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pyrasanth

M51 LRGB

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Having played with the crab nebula I selected a new target. I went for a revisit of M51 but the weather got a bit foggy so I need more data but I've posted what I have.

Atik 460 EX guiding with PHD2 & focus maintained with focus lock

Celestron C11 Edge at F7

Baader LRGB filters 1x1 Bin 5x10 minutes in each channel

Processing in CCDStack & Photoshop

As always let me know what you think. Next clear night I will get more data & a HA Channel for good measure.

M51-LRGB.png

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For those who like to see a less natural colour scheme here is a more vibrant version:

 

Vibrant-M51-LRGB.png

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Nicely done.  Thanks for the image.

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Very nice! Both have their appeal, though I like the fact that you can clearly distinguish the different emission regions in the more saturated version. Did you use Richardson-Lucy deconvolution in the processing steps?

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Just now, NigeB said:

Very nice! Both have their appeal, though I like the fact that you can clearly distinguish the different emission regions in the more saturated version. Did you use Richardson-Lucy deconvolution in the processing steps?

That's interesting that you think the image has used deconvolution- it has not- it is the pure image as captured. I think the vast improvement is down to the accuracy of the new guide system & sharp focus software which constantly monitors the focus. My images have come on leaps and bounds since installing the new guide system. The focus moved 6 mm last night alone across the imaging session so proves that the Celestrons need constant focus attention- it is not enough to focus through each filter change.

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I just spotted a couple of tiny galaxies in the background- interesting that these have been captured under a bright moon- they however are very small & would need a much larger image scale to see anything in them.

Edit the little Galaxy is IC 4277 at about magnitude 16 and estimated at 230 million light years distant- that is 10 times further away than M51- simply amazing that you can image a 16th magnitude galaxy in a light polluted garden!

Edited by pyrasanth

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53 minutes ago, pyrasanth said:

That's interesting that you think the image has used deconvolution- it has not- it is the pure image as captured. I think the vast improvement is down to the accuracy of the new guide system & sharp focus software which constantly monitors the focus. My images have come on leaps and bounds since installing the new guide system. The focus moved 6 mm last night alone across the imaging session so proves that the Celestrons need constant focus attention- it is not enough to focus through each filter change.

Wow - that's really impressive! The reason I asked about it is that long ago I tried M51 through a 12" SCT with an MX716 CCD; it didn't come out anywhere near as nicely as yours. But one minor triumph was that I managed to get rid of the over-exposed central region to reveal the small bright core, as is clear in your image - but only by using R-L deconvolution.

Can I ask what processing steps you did apply? (Not details - just what adjustments, if any, you made).

Nigel

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Hi to anybody following this topic.

How to get a great image- this is what I want to aspire to- not achieved it yet but I'm getting closer!

I  went back to basics & defined what I was after & spent a shed load of cash investing in the best I could afford but often the fundamentals are more important. What makes a great image- that's a question that can run & run but this is what I found & it should help all of us get great images

1. Produce a set of accurate calibration frames for each filter & use them. The difference is light & day even shows dramatically on the first sub before it is stacked.

2. Put a Hutech IDAS LP filter into the imaging train & don't remove it- this should be standard equipment

3. Get very accurate polar alignment & PEC if applicable

4. Guiding needs to be superb. Consider the innovations foresight on axis guider- expensive but the results in guiding accuracy speak for themselves!

5. Focus needs to be spot on with the Cat type optical tubes & you need to be focusing at a minimum on every filter change. Consider automated focusing like the Optec SMFS for the Celestron C11 & C14 with Sharp focus software automation.

6. There is nothing to deconvolve if the data is not present in the image set so lose focus or have guiding issues & deconvolve won't help you.

7. Use GradientXterminator in Photoshop- it will work wonders on images that you thought were fit for the bin and Annie's & Noels actions are great as well.

8. Never give up & keep stacking loads of data. It is better to have 6 hours of L than 6 hours of RGB where perhaps 2 hours would do very nicely. I've seen rubbish RGB data sets sparkle with a good L capture.

Hope this helps but you might know all this so a refresher wont hurt.

 

Edited by pyrasanth
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17 minutes ago, NigeB said:

Wow - that's really impressive! The reason I asked about it is that long ago I tried M51 through a 12" SCT with an MX716 CCD; it didn't come out anywhere near as nicely as yours. But one minor triumph was that I managed to get rid of the over-exposed central region to reveal the small bright core, as is clear in your image - but only by using R-L deconvolution.

Can I ask what processing steps you did apply? (Not details - just what adjustments, if any, you made).

Nigel

I used GradientXterminator in Photoshop CS to clean up the background and a few of the enhancing tools in Noel's actions & that was about it- I was luck to get good data for the reasons shown in my other post.

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Very nice image. I prefer the second processing, but both have their merits.

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Very nice images, and great advice.

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A New image with some more subs is below. Just rough processing at this stage

 

M51-TEST4.png

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Here is another image with a bit more data & altered colours:

 

M51-Test-7.png

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Really nice shot great detail in the dust lanes showing some nice star clusters

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11 minutes ago, andyo said:

Really nice shot great detail in the dust lanes showing some nice star clusters

I'm not sure yet. Let me explain- the more data I pack into the image the more the  colours are becoming vibrant & somewhat garish . I wonder if the time has come to stop capturing colour data & go for the L channel. In fact I'm suspecting that too much colour data is as bad as not enough or is that statement just silly?

The luminous blue zones are stellar nurseries and these have shown up well but I still wonder about the overall colour balance beginning to develop. I will jump on the net & look at some examples before I finish the image. It can all be changed easily provided one has good data. I think I will take a load more L & see how I get on.

Edited by pyrasanth

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17 minutes ago, pyrasanth said:

I'm not sure yet. Let me explain- the more data I pack into the image the more the  colours are becoming vibrant & somewhat garish . I wonder if the time has come to stop capturing colour data & go for the L channel. In fact I'm suspecting that too much colour data is as bad as not enough or is that statement just silly?

The luminous blue zones are stellar nurseries and these have shown up well but I still wonder about the overall colour balance beginning to develop. I will jump on the net & look at some examples before I finish the image. It can all be changed easily provided one has good data. I think I will take a load more L & see how I get on.

I recently did this one and am currently reprocessing It as I felt I had oversaturated it, started to look a bit like the colour was more painted than natural.I have done this target several times and every time I feel the same about the end result regarding the colour.

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I don't think you can add too much data, as for the colour balance its all in the processing and the end result is up to you .

 

Mark

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Here is an RGB shot. The L is still giving me issues. I think I've over processed it- so need to go back to the sub level & try again.

 

M51-RGB.png

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Then I add the L & have the 2 versions below. One is less sharp but perhaps it looks better. I will need to revisit this object again & have a rethink. I went for vibrant colours to keep Olly happy!

 

3_M51-LRGB.png

2_M51-LRGB.png

Edited by pyrasanth

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