The "No EQ" DSO Challenge!

[powerlord]

you dont need a polarscope Lee, synsapp does the work. I get 2 mins reliably with 72ed unguided

[AstroNebulee]

4 minutes ago, powerlord said:

you dont need a polarscope Lee, synsapp does the work. I get 2 mins reliably with 72ed unguided

Fantastic, thank you. Is that the polar align in the synscan pto app. I think polar aligner Pro have a good polar alignment part to their app. Hopefully my star adventurer will be here by middle of May so I can use the wedge and counterweight for eq mode. I know the star adventurer will do all this for me but the ease and quickness of goto are paramount to me. Its lazy I guess but my star adventurer will get me great Widefield images of conjunctions and milky way along with my dslr. 

Thanks again 

[powerlord]

yup - pro app takes you through it. I find it soo easy now. It knocks asiairs method into a cocked hat imho. takes a few mins only.

I had an adventurer on order, but with the performance and easy/vesatility of the gti in eq mode, I swapped the FLO order for another GTI - then yesterday decided one was enough and I'd use the cash towards an EQ6-R.. but point remains.

I just got an M12 threaded rod (7 quid), some bolts, propeller nuts. printed a standard dumbell weight to M12 spacer on my 4d printer, and used 2 spare 1.25 dumbell cast iron weights. And I use it with an ioptron wedge as they were the cheapest. weight easily screws off for transport or AZ mode.

It's a no brainer really honestly - you'll never look back. I really need to try it out with my EQStarPro and guiding - I'm keen to see what accuracy it gets - with easily getting 120 sec unguided, could I hit 5 mins+ ?

I've been mainly using it with my SLR lenses - and that 120 secs is with an APS-C 1200D, and a 1.4x extender with my 300mm L F4. i.e. 1.6x1.4x300 (672*). I've shot 90 secs with  the 2x extender (840*).

*FL pedants - leave me alone - my mind works in 35mm and it's not changing now 😛

[happy-kat]

If the 1.6 is because of the smaller sensor, the sensor size is not effecting magnification but the field of view captured.

[AstroNebulee]

4 hours ago, powerlord said:

yup - pro app takes you through it. I find it soo easy now. It knocks asiairs method into a cocked hat imho. takes a few mins only.

Thank you so much. I'm definitely giving this a go when I get my az gti into eq mode. It's such a versatile mount and with goto and portability, I don't think you can get better. Thank you again be good to hear how you get on with yours. Like you I'm hoping to eventually try to set up a guider using either my finderscope or mount a guidescope on the side of the mount. Anything is possible with this mount I think. 

Clear skies 

Edited April 27, 2021 by AstroNebulee

[Filroden]

21 hours ago, Stu1smartcookie said:

by the way i haven't got a field flattener either so will probably invest in one of those too

I'd weight up the benefits of a field flattener when doing alt/az photography. It helps sharpen stars at the image edge, but this is where you'll get the most distortion from field rotation and are likely to be cropping out of the image anyway. I'd say it would only be worth it if it was a field reducer as well as a flattener to give you a wider field of view or if you moved to equatorial imaging when you can use the full field of the image.

[AstroNebulee]

M104 The Sombrero galaxy taken from North Cornwall 30-4-21 using my sw 72ed ds pro az gti & Canon 600D. 120x27sec lights, no darks, 20 flat & bias frames. Processed in dss & ps4 (using part of a  great processing workflow using masks I've been shown by a good friend) I stacked it with the dark frames and without and dark frames, the final stack  with no darks looked better, after watching @AstroExploringvideo. The mount was playing up a bit last night so that's why the stars are slightly eggy and not up to usual 30 sec subs, will try to reduce purple halos in the next edit, but I'm happy with it 

Edited May 1, 2021 by AstroNebulee

[Heskyyyyy]

Sombrero Galaxy

284 x 15s subs

[AstroNebulee]

32 minutes ago, Heskyyyyy said:

Sombrero Galaxy

284 x 15s subs

You controlled to core really well in processing, great job 👍

[Heskyyyyy]

Just now, AstroNebulee said:

You controlled to core really well in processing, great job 👍

Thank you 😀 I really didn't want to blow out the core because those dust lanes are just TOO BEAUTIFUL

[AstroNebulee]

I have had 3 clear night's on a row here in North Cornwall on Thu, Fri & Sat so tried to make the most of it for the last bits of galaxy season. So my final offerings before the rain, wind & cloud gods descend here tonight is M63 The Sunflower galaxy and NGC 4631 The Whale galaxy & NGC 4656/57 The Hockey Stick galaxy both 120 x 26 sec no darks, 20 flat and bias, stacked in dss and processed in ps using my sw 72ed AzGti Canon 600D.  There's a cheeky 10x26 sec sub of M13 but will give this a proper go next time unless I image more galaxies 🤔

