set ups riddled with intriguing problems that need to be solved and when finally working let us enjoy the excitement of the first sub on a new target downloading, eagerly awaited whilst sitting on the sofa in the warm, with an iPad remote desk-topped in to the obsy PC!!!

1 hour ago, kirkster501 said:

Thanks Dave. So you return to sidereal rate when you've done by just clicking on that script then?

Exactly, double click the vbs file for the rate that you want to set. Give it a go!