Does my andromeda galaxy need more data to bring out outer arms?

[wesdon1]

Hi all. So for a while now I've been really really struggling getting the outer arms of my galaxy images to show in processing. My latest attempt had around 2.4 hours of total integration, but yet STILL in processing, even if i stretch the data so far the core is hideously blown out, the outer spiral arms are still practically invisible?? does this mean the data simply isn't there? Also, I was imaging andromeda about 8 moon diameters from an almost full moon, would this affect outer arms/my ability to capture outer arms?? Tbh i'm getting desperate now, I don't know what I am doing wrong?? ... 

Any tips or advice would be greatly appreciated. Thank You all in advance for anything you can say to help...

140 mins total exposure/integration

Optolong L-pro Filter

Canon T3i unmodded

66/400 refractor ( F5.9 )

HEQ5 Pro Mount

Photoshop

*The second Andro' image is the best I can stretch data so far. Also, I couldn't get a background extraction in SIRIL. Lots more to learn! LOL

Thank You again to everyone who's tried helping me, I really do appreciate it thanks.

Edited September 21, 2023 by wesdon1
missed a bit

[Elp]

What does your histogram look like?

Also drop the Lpro, it's blocking a lot of signal. The arms can be seen a little in your image, I think the data can be pushed harder.

You can remove LP gradients easily in Siril doing the background extraction operation, it'll transform how much you can level stretch the image.

What camera are you using, if it's an astro one typically (most come with glass which passes all light, check the camera spec) for broadband targets you only really need to use a UV/IR block filter or luminence to control star bloat mainly.

Edited September 20, 2023 by Elp

[Albir phil]

Yes the arms are there , as it's been said I to think you push curve's and level's more ,also saturation but be careful with it . Play about with colour channels. You can always give it another try if you go too far with any process.👍

[wesdon1]

35 minutes ago, Elp said:

What does your histogram look like?

Also drop the Lpro, it's blocking a lot of signal. The arms can be seen a little in your image, I think the data can be pushed harder.

You can remove LP gradients easily in Siril doing the background extraction operation, it'll transform how much you can level stretch the image.

What camera are you using, if it's an astro one typically (most come with glass which passes all light, check the camera spec) for broadband targets you only really need to use a UV/IR block filter or luminence to control star bloat mainly.

@Elp Hi and thank you Elp. The camera is a canon T3i unmodded, sorry, I forgot to include it.

I'm at Bortle 7'ish, so would you suggest i do, say, 1 minute or less subs to avoid most the LP and just acquire many hours total integration, while not using the L-pro? 

Ok thanks I'll try BE in Siril like you suggest, and have another few go's at improving my image, thanks Elp

Thank You so much for helping me Elp

[Elp]

Image on a per sub basis according to your LP levels trying to ensure it doesn't encroach on top of the target.

Yes, as you're using a DSLR it's quantum efficiency is already hampered without blocking more signal with an LP filter. It's possible to use but you'd have to image for much longer in total compared to non filtered. Andromeda is reasonably bright so you can get a good image within a few short hours total.

[wesdon1]

11 minutes ago, Albir phil said:

Yes the arms are there , as it's been said I to think you push curve's and level's more ,also saturation but be careful with it . Play about with colour channels. You can always give it another try if you go too far with any process.👍

@Albir phil Hi Phil, thank you for helping.

I'm going to try out both Elp's and your suggestions, thanks mate. As a side note, I sent my t3i camera for an astro-mod and it's due back tomo0rrow, so I might have more luck with galaxy data when using a full spectrum camera. I'll keep the post updated, thanks.

Thanks again Phil, I really do appreciate the help and adsvice.

