First attempt at astrophotography

[Iceman120]

Hi all.

Went out sunday night to a bottle class 4 site and shot some pictures of the andromeda galaxy and the orion nebula.

I recently brought an ioptron skyguider pro which was on a cheap tripod I had brought off amazon some time ago. Took me an hour to get polar aligned which I dont think was too bad for my first time.

I was using a canon 550d with a 70-300mm lens at f5.6. 25 stacked images of 2 minute exposures at ISO 3600 (thinking that might be way too high after seeing most people use 1000-1600) using deep sky stacked and 10 dark frames. 

Any feedback appreciated

Thanks

 

Edited September 22, 2020 by Iceman120

[MarkAR]

Not a bad start, it's not easy getting pointed where you want to be on a tracker but practice makes perfect.

 

[Rustang]

Good start 👍, maybe go with ISO 800 but then the noise doesn't look to bad in your images but the more you stretch the more it will become apparent. Orion has a bright centre so ISO 800 will also help keep the centre from over saturating. Looks like you definitely have some movement, more so in the first image, 2min subs was reaching the limit on my HEQ5 pro mount so guiding will really help with star trailing when your ready but you may reach your limits quickly with that mount, mounts are one of the mount important bits of equipment. Have a play with Focusing also, it maybe the movement though that's making it look slightly out of focus.

Keep going, it will be worth it.

Edited September 22, 2020 by Rustang

[Iceman120]

thanks for the feedback, hoping to get out friday night, thinking of shooting with my 135mm lens that will go as fast as f2.8. spend more time on getting my alignment right and spend longer of the night imaging it. so hopefully will be posting an update pic this weekend.

[Rustang]

Be careful at 2.8, it may have the same negative effect as a high ISO in regards to over saturating parts of your Target, not all targets though but also from memory your best sticking to around f4-f5. Data for astrophotography most importantly comes from long exposures, longer the better so see if you can get set up correctly for 2min exposures if that's still going to be ok for your mount, ISO 800 and around f4-5 then take lots and lots of those subs. 

Edited September 22, 2020 by Rustang

[soundwave]

Welcome aboard! Wonderful start. I had my Skyguider Pro for some months now, and it's a lot of fun indeed. (and I also use the 550d and a cheap tripod with an annoying center-pole).
Polar alignment gets much easier as you get more experienced. What is your polar alignment routine?

It looks like you are a bit out of focus in your images. I also had a difficult time reaching 'perfect' focus with my 70-200 lens using just the live-view 10x.
Eventually I 3d-printed a Bahtinov Mask that fits my lens hood (but you can also make a DIY one) and I highly (HIGHLY) recommend it. Even-though it's not easy to rotate the focus ring by a very small amount, it is possible.

Also, am I understanding correctly that these are stacked images without any post-processing outside of DeepSkyStacker?
If that's the case, then there is much more you could get out of these image.

I've used the free-trial version of Pixinsight along with many tutorials on youtube to remove gradients, color balance, noise reduction, stretching, etc., and it makes all the difference.
I later purchased the software, but there is a new (free) alternative that is emerging now called Siril. 
Cuiv The Lazy Geek did a nice rundown of it here.

I also noticed that Flat frames are very important for the final stacked result.
You can cover the lens hood with a white t-shirt using rubberbands, then place a tablet or something similar with a fully white screen. I like using N.I.N.A (open-source) to capture my frames, and it also has a very nice Flat Wizard which makes the whole process much easier.
You can take flats at home after your return from the field, just be very careful not moving the focus-ring by mistake until you actually take the flats.

For easier framing of targets, I would recommend buying this fairly cheap DEC panoramic-head, along with an arca-swiss dovetail (just the plate).
I truly dislike the DEC head that comes with the SkyGuider Pro, because there is movement of the target when you lock down the 2 screws.
This upgrade saves me a LOT of time with framing, and also allows me to do Manual Dithering by slightly moving the target in the frame on both axis every 3 frames or so.

I'm assuming that you are using the counterweight setup with your gear. The dovetail will also open up the option of balancing on both axis.

If you need any further help, don't hesitate to message me.

[Iceman120]

20 hours ago, Rustang said:

Be careful at 2.8, it may have the same negative effect as a high ISO in regards to over saturating parts of your Target, not all targets though but also from memory your best sticking to around f4-f5. Data for astrophotography most importantly comes from long exposures, longer the better so see if you can get set up correctly for 2min exposures if that's still going to be ok for your mount, ISO 800 and around f4-5 then take lots and lots of those subs. 

ok thanks for the advice. think ill stick with my setup from the other night then and lower my ISO.

8 hours ago, soundwave said:

Polar alignment gets much easier as you get more experienced. What is your polar alignment routine?

