First light @ f/4 - M42

[Stephane]

Hi all,

Below is my first image with the GSO 8" f/4 scope that I recently acquired. M42 was my first light with the f/5 (https://www.iceinspace.com.au/forum/showthread.php?t=195449), so I thought it was only appropriate for it to be the first light of this one too - except that this time, I have a wider FOV and a larger sensor, meaning I was able get Running Man in the frame too.

On a technical note, collimation is a real challenge to say the least. I lost collimation after a simple meridian flip and will need to scratch my head to get good collimation in the first place, and then not to lose it when slewing. A friend suggested foam strips between the primary mirror and mirror holding clips.

I am also aware that there is quite a bit of star flaring. I might mask the the clips on the primary mirror with a design similar to this one (https://shop.deepskydad.com/product/newton-reflector-mirror-aperture-mask/).

Otherwise, hope you enjoy looking. Feel free to comment.

Bigger version here (https://www.astrobin.com/cn8vbq/).

Clear skies,
Stéphane

Integration: 5h @ f/4 over 2 nights
No filter
25ish flats / imaging session

[atalas]

Nice :thumbsup:

[AstroViking]

Well done, Stephane. There is some amazing detail in those gas/dust clouds, and the stars aren't over-bright, either. (But yeah, those diffraction spikes are a bit much, I agree.)

I'd call that one for the "trophy wall", too.

Cheers,
V

[Startrek]

Stephane,

Lovely M42 , well framed and loads of fine detail

Well done !!

Your Astro imaging is growing at a fast rate, one of the fastest learners I’ve come across on the forum. Keep it going !!

Can’t help you with an f4 , I did warn you last year though , they are a different beast to an f5 !!

Maybe Ryan Jones or other folk can assist you with collimation etc…he’s uses an 8” f4 from memory

I’ll be sticking to f5 and f6 with my Newts. If I want to go wider field in the future when I’m really old , I’ll head down the refractor path

Cheers
Martin

[hrcoleman66]

Lovely result!


Do you think that the change in collimation after your meridian flip might be as a result of tube flex?


Cheers,


Hugh

[strongmanmike]

That's a fine Orion's Sword Stephane, with a well handled natural looking core and trapezium blend (rarely done this well). Any minor star shape issue is only detectable at full resolution and is really just a needling issue at best, makes little to no difference to the quality of the image, which is high. The star flaring is also a non issue for me, various optical systems have little quirks like this, to me it is merely a nuanced part of astronomical imaging :thumbsup:

Totally a personal choice but I would try to increase the colour fidelity/saturation just a little bit and see how it looks :thumbsup:

Great job

Mike

[Retrograde]

Very well done Stephane.

Great colours and depth.

[Stephane]

Thanks everyone, I appreciate the nice comments.

Martin, thanks. If there is progress, it's thanks to the high quality help I've been getting. Ryan has been giving me some much needed help with the f/4 already, not to mention the countless other areas I need help with :lol:

Hugh, you raise a good point. I will have to look into this.

Mike, thank you for those kind comments and advice. I have a bit of a tendency to add less colour saturation than what most other people would, but I'll give it a fair try. I always appreciate receiving tips. I hope you are enjoying your new dome.

[Stephane]

Mike, does this look better to you? Too much / not enough ??

[strongmanmike]

I would say that's just about the perfect compromise, Goldilocks would be quite happy :) very well imaged :thumbsup:

Mike

[AdamJL]

Have to say, I always like punchier edits, so I think you're onto something with the second version. Great detail though. Newts scare me too much with all the collimation stuff. Will stick to 'fracs :D

Great first light on your new scope, hope you enjoy it.

[Stephane]

Thanks Adam. I hope I get collimation under control. Otherwise a refractor might end up on the never-ending wishlist. I don’t know if I could give up the diffraction spikes though which I personally love.

[AstroViking]

You can cheat and create the diffraction spikes with a refractor by putting an 'X' shaped cover over the objective. Something like this:

https://www.thingiverse.com/thing:4916220

The spikes won't be as big as what you get on a reflector, but they will be present. (Been there, tried it. Don't know if I like the spikes or not.)

Cheers,
V

[Crater101]

I do like the second version, although there wasn't much I could have found wrong with the first. Well done!

[Startrek]

Stephane,

I must say that for the relatively short time you have been imaging, you certainly have mastered the Newtonian Reflector telescope at both f4 and f5

There’s nothing wrong with your images at all.

It’s probably a biased comment but to me a refractor would be an addition to your imaging artillery not a replacement

Keep it going !!

Best
Martin

[Dave882]

Both of these are wonderful images! I think the second takes it by a small margin for me. Your processing is very good, retaining very natural colour in the dust and trap, and those little niggles that we all obsess over zoomed in at 700x really don’t detract from the overall pic at normal viewing size. I looove your running man- he’s on fire!!! Those are some huge diffraction spikes :eyepop: - is that function of the new scope I wonder?

[Stephane]

Steve, that’s a good suggestion, but I guess not to my taste personally. Hopefully in the coming weeks I can get some more experience with the f/4 and learn to collimate it more effectively.

Warren, thank you. I think my favourite will be somewhere between the two versions. I suppose colour saturation is to each person’s taste, and mine probably leans on the lesser side. I’m glad you like both versions though. Thanks.

Martin, again, I appreciate the kind comments. They encourage me to continue learning. So many experienced imagers here to learn from. True though, I doubt a refractor will be purchased any time soon. I’d much rather put the funds toward a zwo asi2600mm, filter wheel, and some filters.

Dave, thank you so much. I personally love these large diffraction spikes and hope they don’t go anywhere anytime soon. I’m more annoyed with the star flares. I’ve just ordered a primary mirror mask from here (https://shop.deepskydad.com/product/newton-reflector-mirror-aperture-mask/). I’m looking forward to seeing if it makes any difference.

[ChrisV]

That's a really nice one Stephane. Especially the second processing.

[LKD]

Nice M42, I like the colour rendition

[Ryderscope]

That is a fine M42 Stephane. It looks like you have a great imaging set up their now. Well done :thumbsup:

[astro744]

Very impressive! I must be the odd one out though as I prefer the subtle colours of your first version; somehow looks more ‘natural’ even though that is a very subjective view. I liken it to a model with the second one having a bit too much blush on her cheeks.

Very impressive though; have I said that already?!

[Stephane]

Chris, Luke, thanks, I appreciate it.

Rodney, yes it’s taken a while to get a rig I’m quite happy with. A few minor things to get still, but mostly complete now.

Astro744, yes colour saturation is quite a personal thing. It’s nice to see all kinds of images and styles on this forum. But I’m glad you like the first version.

[Addos]

Great shot Stephane, punchy!

[Nikolas]

Either one looks great but my personal preference was the first more muted version.

[ahmed_haider]

Great work Stephane! Absolute top image!

For the collimation issue after meridian flip perhaps have a look at replacing the bobs knobs screws on the secondary, I found them to be a bit fiddly but kept them on because they're easier to use. I'll look for the original screws if I find them i'll mail them to you.

Cheers

[Crater101]

I can only echo what's already been said. Superb work!

[Stephane]

Thanks so much everyone. So many nice comments.

Ahmed, that would be much appreciated. I think it's mostly the primary mirror I am having issues with. The secondary mirror seems to hold collimation well, but it's still quite early to say for sure.

I also tightened the tension screw a little more, and noticed that collimation held better after the meridian flip, so I think I am suffering from flexure in the focuser. Again, too early to say for sure though.

[oska]

Absolutely breathtaking. You certainly give us novices something tangible to aspire to. Bravo.

[IanP]

Beautiful!!!