Please critique my first tracked image

[GazK]

I'd like to get constructive criticism on my first tracked image. I know there's plenty wrong with it, but what should I focus on first? Other than better framing of course 🙂

92 x 15second subs (being cautious) @ISO1600, 23mins total. Darks, bias and flats also used, flats were a bit iffy as zoom kept shifting. Canon 80D, 70-300 lens @ 150mm f5.6, on a Star Adventurer on a video tripod.

Edit: stacked in DSS, post in photoshop with a sprinkling of lightroom at the end.

Thanks in advance - Garry

 

 

Edited February 27, 2022 by GazK

[Stuart1971]

Nothing wrong with that at all, well done…👍🏼
maybe focus could be a tad tighter, and dont worry about trying to get the sky completely black, as it’s not black, you could stretch that a bit more and get more of a neutral slightly lighter background…

[GazK]

1 minute ago, Stuart1971 said:

Nothing wrong with that at all, well done…👍🏼
maybe focus could be a tad tighter, and dont worry about trying to get the sky completely black, as it’s not black, you could stretch that a bit more and get more of a neutral slightly lighter background…

Thanks Stuart, that's great to hear! Yes, I did wonder about focus. I have a basic TS bahtinov, but the diffraction spikes come through very small in live view. Good point about the black as well, I did pull the black point up at the end. Will try undoing that.

How are the colours? I wondered if the stars are a bit cold / monotone.

[Same old newbie alert]

That's a great image to start...

[Sunshine]

It’s great!

[andy fearn]

very nice. nice and clear.👍

[alacant]

1 hour ago, GazK said:

ISO1600, 23mins total. Darks, bias and flats

Hi

Lovely shot.

80D? So ISO 200 and lose the dark frames.

Cheers and HTH

 

[Clarkey]

It's a great start! Just add more data now you know it works. You'll get some excellent images.

As above. Darks and Canon DSLRs does not really work. Stick to flats and bias.

[GazK]

1 hour ago, alacant said:

Hi

Lovely shot.

80D? So ISO 200 and lose the dark frames.

Cheers and HTH

 

Thanks! I've now twigged that the 80D is ISO invariant, so I get dropping the ISO. What is the logic behind dropping the darks?

[alacant]

7 minutes ago, GazK said:

dropping the darks

They introduce artefacts and noise patterns which make processing more difficult. Amongst other problems in their use, it impossible to fulfill the main requirement for dark frame subtraction, that of temperature matching. 

If you really must use them, there are algorithms which attempt to reverse the mismatch. But best to simply avoid. 

Best to dither between frames and stack with a clipping algorithm. Siril is the best we've found for this.

HTH

 

Edited February 27, 2022 by alacant

[Richard_]

Well done Garry, that's a great first picture! You've framed it quite well in my opinion as you can clearly see Orion's belt, and the Orion, Flame and Horsehead nebulae coming through. 

You can probably afford to bump up the exposure time to 60s on the Star Adventurer with your current equipment, which I'm assuming you were going to do once you have confidence in equipment! 

Before framing up your target find a bright star like Betelguese and use that star to focus in live view. I'd use the same focal length during this process as you would the target you're imaging to prevent bumping out of focus when adjusting focal length. 

If you haven't got one already or aren't  using something to control your camera (like a computer or ASI Air), a wireless intervalometer will be a nice, affordable upgrade. Once you're in focus and have framed your target, you won't need to physically touch your camera whilst imaging which reduces the opportunity of knocking camera out of focus or adjusting the zoom. 

[GazK]

1 hour ago, alacant said:

They introduce artefacts and noise patterns which make processing more difficult. Amongst other problems in their use, it impossible to fulfill the main requirement for dark frame subtraction, that of temperature matching. 

If you really must use them, there are algorithms which attempt to reverse the mismatch. But best to simply avoid. 

Best to dither between frames and stack with a clipping algorithm. Siril is the best we've found for this.

HTH

 

OK, thanks. I'm not a patient man, so ditching darks is absolutely fine by me!

[Swillis]

That's looking great for a first attempt! Well done 👍

I think anything I had to say has already been said. You should be able to get up to 60sec with that setup. I have a canon 75-300 lens which is notorious for zoom and focus slippage, but nothing a bit of masking or electrical tape can't solve, just make sure your focus is still good after applying. 

Also recommend giving Siril a look.

[Bluemoonjim]

Congratulations, good shots.
I was using a Canon dslr and found getting the iso down as low as possible (around 200) combined with as many subs as possible was the way to go.
Focus assistant in BackYard EOS was also a game changer.

Cheers
Jack

[happy-kat]

If using a canon if you have an Android phone then the app DSLR controller is great if your particular model is supported (assuming aren't already using a laptop) as get a bigger screen for liveview and controls.

A Lord Y mask is easy to create out of card and creates big spikes to help with focusing.

[AstroMuni]

22 hours ago, GazK said:

92 x 15second subs (being cautious) @ISO1600, 23mins total. Darks, bias and flats also used, flats were a bit iffy as zoom kept shifting. Canon 80D, 70-300 lens @ 150mm f5.6, on a Star Adventurer on a video tripod.

Nice shot. And an excellent one for a first attempt

The areas to improve over and above what has been said by others is the bottom half of your image has oblong stars, while top half is quite round. So thats one to get to the bottom of. Good luck

[dweller25]

That’s a great image 👍

[GazK]

On 28/02/2022 at 14:13, Swillis said:

That's looking great for a first attempt! Well done 👍

I think anything I had to say has already been said. You should be able to get up to 60sec with that setup. I have a canon 75-300 lens which is notorious for zoom and focus slippage, but nothing a bit of masking or electrical tape can't solve, just make sure your focus is still good after applying. 

Also recommend giving Siril a look.

Thanks! Yes I'll try 60secs next, I want that running man! Only ever glimpsed it once visually, after staring at it for an hour through a 12" dob.

[GazK]

On 28/02/2022 at 15:04, Bluemoonjim said:

Congratulations, good shots.
I was using a Canon dslr and found getting the iso down as low as possible (around 200) combined with as many subs as possible was the way to go.
Focus assistant in BackYard EOS was also a game changer.

Cheers
Jack

Thanks! Yes, have dropped the ISO to very positive effect. Will look into backyard.

[GazK]

On 28/02/2022 at 15:43, happy-kat said:

If using a canon if you have an Android phone then the app DSLR controller is great if your particular model is supported (assuming aren't already using a laptop) as get a bigger screen for liveview and controls.

A Lord Y mask is easy to create out of card and creates big spikes to help with focusing.

Thanks! Good point about the app, I use it a lot for normal photography but I forgot it also does live view.

Will look into the Y mask.

[GazK]

On 28/02/2022 at 17:00, AstroMuni said:

Nice shot. And an excellent one for a first attempt

The areas to improve over and above what has been said by others is the bottom half of your image has oblong stars, while top half is quite round. So thats one to get to the bottom of. Good luck

Thanks! Any ideas why that might happen?

[GazK]

On 28/02/2022 at 17:02, dweller25 said:

That’s a great image 👍

Ta!

[AstroMuni]

18 hours ago, GazK said:

Thanks! Any ideas why that might happen?

I have no experience of using DSLRs, so will let others like @alacant respond. Gut feel suggests it could be something with the optics.

[GazK]

On 27/02/2022 at 20:42, alacant said:

Hi

Lovely shot.

80D? So ISO 200 and lose the dark frames.

Cheers and HTH

 

thanks, it does.