I first levelled the tripod using the bubble level on the skyguider, then adjusted my wedge to be pointing somewhere near the 52 degrees (my location), then try and point the guider in the rough direction of polaris and then spent the next hour or so twisting knobs, i used a free app on android called "PolarFinder"

8 hours ago, soundwave said:

It looks like you are a bit out of focus in your images. I also had a difficult time reaching 'perfect' focus with my 70-200 lens using just the live-view 10x.
Eventually I 3d-printed a Bahtinov Mask that fits my lens hood (but you can also make a DIY one) and I highly (HIGHLY) recommend it. Even-though it's not easy to rotate the focus ring by a very small amount, it is possible.

i had looked at getting one of these, will probably be my next purchase if i dont make one in the meantime. thanks for the link looks really useful

 

9 hours ago, soundwave said:

Also, am I understanding correctly that these are stacked images without any post-processing outside of DeepSkyStacker?

it is stacked, 25 light frames. 10 dark frames and 10 bias frames. will attempt flats next time. I used deep sky stacker to put them all together using recommended settings, then imported the tiff file into photoshop and had a play around with the levels and curves and used camera raw filter to try and bring out the galaxy more but ended up blowing most of it out. i have redone it in the siril program that you recommended, had a quick run through and got a better result so thanks for that.

here it is

there is some vignetting that i presume the flat frames will eliminate? and maybe slightly oversaturated but on a whole, i think a better image.

thanks for all the feedback guys i really appreciate it. hopefully next session which hopefully be this weekend i can get an even better result.

[soundwave]

14 hours ago, Iceman120 said:

there is some vignetting that i presume the flat frames will eliminate? and maybe slightly oversaturated but on a whole, i think a better image.

Yes, flats should help a lot with the vignetting and also with some of those dark patches which are probably dust on the sensor.
The color in the new image looks so much better. Is there any chance you could upload the stacked tiff somewhere so I could play around with it in Pixinsight? I wonder what more can be done with that image of Andromeda (and I'll list the steps I've taken).

[peter shah]

I wished my first images looked like that....thats really good  for a attempt at imaging

[Iceman120]

1 hour ago, soundwave said:

The color in the new image looks so much better. Is there any chance you could upload the stacked tiff somewhere so I could play around with it in Pixinsight?

heres the original stack from dss, let me know how you get on, will be interesting to see the result from someone who knows how to tackle the post processing.

Autosave003.tif

[soundwave]

2 hours ago, Iceman120 said:

heres the original stack from dss, let me know how you get on, will be interesting to see the result from someone who knows how to tackle the post processing.

Autosave003.tif 116.09 MB · 4 downloads

Thank you.

I think that Pixinsight did a great job, and you took very nice data.

Sometime later I will try Siril for the first time and try to replicate this result there.

Here is what I did in Pixinisight:

1. Slight crop of stacking artifacts at the edges of the frame
2. Dynamic Background Extraction (By selecting different background samples, it creates the overall gradient to be removed by division and then subtraction from the original image)
3. Color Calibration (By selecting a white reference, area-of-interest and a background sample)
4. EZ DeNoise (with a background sample)
5. EZ Soft Stretch 
6. Range Selection (which is basically creating a mask of everything other than the background)
7. With the mask: Curves Transformation
   1. De-saturated the background to get rid of some color noise
   2. Saturated the foreground just a little bit
8. Then, without the mask: Curves Transformation
   1. Did a small S-Curve for added contrast
9. Export to JPEG

 

Edited September 24, 2020 by soundwave

[Iceman120]

wow that looks so much better, thanks for taking the time to have a play around with it. I will definitely be keeping your work flow for further reference and hopefully mine will look that good.

yesterday you said about making a bahtinov mask, when it comes to the aperture, am i using the size of front lens and dividing that by the f stop number?

thanks

[soundwave]

17 minutes ago, Iceman120 said:

yesterday you said about making a bahtinov mask, when it comes to the aperture, am i using the size of front lens and dividing that by the f stop number?

In the Bahtinov Mask Generator website? The "aperture" in this context means the diameter of the lens. (I think that's the name that stuck in the astronomy field because telescopes can't change their aperture, it's always wide open to the diameter of the scope, but I'm not sure)

So you can set 300mm as the focal length and (I assume) 67 as the diameter ("aperture")

Edited September 24, 2020 by soundwave

[Iceman120]

24 minutes ago, soundwave said:

So you can set 300mm as the focal length and (I assume) 67 as the diameter ("aperture")

oh ok then, that clears things up, i understood it with telescopes but when it came to the camera lens it was confusing me a bit due to the f stop. my lens measures at 52mm so will attempt to make one today and test tonight if we get any clear patches

[soundwave]

Best of luck, keep us updated!

[soundwave]

21 hours ago, Iceman120 said:

I will definitely be keeping your work flow for further reference

I gave Siril a try and came up with the attached result.

This is what I did:

1. Background Extraction: I think I used the red channel, and I did an auto-generate of samples and played with the tolerance so it will sample around the galaxy)
2. Color Calibration: I sampled a small part of the background and clicked 'background neutralization', then sampled the core of the galaxy as the white reference and 'apply')
3. Deconvolution (helped with sharpening a tiny bit)
4. Then I did another Background Extraction, because there was still a bit of a noticeable gradient. This time I manually placed the samples)
5. Histogram Transformation: Clicked the auto-stretch button (gear), but it was too stretched for my taste, so I played with the middle & black sliders a bit)

Then I saved the image and did a bit more processing in Photoshop:

1. Noise removal (with a lot of color-noise removal)
2. Curves: did a slight S-Curve for more contrast
3. Levels to make the background a bit darker

Looking at both results, the Pixinsight photo now looks too beige for my eyes (and this one not beige enough) hehehe So I'll need to work on my color calibration skills a bit more.

Edited September 25, 2020 by soundwave

[Iceman120]

thanks for spending your time, both images are beyond my expectations by far and has gave me some inspiration for my next trip out, think my answer for more detail would be more subs as this was only about 25 frames so only 50 minutes worth of exposure where as other people are doing many hours. thanks for all your advice and time I really appreciate the help.