Too much processing?

[WireD64]

Please ignore the noise as this is only 6 minutes worth of data, purely look at this as whether I've gone over the top on the processing. I think its just right but some extra sub data will only make it better.

M45 - Orion Nebula
12 x 30 second subs @ 800iso

Canon 100D

[StargeezerTim]

Lovely colours... Maybe a little overdone...but very nice. 

[laudropb]

nice but perhaps too much processing. The colours are bright but to my eyes a little unnatural. But I am no expert

[WireD64]

thanks for feedback, i think if i knock back the saturation curve slightly the colours should look a little more natural.

[NGC 666]

To me, the data is nice and solid, but the dimmest parts seem to blend with the sky/background glow because of something you did when processing (I have a feeling it's over sharpening). For example, there are areas darker than the average background glow where there isn't any nebulosity (mid right) - which shouldn't make sense: it shouldn't get any darker than where there is no nebula. My suggestion: either take it easier when sharpening, or only sharpen the centre of the nebula. Then, if you like, you could lower the background level with the levels or curve tool. If your software supports that.

Otherwise, it's good. Nice sharp stars, good colours.

[StargeezerTim]

thanks for feedback, i think if i knock back the saturation curve slightly the colours should look a little more natural.

And less noise too... I've recently been experimenting with Noiseware Community. Its a free programme and seems very good. Trouble is the free version will only save in 8 bit JPEG. That,s OK for web display though.

[wxsatuser]

Your colours are about right, if you had more data it would look better of course.

True colour from an unmodded camera would show M42 as mainly blue with a pinkish/magenta interior and some teal from O III.

De Mairan's Nebula M43 should be pinkish/magenta.

[opticalpath]

My rule-of-thumb for processing: Stop when you think it's done ..... then go back to the previous version!

I find that it's easy to get caught up in the excitement; hard to resist just one last tweak that ends up over-cooking it. Leave it for a while then go back and take a fresh look at the last two or three versions you produced.

Adrian

[WireD64]

Good advice from everyone, it's so easy to get carried away and make it look unnatural. I think I shall stick to optical path's tip of stopping when I think it's done, then take it back a step. 

If I do that, then this is what the result is.

[glowingturnip]

My rule-of-thumb for processing: Stop when you think it's done ..... then go back to the previous version!

I find that it's easy to get caught up in the excitement; hard to resist just one last tweak that ends up over-cooking it. Leave it for a while then go back and take a fresh look at the last two or three versions you produced.

Adrian

I'd agree with that - I find that I very often do a processing step until I've got it about right, and then just opacity blend that back in with the previous step to dilute it a bit.  I reckon not-quite-enough processing always looks better than just-a-bit-too-much

[ollypenrice]

The extent to which you can push an image in processing is proportional to the amount of data you have. I think that the processing routines you've followed here would be fine with a lot more data.

There's only one good kind of noise reduction. More data. Any software NR should be applied sparingly and only to areas of faint signal. I find the easiest way is to make a Ps copy layer, NR the bottom layer globally, then use the colour select tool on the top layer to pick the regions needing NR. Run a partial eraser over these, reduce the fuzziness of the selection a little and maybe run the eraser again to taste. And so on. 

Olly

[WireD64]

Thanks everybody, some real top tips there. Cant wait for M42 to pop back up again to get some more data, amazed at what I got out of 6 minutes, so an hours worth should really eliminate the noise.

 

[reddoss]

Over processing is part of the steep learning curve in astro-imaging.

[WireD64]

Finding the balance between under and over processing is harder than actually processing then, and it seems that I can only learn that from experience and trial and error. Something tells me I won't find a tutorial about that

[Jimtom]

Nice image, I'm looking forward to imaging M45 for the 1st time this season.

PP using PhotoShop has been my main way of wasting time for a few years and yes, overdoing it is very easy! Over sharpening is the usual sin, then there's when you discover something new, HDR was one of those. I thought my images were great ..... until I posted them on my photographic forum :-)

[MartinB]

That second shot is a big improvement.  Congratulations on not having any star halos!

[WireD64]

Nice image, I'm looking forward to imaging M45 for the 1st time this season.

PP using PhotoShop has been my main way of wasting time for a few years and yes, overdoing it is very easy! Over sharpening is the usual sin, then there's when you discover something new, HDR was one of those. I thought my images were great ..... until I posted them on my photographic forum :-)

I just noticed a typo in my original post, this is M42 Orion Nebula, not M45 Pleiades. I quite like having my hard work torn apart as its nice to know where to improve.

That second shot is a big improvement.  Congratulations on not having any star halos!

I think because I was using masks at most stages of processing that helped me avoid the halos.

[Astrosurf]

The extent to which you can push an image in processing is proportional to the amount of data you have. I think that the processing routines you've followed here would be fine with a lot more data.

There's only one good kind of noise reduction. More data. Any software NR should be applied sparingly and only to areas of faint signal. I find the easiest way is to make a Ps copy layer, NR the bottom layer globally, then use the colour select tool on the top layer to pick the regions needing NR. Run a partial eraser over these, reduce the fuzziness of the selection a little and maybe run the eraser again to taste. And so on. 

Olly

That's a great image for so few and short subs. I agree with the comments on here.

Olly, that NR technique looks good, but I'm not totally clear on it. Can you explain in a bit more detail?? Many thanks.

Alexxx

[ollypenrice]

That's a great image for so few and short subs. I agree with the comments on here.

Olly, that NR technique looks good, but I'm not totally clear on it. Can you explain in a bit more detail?? Many thanks.

Alexxx

Sure.

- Start with the un-noise-reduced image and make a copy layer.

- Make the top layer invisible usng the eyeball button and make the bottom layer active.

- Run a noise reduction routine on the bottom layer. (I don't think the one you use is really that important but I might use Noels' Actions or the Photoshop Reduce Noise filter or Despeckle. You can slightly overdo it at this stage because you don't have to keep all of it as you'll see...

- Make the top layer visible and active. Go to Select then Colour Range and click on a part of the image which needs NR. Then use the + eyedropper and add to your selection of noisy parts of the image.The Fuzziness slider increases or reduces the selection you have. It  should not include anything on the image which is noise free. ie no bright signal.

- Feather the selection slightly - maybe by 1.

- Control H will hide the selection 'ants' but they are still active.

- Eraser (my favourite Ps tool for working in layers!!) Make the brush large and set its opacity to a low value like 30% and run it over the top layer. This will take off about a third of the top layer so you'll have about a third of the noise reduction now effective. Not enough? Erase again.

- If you then reduce the size of the selection or feather it by more (say 3) the selection will reduce and be likely to contain the noisiest parts. Another run with the partial eraser will let more of the bottom layer through.

- And so on...

If that's not clear drop me a line.

Cheers,

Olly

[Astrosurf]

Marvellous! Thanks Olly. I'll try that tonight, if I can.

[ollypenrice]

BTW, the same layers-eraser technique can be done for sharpening, too. Sharpen the bottom layer (ideally after excluding the stars) and then erase small sections of the unsharpened top layer very selectively. Only edges need sharpening. More than that and you just sharpen the noise! 

Olly