Back to forums

RCC - I can't figure out how to progress

Request for feedback
9 replies•492 views
Craig Dixon avatar
Craig Dixon avatar

Hi All.

I feel like I’m imaging and processing at an intermediate level but I’m always looking to improve and I feel like I’ve hit a bit of a wall. I have two setups:

Skywatcher 190MN with 533MC Pro - I use Ha/Oiii and Oiii/Sii DNB filters here.

ZWO FF65 with 183MM Pro & 7nm SHO + LRGB

(I’m planning on swapping the cameras around when I reach the end of my next projects).

Here’s my profile:

https://app.astrobin.com/u/craigdixon1986

I’m mostly happy with my images but there are two things that I’d like to improve:

1) I feel that my image sometimes look a little forced or “blocky”. I’m looking for a smooth, natural but colourful result. Here’s a great example of what I mean:

https://app.astrobin.com/i/a281jf

2) I often see images on Astrobin of popular targets that seem to have a lot more signal than most. Here’s a good example:

https://app.astrobin.com/i/rjsn2m

The nebulosity around and extending out from the heart is simply brilliant and I’d like to achieve this kind of result. Here’s my image of the Heart but you can see that I haven’t got nearly as much signal in the outer regions:

https://app.astrobin.com/u/craigdixon1986?i=r9f386

If I try and “push” the data a bit more in the stretch I just end up with a result that looks forced and blocky. If anyone can offer any criticism or advice on either of the above points (or anything else for that matter), I’d very much appreciate it.

On a side note, I’m considering having a go with some of Adam Block’s tutorials. I’ve tried a few in the past and didn’t really take to the teaching style but Adam is a world class processor so it stands to reason that’s a good place to look for some advanced instruction. is anyone able to offer advice here?

Thanks for taking time out of your day to read this!

Well Written Respectful Engaging
andrea tasselli avatar
andrea tasselli avatar
Craig Dixon:
he nebulosity around and extending out from the heart is simply brilliant and I’d like to achieve this kind of result. Here’s my image of the Heart but you can see that I haven’t got nearly as much signal in the outer regions:


You haven't exposed for as long, say by a factor of 10 or thereabout, so little surprise there. Besides, I found the thing rather unimpressive. If you want all your background to look red just raise the red in your background ;)
Drew Hackney avatar
Drew Hackney avatar

I think you’re selling yourself short by saying you’re processing at an intermediate level.

I think Andrea is right - what you’re missing compared to Jeffrey’s image is time. 128+ hours across two panels in a mosaic is an incredible commitment and I think that shows in your final image. But I’m assuming that time is split more or less 50/50 across the two panels. Jeffrey’s image has almost 4 times that on a single panel with his FMA180. You’ve collected about 1/8th of the signal he did on each pixel in your mosaic. I think your image is fantastic nonetheless.

Well Written Insightful Respectful Concise Engaging Supportive
wsg avatar
wsg avatar

Integration time for sure and having just looked at your gallery you might try NOT processing in the

Hubble Palette, especially if you want deep reds and colors other than green and yellow.

scott

Craig Dixon avatar
Craig Dixon avatar

Thanks for the comments. With regards to integration time, I see your point about the heart images specifically. My version was split over two panels so each had about 60 hours each. I did feel at the time though that this was plenty and I’d reached the point at which the returns had diminished so much that it wasn’t worth continuing. Take this image for example:

https://app.astrobin.com/u/craigdixon1986?i=qkqaht

I got over 80 hours of Oiii but the date didn’t look any better than 40 hours. I knew I needed to go long on that target but any more just seemed like it was a waste of time as it wasn’t giving me much if any improvement.

That said, I take the comments about integration time onboard. Maybe I need to go really long on something to see the difference for myself.

I’ve recently discovered Adam Block’s fairly recent method of creating a HOO image and then adding to Sii afterwards to avoid the overly green SHO palette.

Helpful Insightful Respectful Engaging
Randall Wiggins avatar
Randall Wiggins avatar

I think your work looks amazing, and someday hope to afford the equipment beyond my FRA300 and ASI585MC AIR to get my images to look like yours and all the other amazing photographers here.

I have had the same question about integration time floating around in my head: when is enough enough, and when does more integration time just result in diminishing returns?

Well Written Respectful Engaging Supportive
andrea tasselli avatar
andrea tasselli avatar
Randall Wiggins:
I think your work looks amazing, and someday hope to afford the equipment beyond my FRA300 and ASI585MC AIR to get my images to look like yours and all the other amazing photographers here.

I have had the same question about integration time floating around in my head: when is enough enough, and when does more integration time just result in diminishing returns?

You'll be the judge. Look at the dimmest portion of your image that you'd want to show and if it is too noisy then scale the image down by half. This is an increase in exposure by 4x. If it is still too noisy do it again and THAT is a factor of 16x. And so on.
Helpful Concise
Álvaro Méndez avatar
Álvaro Méndez avatar

@Craig Dixon If you are looking for a similar result color-wise as the examples you provided in the Hubble palette, you just need to play with the green curve. That will change the palette hues from “caribbean” to “sunsety” if you know what I mean. Apply a luminance mask, open Curves, select the green curve and apply three equal distance points. Slightly reduce the shadows for a reddish hue. Pushing the medium hues down will give you purplish transitions if you want them. The highlights slightly up will give you the golden tones.

I do recommend following Adam Block’s tutorials. I learnt lots of things from him.

And what @andrea tasselli says about downsampling if needed is right. I don’t know if you, with your image scale, would benefit from that, but in my case, since I am in the 1600 to 2450 mm focal length range, binning makes all the difference in signal. I don’t need a huge but empty picture, I need a picture that correctly represents the object.

Which, by the way, by downsampling, Andrea, you mean integer resampling in the linear stage, right? That’s what I do at least.

Helpful
andrea tasselli avatar
andrea tasselli avatar
Álvaro Méndez:
Which, by the way, by downsampling, Andrea, you mean integer resampling in the linear stage, right? That’s what I do at least.


That's right, just after calibration and stacking.
Randall Wiggins avatar
Randall Wiggins avatar

Wow, I have a lot to learn; I'm not entirely sure what that is or what it does exactly…yet.