Edited May 2, 2021 by AstroNebulee

[AstroNebulee]

M57 The ring nebula and M100 from North Cornwall 6-5-21. Blooming freezing last night wish I could of stayed out longer. Ring nebula is 44x20sec subs 1600iso no darks, 20 flat and bias, M100 is 73x26sec subs 1600iso, no darks, 20 flat and bias. Sw 72ed AzGti Canon 600D, processed in Dss and Ps. I took many more subs of M100 but mount was playing up, so today I've regreased and fitted plastic washer to az axis no so much smoother and free so should sort that issue from last night. My first ever look at M57 so quite happy with that, amazed how bright it is. 

Edited May 7, 2021 by AstroNebulee

[Stu1smartcookie]

3 hours ago, AstroNebulee said:

M57 The ring nebula and M100 from North Cornwall 6-5-21. Blooming freezing last night wish I could of stayed out longer. Ring nebula is 44x20sec subs 1600iso no darks, 20 flat and bias, M100 is 73x26sec subs 1600iso, no darks, 20 flat and bias. Sw 72ed AzGti Canon 600D, processed in Dss and Ps. I took many more subs of M100 but mount was playing up, so today I've regreased and fitted plastic washer to az axis no so much smoother and free so should sort that issue from last night. My first ever look at M57 so quite happy with that, amazed how bright it is. 

Fantastic .. what time did you capture the ring nebula ? It’s certainly on my list . 

[AstroNebulee]

7 minutes ago, Stu1smartcookie said:

Fantastic .. what time did you capture the ring nebula ? It’s certainly on my list . 

Thank you, it was about 11.40pm last night, it had just risen above and to the right of a neighbours house, so wanted to get a few subs of it to test it out as I've never seen it before. I will go back to revisit it soon to image it properly. If it wasn't so cold last night I would of stay out late to image M27 also which is on my list next. 

[Unimatrix0]

Captured back in March via AZ-GTI mount in AZ mode,  W.Optics61 + QHY183 color cooled camera.  Sharpcap Live stack.  No darks, no flats, just let it run and let it stack. 
187x15 seconds.  That's a chimney on the bottom right corner, I kept shooting even when the chimney was already in the picture, just for fun. 

Edited May 7, 2021 by Unimatrix0

[JonCarleton]

I have a new scope/mount on order, so in celebration, we have had non-stop clouds.  I did get one night with enough clear to get 60 @ 20 seconds of the Sombrero Galaxy (M104), however.  It really needs a lot more time to do it justice, but a full night of clear has been a foreigner in these parts of late.

 

[AstroNebulee]

47 minutes ago, JonCarleton said:

I have a new scope/mount on order, so in celebration, we have had non-stop clouds.  I did get one night with enough clear to get 60 @ 20 seconds of the Sombrero Galaxy (M104), however.  It really needs a lot more time to do it justice, but a full night of clear has been a foreigner in these parts of late.

 

Nice image and great for 60x21sec subs, what set up were you using 

[JonCarleton]

1 hour ago, AstroNebulee said:

Nice image and great for 60x21sec subs, what set up were you using 

This was the Skywatcher 250P using the indi_AltAzMount, indi_asi_camera and indi_wmh_focuser drivers on a Pi4 attached to the mount driving the scope via onboard WiFi.  Tracking only, no guiding (that INDI driver doesn't play well with PHD2) .  Alas, no rotator.  The camera was my ASI178MC.  Pointing and Imaging was Carte du Ciel (Skychart) and CCDCiel (also both running on the Pi4 under Ubuntu Mate Linux).  I use a HDKX80-KVM to export the Pi4 keyboard, mouse and HDMI ports over an ethernet cable into the house to a screen, mouse and keyboard.  Stacking with Siril, image correction with StarTools and finished with GIMP.  I did stack it on the Pi4, but running StarTools is a bit much to ask of the Pi4. 

[AstroNebulee]

6 hours ago, JonCarleton said:

This was the Skywatcher 250P using the indi_AltAzMount, indi_asi_camera and indi_wmh_focuser drivers on a Pi4 attached to the mount driving the scope via onboard WiFi.  Tracking only, no guiding (that INDI driver doesn't play well with PHD2) .  Alas, no rotator.  The camera was my ASI178MC.  Pointing and Imaging was Carte du Ciel (Skychart) and CCDCiel (also both running on the Pi4 under Ubuntu Mate Linux).  I use a HDKX80-KVM to export the Pi4 keyboard, mouse and HDMI ports over an ethernet cable into the house to a screen, mouse and keyboard.  Stacking with Siril, image correction with StarTools and finished with GIMP.  I did stack it on the Pi4, but running StarTools is a bit much to ask of the Pi4. 

