Adam1234

Done some very quick and very crude processing in photoshop, literally just aligned the RGB channels by adjusting the levels slider for each channel, a bit more levels and a couple curves adjustments. Done exactly the same for all images (done all the adjustments on the 'lights' image and copy and pasted the adjustment layer to the other images so everything was the same). No cropping, and no other adjustments except simple levels and curves.

My first thoughts are that I can definitely see why flat frames are a must!!! Vignetting is very much reduced and the field is a lot flatter. Stretching the images without flats seems to produce coloured rings around the image (not so much visible in the jpegs but VERY visible in the when working on the .tif file.

Struggling to pick out what effect the dark frames are having (aside from the background colour) in terms of noise, maybe a seasoned expert with a keen eye might be able to tell if the dark frames are reducing noise or just adding to it.

Here are the (very crude) results of my experiment:

Light frames only:

Light frames + Dark frames:

Light frames + flat frames:

Light frames + flat frames + dark flat frames:

Lights + darks + flats + flat darks:

Adam

24 minutes ago, MarkAR said:

Also post process them all the same, would like to see the results.

Good idea, I'll do exactly the same to each, and post the resulting images

1 minute ago, Anthonyexmouth said:

I'm not sure of the technical reason, but far more knowlegable people here have said that CMOS are better calibrated with dark-flats. bias and dark-flats are doing the same job i think and using both causes issues. 

Ah ok!  I've now decided on doing an experiment and going to stack:

- only light frames

- lights + darks

- lights + flats 

- lights + flats + dark flats 

Will be interesting to see what the result of each combination gives, and might help to see if my calibration frames are any good!

15 minutes ago, Pankaj said:

Beautiful. There's a lot that can be done with this small little scope. Best part is its wide FOV. Try 31 next time. It will fill the frame. This image I shot with Orion ST 80 on NEQ6 without guiding.

M31 is now too low on the horizon for me, but I'll be definitely imaging it next time it comes around!

36 minutes ago, Anthonyexmouth said:

Also, I think using bias and dark flats together can be detrimental to the stacking. dark flats are the way to go with a CMOS sensor

How come together they can be detrimental? 

This is my first attempt of M51 the 'Whirlpool Galaxy', and also the first time using my new mount & scope (SkyWatcher EQ6-R Pro and SkyWatcher ED80 DS-Pro). Polar alignment with QHY Polemaster wasn't perfect (when I did the axis rotation I couldn't get the chosen star to exactly on the green circle) and I haven't got a field flattener yet, waiting for that to arrive.

I managed to get 80 x 3 minute lights unguided with my Canon 2000D at prime focus with Optolong L-Pro Broadband light pollution filter, 20 x darks, 40 x bias, 36 x flats and 40 x dark flats, stacked in DSS and processing in photoshop. Total exposure 4 hours.

I cropped the image slightly as I had a horrible dark and grainy gradient on one side of the image when stretching, but couldn't crop too much either or it became too pixelated. 

Hope you like.

Adam

46 minutes ago, 8472 said:

I no longer stack with DSS, but when I did, I was advised to deselect all background calibration options, and check the "Align RGB Channels in final image" option only. 

This was the recommendation when using Startools.

Any idea why it's best to deselect background calibration options?

Cool, I'll try the per channel background calibration. Might try the RGB background calibration and align channels as well and see what difference it makes.

Any idea what 'reduce worker threads priority' mean?  I think mine is checked by default but no idea what that does.

9 minutes ago, Erling G-P said:

Of those you mention, I can only find 'Align RGB channels in final image' (Haven't downloaded the latest version yet, so maybe the others are new features?). 

'Align RGB channels in final image' is not checked, which I believe is the standard or recommended setting - I haven't changed it myself.

Per channel background calibration and RGB background calibration options are in the Stacking parameters section. I have DSS version 4.2.3.

23 minutes ago, geordie85 said:

I never worry about that as I align all 3 channels in Photoshop afterwards 

How do you do that? 

Hi all, I'm just about to stack some images of M51 that I took last night, but I never know what the best settings to use are. Specifically the RGB background calibration. 

Do you guys check use 'RGB channels background calibration' or 'Per channel background calibration? And do you check 'Align RGB channels in final image'?

What are the advantages/disadvantages of these options?

If it helps, I was using the Skywatcher Evostar ED80 DS-Pro and Canon DSLR with the Optolong L-Pro Light Pollution Broadband Filter.

Thanks

Adam

Very nice

Lovely image !

Lovely image 

Welcome

Hi Dan, Welcome from Southampton. 

Good luck with the astrophotography,  I look forward to seeing some images.

Adam

Great image!

Received my EQ6-R Pro and SW ED80 today, thanks to all at FLO!

Lovely shot , well done!

I put in an order on FLO for a new mount and scope literally just before the announcement 🤣🤣😭😭😬😬

Very good start, well done

Hmm that seems to work out more than the agenastro adapter.

I think I might just get an astrophotography dedicated scope, was going to get one sooner or later anyway. Now I got a decide which scope to get.

11 hours ago, alacant said:

https://agenaastro.com/blue-fireball-360-camera-angle-adjuster-rotator-with-m54-male-female-thread-r-03.html

Dunno. Probably cheaper to get one made...

 

No idea how I'd get one made, but if I had to get this one I'll probably get it. I'll try and do some working out and see what room it gives me

2 hours ago, fozzybear said:

Do have any other adapters supplied with scope? like how would you fit an eyepiece as there is an adapter 2" with thumbscrews that would screw onto the focuser drawtube to secure the CC

This is what I use to fit eyepieces (1 1/4inch), I couldn't achieve prime focus with this so I'd have no hope with a cc in line with this.

I think it's M54 I need as the adapter I use to connect to the t ring is M54, but on the M54 version the thread is on the outside 😫😫