M97 Re-visited

[steppenwolf]

Continuing poor conditions made be revisit my first two-colour narrowband image last night to try and practice some of what I was preaching at the SGL Imaging Day and the following is a 'before' and 'after' using star reduction and image sharpening techniques:-

[Beyond_Vision]

Thats certainly worked on both counts

Regards

Kevin

[Tim]

The nebula looks better Steve, but the stars do have those dark haloes you get with deconvulve techniques. You could probably get around that by selecting just the dark clour in PS and selectively lightening it a little perhaps.

Pixinsight has a very powerful deconvulve tool, and it lets you control the dark (and light) haloes very well, its just a bit complicated to figure out!

I got several hours of OIII in 30 minute subs the other night to see if that really faint outer ring was enhanced. It was, but not by much, need to go longer still i think, maybe up to 60 mins. Interestingly, more detail started coming out in the OIII with the longer subs, much as it does with Ha. I was worried it might have just washed out.

There is a little tiny bit of OIII nebulosity just off to the side of M97, any idea if it is related or entirely seperate from M97?

Cheers

Tim

[MikeD]

Defiantly sharper, just not sure it's a positive thing (for this image).

The red (or Ha?) is starting to look superimposed rather than part of the image if you see what I mean.

It's all a matter of personal taste, for me a natural look is more important than getting as much detail as posible.

Mike.

[steppenwolf]

Interestingly, more detail started coming out in the OIII with the longer subs, much as it does with Ha.

OIII is great stuff for planetaries - I am looking forward to having a go at M27 again now I have this filter.

There is a little tiny bit of OIII nebulosity just off to the side of M97, any idea if it is related or entirely seperate from M97?

I haven't gone deep enough for this yet but I will be interested to see what transpires if I do.

Defiantly sharper, just not sure it's a positive thing (for this image).

The red (or Ha?) is starting to look superimposed rather than part of the image if you see what I mean.

I do know what you mean and I originally left the image as it was to maintain a more 'natural' effect but to be honest, I am not sure what is 'natural' for this object - many of the images of this object on the internet are pretty dire so it is hard to get a consensus. I am not a great fan of sharpening DSO images generally but it can be used to very good effect on galaxies in particular and perhaps on planetaries like this too as the detail is so wispy and indistinct generally. Red and blue are an unfortunate combination in this regard and they are often used together in marketing environments as they fool the eye into seeing a 3D-like image which is what is happening here, thus the 'superimposed' look.

[Tim]

Im getting for my sisters wedding, at least supposed to be, but have been having a quick play and look on the www at some M97's. As you say, there isnt really much :s

Here's one of the best I found, which shows the bright nebulosity to be a galaxy rich in Ha too,

http://www.starshadows.com/_img/image/gallery/4/M97_master.jpg

I've just done a massive overstretch of my 30 min subs, and the outer ring is a very peculiar shape, whereas the main neb is pretty rounded, the outer ring almost seems to have a shockwave on it, like a comet, i'd be very interested in the explanantion for that. Notice there is still a gradient from LP even with an OIII filter

I think you would like the HDRWT in PI Steve, when we finally meet up, i'll have to show you

[steppenwolf]

I think you would like the HDRWT in PI Steve, when we finally meet up, i'll have to show you

I shall look forward to that - my personal learning curve is still a sharp one so the more I get exposed to, the better!

Thanks for the link to that lovely image, certainly a very nice one and that extra bit of luminosity off the the right is fascinating. I have looked closely at my tiny image but the image scale is just too small to discern whether I have caught any of it or not but I don't think I have for one minute!

[ollypenrice]

Lovely stuff but I certainly prefer the unmodified stars without the halo effects. I have noticed that some screens are very punishing at showing such effects and others not. I'm unsure on the nebulae. They are both delightful.

Olly

[steppenwolf]

I certainly prefer the unmodified stars without the halo effects. I have noticed that some screens are very punishing at showing such effects and others not.

Ironically, there are no halos visible on my screen but I have no doubt that they are there as they were processed although I use NC's tools (star reduction) on them and my own sharpening method on the nebula itself.

I love all this, so many facets and ways to do and present stuff - who needs clear skies? Uhhh, actually, I could really really do with some right now ....

[MartinB]

I would go for the first one which is nicely detailed and a good balance of Ha and OIII. The background looks unnatural in the second one. have you upped the black point to remove halos?

[steppenwolf]

No, I haven't touched the background per se as I was not (and am still not!) aware of the halos.

[MartinB]

No I can't really see any halos, just wondered if they had been masked by tweaks to the back ground

[adamsp123]

To be honest I prefer the first image, which is very good, I think this object could be filed under the "it's a pig to do" section looking at the many images of the Owl.

I suspect there is no real very fine detail to grab, unless you have the HST!

Pete

[Whippy]

They're both lovely Steve but if I had to choose it'd be the first one as the second looks a little (and I mean little) overcooked.

Tony..

[steppenwolf]

I think this object could be filed under the "it's a pig to do" section looking at the many images of the Owl.

I'd file it there too - perhaps I should have been happy with the original but I just feel that there must be more to this object than I am currently seeing - but maybe not ....

[Whippy]

I know how you feel Steve, the feeling of 'is that it?' after several hours' worth of data isn't a satisfying one!

Tony..