That's a great set up you have there, 

[Planitair]

On 27/01/2021 at 12:36, Planitair said:

IC5070 The Pelican Nebula H11 Region

Alt/Az Skywatcher GT5

Skywatcher 80mm + Optolong L-eNhance filter

ZWO ASI533 OSC

Taken 30sec subs 60min

70% Moon

Bortle 6/7 sky

Target W/NW

Curves & Levels in PSC2

Since 'discovering' Sharpcap pro PA and how easy it is, I now have moved on to EQ imaging.

[Stefan87]

Hi everyone! I have signed up to this forum purely to thank everyone on this post who has contributed their knowledge in alt-az astrophotography. Just like the OP and many others in this post, I was told I was wasting my time if I attempt to use my Nexstar 6SE for photography. Until I came across this wonderful post with some incredible contributions and top-shelf human beings helping each other achieve what many people laughed at! So thank you! In particular The Admiral, Happy-Kat, Filroden, Nigel and SteveNikkols. I haven't read anywhere near every single page in this thread so I'm sure I am missing some people and I do apologise for that.  I have learnt quite a bit from you guys in particular. Everything I have learnt about AP and Telescopes has been in the past month or two and I know for a fact that my learning process has been expedited by you amazing people. So thanks a million!! I can't imagine how many people you have helped that haven't signed up to say thanks haha

It's only fair that I share some of my contributions and knowledge that I've gained. I'm running a Celestron Nexstar 6SE on the stock mount. I only used a Focal Corrector for the Southern Pinwheel Galaxy and I am using a Nikon D5300 as a camera. All taken in Bortle 6 Skies South of Brisbane, Australia. Always stacked with 30 bias and 30 flats. I stopped using Darks thanks to Filroden's fantastic advice, which has saved me MUCH time.

First one is Centauras A. This was 48 minutes total exposure using a mix of half 25s and half 30s exposures. Stacked in DSS and processed in Gimp. 

I attempted to reprocess that stack in Star Tools but side by side, my Gimp effort actually looked better for the galaxy core. Even with the horrible background gradient still there on the Gimp image! The reason being is after performing a firmware update on my Nikon D5300, all my images are displaying a concentric ring pattern. It's a major bug caused by a terrible compression algorithm that only rears it's ugly head at exposure levels associated with AP. There is unfortunately not much of a solution for this from Nikon. When I attempted to "wipe" the pattern in Star Tools, the wipe had to be extremely strong which ultimately made the picture look more noisy and messy than just a simple heavy crop. A top bloke from CloudyNights has developed a piece of software to fix the histogram damage caused by lossy compression on Nikon Cameras but I'm yet to try it. I will be doing this today most likely as I'm off work. Happy to share the link to the app if required.

 For anyone else reading this that is using Gimp to process their stacks; I followed this Tutorial to learn Star Mask, Background Mask, Galaxy Masking and of course basic stretching. I found these masking steps CRUCIAL in Gimp to the stretching process and getting the most out of the data to produce a commendable final product. But really, there is no comparison to purpose built Astrophotography processing software. 

Next Image is the Southern Pinwheel Galaxy. This was around 1 hour of total integrated exposure time. I think around 170 x 15 second subs grouped with around 30 x 30 second subs (This is from memory, so not entirely accurate sorry.) I decided to use shorter subs for the main group stack as I was struggling to retain data on my previous attempts due to tracking errors. It was very annoying. I set up to capture 30 second subs for 1 hour as I have seen (I think on this thread??) somebody share a combined stack and they had a much better signal when combing just a few longer exposures with a bunch of shorter exposures. I feel this has worked in my example.
This session was particularly frustrating for me as I could only retain 1 hour of data from a 4 hour attempt using a focal reducer AND stupidly short subs!!! There was no wind and I have done everything I can to ensure mount stability. I even purchased "Astrophotophraphy on the Go" as recommeded by Ian and followed his steps to get he most out of my mount to no avail. I was tracking this target due west from around 60 degree altitude until it left site at around 20-30 degrees altitude. Although I'm happy with the result, the lost time due to discarded subs has completely negated the time saved by not needing to set up an EQ mount IMO. 
I've made a few attempts at processing this stack and processing this in Star Tools REALLY helped me pull much more signal from the tails of the galaxy compared to Gimp. I was using the Colour select Tool in gimp to create my galaxy mask previously and because the tails were so faint it did not work as well as Star Tools for retaining the extremely faint signal.