[Albir phil]

Yes the arms are there , as it's been said I to think you push curve's and level's more ,also saturation but be careful with it . Play about with colour channels. You can always give it another try if you go too far with any process.👍

[Elp]

As it's full spectrum you'll need to use a UV/IR block filter otherwise the colours may be wrong due to the infra red (I've only seen daytime IR images which appear white on the subjects). The mod will also increase the sensitivity to hydrogen alpha so you'll capture more of the red gaseous emission regions. It doesn't really help with broadband targets like galaxies (other than the red regions) but you'll notice the difference when imaging emission nebulae.

Edited September 20, 2023 by Elp

[wesdon1]

1 minute ago, Elp said:

Image on a per sub basis according to your LP levels trying to ensure it doesn't encroach on top of the target.

Yes, as you're using a DSLR it's quantum efficiency is already hampered without blocking more signal with an LP filter. It's possible to use but you'd have to image for much longer in total compared to non filtered. Andromeda is reasonably bright so you can get a good image within a few short hours total.

I for got to mention to you Elp, I sent my T3i off for an astro-mod, specifically a hot filter removal, if I recall correctly. So i'm hoping that will help in some way with galaxy data, but i'm also excited about it's potential with emission nebs, I hear they really pop with the astr-mods?

Thanks again Elp, i'll keep the post updated, thanks mate.

[Albir phil]

Hi again a modified is not the best for galaxy imaging 

[wesdon1]

1 minute ago, Elp said:

As it's full spectrum you'll need to use a UV/IR block filter otherwise the colours will be wrong due to the infra red. The mod will also increase the sensitivity to hydrogen alpha so you'll capture more of the red gaseous emission regions. It doesn't really help with broadband targets like galaxies (other than the red regions) but you'll notice the difference when imaging emission nebulae.

@Elp yes i'll use a uv/ir filter when imaging galaxies with it, thanks Elp. I don't expect miracles with the astro-mod on galaxy data, but getting more red Ha data will definitely be a bonus!

[Albir phil]

Yes modified is good for emission neb it dose make a lot of difference 

[wesdon1]

1 minute ago, Albir phil said:

Hi again a modified is not the best for galaxy imaging 

@Albir phil Yes I have just mearned this from Elp thanks Phil, but i am hoping to get better red ha data in galaxies, which will helpo with overall colour variation in my galaxy images. The most exciting part of astro-mod for me is the nebula potential, I'm really looking to getting better neb data!

[Swillis]

Which mod is it?

For the usual astro-mod (removal of the rear filter only) you should not need a UV/IR filter. But for a full spectrum mod you will need a UV/IR filter

Happy to be corrected on this...

[wesdon1]

58 minutes ago, Swillis said:

Which mod is it?

For the usual astro-mod (removal of the rear filter only) you should not need a UV/IR filter. But for a full spectrum mod you will need a UV/IR filter

Happy to be corrected on this...

Hi @Swillis thanks for chipping in/helping.

It's just the hot filter removal, not the full spectrum mod. So i'm guessing the other filter will remain in place? If so then just to confirm, I won't need the IR/UV cut filter?

I sent the camera to Andy Ellis of Astronomiser website, he was recommended by experienced folk on here. Andy has posted it back and i'm expecting it tomorrow or friday.

 

[Swillis]

@wesdon1 After rereading the astronomiser page I may be wrong. I'm assuming it is the rear filter which has been removed. So if your using a refractor you may need a UV/IR filter. I'd wait for one of the more knowledgeable people on here to come back!

'The front filter remains and blocks the vast majority of the UV and IR light which is not wanted for normal astroimaging because, with refractors, this UV and IR light is not brought to focus at the same point as visible light and causes 'star bloating' where stars appear as larger white discs rather than pinpoints of light'

So if your using a refractor you may need a UV/IR filter. I'd wait for one of the more knowledgeable people on here to come back!

I have a modded 600d with a samyang 135 which begs the question of should I be using one!??

[alacant]

4 hours ago, wesdon1 said:

hot filter removal

Therefore keep it simple. The filter you need is retained. Only the IR mirror/reflector has been removed.

