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M27 with Quattro


Singlin
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You seem to have nailed the scope! Sharp as you like.

Great image but two small things would improve it in my view.

1) it's a little black clipped, with an over-dark sky - and I bet that has taken out the hints of outer halo which will surely have been in your data. Have a good look; I bet they're there.

2) Star colour is lacking as is often the case with DSLR images, but some manage it so it can be done. I suspect the stars must be over exposed, burning out the colour. I don't use a DSLR so I can't give specific advice but maybe a star mask while stretching would help preserve the colour.

The nebula is stunning on all counts. Sharp, smooth, nicely colour balanced.

Great stuff.

Olly

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Excellent image, the field is lovely and flat so as Olly said 'Nailed it '

Perhaps you should take couple of short subs for the stars, save them to one side in a star mask and overlay the coloured stars later.. I used to manage better stars when I used DSLR and that's what I did..

Doug's tutorial is handy as is Dave's

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I have been trying to create a star mask and I have a couple of queries.

Do I create the star mask at the beginning of the processing and how do I avoide the brighter stars having a blotch around them?

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In Ps at the linear stage I create a copy layer, then a layer mask, paste the image onto that and Ctrl I to make it the negative on the mask. I then clip the mask in Levels to remove any nebulosity, leaving only the stars. I then select and expand the dark stars on the mask, and blur them considerably. Even so I never find I can give a hard stretch so I do a slight stretch, ensuring that the stars look OK, and I flatten to lose the layer mask. Even this small pre-stretch with the stars masked means that a subsequent hard stretch gives significantly smaller stars. The star mask stretch really is 'softly softly.' I've seen video tutorials on star masking in which the presenter stretches like crazy under the star mask and produces lousy looking stars without seeming to mind! If anyone knows of a way to star mask while giving a hard stretch then I'm all ears but frankly, given the nature of the problem, I doubt that it exists. Happy to be proved wrong.

Olly

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Another question for Maestro Olly.

How long are your leads from your sliding shed to the telescope ?

Are the leads routed to the shed through the ground,pipe or are they just dangling from the scope to the shed?

I am trying to get my act together viz a vie the Observatory.

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I'm really liking this - especially the image in post #8.

I'm a bit surprised that there aren't more images posted using the Quattros - they must be awesome scopes and I can only assume that the challenges of nailing collimation of such a fast Newtonian have put people off...

Edited by x6gas
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The last one is certainly clipped. My own rule is to aim for a background sky value of 23. Exceptionally this just doesn't look right so I might go as low as 19. This is very exceptional and I don't understand why some images seem to want such a low value. Bringing the background down to 23 is the last thing I do in the processing.All through the processng I keep it higher, around 27, because you may need room to manoeuvre and you never can tell... I think that keeping the background sky up to a reasonable value and leaving the stars unsharpened are things that you come to do gradually but I really believe they make an image.

There is a strong temptation to black clip when there is something wrong with the background sky. Maybe a gradient, maybe effects of LP. However, the best solution is to correct the defects, not clip them out. Pixinsights DBE (or even just Automatic Background Extraction) make these corrections easy.

I agree with the others that you've done a great job sorting the Quattro.

Olly

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I almost wanted to sell the scope when I could not find any images except for the odd Globular cluster as this indicated that people were not satisfied with the results and therefore not posting them.I should have checked before the purchase.

This is a summary of what I HAD to do to start to achieve acceptable results.

1.Purchase a Cats eye collimator

2.Purchase the skywatcher f3.5-4 coma corrector

3.Purchase a Bahtinov mask

4.Check that the primary mirror is not pinched by loosening the bolts

5.dismantle and check the focuser is all square.

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I almost wanted to sell the scope when I could not find any images except for the odd Globular cluster as this indicated that people were not satisfied with the results and therefore not posting them.I should have checked before the purchase.

This is a summary of what I HAD to do to start to achieve acceptable results.

1.Purchase a Cats eye collimator

2.Purchase the skywatcher f3.5-4 coma corrector

3.Purchase a Bahtinov mask

4.Check that the primary mirror is not pinched by loosening the bolts

5.dismantle and check the focuser is all square.

As you say these scopes require some tweaking to perform their best. However you have shown that it is possible with patience. Buying a collimation tool, coma corrector and focusing mask should be taken as read for many scopes. A lot of scopes also require a modicum of fine tuning. It's the dismantling, strengthening and re-builds that we should not have to do!

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Yet another go with the same data.

This time I was concentrating on keeping my colours in line when stretching by using the histogram. I also tried to protect my background colour when applying curves.

I am still fiddling with star layers and trying to work out the correct work-flow order when using a star layer.

post-19057-0-57311800-1373495431_thumb.j

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