The final image of the Sombrero Galaxy was made from 20x40 second stacks for 13 minutes total integrated exposure time. I unfortunately had to throw out the majority of the stacks in this attempt. I kept 13 minutes from over 2 hours attempting to capture. There are two tables I use to roughly calculate Maximum exposure time before field rotation becomes an issue. They both have different calculations but 40 seconds was well within both tables calculations. It seems that the reason I have so much trouble retaining data is due to tracking errors, not field rotation. It most certainly is not from wind where I live. I actually tried Sombrero before attempting the Southern Pinwheel and that experience Is why I decided to go for 15 second subs using the focal reducer for the Pinwheel. Alas, I still had to discard 70% of my subs  

In saying that I also tried processing the Sombrero stack in both Gimp and Star Tools and just like the Southern Pinwheel Galaxy, Star Tools really did a fantastic job at preserving the faint signal while not displaying as much background noise. The difference was chalk and cheese. Consdering how low my SNR was due to low total integrated exposure time, I think the final product has exceeded my expectations.

Thanks again guys! I more than welcome any constructive criticism! I have a bit more data sitting here to process that I will surely share!



 

 

Edited July 21, 2021 by Stefan87

[happy-kat]

Great read and welcome

You'll find out about your concentric rings on your D5300 here. It's a long read but it explains them.

https://www.cloudynights.com/topic/746131-nikon-coloured-concentric-rings/

 

[The Admiral]

Welcome Stefan. To be honest I think that your results are pretty good despite your trials and tribulations.

You will always have to reject subs if you are after decent results. The mount of course has a big influence on the proportion of rejects, and entry-level AZ mounts will be worse than high end. I recall that Filroden's EVO mount seemed to perform better than my SE mount. But I think the biggest challenge you will face is that you are using a long focal length 'scope, 1500mm. This means that any mount deficiencies will be magnified. When we started, the focal lengths we used were about a third or less of that and we were taking wider field views. Now that doesn't help you I'm afraid, though there are many examples on here which 'disprove' that, but I think imaging small objects will always be more challenging. If it were me, I'd use an f/6.3 reducer which will reduce the focal length to ~950mm, though I say this without any practical experience of this as I imaged with a refractor, not an SCT. But, as I said earlier, don't be discouraged, because what you have achieved so far shows that you are well on the way. But just be prepared for the collateral in sub rejects.

Other views may vary .

Ian

[The Admiral]

1 hour ago, happy-kat said:

Great read and welcome

You'll find out about your concentric rings on your D5300 here. It's a long read but it explains them.

https://www.cloudynights.com/topic/746131-nikon-coloured-concentric-rings/

 

That is a long thread but Mark Shelley has come up trumps. Skip to the end to find the solution! I don't use Nikons but it will be a saviour for those that do.

Ian

[Stefan87]

Thanks for sharing the link Happy-Kat! That is exactly what I was referring to. I was maybe a bit too lazy at the time to retrieve it 😴 It may be important to clarify for others that have found this thread that this fix will work on many different models of Nikon. 

Yes Ian it's a long read but well worth it. It seems Mark Shelley is some sort of genius! 

On another note I thought I would share another process of data that I originally thought I may need to discard after a first attempt in Gimp. Star tools has come to the rescue and provided an image that I'm somewhat happy with. 

Here is M65 with 40 minutes of 15 second subs at F/10 (1500mm) on a Nexstar 6SE with a Nikon D5300. 20 flat and 20 bias. As you all will most likely know this galaxy is one of the Leo Triplet, but taken at a high focal ratio so a far less impressive capture than what is possible. Definitely not overly pleased with the end result, but at the same time not too disappointed either.  I will make sure I revisit this target with my Focal Reducer installed to include it's "siblings". Considering this is a magnitude 10.25 target and I captured it with just 15 second subs, I probably shouldn't complain. 

One point of discussion I wish to raise is export formats. I do apologise if this has been covered before. I have not read every page of this thread (yet). I have been making the mistake of exporting in JPG!!! I was not aware that if you export with JPG in star tools, it will export as 8-bit. I only became suspicious when I reviewed my post on this thread and the quality and noise in the pictures I posted was so much worse than the final product I remember exporting from StarTools. I did a rather quick process of my M65 stack (~10 minutes work) and exported in what I believe are the only 3 available export formats. JPG(8-bit), TIFF and PNG (both 16-bit???). 

There is clearly a LARGE difference between the JPG and the TIFF formats. I know this is a rookie error but I thought I would share it anyway in case others are not aware of the importance of avoiding JPG. It appears the TIFF an PNG retain the same level of data. Is this correct? What is everyone's preferred export format?
The JPG export is just 41kb. The PNG export is 555kb and the tiff export is 4.1mb. Quite a large difference in file size, but the quality difference between PNG and TIFF did not seem to noticeable on my PC. Especially considering the size difference. 

M65 TIFF.tiff

Edited July 22, 2021 by Stefan87