Depending upon the type, in a light polluted sky, the L-pro does a good job of passing what you want whilst eliminating the rubbish. It will help you expose for longer; which is what you need to get those elusive spiral arms.

On one occasion, imaging only 5km or so from Alicante, it allowed us to double the exposure time of our non-filtered frames.

Siril? We put together a simple processing guide for EOS/Ti models:

https://linuxcb.blogspot.com/2023/09/siril-dslr-processing.html

Cheers and HTH

Edited September 20, 2023 by alacant

[ollypenrice]

M31 reaches well beyond your present field of view.

This will give you an idea of what's to be had within your field and either side of it. You certainly need a lot more signal but this won't do you much good unless you can flatten your image effectively - that's to say remove sky gradients.  In this orientation the upper left half of your image has a very bright patch of background which will probably be coming from LP. It is certainly not signal from M31.

Because I shoot from a dark site I'm not very experienced in fighting severe gradients like this but the starting point would be something like Dynamic Background Extraction in Pixinsight or one of the other gradient tools from another astro-specific software. These will all be more successful with more exposure - much more.

Olly

Edited September 21, 2023 by ollypenrice
typo

[wesdon1]

16 hours ago, alacant said:

Therefore keep it simple. The filter you need is retained. Only the IR mirror/reflector has been removed.

Depending upon the type, in a light polluted sky, the L-pro does a good job of passing what you want whilst eliminating the rubbish. It will help you expose for longer; which is what you need to get those elusive spiral arms.

On one occasion, imaging only 5km or so from Alicante, it allowed us to double the exposure time of our non-filtered frames.

Siril? We put together a simple processing guide for EOS/Ti models:

https://linuxcb.blogspot.com/2023/09/siril-dslr-processing.html

Cheers and HTH

Thank you for the processing guide @alacant I will give it a try this evening. Also thanks so much for going to the trouble of trying to help me, I would be lost without places like SGL.

[wesdon1]

5 hours ago, ollypenrice said:

M31 reaches well beyond your present field of view.

This will give you an idea of what's to be had within your field and either side of it. You certainly need a lot more signal but this won't do you much good unless you can flatten your image effectively - that's to say remove sky gradients.  In this orientation the upper left half of your image has a very bright patch of background which will probably be coming from LP. It is certainly not signal from M31.

Because I shoot from a dark site I'm not very experienced in fighting severe gradients like this but the starting point would be something like Dynamic Background Extraction in Pixinsight or one of the other gradient tools from another astro-specific software. These will all be more successful with more exposure - much more.

Olly

@ollypenrice Thanks so much for such a detailed and helpful message Olly. I agree the light patch in my image is indeed LP, specifically these two pain in the backside white LED lights that shine right into my refractors objective from the right side of my rig outside, so i'm going to have to find a way shielding the refractors objective from those damn lights.

Yes I will keep getting more and more data on M31 until i have many hours total, then see how i get on processing.

Thanks Olly

[wesdon1]

17 hours ago, Swillis said:

@wesdon1 After rereading the astronomiser page I may be wrong. I'm assuming it is the rear filter which has been removed. So if your using a refractor you may need a UV/IR filter. I'd wait for one of the more knowledgeable people on here to come back!

'The front filter remains and blocks the vast majority of the UV and IR light which is not wanted for normal astroimaging because, with refractors, this UV and IR light is not brought to focus at the same point as visible light and causes 'star bloating' where stars appear as larger white discs rather than pinpoints of light'

So if your using a refractor you may need a UV/IR filter. I'd wait for one of the more knowledgeable people on here to come back!

I have a modded 600d with a samyang 135 which begs the question of should I be using one!??

@Swillis I'm not sure if you need one for yours mate? If your mod is same as mine then maybe try the UV/IR filter with your samyang 135 and see how your images look? 

Btw thanks so much for helping me, I really appreciate it thanks. I'd be lost without the help and guidance from yourself and other SGL members!